   

 

 

 

 

 

 

 

 

 

 

 

 

c\-.¢oo.o -‘-I art: I..-

 

.

.
--

- . .

.

0

, .‘

.....

0.‘~ .
.

. .

. ..
..

a.

.-

- o

.‘.
...
. .
. ..
v...
-.
.

..
V...
. ..

.
.
. u.
.
.. _,
a
.
..
- .
.‘
.,
~ 1
.
. .
0

~.

.
.
..
.
.
.
.

 

 

 

 

 

 

“.._..u.

 

 

 

-
o.
..-
u
.. -
-..
y , .
-
...
n
o . ..
..
. .
.. .
..
.
.-
. .I
- u
-
o
I
.
u
o
.
a
.,
o
it _
o

 

.
.
o
o
.
- u
.

 

LIBRARY
Michigan State
University

 

 

 

This is to certify that the
dissertation entitled

DEVELOPMENT AND DELIVERY OF BlOPESTICIDE-BASED
PEST MANAGEMENT FOR MICHIGAN APPLE PRODUCERS

presented by

DAVID LAWRENCE EPSTEIN

has been accepted towards fulﬁllment
of the requirements for the

degree In Entomology

 

 

ﬁﬁ/ﬂﬂi’

0 Mail/ Professor’s Signature

June 11, 2010

 

Date

MSU is an Aﬁirmative Action/Equal Opportunity Employer

 

 

*a——_‘_M- -.—-—-h
‘ __.__-—

 

PLACE IN RETURN BOX to remove this checkout from your record.
To AVOID FINES return on or before date due.
MAY BE RECALLED with earlier due date if requested.

 

DATE DUE DATE DUE DATE DUE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5108 KIProj/Aoc&Pros/CIRCIDatoDua.indd

 

 

DEVELOPMENT AND DELIVERY OF BIOPESTICIDE-BASED PEST
MANAGEMENT FOR MICHIGAN APPLE PRODUCERS

By

David Lawrence Epstein

A DISSERTATION
Submitted to
Michigan State University
in partial fulﬁllment of the requirements
for the degree of
DOCTOR OF PHILOSOPHY
Entomology

2010

 

 

ABSTRACT

DEVELOPMENT AND DELIVERY OF BIOPESTICIDE-BASED PEST
MANAGEMENT FOR MICHIGAN APPLE PRODUCERS

By

David Lawrence Epstein

Field investigations were conducted to develop effective and economical
biopesticide-based management programs for control of two tortricid moth
species, codling moth (CM) (Cydia pomonella L) and Oriental fruit moth (OFM)
(Grapholita molesta Busck). Experiments were conducted: i) to determine
mechanisms by which pheromone-mediated mating disruption (MD) operates for
control of CM and OFM, ii) to evaluate pheromone dispenser deployment
strategies, iii) to evaluate effects of moth behavior on dispenser deployment
strategies, and iv) to evaluate use of CM Granulosis virus for CM population
suppression. I found that: i) MD of both moth species is improved by increasing
density and distribution of pheromone release sites, ii) CM adults are distributed
throughout the tree canopy during evening activity periods, iii) MD dispensers
placed in the top and mid tree canopy resulted in lower percentages of mated
females than distribution at one height, only, iv) adult CM leave the tree canopy
to inhabit drive-row grass and herbicide strip vegetation during daytime inactivity
periods, v) frequent applications of a low rate of virus yielded excellent,
economical control of CM, and vi) an areawide approach to deploying CM MD

reduced male moth capture and incidence of larval injury to fruit with less

insecticide use than MD in small individual orchard blocks or insecticide only

programs.

ACKNOWLEDGEMENTS

I will break with tradition and ﬁrst acknowledge those in my personal life
without whom pursuit of my Ph.D. would never have been possible. To the
fabulous Jane Stevenson, without whom none of it matters, I love you. I am one
lucky man. To my daughters, Evan and Molly, who were dragged around the
country on a vow of academic poverty while their old man became educated,
thank you. To my parents, Joyce and Jack, the template for good parenting who
supported me in everything I have ever done (OK not everything), thank you. To
my chosen family in CA and NY, Gary, Amy, Jonny, Morris, Amy, Gerald, BK,
Brenda and George, and to my many friends in Michigan thank you for all your
love and support.

Everyone needs a champion to guide them through the turbulent waters of
academia and the professional world. Mine is Larry Gut. You’ve been far more
then a major professor and mentor. Your genius for experimental design and
team building is surpassed only by your generosity and compassion as a human
being. Thank you for all of it.

My thanks to my Ph.D. committee members, James Miller, Mark Whalon,
Larry Olsen and Randy Beaudry, for their guidance, patience, and support
throughout the course of my Ph.D. program and all the challenges that it, and life
present. Your collegial respect and friendship means a great deal to me.

GraterI thanks to all of the colleagues and students who helped in the

conduct of the research and analyses involved in my Ph.D. research: Peter

McGhee, Mike Haas, Lukasz Stelinski, Matt Grieshop, Dick Ledebuhr, Rufus
lsaacs, John Vtﬁse, Alison Gould, VVIII Bristol, Jason Vandenbrink, Sam Leitkam,

and Dee Smith.

Thank you to the apple growers of Michigan who supported this research

and provided me access to your farms.

TABLE OF CONTENTS

LIST OF TABLES .................................................................................. x
LIST OF FIGURES ............................................................................... xiii
INTRODUCTION ................................................................................... 1
Apple Agriculture in Michigan .......................................................... 1
Codling Moth and Oriental Fruit Moth ................................................ 1
Biopesticides ............................................................................... 2
Mating Disruption ......................................................................... 3

a. Background / Current Status .............................................. 3

b. Mechanisms of MD .......................................................... 5

c. Pheromone Dispenser Point Source Distribution .................... 7

d . Canopy Distribution of Reservoir Dispensers ........................ 9

e. High-Density Mating Disruption Formulations ...................... 11

f. Areawide Mating Disruption ............................................. 13

Cydia pomonella Granulosis Virus .................................................. 14
Dissertation research ................................................................... 17

CHAPTER ONE: HIGHER DENSITIES OF DISTRIBUTED PHEROMONE
SOURCES PROVIDE DISRUPTION OF CODLING MOTH
(LEPIDOPTERA: TORTRICIDAE) SUPERIOR TO THAT OF
LOWER DENSITIES OF CLUMPED SOURCES

Abstract ............................................................................................. 19
Introduction ......................................................................................... 20
Materials and Methods..- ....................................................................... 21
Reducing release site density while maintaining total pheromone
applied per ha constant ........................................... 21
Increasing both point-source density and total pheromone applied
per ha from parafﬁn-wax drops ................................... 24
Evaluating attractiveness of parafﬁn-wax dispensers to male
codling moths ......................................................... 26
Direct observation of codling moth males in plots treated with
various densities of wax drops ................................... 26
Measuring pheromone release rate from 0.1 ml wax drops ....... , ........... 27
Statistical analysis ....................................................................... 27
Results .............................................................................................. 28
Reducing release site density while maintaining total pheromone
applied per ha constant ........................................... 28
Increasing both point-source density and total pheromone applied
per ha from parafﬁn-wax drops ................................... 32
Evaluating attractiveness of parafﬁn-wax dispensers to male
codling moths ......................................................... 32

vi

Direct observation of codling moth males in plots treated with

various densities of wax drops ................................... 33

Measuring pheromone release rate from 0.1 ml wax drops ................. 35
Discussion .......................................................................................... 36
Acknowledgements ............................................................................... 39

CHAPTER TWO: HIGHER DENSITIES OF DISTRIBUTED PHEROMONE
SOURCES PROVIDE DISRUPTION OF ORIENTAL FRUIT
MOTH (LEPIDOPTERA: TORTRICIDAE) SUPERIOR TO
THAT OF LOWER DENSITIES OF CLUMPED SOURCES

Abstract ............................................................................................. 41
Introduction ......................................................................................... 42
Materials and Methods .......................................................................... 43
Results ............................................................................................... 47
Discussion .......................................................................................... 49
Acknowledgements .............................................................................. 50

CHAPTER THREE: WITHIN-CANOPY ADULT DISTRIBUTION OF CODLING
MOTH (LEPIDOPTERA: TORTRICIDAE) IN MATING
DISRUPTED AND NON-DISRUPTED APPLE

ORCHARDS

Abstract .............................................................................................. 52
Introduction ......................................................................................... 53
Materials and Methods ........................................................................... 53
Vacuum .................................................................................... 53
Recovery Efﬁcacy of Vacuum ........................................................ 54
Orchard Vacuum Trials ................................................................ 54

Tree Fogging ............................................................................. 55
Statistical Analysis ..................................................................... 56

Results .............................................................................................. 56
Recovery Efﬁcacy of Vacuum ........................................................ 56
Orchard Vacuum Trials ................................................................ 56

Tree Fogging ............................................................................. 59
Discussion .......................................................................................... 61
Acknowledgements ............................................................................... 63

CHAPTER FOUR: EFFECTS OF VARYING CANOPY HEIGHT OF HAND-
APPLIED RESERVOIR DISPENSERS ON EFFICACY OF
PHEROMONE-MEDIATED MATING DISRUPTION OF
CODLING MOTH (LEPIDOPTERA: TORTRICIDAE) IN

APPLE
Abstract .............................................................................................. 65
Introduction ......................................................................................... 66
Materials and Methods ........................................................................... 67
Results ............................................................................................... 69
Discussion .......................................................................................... 74

vii

Acknowledgements ............................................................................... 75

CHAPTER FIVE: CODLING MOTH, CYDIA POMONELLA (L.),
ADULT DIEL ACTIVITY IN APPLE ORCHARDS

Abstract ............................................................................................. 77
Introduction ......................................................................................... 78
Materials and Methods .......................................................................... 79
Vacuum .................................................................................... 79
Screen Tents .............................................................................. 79
Release l recaptures .................................................................... 80
Statistics .................................................................................... 82
Results ............................................................................................... 82
Discussion .......................................................................................... 86
Acknowledgements ............................................................................... 88

CHAPTER SIX: EFFICACY AND OPTIMUM USE PATTERNS OF CM
GRANULOSIS VIRUS [FAMILY BACULOVIRIDAE, GENUS
GRANULOVIRUS] FORMULATIONS FOR CONTROL OF
CODLING MOTH, CYDIA POMONELLA (L.), IN MICHIGAN

APPLE
Abstract .............................................................................................. 90
Introduction ......................................................................................... 91
Materials and Methods ........................................................................... 92
Small Plot Trials to Evaluate Application
Rates and Frequency .................................................................. 92
Small-plot experiment to compare Carpovirusine and Virosoft ............... 93
Large On-Farm Plot Trials to Evaluate Efﬁcacy .................................. 95
Results ............................................................................................... 97
Small Plot Trials to Evaluate Application Rates and Frequency
First Generation ................................................................. 97
Second Generation .............................................................. 98
Small-plot experiment to compare Carpovirusine and Virosoft
First Generation ................................................................. 99
Second Generation ........................................................... 101
Large On-Farm Plot Trials to Evaluate Efﬁcacy ................................. 103
Discussion ......................................................................................... 107

CHAPTER SEVEN: QUANTIFYING THE BENEFITS OF AREAVVIDE
PHEROMONE MATING DISRUPTION PROGRAMS
FOR CODLING MOTH (LEPIDOPTERA: TORTRICIDAE)

Abstract ............................................................................................ 1 10
Introduction ........................................................................................ 1 1 1
Materials and Methods ......................................................................... 113
Experimental Layout ................................................................... 1 13
Pheromone Disruption ................................................................ 1 13
Monitoring ................................................................................ 1 14

viii

Evaluation of Control Programs

Fruit Injury ....................................................................... 115

Chemical Control Programs ................................................ 1 15

Economics ....................................................................... 1 15

Data analyses ........................................................................... 1 16

Results ............................................................................................. 1 17

Moth Capture ............................................................................. 1 17

Fruit Injury ................................................................................ 121

Chemical control programs ........................................................... 125
Economics

Costs ............................................................................. 126

Returns .......................................................................... 126

Fruit Injury ...................................................................... 126

Discussion ......................................................................................... 127

Acknowledgements ............................................................................. 130

SUMMARY AND CONCLUSIONS .......................................................... 131

LITERATURE CITED ........................................................................... 136

LIST OF TABLES

Table 1. Description of orchards used in Experiment 1 in which density of release
sites (Isomate—C Plus dispensers) per ha was varied without varying total amount
of pheromone deployed per ha ................................................................ 24

Table 2. Description of orchards used in which density of release sites (Isomate-
C Plus dispensers) per ha was varied without varying total amount of pheromone
deployed per ha ................................................................................... 44

Table 3: Percent orientation disruption to traps placed in the center versus the
edge of plots treated with Isomate-M Rosso (mean :I: S.E.). Values in a row
followed by the same letter are not signiﬁcantly different (\NIlcoxon Signed-Rank
Test P 2 0.05) ...................................................................................... 48

Table 4. Total moths collected with vacuum in 2005 orchard samples during
daylight (09:00-16:00) and evening twilight (18200-21z30) hours. (Day. Cap. =
daytime captures, Eve. Cap. = evening captures) ........................................ 57

Table 5. 2005 moth captures were signiﬁcantly higher in the evening hours for all
tree canopy heights sampled (576 samples collected) (Numbers within row with
same letter not signiﬁcant at p < 0.05) ....................................................... 57

Table 6. Statistical comparisons of moths collected with vacuum in 2005 orchard
samples during twilight (18:00-21 :30) hours (Numbers within row with same letter
not signiﬁcant at p < 0.05) ....................................................................... 58

Table 7. Statistical comparisons of moths collected with leaf blower vacuum in
plots with and without pheromone mating disruption. Samples were collected
during twilight (18:00-21 :30) hours in 2005 (Numbers within row with same letter
not signiﬁcant at p < 0.05) ....................................................................... 60

Table 8. Percent distribution of male and female codling moths collected with leaf
blower vacuum in plots with and without pheromone mating disruption. Samples
were collected during twilight (18:00-21230) hours in 2005 ............................. 60

Table 9. Statistical comparisons of female moths collected with leaf blower
vacuum in plots with and without pheromone mating disruption. Samples were
collected during twilight (18200-21230) hours in 2006 (Numbers within row with
same letter not signiﬁcant at p < 0.05) ....................................................... 61

Table 10. Tukey multiple comparison of the means of male moth capture in
varying dispenser height treatments (M = Mixed, 1 dispenser each @2m and 4m;
H = high, 2 dispensers @ 4m; L = low, 2 dispensers @2m; and N = no
pheromone dispensers) * indicates signiﬁcant p value @ a < 0.05 .................. 70

Table 11. Mating of tethered female moths in pheromone dispenser trials was
lowest where dispensers were arranged both at 2m and 4m heights in the tree
canopy ............................................................................................... 72

Table 12. Percent of tethered virgin female codling moths mated when deployed
on ﬁve dates at 2m and 4m heights in tree canopies in plots with varying
dispenser height treatments (Mixed = dispensers @ 2m and 4m, High =
dispensers at 4m, Low = dispensers @ 2m) ............................................... 72

Table 13. Tukey multiple comparison of the means of mating in varying dispenser
height treatments (M = mixed, 1 dispenser each @2m and 4m; H = high, 2
dispensers @ 4m; L = low, 2 dispensers @2m; and N = no pheromone
dispensers) * indicates signiﬁcant p value @ a < 0.05 .................................. 73

Table 14. Percent male and female codling moth adults recovered in ﬁve habitats
in release I recapture trials in 2006-2007 (* = release cage) ........................... 84

Table 15. Tukey multiple comparison of the means of percent moth recapture in
varying habitats (H = Herbicide Strip, G = Grass; T = Tree; * indicates signiﬁcant
p value @ alpha = 0.05) ......................................................................... 85

Table 16. Percent moths recovered from grass plus herbicide strip habitats over
three months of release I recapture trials in 2006-2007 ................................. 85

Table 17. Recovery of wild type moths in ﬁve habitats 16 and 64 hours post
release in release / recapture trials in 2006-2007 (* = release cage) ................ 86

Table 18. Mid season codling moth (CM) or Oriental fruit moth (OFM) fruit injury
in small plots treated with Carpovirusine (Virus) at the indicated rate or untreated
(Means followed by the same letter do not differ signiﬁcantly, p =

0.05) .................................................................................................. 97

Table 19. Density and health status of larvae recovered in tree bands placed in
small plots treated with Carpovirusine (Virus) at the indicated rate or untreated
(Means followed by the same letter do not differ signiﬁcantly, p =

0.05) .................................................................................................. 98

Table 20. Pre-harvest codling moth (CM) or Oriental fruit moth (OFM) in small
plot trials treated with Carpovirusine (Virus) at the indicated rate or untreated
(Means followed by the same letter do not differ signiﬁcantly, p = 0.05) ............ 99

Table 21. Evaluation of 1‘t generation fruit injury in virus treated and untreated
plots. Means followed by the same letter do not differ signiﬁcantly, Tukey’s HSD,
p = 0.05. (Carpovirusine (Carpo-V); codling moth (CM); Oriental fruit moth

(OFM) ............................................................................................... 100

xi

Table 22. The health status of 1"t generation CM larvae recovered from
cardboard bands in virus treated and untreated plots (Means followed by the
same letter do not differ signiﬁcantly, Tukey’s HSD, p = 0.05) ....................... 100

Table 23. Evaluation of 2nd generation fruit injury in virus treated and untreated
plots (Means followed by the same letter do not differ signiﬁcantly, Tukey’s HSD,
p = 0.05) ............................................................................................ 102

Table 24. The health status of 2nd generation CM larvae recovered from
cardboard bands in virus treated and untreated plots (Means followed by the
same letter do not differ signiﬁcantly, Tukey’s HSD, p = 0.05) ...................... 102

Table 25. Codling moth (CM) fruit injury and larval densities in plots treated with
Carpovirusine (Carpo-V) or not treated with virus (standard) at four sites ....... 104

Table 26. Codling moth (CM) fruit injury and larval densities in plots treated with
ViroSoﬂ or not treated with virus (standard) at four sites ............................. 104

Table 27. Codling moth (CM) fruit injury and larval densities in plots treated with
Cyd-X or not treated with virus (standard) at three sites .............................. 105

Table 28. Codling moth (CM) larval densities in plots treated with one of three
granulosis virus formulations compared to plots not treated with virus (standard)
based on tree banding ......................................................................... 105

Table 29. Captures of male moths was signiﬁcantly lower in AW-CMMD vs. No-
CMMD for every generation in all 4 years, except for the 1st generation,
2004 ................................................................................................ 1 18

Table 30. Mean captures of 1" and 2"d generation male codling moth in AW-
CMMD, Block-CMMD, and No-CMMD apple orchards 2004-2007 ................. 119

Table 31. Fishers PLSD table for effect of treatment on male moth capture in
pheromone-baited traps. Signiﬁcantly different P values, alpha = 0.05, are bolded
and marked with the symbol, * (AW = AW-CMMD, NoMD = no disruption, Block
= Block-CMMD) .................................................................................. 120

Table 32. Fruit injury from CM was signiﬁcantly lower in AW-CMMD vs. No-
CMMD for every generation in all 4 years ................................................. 122

Table 33. Fishers PLSD table for effect of treatment on injury to fruit from CM

feeding. Signiﬁcantly different P values, alpha = 0.05, are marked with the
symbol, * (AW = AW-CMMD, NoMD = no disruption, Block = Block-CMMD)...123

xii

LIST OF FIGURES

Figure 1. Diagram of a 0.4 ha orchard plot containing 4 release sites of clustered
lsomate-C Plus dispensers. Shaded boxes (not to scale) represent 100 clustered
lsomate-C Plus dispensers. Other release-site densities were likewise regularly

distributed .......................................................................................... 23

Figure 2. Mean captures of codling moth males in lure-baited delta traps in A)
centers and B) borders of plots containing various release-site densities of
Isomate-C Plus dispensers while maintaining the total number of dispensers at
1000 I ha. Means followed by the same letter are not signiﬁcantly different at a <
0.05 .................................................................................................. 30

Figure 3. Mean percent fruit injury due to codling moth larval infestation in A)
centers and B) borders of plots containing various release-site densities of
lsomate-C Plus dispensers while maintaining the total number of dispensers at
1000 I ha. Means followed by the same letter are not signiﬁcantly different at a <
0.05 .................................................................................................. 31

Figure 4. Mean captures of codling moth males in lure-baited delta traps in plots
containing various densities of 0.1 ml parafﬁn-wax drops containing 5 %

codlemone. Means followed by the same letter are not signiﬁcantly different at a
< 0.05 ............................................................................................... 33

Figure 5. Numbers of codling moth males observed approaching parafﬁn-wax
drop dispensers of pheromone in plots receiving various densities of dispensers.
All moths observed approached within 130 cm of dispensers. Observations were
conducted on seventeen evenings between 17 May and 12 June. Means
followed by the same letter are not signiﬁcantly different at a < 0.05 .............. 34

Figure 6. Release proﬁles of 0.1 ml parafﬁn-wax drops containing 5 %
codlemone ﬁtted with exponential decay curves ........................................ 35

Figure 7. Diagram of a 0.4 ha orchard plot containing 4 release sites of clustered
lsomate-M Rosso dispensers. Shaded boxes (not to scale) represent 50
clustered lsomate-M Rosso dispensers. Other release-site densities were
likewise regularly distributed .................................................................. 45

Figure 8. Numbers of male G. molesta captured in lure-baited traps in plots
treated with lsomate-M Rosso during G. molesta generations one, two, and three
(mean :I: S.E.). Bars labeled with the same letter are not signiﬁcantly different

(T ukey, P 2 0.05). Percent orientation disruption values (mean :I: S.E.) are written
above treatment bars ........................................................................... 47

xiii

Figure 9. Vacuum Samples showed that males and females were present in both
orchard edges and middles ..................................................................... 59

Figure 10. Interaction plot of effects of treatment and trap height on male moth
capture (Mixed = dispensers high and low, H = high dispenser placement, L =
low dispenser placemen and N = no pheromone dispensers) ......................... 70

Figure 11. Captures of male moths in plots where pheromone dispenser and trap
height was varied (High = 2@ m, Low = 2 @ 2m, Mixed = 1 @ m and 1 @ 2m).
Means followed by the same letter are not signiﬁcantly different at a < 0.05......71

Figure 12. Mating of tethered females at 2m and 4m in plots where dispenser
height was varied (High = 2@ 4m, low = 2@ 2m, Mixed = 1@ 2m, 1@4m) ...... 73

Figure 13. Release cages used in moth release / recapture trials .................... 81

Figure 14. On-fann comparison of CM control in plots treated or not treated with
one of three Cva virus formulations: Carpovirusine (Carpo-V), Cyd-X, or
ViroSoftCP‘ (\frroSoft) ........................................................................... 106

Figure 15. AW-CMMD was signiﬁcantly better at protecting fruit from injury by
CM larvae than both Block-CMMD and No-CMMD in all four years, 2004-
2007 ................................................................................................ 124

Figure 16. Number of insecticide applications for farms under areawide disruption

(AW-CMMD), disruption in individual orchard blocks (Block-CMMD) and no
disruption (No-CMMD) over the years 2004-2007 ....................................... 125

xiv

INTRODUCTION
Apple Agriculture in Michigan
With over 107,000 acres of orchards, Michigan is the leading producer of
tree fruits in the Midwest (Michigan Department of Agriculture, 2008), and the
third largest apple producing state in the USA, behind Washington and New
York (Michigan Agricultural Statistics, 2009). Michigan had 36,500 bearing acres
of apple in 2008 worth a farm level value of $117.4 million (Michigan Agricultural

Statistics, 2009).

Codling Moth and Oriental Fruit Moth

Management of over two-dozen insect pests in apple in the upper Midwest
is a difﬁcult task (Howitt 1993, Epstein and Gut 2000, Epstein et al. 2002), and
lPM programs for these crops are complex. The most challenging species to
manage are the direct pests whose larvae feed internally within fruit (internal
feeders) rendering it unmarketable. Two lepidopterans from the family,
Tortricidae, codling moth, Cydia pomonella (L.) and Oriental fruit moth,
Grapholita molesta (Busck), are introduced species that have become the
principal direct pests of North American apples. The larvae of both species
overwinter as mature larvae in litter on the ground or under bark on the tree
(Borror et al., 1989). Three full generations of Oriental fruit moth occur in
Michigan; the ﬁrst generation emerges as adults around the last week of April
(Epstein and Gut, 2000). Codling moth typically emerge as adults in Michigan the
second to third week of May. There are generally two full generations of codling

moth per year in Michigan (Epstein and Gut, 2000). Larvae of both species

tunnel into the fruit shortly upon eclosion, and are morphologically distinguishable
only by the presence (Oriental fruit moth) or absence (codling moth) of an anal
comb located ventrally on the terminal abdominal segment (Epstein and Gut,
2000). Oriental fruit moth has become an increasingly important pest of apples
east of the Mississippi river within the past ten years. Many Michigan apple
growers now treat codling moth and Oriental fruit moth with the same high
degree of concern. In the absence of control measures, greater than 75% of the
apple crop in Michigan orchards can be damaged by the two species (Wise and
Gut 2000, 2002).

Biopesticides

Pest control for Michigan apple growers is currently a major challenge,
and is likely to become more difﬁcult in the foreseeable future due to loss of
compounds through US. Environmental Protection Agency (EPA) regulatory
restrictions to protect citizens from the harmful effects of pesticides in food, air,
and water (Food Quality Protection Act, 1996, HR. 1627), the development of
pest resistance to currently used pesticides, and a shortage of economic and
effective alternatives. A pheromone-trap bioassay (Riedl et al., 1985) was
conducted to assess the susceptibility of codling moth to azinphosmethyl, the
primary organophosphorous (OP) insecticide used for codling moth control in
Michigan since the middle of the 20th century (Gut et al., 2001; Gut and Wise,
2004). Resistance testing revealed that high levels of codling moth resistance

were present on farms around Michigan (Mote-Sanchez et al., 2008). Based on

the MI resistance bioassays, it appears likely that many codling moth control
failures are related to a reduced effectiveness of OP’s.

New control tactics, with novel modes of action are needed to sustain an
economically viable Michigan apple industry. Among the most promising
candidates is a group of tactics collectively referred to as biopesticides.
Biopesticides are biological pesticides derived from natural sources that the EPA
categorizes into three major classes. The ﬁrst two, microbial pesticides (a
microorganism is the active ingredient), and plant-incorporated-protectants
(genetic manipulation of plant to self-produce toxins) are toxic control agents.
The third class, biochemical pesticides, manages pests through non-toxic means
(US EPA, 2006). Biochemical pesticides include insect sex pheromones and

plant volatiles.

Mating Disruption
a. Background / Current Status

Pheromones are chemicals secreted by an animal that inﬂuence the
behavior or development of others of the same species (Wilson and Bossert,
1963). Mating (sex) pheromone is used by individuals of a species to attract
mates for reproduction. In the case of codling moth and Oriental fruit moth, the
female calls the male by emitting sex pheromone, sensed by males from
distances of up to 40m or more (Rodriguez-Saona and Stelinski, 2009) on wind
borne plumes consisting of a series of ﬁlaments of pheromone interspersed with
pockets of zero to low concentrations due to natural turbulence in the air

(Sanders 1997). Responsive male moths follow the pheromone plume to the

female; engage in courtship behaviors and copulate. Codling moth female sex
pheromone was ﬁrst identiﬁed by Roelofs et al. (1971), and Oriental fruit moth
female sex pheromone was discerned by Cardé et al. (1979).

The deployment of synthetic sex pheromone to interfere with mate ﬁnding
orientation and subsequent mating behavior is called mating disruption. Mating
disruption, as it is commercially practiced today, is largely achieved through the
manual application of reservoir-type release devices (Cardé and Minks, 1995).
Approximately 100-fold quantities of synthetic pheromone are released from
these dispensers as compared to the pheromone release rate of a calling female
(Cardé and Minks, 1995).

Pheromone mating disruption is a feasible tactic for control of codling
moth and Oriental fruit moth in fruit orchards. In the USA, disruption products
for codling moth are currently deployed on more than 130,000 acres of apple and
pear, and over 45,000 acres of apple and peach are being treated with Oriental
fruit moth disruption products (Gut et al., 2004, Witzgal et al., 2008). As it has
been practiced for the past two decades, mating disruption for codling moth and
Oriental fruit moth has not generally been a stand-alone tactic capable of
achieving adequate protection of apple fruit from larval entries without additional
application of insecticides targeting these two pests. Efforts to improve
application of this technology are necessary to limit agricultural use of pesticides,
reduce control program costs and to facilitate widespread adoption of mating

disruption by the grower community.

b. Mechanisms of MD

Although mating disruption of codling moth and Oriental fruit moth with
synthetic pheromone has been commercially deployed in apple orchards
internationally since the early 1990’s, there is still no consensus among the
scientiﬁc community as to the mechanism(s) by which disruption acts to interfere
with moth orientation and mating behavior. There are four principal mechanisms
that are thought to underlie mating disruption: ( 1) desensitization — including (a)
adaptation of males’ peripheral sensors (antennae) due to exposure to constant,
high levels of the pheromone stimulus that prevents males from being able to
detect pheromone. Recovery can occur shortly upon removal of the stimulus
source so that the male can detect pheromone upon stimulus reintroduction; and
(b) habituation of the males’ central nervous system resulting from long-term
exposure to high pheromone concentrations that inhibits the male from
responding, even upon withdrawal of the high concentration stimulus source.
Habituated males become less responsive to the pheromone stimulus for long
periods after exposure to high concentrations, (2) Camouﬂage, or masking of the
pheromone plumes emitted from females by a high background concentration of
pheromone. The male’s sensory apparatus is functioning properly in this model,
but is inefﬁcient for locating females in a uniform and high background level of
pheromone in the orchard; (3) False-plume following (competition) preventing the
male from locating the female; the males can still sense and respond to the
pheromone stimulus but are inhibited from ﬁnding mates due to time and energy

spent pursuing and/or becoming arrested on false trails from synthetic

dispensers placed throughout the orchard and (4) Sensory imbalance resulting
from a compromise in the chemical composition of the female pheromone, such
that the active ingredient released from dispensers distorts the normal perception
of the signal (Bartell, 1982; Cardé, 1990; Cardé and Minks, 1995; Gut, et al.,
2004; Gut et al. 2008, Sanders, 1997).

Miller et al. (2006 a, b) divided the four proposed mating disruption
behavioral mechanisms into two categories, competitive (false-trail following or
competitive attraction) that is predicated on males being attracted to dispensers,
and non-competitive (desensitization, camouﬂage and sensory imbalance) that
operates by interfering with the male's ability to sense and respond normally to
pheromone. Competitive attraction is distinguished from the other mechanisms
by requiring attraction to pheromone dispensers as the ﬁrst step in response to a
mating disruptant. Three main lines of evidence support competitive attraction as
the primary mechanism operating in the ﬁeld using current mating disruption
technologies (Miller et al., 2006b, Gut et al., 2008). In practice, mating disruption
appears to be highly density dependent. If mating disruption operated in a non-
competitive means, all males within the adequately treated area, regardless of
density, should be unresponsive to females. Males of four tortricid moth species,
Oriental fruit moth (Grapholita molesta), obliquebanded leafroller (Chon‘stoneura
roseceana), redbanded leafroller (Argyrotaenia velutinana) and codling moth
(Cydia pomonella) have all been observed readily approaching their respective
polyethylene tube pheromone dispensers (Stelinski et al. 2005b; Judd et al.

2004). The most persuasive evidence is provided by Miller et al.’s (2006b)

examination of dosage response proﬁles generated from published work with
sufﬁcient data for analysis. Disruption proﬁles for 11 of 13 data sets adhered to
the predictions of a competitive attraction model.

Cardé et al. (1997, 1998) point out that two or more of these mechanisms
may act together to successfully prevent moth mating in a synergistic or additive
fashion, such as false-plume following resulting in short-term adaptation to
pheromone upon male moth contact with a dispenser. Additionally, varying
physiological response to pheromone among moth species (Stelinski et al.
2005b) and species variation in chemical characteristics of pheromones (Gut et
al., 2004) provide evidence that some moth species are inherently more difﬁcult

to disrupt than other species.

c. Pheromone Dispenser Point Source Distribution

Nine codling moth and seven Oriental fruit moth disruption products
commercially are available in the USA. Five hand-applied reservoir dispensers,
Isomate® 0+ and CTT (Shin-Etsu Chemical Co., Tokyo, Japan), Scentry
NoMate® codling moth Spirals (Scentry Biologicals, Billings, Montana), Hercon
Disrupt codling moth (Hercon Environmental, Emigsville, PA), and CheckMate®
codling moth XL 1000 (Suterra, Bend, OR) are available in the US. market for
codling moth. Isomate® M 100, Isomate® M Rosso, Scentry NoMate® Oriental
fruit moth Spirals, and CheckMate® SF are the reservoir dispensers available for
Oriental fruit moth. Label rates for Oriental fruit moth reservoir dispensers vary

from 250 to 500 per hectare.

Label rates for reservoir dispensers for codling moth disruption vary from
300 to 1000 per hectare, and growers typically select a rate at the lower end due
to economic and labor concerns. The hand application of codling moth
dispensers is a labor intensive process (approximately 5 hours / ha at the full
label rate), adding labor costs as well as competition for labor at times of the
growing season when many Michigan growers are busy working in other crops,
and has been identiﬁed as a major impediment to widespread adoption of mating
disruption (Epstein et al., 2002b).

The predominant formulation currently used in the U.S.A. for codling moth
is the lsomate-C Plus polyethylene tube dispenser (Shin-Etsu Chemical Co.,
Tokyo, Japan) with a label rate of 1000 per ha (Thomson et al. 2001, Witzgal et
al., 2008). However, there are several commercially available disruption products
for codling moth that claim that disruption can be achieved with reduced numbers
of dispensers per ha. For example, lsomate-CTT (Shin-Etsu Chemical Co.,
Tokyo, Japan) dispensers contain twice as much pheromone as the lsomate-C
Plus dispenser and are designed for application at a rate of 500 / ha (Alway
2002). Some researchers (Shorey and Gerber 1996, Knight 2004, Welter et al.
2005b) suggest that mating disruption efﬁcacy can be maintained while reducing
the density of release sites, if overall release rate of pheromone per ha is
maintained or increased. A saving in labor is postulated for a given number of
lsomate dispensers assembled into clusters rather than distributed individually
(Knight 2004), or with the use of battery-powered aerosol emitters, deployed at a

rate of 5 per ha, dispensing daily rates of (E,E)-8-10-dodecadienol, codling moth

sex pheromone, equivalent to a full label rate of lsomate-C Plus (Welter 2005).
However, Suckling and Angerilli (1996) falsiﬁed this idea for lightbrown apple
moth, Epiphyas postvittana (Walker). Their study revealed that if the total number
of dispensers was held constant, plots with higher densities of release sites best-
disrupted moth catches in pheromone traps. Most recently, Stelinski et al., (2007)
reported very low levels of 24-26% disruption of codling moth male orientation to
pheromone traps in plots treated with aerosol dispensers deployed at the
recommended rate of 2.5 units per ha.

Miller et al. (2006 a, b) argue that competitive attraction is the predominant
mechanism of disruption, and that practical implications for improving application
of mating disruption are that 1) attractiveness should be competitive with
females, 2) dispenser density should be high, and 3) distribution of pheromone
dispensers should be uniform rather than clumped. Understanding how
distribution of pheromone release devices in an orchard affects orientational
disruption of male moths is necessary to Optimize efﬁcacy of mating disruption for

codling moth and Oriental fruit moth.

d. Canopy Distribution of Reservoir Dispensers

Should competitive attraction be the predominant mechanism in mating
disruption, a factor to consider in point source distribution of reservoir pheromone
dispensers is location of dispensers within the tree canopy to compete with
calling females. However, the distribution of calling codling moth females within

the tree canopy has yet to be directly studied. Research with pheromone baited

traps showing male ﬂight behavior to be concentrated in the top third of the tree
canopy is primarily responsible for the standard recommendation that reservoir
dispensers be applied within the top meter of the tree canopy (Barret 1995,
Knight 2000, McNally and Barnes 1980).

Behavioral and biological studies of codling moth also support moth
activity being centered in the tops of tree canopies. Geier (1963) stated that
moths spend the majority of their time in tree crowns when not in ﬂight (though
providing no data to support this statement), Witzgall et al. (1998) visually
observed male moths ﬂying and searching branches in the upper half of tree
crowns, and Stoeckli et al. (2008) found highest mean values of larval infestation
of fruit in the top and middle tree canopy heights, providing further support for
deployment of pheromone dispensers high in the canopy. The location of both
adult males and females during daylight hours also has not been well
documented, and it is largely assumed that adult moths conﬁne themselves
within the tree canopy during periods of biological inactivity.

Research data on direct sampling of calling female moths in tree canopies
is not reported in the literature. In discussing pheromone trap placement for
capture of male moths, McNeil (1991) points out that trap placement within the
tree canopy can impact the structure and trajectory of a pheromone plume and
therefore the probability and distance over which males will be able to locate the
source. mm at al. (2005) found that height within the tree canopy signiﬁcantly
affected air temperature within the canopy, a factor possibly affecting

microhabitat selection by calling females. Improved knowledge of codling moth

10

bionomics, including the location of calling females, diel behavior patterns and
the affects of factors such as age and prevailing climatic conditions on female
behavior, could be of critical importance in optimizing dispenser placement within
the tree canopy and in ultimately improving the performance of mating disruption

of tortricid moth pests.

e. High-Density Mating Disruption Formulations

Miller et al. (2006a and b) have recently presented a strong case that
pheromone dispenser point source density is strongly correlated to pheromone
treatment efﬁcacy, and that high-density formulations are optimal to take
advantage of false trail following found in the competition model of mating
disruption. Machine-applied formulations that disperse pheromone via numerous
small releasers are being evaluated for disruption of Oriental fruit moth and
codling moth. Hercon® ﬂakes (Hercon, Emigsville, PA) and Scentry® ﬁbers
(Scentry, Billings, MT) are formulations targeting codling moth control that are
applied either by ground or air, allowing large areas to be treated in a much
shorter time than with hand-applied reservoir dispensers. A sticker is added so
that ﬁber and ﬂake particles will adhere to foliage and wood. These types of
dispensers are formulated to be applied at much higher densities (about 37,000 I
ha vs. 1,000 hand-applied dispensers I ha), compared with lsomate dispensers,
and release pheromone at rates similar to those emitted by female moths
(Swenson and Weatherston 1989, Welter and Cave 2005). Fibers and ﬂake have

the potential to provide adequate levels of codling moth disruption, but have

11

limited commercial viability due to insufﬁcient product adherence and lack of
rainfastness (Stelinski et al., 2008)

Parafﬁn-based emulsiﬁed wax is another dispensing formulation being
tested for use in mating disruption (Atterholt 1998, de Lame 2003, Miller 2006a
and b). Stelinski et al. (2006) developed a tractor-mounted mechanical
dispensing system for high-density application of wax dispensers for mating
disruption of Oriental fruit moth. The wax applicator delivered about 160 wax
drops per tree at a speed of 22.5 minutes I hectare (Stelinski et al., 2006). A
single application of wax drops provided 97% orientation disruption of
pheromone-baited traps for 55d and completely prevented mating of tethered
virgin females throughout the season (Stelinski et al., 2007c). A version of this
wax formulation is currently marketed by ISCA Technologies (Riverside, CA,
USA) under the trade name, SPLAT.

Pheromone also has been formulated into microcapsules or beads that
are delivered through conventional spray equipment at densities in excess of one
hundred thousand per hectare. Each capsule releases pheromone at a rate
below that of a calling female resulting in an approach that appears to disrupt
mate ﬁnding by camouﬂaging the female's signal (Stelinski et al., 2005b).
Sprayable pheromone has been quite effective for Oriental fruit moth (Il”lchev et
al., 2006), while codling moth control using the approach has proved more
difﬁcult (Stelinski et al., 2007b). The highest level of disruption is achieved when
the sprayable product is applied using very low gallonages of water (Knight and

Larsen, 2004). However, high or low gallonage applications require multiple

12

sprays through the season and reapplication after a rain event to maintain

disruption (Stelinski et al. 2007b, Waldstein and Gut 2005).

f. Area wide Mating Disruption

A major challenge to the expanded adoption of tortricid moth mating
disruption as it is currently practiced with reservoir-type release devices is the
cost associated with deploying a pheromone program that also requires the
application of numerous insecticide sprays per growing season to prevent
unacceptable levels of larval feeding injury to fruit. An areawide or whole-farm
deployment strategy can help to achieve attainment of high performance
disruption that provides acceptable control with reduced insecticide use.

Areawide management promotes a cooperative effort by neighboring
growers with contiguous acreage to deploy mating disruption on all of the
acreage on their farms to directly address key concerns regarding orchard
perimeters in smaller, individualized mating disruption programs; the immigration
of mated females into a disrupted orchard, and lower pheromone concentrations
along orchard perimeters (Gut and Brunner, 1998; Knight, 1995). Areawide
disruption programs of 1,100 contiguous ha of apples and pears in Australia, and
1,200 ha of mixed stone fruits in the Tulbagh valley in South Africa resulted in
excellent control of Oriental fruit moth (ll’ichev et al., 2002; Barnes and
Blomeﬁeld, 1997). Successful areawide mating disruption programs targeting
codling moth were conducted in pome fruit in the western U.S.A. during the years

1994 to 1998 (Calkins et al., 2000; Brunner et al., 2001) and in Michigan during

13

the years 2004-2009 (McGhee et al., 2009). None of these programs relied solely
on the use of mating disruption to achieve successful control, but incorporated
judicious and timely applications of insecticides. Direct comparisons with
conventional programs outside the project areas revealed reductions in the
number of insecticides applied for codling moth and Oriental fruit moth control.
Areawide disruption projects have also successfully controlled pink bollwonn in
large, contiguous areas of cotton in the southwestern U.S.A. (Staten et al., 1987)

and Egypt (Jones and Casagrande, 2000).

Cydia pomonelIa Granulosis Virus

Since it was ﬁrst collected in Mexico over 40 years ago (Tanada, 1964)
and underwent its initial orchard trials in the 1960’s, codling moth granulosis virus
(CpGV) has been researched as a codling moth control (Falcon et al., 1968). The
Granulosis virus is a highly lethal baculovirus, protected by a protein occlusion
body made from granulin. The occlusion body is ingested by neonate larvae and
dissolved in the alkaline midgut. Virus particles are released, initiating a primary
infection of midgut epithelium cells, which, in turn produces budded viruses that
spread secondary infection to other tissues (i.e. neuronal cells and fat bodies)
(Lacey and Shapiro-llan 2003; Jehle et al. 2006, Weeden et al. 2007). Mortality
occurs within 5 to 10 days and cadavers release billions of viral occlusion bodies
into the environment (Jehle et al., 2006). There are no known negative effects on
plants, mammals, birds, ﬁsh, or non-target insects (Weeden et al. 2007).

Although laboratory bioassays conﬁrmed CpGV to be highly active against

neonate larvae (Jaques et al. 1987), effectiveness in the ﬁeld was inconsistent

14

(Charrnillot et al. 1993, Huber and Dickler 1977; Jaques et al. 1987; Laing and
Jaques 1980; Rashid et al. 2001; Vail et al., 1991). Recent efforts to reforrnulate
Granulosis virus products in Europe, Canada and New Zealand have resulted in
reports of consistently good codling moth control and CpGV products are now
applied on more than 100,000 ha of sustainable codling moth control programs in
combination with mating disruption in Europe (Charrnillot et al. 1998; Lacey and
Shapiro-llan 2003; Eberle and Jehle 2006).

Three commercial formulations are available in Michigan, Carpovirusine
(Arysta LifeScience, Cary, NC), Cyd-X (Certis USA, Columbia, MD), and
Virosoft0P4 (BioTepp, Canada). Carpovirusine contains 1013 viral particles / liter,
and is applied at a label rate of 0.5-1 liter virus/ 1000 liters water I hectare. Cyd-X
contains 3 x 1013 viral particles I liter, and is applied at a label rate of 74 - 266 ml
I hectare. Virosoftcp‘ contains 4 x 1013 viral particles / liter and is applied at a
label rate of 250 ml / hectare. The virus requires frequent reapplication using
standard farm spray equipment due to very short residual activity in the ﬁeld
resulting from viral inactivation from exposure to ultraviolet radiation and high
temperatures (Lacey and Shapiro-llan, 2003). Researchers are currently
investigating CpGV use patterns comparing the efﬁcacy of frequent applications
(5-7 day re-applicationintervals) of virus at low rates vs. higher rates at 14-21
day application intervals, efﬁcacy against different codling moth generations, and
vertical transmission of CpGV between generations (Epstein et al., 2006; Hull

and Krawczyk 2005; Quénin and Laur 2006).

15

Multi-year programs combining CpGV and mating disruption in Europe,
New Zealand and the United States have noted a pattern where initially high
numbers of codling moth adults and high percentages of partial larval entries into
fruit declined over 2-4 year period resulting in reduced pest densities and
reduced injury to fruit (Charmillot et al. 1998; Wearing et al. 1994).

Control failures have also been reported. Reduced susceptibility of codling
moth to CpGV of up to 1000-fold less, based on LC5o values, was ﬁrst reported in
organic apple orchards in 2005 in Germany and France, where CpGV and
pheromone mating disruption constitute the backbone of organic management of
codling moth (Fristch et al. 2005, Jehle et al. 2006, Eberle 2006). Asser-Kaiser et
al. (2007) described codling moth resistance to CpGV as the interaction of three
factors: sex-linkage (located on the Z-chromosome of the moth, favoring rapid
resistance development under continued selection pressure), concentration
dependent dominance (resistance is higher in heterozygous males at low virus
concentrations), and uniformity of the selective agent (Mexican isolate, CpGV-M).

Newly identiﬁed CpGV isolates of varying virulence have been identiﬁed
(CpGV-I12 from Iran; Madex Plus, Andemiatt Biocontrol, Switzerland; and 3
unregistered isolates from Jehle lab in Germany) and tested in Europe (Eberle et
al. 2008; Jehle 2008). All new isolates show good efﬁcacy against resistant
populations and offer a broad genetic basis for development of resistance
management strategies along with the development of resistance monitoring

techniques (Jehle 2008).

16

Dissertation research

The overall aim of this thesis research was to develop and deliver effective
and economical biopesticide-based management programs for codling moth
(CM) and Oriental fruit moth (OFM) control that rely on mating disruption,
granulosis virus, and the judicious use of reduced-risk or conventional
insecticides for control of these key pests. To accomplish these goals
experiments were conducted to better understand mechanisms by which
pheromone mediated mating disruption operates for control of CM and OFM,
evaluations of pheromone dispenser types and deployment strategies, how moth
behavior may affect dispenser deployment strategies, and use of codling moth
Granulosis virus with pheromone disruption for CM population suppression.
Speciﬁc objectives were to determine: 1.) the effect of dispenser point source
distribution on CM and OFM orientation disruption, 2.) within-canopy adult
distribution of CM in disrupted and non-disrupted apple orchards, 3.) diel
distribution of adult CM in disrupted and non-disrupted apple orchards, 4.)
efﬁcacy and optimum patterns of use of CM Granulosis virus formulations, and
5.) the effectiveness of a whole-farm or areawide program for codling moth
control that relies on mating disruption, granulosis virus, and the judicious use of

reduced-risk or conventional insecticides for control of this key pest.

17

CHAPTER ONE
Higher densities of distributed pheromone sources provide disruption of
codling moth (Lepidoptera: Tortricidae) superior to that of lower densities of

clumped sources

Also published as:

Epstein, D.L., L.L. Stelinski, J. Miller, T.P. Reed, and L. Gut. 2006. Higher
densities of distributed pheromone sources provide disruption of codling
moth (Lepidoptera: Tortricidae) superior to that of lower densities of
clumped sources, Econ. Entomol. 99(4): 1327-1333.

18

ABSTRACT

Field experiments quantiﬁed the effect of synthetic pheromone release-
site density and distribution on: 1) orientational disruption of male codling moths,
Cydia pomonella L., to pheromone-baited traps, and 2) fruit injury. A clustering
test varied pheromone release-site density from 0 - 1000 lsomate-C Plus
dispensers I ha while maintaining the total number of dispensers at 1000.
Percent orientational disruption of pheromone-baited traps increased signiﬁcantly
as a function of increasing density of release sites. Fruit injury decreased as the
density of release sites increased and was lowest in plots treated with lsomate-C
Plus dispensers distributed as 1,000 point sources I ha. We also manipulated
point source density of 0.1 ml parafﬁn-wax drops containing 5 % codlemone
((E,E)-8,10-dodecadien-1-ol), and thus, total amount of pheromone deployed per
ha. Percent disruption of traps baited with either 1.0 or 0.1 mg codlemone lures
increased with increasing density of wax drops deployed. Both trapping and ﬁeld
observations conﬁrmed that wax drops were attractive to male codling moths,
suggesting that disruption was mediated by competitive attraction. Development
of dispensers that can be mechanically applied at high densities has potential to
improve the efﬁcacy and economics of codling moth disruption at high population

densities.

19

INTRODUCTION

Mating disruption of codling moth (CM), Cydia pomonella L., in the U.S.A.
is implemented on over 54,000 ha of pome fruits and walnuts, with varying
degrees of success (Gut et al. 2004). The predominant formulation currently
used in the U.S.A. is the lsomate-C Plus polyethylene tube dispenser (Shin-Etsu
Chemical Co., Tokyo, Japan, Thomson et al. 2001) applied at densities of 500 to
1000 per ha, which equates with ca. 1 to 2 per fruit tree. Some researchers
(Shorey and Gerber 1996, Knight 2004) suggest that efﬁcacy can be maintained
while reducing the density of release sites, if overall release rate per ha is
maintained or increased. A saving in labor is postulated for a given number of
lsomate dispensers assembled into clusters rather than distributed individually
(Knight 2004). However, Suckling and Angerilli (1996) falsiﬁed this idea for
lightbrown apple moth, Epiphyas postvittana (Walker). Their study revealed that if
the total number of dispensers was held constant, plots with higher densities of
release sites best-disrupted moth catches in pheromone traps.

There are several commercially available disruption products for CM in
addition to lsomate-C dispensers. For example, lsomate-CTT (Shin-Etsu
Chemical Co., Tokyo, Japan) dispensers contain twice as much pheromone as
the lsomate-C Plus dispenser and are designed for application at a rate of 500/
ha (Alway 2002). Other products, such as Hercon Disrupt CM ﬂakes (Hercon,
Emigsville, PA) and Scentry NoMate CM Fibers (Scentry, Billings, MT) are

applied at higher densities (ca. 37,000 I ha), compared with lsomate dispensers,

20

and release pheromone at rates similar to those emitted by female moths
(Swenson and Weatherston 1989, Welter and Cave 2005). Understanding how
distribution of pheromone release devices in an orchard affects orientational
disruption of male moths is necessary to optimize efﬁcacy of mating disruption for
CM.

The overall goal of this investigation was to determine whether CM
disruption is improved by increasing density and distribution of pheromone
release sites. Studies were also conducted to determine whether male moths
approach dispensers in order to provide insight into the mechanism(s) by which
disruption may be operating. Our speciﬁc objectives were to determine whether:
1) a given number of lsomate-C Plus dispensers were equally efﬁcacious
whether clumped or distributed, and 2) CM disruption could be improved over
that by lsomate dispensers if multiple parafﬁn-wax drops were deployed per tree
as Stelinski et al. (2005a) demonstrated was effective for Oriental fruit moth,
Grapholita molesta (Busck). A trapping study and direct ﬁeld observations were
conducted to determine whether wax drops attract male CM. Pheromone release
rate from wax drops was also quantiﬁed by gas chromatography.

MATERIALS AND METHODS

Experiment 1: Reducing release-site density while maintaining total
pheromone applied per ha constant. This study was conducted 10 May to 30
September, 2003. The objective was to evaluate the effect of clustering
pheromone release sites on disruption efﬁcacy while maintaining a total of 1000

lsomate-C Plus dispensers I ha. These dispensers contained 205 mg of 53.0 %

21

codlemone ((E,E)-8,10—dodecadien-1-ol), 29.7 % 120H, 6.0 % 14OH, and 11.3
% inert ingredients. Densities of release sites per ha were: 0, 10, 25, 100, 500,
and 1,000. Dispensers were applied individually in the top m of trees for the 500
and 1000 I ha treatments. Two dispensers were spaced 2.5 cm apart in the 500
release site I ha treatment. Multiple dispensers in the 10, 25 and 100 release site
I ha treatments were attached to horizontally mounted, (1 intersection / cmz)
galvanized-metal hardware cloth (‘IWP Wire Mesh, Berkeley, CA, U.S.A.), each
dispenser spaced 2.5 cm apart as per Suckling and Angerilli (1996). The 100
release sites / ha treatment consisted of 10 dispensers per cluster; the 25
release sites I ha treatment consisted of 40 dispensers per cluster, and the 10
release sites I ha treatment consisted of 100 dispensers per cluster. Pheromone
release sites were spaced equidistantly throughout each 0.4 ha plot (Fig. 1).
Experimental design was a randomized complete block with two replicates
(blocks) located at the Trevor Nichols Research Complex (T NRC) of Michigan
State University in Fennville, MI and one each in two commercial orchards in
South Lyon and Flushing, MI. The two blocks at TNRC were separated by at
least 300 m and treatment plots at all commercial orchards were separated by at
least 45 m. Experimental sites and tree composition are described in Table 1.
Disruption of male moth orientation to sex pheromone was assessed using 3
pheromone traps (LPD Soenturian Guardpost, Suterra, Bend, OR) / 0.4 ha plot
baited with 1 mg codlemone rubber septum lures and placed in the upper third of
tree canopies on a diagonal transect across each plot (Fig. 1). Lures were red

rubber septa loaded with codlemone (> 98 % isomeric and chemical purity,

22

Suterra, Bend, OR). New pheromone lures were deployed every two weeks
during each moth generation. Moths captured in traps were counted and

removed once weekly.

 

 

 

 

 

 

 

 

 

 

4: 63m i.
Trap 1
15m 15m 15m 15m

E] (=5-—- —-—'==§
15m o:
DO
3

Trap

 

 

 

 

 

 

 

 

Trap

l

i

 

 

 

 

Figure 1. Diagram of a 0.4 ha orchard plot containing 4 release sites of clustered
lsomate-C Plus dispensers. Shaded boxes (not to scale) represent 100 clustered
lsomate-C Plus dispensers. Other release-site densities were likewise regularly
distributed.

23

Table 1. Description of orchards used in Experiment 1 in which density of release
sites (lsomate—C Plus dispensers) per ha was varied without varying total amount
of pheromone deployed per ha.

 

 

Orchard No. Cultivar(s) Tree Age Canopy Height Tree Spacing
1 Red Delicious 16 yrs 3.5 — 4.5 m 3 x 6 m
2 Golden 10 yrs 3.5 — 4.5 m 1.8 x 4.6 m
Delicious
Red Delicious 10 yrs 3.5 - 4.5 m 3 x 5.5 in
Red Delicious 20 yrs 4 - 5 m 3 x 5.5 m
Rome 8 yrs 3 - 4 m 2.4 x 5.5 m
3 Braeburn 7 yrs 2.4 — 3.1 m 2.7 x 4.9 m
Macintosh 7 yrs 2.4 — 3.1 m 2.7 x 4.3 m
Fuji 7 yrs 2.4 - 3.1 m 2.4 x 4.6 m
Jonagold 7 yrs 2.4 - 3.1 m 2.4 x 4.6 m
Northern Spy 7 yrs 2.4 - 3.1 m 2.4 x 5.5 m
4 Gala 20 yrs 2.4 — 3.1 m 2.4 x 4.6 m
Gala 20 yrs 3 — 4 m 2.7 x 4.9 m

 

CM fruit injury was evaluated in all plots following ﬁrst generation moth

ﬂight and immediately prior to harvest. Thirty apples per tree, ﬁfteen high in the

canopy and 15 low in the canopy, were examined from 20 trees per plot (600 fruit

/ plot total).

Experiment 2: Increasing both point-source density and total pheromone

applied per ha from parafﬁn-wax drops. Parafﬁn-wax dispensers (Stelinski et al.

2005a) were used because a larger range of densities could be compared than

with lsomate-C Plus dispensers, while applying less total pheromone I ha than

could be achieved with lsomate-C Plus dispensers. This study was conducted 13

24

May to 3 June of 2004 at TNRC. This experiment ran for only 2 wk because
disruption efﬁcacy was rapidly lost thereafter. Experimental site, tree
composition, and maintenance protocol of orchards are described in Stelinski et
al. (2005a). Orientational disruption trials were conducted comparing ﬁve
application densities of 0.1 ml drops of parafﬁn wax containing 5% pheromone.
Parafﬁn-wax dispensers were formulated as described in Stelinski et al. (2005a).
Brieﬂy, parafﬁn-wax formulation consisted of: 30 % parafﬁn wax (Gulf wax, Royal
Oak Sales, Inc., Roswell, GA), 4 % soy oil (Spectrum Naturals, Inc., Petaluma,
CA), 2 % Span 60 (Sorbitan monostearate, Sigma-Aldrich Co., St. Louis, MO), 1
% vitamin E ([il-a-tocopherol, Sigma Chemical Co., St. Louis, MO), 5 %
codlemone (Bedeukian Co., Danbury, CT, > 98% purity conﬁrmed by gas
chromatography), and 58 % (by total weight) de-ionized water. Wax drops were
hand-applied to branches of trees using 5 ml plastic syringes. Densities of wax
drops compared were: 0 per tree, 3 per tree (820 I ha, 3.3 g A. I. I ha); 10 per
tree (2,700 / ha, 11 g A. l. I ha); 30 per tree (8,200 I ha, 33 g A. l. I ha); and 100
per tree (27,300 / ha, 109 g A. l. I ha). Experimental design was a randomized
complete block with treatments applied to 0.07 (16 tree) ha plots replicated 5
times. Replicate orchards (blocks) were separated by at least 35 m and
treatment plots by at least 15 m. Orientational disruption of male catches was
assessed using two pheromone traps, baited with either 1.0 or 0.1 mg of
codlemone, placed in two of four central trees of each plot. Traps were hung ca.

2 - 3 m above ground level in the upper third of the tree canopy. Wax dispensers

25

were never placed closer than 50 cm from monitoring traps. Moths captured in
traps were counted and removed twice weekly.

Experiment 3: Evaluating attractiveness of paraﬂin-wax dispensers to
male codling moths. We compared captures of male CM in traps baited with 0.1
ml parafﬁn-wax drops formulated as above with that of rubber septum lures
loaded with 1 mg of codlemone (described above) known to be highly attractive.
These tests were conducted 6 July through 19 September, 2004 in plots not
being used for mating disruption studies. Parafﬁn-wax dispensers containing
pheromone were pipetted onto 2 x 5 cm strips of aluminum foil and allowed 24 h
to dry before strips were deployed in traps. Fresh lures were installed every two
weeks into plastic delta traps deployed in unsprayed 0.4 ha plots of apples, as
above. Unbaited traps were used as a negative control. Parafﬁn-wax treatments
were replaced every four weeks. The experiment was arranged in a randomized
complete block with 6 replicates. Traps were spaced ca. 26 m apart and rotated
weekly. Traps were hung ca. 1.5 - 2 m above ground level in the upper third of
the tree canopy. Moths captured in traps were counted and removed twice
weekly.

Experiment 4: Direct observation of codling moth males in plots treated
with various densities of wax drops. Direct observations of male CM visits to wax
drops in trees were conducted as detailed in Stelinski et al. (2005a).
Observations were conducted on 17 nights during ﬁrst CM generation. One wax
drop containing pheromone was observed in control plots that were otherwise

untreated.

26

Experiment 5: Measuring pheromone release rate from 0.1 ml wax drops.
Release rate of codlemone from parafﬁn-wax dispensers was determined using
protocol reported by Stelinski et al. (2005a). Brieﬂy, parafﬁn-wax drops (0.1 ml)
were applied to 1 x 5.5 cm pieces of ﬂat, wooden Craft Sticks (Diamond Brands,
Cloquet, MN) using an Eppendorf repeat pipetter. Resulting drops were ca. 7 mm
in diameter and 2 mm thick. Samples were attached with plastic ties to branches
of ﬁve 5 - 7 m tall apple trees at a height of 2 - 3 m within the tree canopy.
Samples were maintained in the ﬁeld and in a laboratory fume hood from 3
August to 8 October, 2004. Five samples were collected immediately at
application to determine pheromone concentration in wax drops at test onset.
Thereafter, three samples were collected approximately every 24 h for 4 d and
then every other d for 80 d. Pheromone extracted from samples was quantiﬁed
using a gas chromatograph (HP-6890, Hewlett-Packard Co.) ﬁtted with a
DBWAXETR polar column (model # 122-7332, J&W Scientiﬁc, Folsom, CA) of
length 30 m and internal diam. 250 um. Initial oven temperature was 130 °C for 2
min and then it was ramped at a rate of 2.5°C / min to 160°C, where it was held
for 2 min. The program then ran at 40°C l min to a ﬁnal temperature of 230 °C.
The carrier gas, He, entered the column at 20 psi.

Statistical analysis. For orientational disruption and trapping studies, data
were transformed to In (x + 1) (which normalized distributions and homogenized
variance) and then subjected to analysis of variance (ANOVA). Fruit injury data
were arcsine transformed prior to ANOVA. Differences in pairs of means were

separated using the LSD test (SAS Institute 2000). Fruit injury data were also

27

subjected to regression analysis to describe the overall relationship between fruit

injury and logo of pheromone release-site density. Observational data of moth

visits to parafﬁn wax drops in the ﬁeld were subjected to )8 analyses. Percent

orientational disruption was calculated as 1 - (mean moth catch per trap in the

pheromone-treated plot / mean moth catch per trap in the control plot) x 100.
RESULTS

Experiment 1: Reducing release-site density while maintaining total
pheromone applied per ha constant. Overall, percent disruption of pheromone-
baited traps increased signiﬁcantly as a function of increasing density of
pheromone release sites (Fig. 2 A). Traps in plot centers treated with 1,000 or
500 release sites I ha captured signiﬁcantly (F = 14.2, df = 5, 18, P < 0.01) fewer
males than those in plots treated with 0, 10, or 25 release sites I ha (Fig. 2 A).
Also, signiﬁcantly (P < 0.01) fewer males were captured in plots with 1000
release sites I ha than in plots with 100 release sites I ha (Fig. 2 A). There was
no signiﬁcant (P > 0.05) difference in male catch in central traps among plots
treated with 10 and 25 release sites I ha (Fig 2 A).

Traps placed on plot borders treated with 500 and 1,000 point sources /
ha captured signiﬁcantly (F = 8.3, df = 5, 18, P < 0.01) fewer males than those
placed on plot borders with 0, 10, 25, or 100 release sites I ha (Fig. 2 B). There
was no signiﬁcant difference among male captures in border traps of plots
treated with 10 or 100 release sites I ha (Fig. 2 B). As with central traps,
orientational disruption of border traps was highest for the two highest release-

site density treatments (Fig. 2 B).

28

Percentage of infested fruit decreased as density of release sites
increased. Fruit injury in both plot centers and borders was signiﬁcantly (F’s =
4.4, 5.0, respectively, df = 5, 18, P < 0.01) reduced relative to control in plots
treated with 1,000 release sites I ha (Fig. 3 A, B). Among pairs of means, there
was no signiﬁcant (P > 0.05) difference between fruit injury in plots with 100
through 1000 release sites I ha. Overall relationships between decreasing fruit
injury as a function of increasing log1o of release-site density were described by y
= - 0.23 x + 3.8 (R2 = 0.84) and y = - 0.25 x + 4.2 (R2 = 0.8) for plot centers and
borders, respectively. Slopes for these relationships were signiﬁcantly (F’s =

20.5, 13.1, df = 1, 5, P < 0.05) negative.

29

A. Center traps

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A 250 ~ -
E

200 ~ a
(I)
H l

150 4 i
g x
a) 100 i 77%
E b 83% 93%
v b ° 96% 97%
C 50 I C Cd d
8 1 PL]
m OTI T 'T—“H —l'— di‘ 1“ I:_1_-‘_‘1”I!LI_—:1ﬂ"'l
a)
(D o 10 25 100 500 1000
L
a)
0- B. Border traps
fit
I: 250 ~
5

a
8 200 . i
m I 73% 51% 79% 93% 97%
5 150 . b
o
2' l
C) 100 ‘
bc
g I c
'8 50 . i
I d d
O
O I I ' r rﬁ 7
o 10 25 100 500 1000

Release Sites per ha

(always 1000 lsomate-C Plus dispensers/ ha)

Figure 2. Mean captures of codling moth males in lure-baited delta traps in A)
centers and B) borders of plots containing various release-site densities of
lsomate-C Plus dispensers while maintaining the total number of dispensers at
1000 / ha. Means followed by the same letter are not signiﬁcantly different at a <

0.05.

30

A. Plot centers

251 -, ~ - -
2o~

15 ‘ ab

 

 

 

ab

10- . L l [ I
5- I l .

O 1 0 25 1 00 500 1000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

B. Plot borders

N
U1
l

204 3

Percent Fruit Injury (Mean 1 SEM)

151

 

ab
ab

104 ,_ _ l I J b

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

O 10 25 1 00 500 1 000

Release Sites per ha
(always 1000 lsomate-C Plus dispensers/ ha)

Figure 3. Mean percent fruit injury due to codling moth larval infestation in A)
centers and B) borders of plots containing various release-site densities of
lsomate-C Plus dispensers while maintaining the total number of dispensers at
1000 / ha. Means followed by the same letter are not signiﬁcantly different at a <
0.05.

31

Experiment 2: Increasing both point-source density and total pheromone
applied per ha from parafﬁn-wax drops. Mean numbers of moths captured in
traps decreased as a function of increasing wax-drop density. Signiﬁcantly (F’s =
11.4,12.2, respectively, df = 4, 20, P < 0.01) fewer males were captured in traps
baited with 1.0 and 0.1 mg lures in plots treated with 27,300 wax drops / ha than
in plots with 0, 820, and 2,700 drops I ha (Fig. 4 A, B). However, this analysis of
pairs of means revealed no signiﬁcant (P > 0.05) differences in numbers of males
caught with both lure loadings between plots with 8,200 and 27,300 point
sources (Fig. 4 A, B). Overall, percent disruption of traps baited with either 1.0 or
0.1 mg lures increased with increasing density of point sources deployed (Fig. 4
A, B). Ninety-four and 99 % orientational disruption was achieved with 27,300
point sources I ha for 1.0 and 0.1 mg lures, respectively.

Experiment 3: Evaluating attractiveness of paraffin-wax dispensers to
male codling moths. Signiﬁcantly (F = 16.2, df = 3, 20, P < 0.01) more male CM
were captured in traps baited with each pheromone treatment than in blank
controls which captured 0.06 :t 0.05 (mean :I: SE) males over the season. There
was no statistical (P > 0.05) difference in mean number of males captured in
traps baited with red septa (65.5 :I: 13.4), 0.1 ml wax drops with 98% pure
codlemone (81.8 :I: 18.5), or 0.1 ml wax drops with codlemone extracted from

lsomate-C Plus dispensers (74.3 :I: 9.2).

32

Imme4'
CODIainan
905.

&'
W7 Van‘o
DMSaai

mmmﬂ

matsthan

A. Traps with 1.0 mg lures

80

2 a

3‘) 60

*1 50%*

a 40 b

E 79%*

"‘ 87‘V"

'g 20 c C; 94%*

d

U)

E.

o 0 —---~ - ~ —- -——- —-—-

CE” 0 820 2700 8200 27300

.E

’8 B. Traps with 0.1 mg lures

Q

'05 80-

L.

B 60 a

E

E 40

c 72%* ,

m b 84% 90%*

o bc 99%*
O . ._..__.. . .___._ ._.__.... .._.__._. ._..._

o 820 2700 8200 27300

Number of point sources per ha

Figure 4. Mean captures of codling moth males in lure-baited delta traps in plots
containing various densities of 0.1 ml parafﬁn-wax drops containing 5 %
COdlemone. Means followed by the same letter are not signiﬁcantly different at a

< 0.05.

Experiment 4: Direct observation of codling moth males in plots treated
With Various densities of wax drops. CM males approached wax drops in treated
P'Ots at all dispenser densities (Fig. 5). Signiﬁcantly (X2 = 7, df = 1. P < 0-01)
more males approached a single drop under observation in otherwise untreated

P'Ots than in plots with 820 drops I ha and likewise signiﬁcantly (X2 = 20, df = 1. P

33

(0.01) more "'

ﬁhﬂldmcs

 

hs
‘EErOps
5g

Wax
#

m M
dling
Co
ber Ofer'ved
u bs _.
Total 2:1an 0 ’
roa _.
Akrara

Figure 5_ N
drop dlSpe.
A“ mOII‘lS c
00.000th
Same Ielle

males Obs
approache
Cm, Follow
walla, lap.

lam O"Spelt

< 0.01) more males approached a single drop under observation in plots treated

with 820 drops / ha than in plots treated with 2,700 drops I ha. Sixteen of 81

0"
o
4]

A
o
I

(a)
O
I

 

N
O
1

C

H , lcl , .2

Control 820 2,700 8,200 27,300
(1 drop)

Total Number of Codling Moths
Approaching Observed Wax Dr0ps

 

 

 

 

 

 

O

Wax Drops per ha

Figure 5. Numbers of codling moth males observed approaching parafﬁn-wax
drop dispensers of pheromone in plots receiving various densities of dispensers.
All moths observed approached within 130 cm of dispensers. Observations were
conducted on 17 evenings between 17 May and 12 June. Means followed by the
same letter are not signiﬁcantly different at a < 0.05.

males observed made direct contact with drops, 88% of observed males
approached within 20 cm of wax drops, and all observed moths came within 130
cm. Following landing on foliage near wax drops, males fanned their wings and

walked rapidly. None of the visits lasted longer than 2 min, and 90 % ﬂew away

from dispensers within 60 s.

Experiment 5: Measuring pheromone release rate from 0.1 ml wax drops.
Release proﬁles of codlemone from wax drops in a laboratory fume hood and in
the ﬁeld are shown in Fig. 6, ﬁtted with exponential decay curves. Laboratory
samples yielded an R2 of 0.98 and a decay constant value of - 0.028, while ﬁeld
samples gave an R2 of 0.94 and a higher decay constant value of — 0.051.
Release rate of codlemone from a wax drop was ca. 2.1 and 3.3 pg I h over the
ﬁrst 14 d of release in the laboratory and ﬁeld, respectively. Between d 14 and

35, release rate decreased to ca. 1.3 to 0.5 pg I h.

   
  
   

 

 

 

 

 

'6
c: 5 *
.9 A Laborato Sam les ,
'° 2 _ ry 00fo _ __ Field Samples
4 Y 3 7472
8 m - - e _ -0.51x
% a) R2 = 0 98 y; 5.7993e
3 3 3 7 ' R = 0.94
d: 8’
‘1. § 2 d
r e 1
ﬂ q 15‘
9"; é, o 6. .1 T ‘ ‘- — ma ,
c»
E

0 7 14 21 28 35 42 49 56 63 70 77 84

Days after Deployment

Figure 6. Release proﬁles of 0.1 ml parafﬁn-wax drops containing 5 %
codlemone ﬁtted with exponential decay curves.

35

DISCUSSION

The highest density of pheromone-dispenser release sites yielded the best
orientational disruption of male CM to traps and lowest fruit injury. Increased
orientational disruption as a function of increasing release-site density occurred
both when the total amount of pheromone per ha was increased, and when it
was held constant. These results corroborate ﬁndings of previous studies of
release-site density on disruption for other moth species (Charlton and Cardé
1981, Palaniswamy et al. 1982, Suckling et al. 1994, de Lame 2003). In the
current study, 96-97 % orientational disruption was achieved with 1000 lsomate
C Plus ropes I ha distributed as 1000 point sources I ha, and 94-99 % disruption
was achieved with 27,300 parafﬁn-wax drops per ha. Given that lsomate-C Plus
dispensers release pheromone at ca. 20 pg / h (Knight 1995b), and parafﬁn-wax
drops released ca. 2 pg I h during the ﬁrst 2 weeks in the ﬁeld, the amount of
pheromone released / ha I h for 1000 lsomate dispensers and 27,300 wax drops
was ca. 20 and 55 mg, respectively.

Alford and Silk (1983) and Suckling and Angerilli (1996) also varied
release-site density while maintaining total number of pheromone point sources
per ha constant. The former study was conducted with the spruce budworm,
Choristoneura fumiferana (Clemens), and Hercon ﬂakes (Hercon, Emigsville, PA)
as the dispenser of synthetic pheromone. Intermediate densities of 33 and 100
points I m2 of 60 and 20 ﬂakes per release site yielded higher disruption than a
uniform distribution of single ﬂakes or 9 release sites of 222 ﬂakes I site. These

results are consistent with the current study in that the treatment with fewest

36

release sites disrupted the least. That intermediate densities of ﬂakes proved
slighﬂy better than the completely uniform distribution of one ﬂake per release
site in the Alford and Silk study is likely because clumps of 20 and 33 ﬂakes I site
competed with females to a higher degree than single ﬂakes / site, given the low
pheromone release rate from these dispensers. However, even with intermediate
clumping, treatments with 20 and 33 ﬂakes I release site were applied at high
densities of 2000 and 660 total release sites I ha. Suckling and Angerilli (1996)
studied the lightbrown apple moth and used polyethylene, reservoir-type
dispensers similar to those used in our study. Our results were consistent with
the above studies in that clumping of dispensers decreased disruption.

Current results are inconsistent with those of Knight (2004), who found
that highly-spaced clusters of 100 lsomate-C Plus dispensers (4 I ha) disrupted
CM males comparably to 500 dispensers I ha distributed individually. However,
Knight’s cluster treatment was supplemented by a 10-20 m-wide border
application of lsomate-C Plus dispensers at a density equivalent to 1000 I ha,
which was not applied to the highly-distributed lsomate—dispenser treatment. In
addition, CM density in the current study was high (> 300 moths I trap for the
season in control plots based on 3 traps per 0.4 ha) but was low in the Knight
study (< 8 moths Itrap for the season in control plots based on 2 traps I ha).
Thus, contradicting results between our study and Knight’s are likely due to
differences in experimental design and CM population density.

On both plot borders and in plot centers, fruit injury was lowest when

lsomate-C Plus dispensers were most highly distributed. Fruit injury in the 1,000

37

point source I ha treatment was almost two-fold less than in the 500 point source
I ha treatment (Fig. 3 A, B). In addition, there was a signiﬁcant overall
relationship between increased release-site density and decreased fruit injury. It
is important to note that seemingly small differences in percent disruption as
measured by traps (eg. 93 — 96 % vs. 97 - 99 %) may be associated with widely
differing crop protection outcomes.

CM males have been observed orienting to and landing within close
proximity (mean 50 cm) of lsomate-C Plus dispensers placed directly within trees
in pheromone-treated orchards (Stelinski et al. 2005b). In our recent ﬂight-tunnel
studies with CM males, pre-exposure of moths to lsomate-C Plus dispensers
decreased male responsiveness to otherwise highly attractive lures (Stelinski et
al. in review). This suggests that desensitization following pre—exposure to
lsomate dispensers may have contributed to disruption of CM. More research will
be required to determine relative importance of desensitization following pre-
exposure to high-release, reservoir dispensers versus pure competitive attraction
to false plumes.

Both trapping experiments and ﬁeld observations conﬁrmed that wax
drops were highly attractive to male CM, suggesting that orientational disruption
by wax drops functioned primarily by competitive attraction (false-plume
following). Deployment of parafﬁn-wax dispensers at 8,200 and 27,300 drops I ha
has recently been shown to provide better mating disruption of Oriental fruit
moth, Grapholita molesta (Busck), than standard applications of lsomate—M

Rosso dispensers in small plot trials (Stelinski et al. 2005a). However, this wax

38

formulation still needs improvement for CM under high population densities in MI.
Although 99 % orientational disruption was achieved in the current study with
27,300 drops / ha, this result lasted only ca. two weeks, after which disruption
was not better than 50 % relative to control plots. This may have been due to the
drop in codlemone release rate after (I 14 (Fig. 6) or codlemone degradation
(Millar 1995) after this interval. That wax drops deployed within delta traps were
attractive to CM for up to four wk in our trapping study, while disruption failed
after 2 wk, suggests photo-degradation of codlemone was a problem. A recently
improved formulation incorporating antioxidants, as well as UV and visible light
blockers deployed at 27,300 drops I ha proved equally effective to lsomate C-
Plus dispensers at 1000 I ha for an entire moth generation (Stelinski et al.
unpublished data) and holds promise as a cost-effective alternative mating
disruption formulation for CM that can be machine-applied. The addition of
insecticides to this formulation might enhance efﬁcacy through removal of
attracted males (Krupke et al. 2002).

ACKNOWLEDGEMENTS
We thank Krista Buehrer, Racheal Mallinger, Alison Gould, and Kevin Vogel for
assistance with ﬁeld application of pheromone dispensers and collection of
trapping data. This research was funded in part by Michigan State University
Project GREEEN.

39

CHAPTER TWO
Higher densities of uniformly distributed pheromone sources provide disruption of
Oriental fruit moth (Lepidoptera: Tortricidae) superior to that of lower densities of

clumped sources

Portions of this chapter are in press as:
de Lame' F.M., D.L. Epstein, L.J. Gut, H. Goldfarb, and JR. Miller. 2010. Impact
of Varying Density of Pheromone Point Sources on the Success of Mating

Disruption of Grapholita molesta (Lepidoptera: Tortricidae), Econ. Entomol.

4O

ABSTRACT

Field experiments quantiﬁed the effect of synthetic pheromone release-
site density and distribution on: 1) orientational disruption of male Oriental fruit
moths, Grapholita molesta (Busck) to pheromone-baited traps, and 2) fruit injury.
A clustering test varied pheromone release-site density from 0 - 500 lsomate-M
Rosso dispensers per ha while maintaining the total number of dispensers at
500. Percent orientational disruption of pheromone-baited traps increased
signiﬁcantly as a function of increasing density of release sites. Fruit injury
decreased as the density of release sites increased and was lowest in plots

treated with lsomate-M Rosso dispensers distributed as 500 point sources I ha.

41

INTRODUCTION

Mating disruption of Oriental fruit moths, Grapholita molesta (Busck), in
the U.S.A. is implemented on over 45,000 acres of apple and peach (Gut et al.,
2004, Witzgal et al., 2008) and has a long history of success worldwide
(Rothschild 1975, 1979, Vickers et al. 1985, Pfeiffer and Killian 1988, Audemard
et al. 1989, Sexton and Il’ichev 2000, de Lame et al. 2007). Isomate® M 100,
Isomate® M Rosso, Scentry NoMate® Oriental fruit moth Spirals, and
CheckMate® SF are the reservoir dispensers available for Oriental fruit moth
(OFM), with label rates varying from 250 to 500 per hectare.

Because the input costs of mating disruption products are often relatively
expensive, many growers are apprehensive about using these products.
Additionally, the application of hand applied dispensers is a labor intensive
process (approximately 2 h per acre), adding labor costs as well as competition
for that labor at times of the growing season when many growers are busy
working in other crops.

Some researchers (Shorey and Gerber 1996, Knight 2004) suggest that
mating disruption efﬁcacy can be maintained while reducing the density of
release sites, if overall release rate per ha is maintained or increased. A saving in
labor is postulated for a given number of reservoir dispensers assembled into
clusters rather than distributed individually (Knight 2004). However, Rothschild
(1975) and Stelinski et al. (2005) showed that orientation disruption of male G.

molesta to traps increased with increasing numbers of pheromone point sources.

42

Stelinski et al. (2005) showed decreased mating of tethered virgin females with

increased numbers of pheromone dispensers. Only Rothschild (1975) kept the

amount of pheromone applied per area constant. We report on studies

investigating the effect of reducing point source densities while maintaining

overall equivalent amounts of pheromone per unit area on orientation disruption

of G. molesta using lsomate OF M-Rosso (Shin-Etsu Chemical Co., Ltd., Tokyo,

Japan). Understanding how distribution of pheromone release devices in an

orchard affects orientational disruption of male moths is necessary to optimize -"

efﬁcacy of mating disruption for OFM.

MATERIALS AND METHODS

Experiments directly compared effects of varying numbers of pheromone
point sources per unit area on G. molesta orientation disruption. Total
pheromone per unit area was kept constant, while varying the number of evenly
distributed point sources. Experiments were set up as randomized complete
block designs with individual orchards as blocks.

This experiment was replicated in two apple orchards at TNRC, and in two
commercial orchards in South Lyon and Flushing, MI, 4 May to 23 September,
2003 (T able 2). The two blocks at the TNRC were separated by at least 300 m
and treatment plots at all commercial orchards were separated by at least 45 m.
Four-hundred and ninety-four (1239 active ingredient) lsomate-M Rosso
polyethylene tube dispensers (Shin-Etsu Chemical Co., Ltd., Tokyo, Japan) were

applied per ha in the upper third of tree canopies. The densities of release sites

43

per ha were: 0 (0 point sources / plot, or 0 PTS), 10 PTS, 25 PTS, 90 PTS, 250
PTS, and 500 PTS. For the 500 PTS treatment, the dispensers were applied
individually. For the 250 PTS treatment, two dispensers were spaced 2 - 3 cm
apart at each release site. The 90 PTS treatment consisted of 5 dispensers per
cluster; the 25 PTS treatment consisted of 20 dispensers per cluster, the 10 PTS
treatment consisted of 50 dispensers per cluster. Pheromone release sites were

spaced equidistantly throughout each 0.4 ha plot (Figure 7).

Table 2. Description of orchards used in which density of release sites (lsomate-
C Plus dispensers) per ha was varied without varying total amount of pheromone

 

 

deployed per ha.
Orchard No. Cultivar(s) Tree Age Canopy Height Tree Spacing
1 Red Delicious 16 yrs 3.5 — 4.5 m 3 x 6 m
2 Golden 10 yrs 3.5 - 4.5 m 1.8 x 4.6 m
Delicious
Red Delicious 10 yrs 3.5 - 4.5 m 3 x 5.5 in
Red Delicious 20 yrs 4 — 5 m 3 x 5.5 m
Rome 8 yrs 3 — 4 m 2.4 x 5.5 m
3 Braeburn 7 yrs 2.4 — 3.1 m 2.7 x 4.9 m
Macintosh 7 yrs 2.4 — 3.1 m 2.7 x 4.3 m
Fuji 7 yrs 2.4 — 3.1 m 2.4 x 4.6 m
Jonagold 7 yrs 2.4 — 3.1 m 2.4 x 4.6 in
Northern Spy 7 yrs 2.4 — 3.1 m 2.4 x 5.5 m
4 Gala 20 yrs 2.4 - 3.1 m 2.4 x 4.6 m
Gala 20 yrs 3 - 4 m 2.7 x 4.9 m

 

 

II
ii

-._ ,, _ 63m

 

Trap

15m 15m 15m 15m

 

 

[1
ii
[:I

 

 

15m

“189

Trap

Trap

 

 

 

 

Figure 7. Diagram of a 0.4 ha orchard plot containing 4 release sites of clustered
lsomate-M Rosso dispensers. Shaded boxes (not to scale) represent 50
clustered lsomate-M Rosso dispensers. Other release-site densities were
likewise regularly distributed.

Multiple dispensers in the 10 PTS, 25 PTS, and 90 PTS treatments were
attached to horizontally-mounted, (1 intersection/cmz) galvanized-metal hardware
cloth (TWP VWe Mesh, Berkeley, CA); dispensers were spaced 2.5 cm apart, as
per Suckling and Angerilli (1996). Disruption of male moth orientation to sex
pheromone was assessed using three pheromone-baited traps (LPD Soenturian
Guardpost, Suterra, Bend, OR) per 0.4 ha plot, placed on a diagonal transect

across each plot in the upper third of tree canopies. Two traps were located in

plot outer corners, taking into account edge effects, while one was located in the

45

center of each plot. The lures were red rubber septa loaded with 0.1 mg G.
molesta sex pheromone. New pheromone lures were deployed every four weeks
during each moth generation. Moths captured in traps were counted and
removed once weekly. OFM fruit injury was evaluated in all plots in July and
immediately prior to harvest. Thirty apples per tree, ﬁfteen high in the canopy and
15 low in the canopy, were examined from 20 trees per plot (600 fruit I plot total).
The level of signiﬁcance for all statistical tests was a = 0.05. For
orientational disruption and trapping studies, data were transformed to In (x + 1)
(which normalized distributions and homogenized variance) and then subjected
to analysis of variance (ANOVA) with orchard as a blocking factor. Means were
separated with Tukey’s HSD test (StatSoft, Inc. 1984-2008). The Kruskal-Wallis
test was also used to analyze orientation disruption data. If signiﬁcant differences
were identiﬁed using the Kruskal-Wallis test, means were separated with multiple
comparisons of the mean ranks. The Wilcoxon Signed Rank test was used to
analyze the effect of trap location (center or edge) on percent orientation
disruption of G. molesta in plots treated with lsomate-M Rosso. Fruit injury data
were arcsine transformed prior to ANOVA. Differences in pairs of means were
separated using the LSD test (SAS Institute 2000). Fruit injury data were also
subjected to regression analysis to describe the overall relationship between fruit

injury and logo of pheromone release-site density.

46

RESULTS
Overall, percent disruption of pheromone-baited traps increased
signiﬁcantly as a function of increasing density of pheromone release sites
(F=12.71, df = 5, P < 0.000) (Figure 8). Only at the highest densities of point
sources per he tested (250/ha & 500/ha), did dispensers perform well, with most

plots achieving at least 95% orientation disruption.

 

 

 

   

500 ,
E 400 57% 1 7% 51% 115% 78% 112% 96% 1 2% 96% 1 3%
1' I
8. 300
. I
g ;
E 200 I
3
O

i "ii bc c
0 ' _. T #—

 

 

 

 

 

 

 

 

10 PTS 25 PTS 90 PTS 250 PTS 500 PTS
Treatment

Figure 8. Numbers of male G. molesta captured in lure-baited traps in plots
treated with lsomate-M Rosso during G. molesta generations one, two, and three
(mean :I: S.E.). Bars labeled with the same letter are not signiﬁcantly different

(T ukey, P 2 0.05). Percent orientation disruption values (mean :I: S.E.) are written

above treatment bars.

Orientation disruption was 40% lower in traps placed in plot edges than
traps placed in plot middles in the 10 PTS plots, 57% lower in 25 PTS plot, and
43% lower in the 100PTS plot (Table 3). It was only when point source density
increased to 250 and 500 PTS that orientation disruption was more uniform

across the entire plot. Orientation disruption at 250 PTS and 500 PTS was 6%

47

and 7% lower in edge traps respectively. There was no signiﬁcant effect of

generation (8 = 2.56, df = 2, P = 0.28).

Table 3: Percent orientation disruption to traps placed in the center versus the
edge of plots treated with lsomate-M Rosso (mean :I: S.E.). Values in a row
followed by the same letter are not signiﬁcantly different (Wilcoxon Signed-Rank
Test P 2 0.05).

 

Trap Location

 

Treatment Center Edge 2 P
10 PTS 77.7 :t 9.43 58.7 :I: 10.6a 1.41 0.16
25 PTS 86.5 :I: 4.5a 29.8 :I: 15.5b 2.85 0.004
90 PTS 99.8 1: 0.13 64.1 :I: 12.7b 2.67 0.008
250 PTS 99.1 :I: 0.4a 95.9 :1: 16b 2.67 0.008
500 PTS 100.0 1: 0.03 94.3 t 4.2b 2.02 0.04

 

 

Percentage of infested fruit decreased as density of release sites
increased. Fruit injury in both plot centers and borders was signiﬁcantly reduced
relative to control in plots treated with 500 release sites I ha (F’s = 4.4, 5.0,
respectively, df = 5, 18, P < 0.01). Among pairs of means, there was no
signiﬁcant (P > 0.05) difference between fruit injury in plots with 100 through 500
release sites I ha. Overall relationships between decreasing fruit injury as a

function of increasing logo of release-site density were described by y = - 0.23 x

+ 3.8 (R2 = 0.84) and y = — 0.25 x + 4.2 (R2 = 0.8) for plot centers and borders,

respectively. Slopes for these relationships were signiﬁcantly (F’s = 20.5, 13.1,

df = 1, 5, P < 0.05) negative.

48

DISCUSSION

These studies show that decreasing point source density, even while
keeping the amount of pheromone applied per ha constant, is not a viable option
for reducing the cost of deploying G. molesta mating disruption with hand-applied
dispensers. Only at the highest densities of point sources per ha tested did
dispensers perform well, achieving at least 95% orientation disruption. Also,
orientation disruption was signiﬁcantly higher in center traps versus edge traps in
all treatments except for the 4 PTS treatment, and variability in percent
orientation disruption was consistently higher in edge traps versus center traps,
although the difference was smaller for the 4 PTS treatment. These results agree
with prior studies of tortricid mating disruption that identify orchard borders as
being more susceptible to higher levels of fruit injury, reinforcing the need for
area-wide mating disruption programs to make the best use of the mating
disruption technique (Thompson et al. 1999, ll’ichev et al. 2002, Gut et al. 2004).

These results are at odds with Rothschild (1975), who found no signiﬁcant
difference in the numbers of G. molesta captured in pheromone-baited traps
when the dispensers were applied at a range of 25 to 200 point sources per
hectare. Stelinski et al. (2007) achieved 94% and 97% orientation disruption of
G. molesta with a perimeter application of 2.5 Pufferslha releasing 600 mgIhaId
of pheromone. Average total moth captures per trap in Stelinski et al.’s (2007)
control plots were 26.4 during the ﬁrst generation, and 70.1 during generations
two and three combined. Moth captures in the control plots in the current

experiments were up to eight times higher (Fig. 2). Low moth populations may

49

explain the higher than expected level of G. molesta orientation disruption with
Puffers in Stelinski et al.’s (2007) experiments. Stelinski et al. (2007) states that
puffers may result in mating disruption by different mechanism(s) than hand-
applied dispensers. Most hand-applied dispensers cause mating-disruption by
competitive attraction (Miller et al. 2006b). Perhaps Puffers function by other
mechanisms, such as camouﬂage, desensitization, or sensory imbalance (Miller
et al. 2006a). Alternatively, perhaps aerosolizing pheromone leads to better
distribution of the compounds throughout an area, versus diffusion of pheromone
through a matrix. Further studies should be conducted to investigate the effect of
varying point source densities of Puffers versus hand-applied dispensers while

keeping the rate of pheromone released per be constant.

50

CHAPTER THREE
Within-canopy adult distribution of codling moth (Lepidoptera: Tortricidae) in

mating disrupted and non-disrupted apple orchards

51

ABSTRACT

A study aimed at determining the location of searching codling moth
(Cydia pomonella [L.]) (Lepidoptera, Tortricidae) males and calling females in
mating disrupted and non-disrupted plots was conducted in Michigan, USA in
2005. A leaf blower, converted into a vacuum for sampling codling moth adults
on branches and in the tree canopy, had a 20-24% success in recovering
released moths in orchard conditions. A series of four collections was made
during the hours of 09:00-18:00 from May 25 through June 15, and a second
series of four collections was completed during the hours of 18:00-22:00 from
July 20 to August 22. Only eight codling moth adults were collected during the
four daylight samples; one female and two male moths were sampled from the
top third of the tree canopy, four males were sampled from the middle third of the
tree canopy, and one male was sampled from the lower third of the tree canopy.
Distributions of adults were also assessed during daytime hours (09:00-18200) by
fogging trees with various pyrethroid insecticides. No codling moth adults were
collected in any of these samples. In contrast to the low number of moths
collected in the daytime samples, 94 moths were collected during four twilight
samples, with equal numbers sampled in disrupted and non-disrupted plots. In
mating disruption plots, 42% of females were found in the top third of the tree
canopy, 46% were found in the middle third, and 12% were recovered in the
lower third. The 22 females sampled from non-disrupted plots were more evenly
distributed, with 36.4% in the top third, 36.4% in the middle third, and 27.2% in

the lower third of the tree canopy.

52

INTRODUCTION

Mating disruption of codling moth (Cydia pomonella [L].) using various
hand-applied dispensers has become an accepted practice, with approximately
77,000 ha of apple in North America treated in 2008 (Vlﬁtzgal et al. 2008).
Research with pheromone baited traps showing male activity to be greater in the
upper than the lower portion of the tree canopy has resulted in the standard
recommendation that dispensers be applied within the top meter of the tree
canopy (Barret 1995, Knight 2000, McNally and Barnes 1980). Witzgall et al.
(1998) visually observed male moths ﬂying and searching branches in the upper
half of tree crowns, providing further support for deployment high in the canopy.
However, the distribution of codling moth females within the tree canopy has yet
to be determined.

The studies reported here summarize an investigation of the location of
codling moth males and females in apple orchards during daylight and twilight
hours. To directly measure moth spatial distribution within the tree canopy, a
vacuum sampling technique was developed. The long-tenn aim of this work is to
improve the effectiveness of codling moth mating disruption based on a solid
understanding of adult distribution within the canopy.

METHODS AND MATERIALS

Vacuum: A 10 horsepower (Briggs & Stratton lntek engine) leaf blower
(MacKissic lnc., PA, USA) with 3 34cm diameter impeller and 322KPH air
velocity, was converted into a vacuum powerful enough to remove codling moth

adults from sampled surfaces. A 2m length of 15cm diameter reinforced rubber

53

air hose (Cathey Co, Lansing, MI) was attached to the leaf blower air intake
opening. The open end of the rubber hose was attached to a 2m long wand
constructed of 15cm diameter heat duct sheet metal. A handle constructed of 1m
long, 2.5cm diameter metal was attached to the wand with hose clamps. Four
3.5cm long bolts were attached at 90-degree spacing 2.5 cm from the end of the
sheet metal wand. Moths were collected from trees into a 19-liter nylon mesh
paint strainer bag (Master Craft, El Monte, CA, USA) inserted into the wand,
folded back over the bolts, and secured with rubber bands to prevent the bag
from being suctioned into the impeller.

Recovery Efﬁcacy of Vacuum: Mark, release and recapture trials were
used to test the efﬁciency of the vacuum. An initial 2005 test of whether the
vacuum was capable of collecting moths from apple trees was done using 2m tall
potted Red Delicious trees in a glass greenhouse at Michigan State University.
The procedure entailed three individual releases of twenty laboratory-reared
moths onto four trees and immediately vacuuming the trees to recover moths.

Two release/recapture trials were performed in the ﬁeld in 2005 with the
10 hp leaf blower vacuum. Moths were marked by placing them in a 19L plastic
pail and spraying 0.59 dye in 75ml acetone through cheesecloth covering the top
opening of the pail. Forty laboratory-reared moths were marked and released on
two occasions onto individual 16-year old trees, 3 X 6m Red Delicious, 4m-5m in
height, at the Trevor Nichols Research Complex.

Orchard Vacuum Trials: All orchard vacuum collections were done in six

0.4 ha apple plots at the Trevor Nichols Research Center, Fennville, MI

54

(42°35'38.10"N, 86°06'05.92"W). Four plots were 16 year old Red Delicious (3 x
6m planting), 4m-5m in height, and two plots were 23 year old Macspur, (5.5m x
6m), 5m in height. Two of the Red Delicious plots and one Macspur plot were
treated with lsomate C+ (Shin-Etsu Chemical Co., Tokyo, Japan) at the full label
rate of 1000 dispensers/ha. The remaining three plots were not treated with
pheromone. Daytime samples were collected between the hours of 9:00 to 16:00,
twilight collections occurred between 18:00-21 :30 hours. Twelve trees from each
of the six plots were sampled on four dates for both daytime and twilight samples
in 2005. Six of the 12 sample trees were located on plot perimeters and six trees
were located in plot middles. Thirty-second samples were collected from the top
third, middle third, and lower third of each tree. The lower third of the tree sample
included the trunk to the soil surface, and weeds growing within 0.5m of the tree
trunk. Sample contents were transferred from the nylon mesh collection bag
located in the vacuum wand into 4L freezer bags, and identiﬁed in the laboratory.
Only adult codling moths were counted in these collections, even though the
vacuum was powerful enough to remove cocooned larvae (5 individuals) and
pupae (7 individuals) from the trunks and scaffold branches of the trees in 2005
ﬁeld trials. One trap (LPD Soenturian Guardpost, Suterra, Bend, OR) baited with
a 1 mg codlemone rubber septum lure was placed in the upper third of the tree
canopy in each non-mating disrupted plot to monitor codling moth ﬂight.

Tree Fogging: Twelve trees were fogged with pyrethroid insecticides
(tetramethrin and sumithrin) on two separate dates in 2005 to test this method for

sampling codling moth adults in the tree canopy. Aerosol foggers were attached

55

to the trunks of each tree. Trees were covered with 4ml plastic, and the foggers
were activated until empty of contents. After a 10-minute interval, the plastic
covers were removed, and trees shaken to dislodge codling moth adults, as well
as other insects, onto tarps placed on the ground under each tree. All specimens
were collected off of the tarps and taken to the laboratory for later identiﬁcation.

Statistical Analysis: Statistical analyses were done using the chi-square
goodness of ﬁt test at alpha = 0.05.

RESULTS

Recovery Efﬁcacy of Vacuum: The leaf blower vacuum recovered 70%-
80% of moths released onto potted trees, and 24% of moths released in trees at
the Trevor Nichols Research Center orchards in 2005. Recovery of released
moths (14 releases) from covered trees within screened tents in 2006 was
20.6%.

Orchard Vacuum Trials: A total of 8 moths were collected during 576
individual daylight samples in 2005, 6 males and 2 females. The 2 females were
captured from the top third of tree canopies (Table 4). Of total males captured,
one was located in the top third, four in the middle third, and one in the bottom
third of the tree canopies (Table 4). Twilight samples (576 individual vacuum
samples) resulted in the capture of 94 moths distributed throughout the tree
canopies; 15 males and 18 females in the top third of tree canopies, 23 males
and 19 females from the middle third, and 10 males and 9 females from the
bottom third of the tree canopies (Table 4). Moth captures were signiﬁcantly

higher in the evening hours for all tree canopy heights sampled (Table 5).

56

Table 4. Total moths collected with vacuum in 2005 orchard samples during
daylight (09:00-16200) and evening twilight (18:00-21230) hours. (Day. Cap. =
daytime captures, Eve. Cap. = evening captures).

 

Top 1I3 Middle 1I3 Low 1I3
Canopy Canopy Canopy Total

 

Day Eve. Day Eve. Day Eve.

Cap. Cap. Cap. Cap. Cap. Cap. Day Eve.
Male 1 15 4 23 1 10 6 48
Female 2 18 0 19 0 9 2 46

 

Table 5. 2005 moth captures were signiﬁcantly higher in the evening hours for all
tree canopy heights sampled (576 samples collected) (Numbers within row with
same letter not signiﬁcant at p < 0.05).

 

2005 Day vs. Night Total Moths (w/in Height)
Height Daytime Captures Evening Captures Chi Square Statistics

 

A" 3'0 943 x2 = 72.5, df = 1,
p < 0.0000

High 30 33a x2 ___ 25, df = 1’
p < 0.0000

Middle 4b 428 x2 = 31.4, df = 1’
p < 0.0000

LOW 1b 198 X2=16.2, df=1,
p < 0.0001

 

Evening moth samples were not signiﬁcantly higher between the top 1/3 of
the tree canopy and the middle third, but were signiﬁcantly higher in the top 1I3
of the canopy when comparing high and low, signiﬁcantly higher in the middle 1I3

canopy compared to the lower 1I3, and signiﬁcantly higher in the combined lower

57

2I3 of the tree canopy as compared to the top 1I3 (Table 6). No differences were

seen either by gender or time of evening sampled.

Table 6. Statistical comparisons of moths collected with vacuum in 2005 orchard
samples during twilight (18:00—21:30) hours (Numbers within row with same letter
not signiﬁcant at p < 0.05).

 

2005 Evening (w/in Height)

 

Height Total Captures Total Captures Chi Square Statistics
High vs. Mid High: 33a Mid: 42a X2 = 1.1. df = 1’
p < 0.2987
High vs. Low High: 33b Low: 19a x2 = 33, df = 1,
p < 0.0522
Middle vs. Low Mid: 425 Low: 19a x2 ._. 8], df = 1’
p < 0.0032
High vs. lower High: 33b Mid + Low: 61a x2 = 83’ df = 1
2’3 p < 0.0039

 

Moths were distributed evenly between plot perimeters and plot centers in
both pheromone mating disrupted and non-disrupted plots in the 2005 vacuum
samples (Figure 9). In pheromone mating disruption plots there were signiﬁcantly
more males in the combined lower 2/3 of tree canopy vs. top 1I3 of canopy
(T able 7). No signiﬁcant differences in male capture were seen in comparisons of
high vs. middle, high vs. low or middle vs. low. In disrupted plots, 46% of female
moths and 43% of male moths were collected from the middle third of the tree
canopies, while 42% of females and 22% of males were in the top third of the

tree canopies (T ables 7, 8 and 9). An equal percentage of females in non-

58

disrupted plots were collected from the top (36%) and middle (36%) thirds of the
tree canopies. Male distribution in plots not treated with pheromone was skewed
toward the top two thirds of the tree canopies, with 52% collected from the middle
and 40% from the top (T ables 7, 8 and 9). Thirty-ﬁve percent of males were
collected from the bottom third of the tree canopies in disrupted plots, while only
8% were vacuum collected in the lower canopy in non-disrupted plots.

Tree fogging with pyrethroid insecticides applied on 2 occasions to 12
covered trees during daylight hours did not result in the capture of any codling

moth in 2005.

25 TF"""__"’ ”TM|
._. ae
20 IFemale

#CM 15 —
Adults

10

 

 

       

 

 

 

 

 

 

 

Edge Middle Edge Middle

Figure 9. Vacuum Samples showed that males and females were present in both
orchard edges and middles.

59

Table 7. Statistical comparisons of moths collected with leaf blower vacuum in
plots with and without pheromone mating disruption. Samples were collected
during twilight (18:00-21:30) hours in 2005 (Numbers within row with same letter

not signiﬁcant at p < 0.05).

 

2005 Male Moth Captures in MD Plots vs. Non-MD Plots

 

MATING DISRUPTED PLOTS - MALES
# Moths
Mid: 103

Height # Moths
High vs. Middle High: 5a

High vs. Low High: 5a
Middle vs. Low Mid: 10a

High vs. low 2I3 High: 5a

Height # Moths
High vs. Middle High: 10a

High vs. Low High: 10a
Middle vs. Low Mid: 13a

High vs. low 2I3 High:10a

Low: 8a

Low: 8a

Chi Square Statistics
x2: 1.7, df= 1, p < 0.1966
x2 = .692, df = 1, p < 0.4054

x2 = .692, df = 1, p < 0.6375

Mid + Low: 18b x2 = 735, df = 1, p < 00067

NON-MATING DISRUPTED PLOTS - MALES
# Moths
Mid: 13a

Low: 2b

Low: 2b

Chi Square Statistics
x2 = .391, df= 1, p < 0.5316

x2 = 5.33, df = 1, p < 0.0209
x2 = 8.07, df = 1, p < 0.0045

Mid + Low: 15a x2=1, df=1,p < 0,3137

 

Table 8. Percent distribution of male and female codling moths collected with leaf
blower vacuum in plots with and without pheromone mating disruption. Samples
were collected during twilight (18200-21230) hours in 2005.

 

 

MD No MD
Male Female Male Female
High 21.7% 41.6% 40.0% 36.4%
Middle 43.5% 45.8% 52.0% 36.4%
Low 34.7% 12.5% 8.0% 27.3%

 

60

Table 9. Statistical comparisons of female moths collected with leaf blower
vacuum in plots with and without pheromone mating disruption. Samples were
collected during twilight (18:00—21z30) hours in 2005 (Numbers within row with
same letter not signiﬁcant at p < 0.05).

2005 Female Moth Captures in MD Plots vs. Non-MD Plots
MATING DISRUPTED PLOTS - FEMALES

 

 

Height # Moths # Moths Chi Square Statistics

High vs. Middle High: 10a Mid: 113 x2 = .043, df = 1, p < 0,8257
High vs. Low High: 10a Low: 3b x2 = 377, df = 1, p < 0,0522
Middle vs. Low Mid: 11a Low: 3b X2 = 4.57, df = 1, p < 00325

High vs. low 213 High: 10a Mid + Low: 14a x2 = .667, df= 1, p < 0.4141
NON-MATING DISRUPTED PLOTS - FEMALES

Height # Moths # Moths Chi Square Statistics

High vs. Middle High: 8a Mid: 8a x2 = 0, df = 1, p < 1

High vs. Low High: 8a Low: 6a X2 = 029’ df = 1, p < 0,5923

Middle vs. Low Mid: 8a Low: 6a X2 = 029, df = 1, p < 0,5923
2

High vs. low 2I3 High: 8a Mid + Low: 143 X = 15’ df= 1’ p < 02009

 

DISCUSSION

Orchard vacuum samples show codling moth adults to be distributed
throughout all parts of the tree canopies during evening periods when female
calling and male searching activity is occurring. Higher numbers of moths were
captured at mid-tree canopy than in either the top 1I3 canopy or low 1I3 canopy,
with signiﬁcantly more moths captured in the combined lower 2I3 than in the top
1/3 of the tree canopy (Table 6).

The pheromone treatment did have a fairly pronounced effect on the
distribution of codling moth adults. In plots under pheromone mating disruption,

female moths were captured in approximately equal numbers from the top 1I3

61

and mid 1I3 of tree canopies, with few captured in the lower 1/3 of tree canopies
(Tables 8 and 9). In non-mating disrupted plots, female moths were captured in
relatively equal amounts from all three strata (Tables 8 and 9). The effect of the
pheromone treatment was more evident with respect to male distribution. Male
moths were collected in greater numbers in the lower 2I3 of trees in mating
disrupted plots, and the upper 2I3 of trees in non-mating disrupted plots,
suggesting that the presence of dispensers had an inhibitory effect on male
behavior. The largest number of males was collected from the middle tree
canopy in both disrupted and non-disrupted plots (Tables 7 and 8).

Current protocols for the deployment of hand applied mating disruption
dispensers call for dispensers to be placed exclusively in the top meter of tree
canopies, based on research showing male activity to be concentrated in the top
third of the tree canopy (Barret 1995, Knight 2000, McNally and Barnes 1980,
Witzgall et al. 1998). Our research with the vacuum sampling of male and female
moths disputes these ﬁndings for males, and is unique in determining the
locations of calling female moths. The results of this study indicate the need to
conduct additional research addressing whether placement of dispensers at a
range of heights within the tree may improve the overall performance of mating
disruption targeting codling moth.

The low number of moths captured with the vacuum during daylight
collections, paired with zero capture of moths with the pyrethroid treatments
raises the question of whether moths move to other habitats during periods of

behavioral inactivity. Tree fogging with pyrethroid insecticides applied on 2

62

occasions to 12 covered trees during daylight hours did not result In the capture
of any codling moth in 2005. It is possible that the failure to collect moths using
these techniques resulted from a lack of moths in the tree at the time of
sampling, inadequacy of the techniques for sampling inactive adults, or a
combination of both.

ACKNOWLEDGEMENTS
We thank the Michigan Apple Research Committee for funds supporting this

research.

63

CHAPTER FOUR

Effects of varying height in the canopy of hand-applied reservoir
d i spensers on efﬁcacy of pheromone-mediated mating disruption of codling moth

(Lepidoptera: Tortricidae) in apple

ABSTRACT

Trials investigating the effects of varying height in the tree canopy of

codling moth (Cydia poImoneIIa L.) mating disruption reservoir dispensers were
so nducted in 2007. Two lsomate-C Plus dispensers I tree were placed at heights
of 2m, 4m and/or a combination of one dispenser at each height. Pheromone-
b a ited traps and tethered virgin female moths were similarly placed in plots at 2m
a rod 4m to assess treatment effects. Traps placed high in tree canopies captured
9 reater numbers of male moths than traps placed low, regardless of dispenser
positioning. The fewest moths were captured where both traps and dispensers
were placed high in the tree. Mating of virgin female moths was highest when

moths were tethered at the 2m height in plots with dispensers placed at 4m, and

when moths were tethered at the 4m height in plots with dispensers placed at

2m . Overall, mating of females was lowest where dispensers were equally

distributed at 2m and 4m in the tree canopy.

65

INTRODUCTION

Mating disruption of codling moth (Cydia pomonella [L].) using various
h and-applied dispensers has become an accepted practice, with approximately
7' 7 , 000 ha of apple in North America treated in 2008 (Witzgal et al. 2008).
Research with pheromone baited traps showing male ﬂight behavior to be
concentrated in the top third of the tree canopy has resulted in the standard
recommendation that dispensers be applied within the top meter of the tree
ca nopy (Barret 1995, Knight 2000, McNally and Barnes 1980). Witzgall et al.
( 1 998) visually observed male moths ﬂying and searching branches in the upper
h alf of tree crowns, providing further support for deployment high in the canopy.
Epstein et al. (unpublished, chapter 3 of this dissertation) developed a
vacuum sampling technique to directly measure male and female moth spatial
distribution within the tree canopy in orchards with and without codling moth
mating disruption. Results from this study showed male moths were collected in
9 reater numbers in the lower 2I3 of tree canopies in plots under pheromone
mating disruption, while female moths were captured in approximately equal
numbers from the top 1I3 and mid 1/3 of tree canopies in disrupted plots. In plots
not treated with pheromone, male moths were collected in greater numbers in the
Upper 2I3 of trees, and female moths were captured in relatively equal amounts
from all parts of the tree. More males were found in the middle tree canopy in
bOth disrupted and non-disrupted plots (Epstein et al., unpublished).
Recent work by Miller et al. (2006a and 2006b) provides strong evidence

of competitive attraction as a primary mechanism by which pheromone mating

66

disruption of codling moth operates in the ﬁeld. Optimum disruption is likely to be
achieved when calling females and competing dispensers are in close proximity.
Th us, if calling female moths are distributed in equal amounts in both upper and
n"- iddle tree canopies (Epstein, unpublished), dispenser placement should not be

co nfined solely to the top 1I3 tree canopy as is currently practiced, but placed in

the middle tree canopy as well.
The studies reported here summarize an investigation of the effects of

d istributing pheromone mating disruption dispensers at varying heights within the
tree canopy on orientational disruption of male moths to pheromone baited traps,
a nd mating of tethered virgin female moths. The long-term aim of this work is to
im prove the effectiveness of codling moth mating disruption based on improved
u nderstanding of adult distribution within the canopy and the impact of dispenser
placement on moth behavior.
METHODS AND MATERIALS
Four 1.2ha replications of 4 dispenser height treatments were randomly
assigned to orchard plots at the Trevor Nichols Research Complex, Fennville, MI
(42 °35'38.10"N, 86°06'05.92"W) in a 16 year old Red Delicious planting, 3 x 6m
tree spacing, 4m-4.5m tree height. All pheromone mating disruption plots were
treated with lsomate c+ (Shin-Etsu Chemical Co., Tokyo, Japan) at the full label
" ate of 1000 dispensers/ha. The four dispenser height treatments were: 1) two
'Som ate C+ dispensers at 4m height in the tree canopy (High), 2) two dispensers
at 2m height in the tree canOpy (Low), 3) one dispenser at 4m and one dispenser

at 2m in the tree canopy (Mixed), and 4) no dispensers deployed.

67

Inhibition of moth catch in pheromone traps was the principal means of
assessing treatment effects. Four traps (LPD Soenturian Guardpost, Suterra,
Bend, OR) baited with 1 mg codlemone rubber septum lures (Suterra, Bend, OR)
we re placed in each treatment (64 total), two at a height of 4m, two at a height of
2 m - In all disrupted plots, traps were positioned at least 1 m away from an
lsomate dispenser. Lures were replaced every two weeks. Traps were checked

Mice a week beginning at the start of ﬁrst generation CM ﬂight activity, from May

 

1 1 to August 24, 2007. At each collection date, the number of moths captured
was recorded for each trap, trap liners cleaned or replaced, and traps at 2m were
rotated to a 4m height, and traps at 4m were rotated to a 2m height within the
same trees. Branches were ﬂagged with colored plastic tape at the 2 and 4m
heights to ensure that the traps returned to the same high and low positions upon
rotations.

In addition to orientational disruption to traps, mating disruption was
assessed based on mating of tethered, virgin females. Female C. pomonella
used for tethering were reared from pupae purchased from Benzon Research
Inc. , Carlisle PA. Females were sorted in the pupal stage and placed into 50-ml
plastic cages containing 5% sucrose in plastic cups with cotton dental wick
Protruding from their lids. Female C. pomonella were deployed within two days of
puDal emergence for 16h (17:00 — 09:00hrs) in all treatment plots on ﬁve dates
COinciding with peak moth presence during the ﬁrst and second generations (13

June, 15 June, 26 July, 1 August and 2 August). Four female moths were

tethered per treatment replicate (64 total), two at 4m and two at 2m in the tree

68

ca nopy, during each deployment period. Female moths were secured to

b ranches of trees with polyester thread (Jo-Ann Stores, Inc., Hudson, OH) tied to
the base of the left wing. Moths were given at least 60 cm of thread and were
observed for at least 30 s after deployment to ensure they remained tethered and
m obile upon the branch. Approximately 68% of tethered females were recovered
over the ﬁve deployments. Female moths were placed into alcohol in 8-dram
9 l as vials upon collection, and dissected in the laboratory within 24h to

CI eterrnine mating status. Mating status was based on the presence or absence

of a sperrnataphore in the bursa copulatrix.
Generalized linear models were evaluated to assess the characteristics of

male moth capture in pheromone-baited traps and of mating of female moths.

M oth capture and mating data were log transformed to address concerns with

normality of error distribution. Generalized linear model analyses were performed

i n R version 2.10.0 (R Development Core Team, 2009, R Foundation for
Statistical Computing, Vienna, Austria, http://wwwR-projectorg); the mating data

as a binomial distribution. The ANOVA command in R was used to test

parameter signiﬁcance of each model using analysis of deviance, and the Tukey
m ultiple comparisons test was used for means separation.
RESULTS
Traps placed high in the tree canopy captured greater numbers of male

moths at all dispenser height treatments (dﬁ3, F=2.994, P< 0.0297), with the

fewest moths were captured when both traps and dispensers were placed high in

69

 

the tree (ﬁgure 10). Signiﬁcantly fewer moths were captured in all pheromone

treatments as compared to the no pheromone control (Table 10, Figure 11).

 

08 Twp '9

 

 

 

 

 

C M L N

 

Figure 10. Interaction plot of effects of treatment and trap height on male codling
moth capture (Mixed = dispensers high and low, H = high dispenser placement, L
= low dispenser placemen and N = no pheromone dispensers).

Table 10. Tukey multiple comparison of the means of male moth capture in
varying dispenser height treatments (M = Mixed, 1 dispenser each @2m and 4m;
H = high, 2 dispensers @ 4m; L = low, 2 dispensers @2m; and N = no
pheromone dispensers) * indicates signiﬁcant p value @ a < 0.05.

 

 

Comparison Difference Lower Upper P Adj
M-N -0.2843 - 0.3512 -0.2173 0.0000*
H-N -0.3521 0.4190 0.2852 0.0000*
L-N -0.2426 -0.3099 -0. 1753 0.0000*
H-M -0.0679 -0.1347 -0.0010 0.0449*
L-M 0.0417 -0.0255 0.1089 0.3815
L-H 0.1096 0.0424 0.1767 0.0002*

 

70

 

Male Moth Captures - Dispenser Height Trials 2007

     
       
     

12 -
I High Traps

9 1 I Low Traps
in
.5
1% c
o 5 -
:9
o
2 b
2 ‘- ‘2b “Eb

’3’ A” ' (M 5.“.‘13 I; . ‘

 

 

 

 

No MD Dispensers High Mixed Dispensers Low

 

Figure 11. Captures of male moths in plots where pheromone dispenser and trap
height was varied (High = 2@ m, Low = 2 @ 2m, Mixed = 1 @ m and 1 @ 2m).
Means followed by the same letter are not signiﬁcantly different at a < 0.05.

Evaluations of moth mating, though, reveal that a distribution of
dispensers at a combination of heights, 4m and 2m, resulted in the lowest overall
mating in these trials (df = 222, z = -3.7, p < 0.00025). Mean percent mated
female moths was 15% in the mixed plots, followed by 19% mating in plots with 2
dispensers @ 4m, 21% mating in plots with 2 dispensers @ 2m and 46% in plots
where no dispensers were deployed. Mating of virgin female moths was highest
where moths were tethered at a 2m height in plots with dispensers placed at 4m
and where moths were tethered at the 4m height in plots with dispensers placed

at (Tables 11-13, Figure 12).

71

Table 11. Mating of tethered female moths in pheromone dispenser trials was
lowest where dispensers were arranged both at 2m and 4m heights in the tree

canopy.

 

 

Treatment df 2 value Pr(>|z|)
No Dispensers 222 -0.267 0.78931
Mixed (1 ea. @ 2m & 4m) 222 -3.662 0.00025 *
High (2 dispensers @ 4m) 222 -3.525 0.00042 *
Low (2 dispensers @ 2m) 222 -2.855 0.00431 *

 

Table 12. Percent of tethered virgin female codling moths mated when deployed

on ﬁve dates at 2m and 4m heights in tree canopies in plots with varying

dispenser height treatments (Mixed = dispensers @ 2m and 4m, High =
dispensers at 4m, Low = dispensers @ 2m)

 

 

Pheromone Female
Treatment Height 13-Jun 15-Jun 26-Jul 1-Aug 9-Aug Means
No MD 4m 1.00 0.86 0.25 0.40 0.00 0.50
No MD 2m 0.67 0.75 0.33 0.20 0.17 0.42
Mixed 4m 0.00 0.50 0.20 0.00 0.00 0.14
Mixed 2m 0.17 0.50 0.17 0.00 0.00 0.17
High 4m 0.67 0.40 0.00 0.00 0.13 0.24
High 2m 0.14 0.20 0.17 0.00 0.17 0.14
Low 4m 0.43 0.20 0.20 0.20 0.33 0.27
Low 2m 0.14 0.20 0.00 0.00 0.40 0.15

72

Table 13. Tukey multiple comparison of the means of mating in varying dispenser
height treatments (M = mixed, 1 dispenser each @2m and 4m; H = high, 2
dispensers @ 4m; L = low, 2 dispensers @2m; and N = no pheromone
dispensers) * indicates signiﬁcant p value @ a < 0.05.

 

 

Treatments Diff lwr upr p adj
M-N -0.3571 -0.5685 -0. 1458 0.0001*
H-N -0.3103 -0.5069 -0.1137 0.0004*
L-N -0.2640 -0.4679 -0.0600 0.0052*
H-M 0.0469 -0.1583 0.2520 0.9346
L-M 0.0932 -0.1 190 0.3054 0.6673
L-H 0.0463 -0.1513 0.2439 0.9298

 

Percent Mating of Tethered Female Moths in Dispenser Height

L

Trials

W e
' i————-i
Mm -

 

 

High —’ if ‘

Low Tether

I High Tether

 

 

l 1 1
°°""°' — 1

0.00

0.10

0.20

0.30

0.40

0.50 0.60 0.70

Percent Mated Female Moths

FIgure 12. Mating of tethered females at 2m and 4m in plots where dispenser
height was varied (High = 2@ 4m, low = 2@ 2m, Mixed = 1@ 2m, 1@4m).

73

DISCUSSION

Many researchers have concluded that codling moth distribution and
behavioral activity is greatest in the top 1m of tree canopies, both in pheromone
mating disrupted orchards and in non-disrupted orchards (Barret 1995, Knight
2000, McNally and Barnes 1980, Riedl at al. 1979). Weissling and Knight (1995)
found that males responded in greatest numbers to tethered females high in tree
canopies in mating disrupted orchards where dispensers were all placed at either
2m or 4m, but that there was no statistical difference in the number of mated
females tethered at 2m or 4m in either treatment. These ﬁndings have resulted in
the recommendation that pheromone dispensers be placed high in the tree
canopy.

Orchard vacuum samples in 2005 showed both codling moth male and
female adults to be distributed throughout all parts of the tree canopy during the
time periods when female calling and male searching activity is occurring
(Epstein, unpublished). Weissling and Knight (1995) also found that high

captures of male and female moths on unbaited sticky traps occurred at mid and

upper-canopy heights.

With the determination of Miller et al. (2006a and b) that competitive
attraction is a primary mechanism in pheromone-mediated disruption of codling
moth, it follows that a distribution of female moths throughout the tree canopy
calls for a similar distribution of dispensers in the upper and mid canopy levels to

red uoe codling moth mating. The ﬁndings of this study shows that a distribution

01‘ pheromone dispensers in the upper and mid canopies of trees did, indeed,

74

result in reduced overall mating of tethered female moths, and suggests that
recommendations for placement of pheromone ties should be revisited based on
recent ﬁndings of moth distribution and mechanism of codling moth pheromone

disruption.
ACKNOWLEDGEMENTS

We thank the Michigan Apple Research Committee for funds supporting this

research.

75

CHAPTER FIVE
Codling Moth, Cydia pomonella (L.),

adult diel activity in apple orchards

76

ABSTRACT

Release I recapture studies of marked adult codling moths were
conducted in 2006 and 2007 in screened tents to discern within orchard habitats
for adult moths during the daylight hours, 09:00 - 18:00. A leaf blower, converted
into a vacuum for sampling codling moth adults in the tree canopy and from
ground surfaces, had a 20-24% success in recovering released moths in orchard
trees and a 22% recovery rate from the orchard herbicide strip and drive-row
grass. Of moths recaptured, 9% of females and 9% of males were recaptured
from the ground (herbicide strip and drive-row grass) 16 hours post release, 40%
of females and 8% of males from the ground 40 hours post release, and 52% of
females and 24% of males from the ground 64 hours post release. Weather data
loggers monitored over three months during release I recapture trials showed
little variance in temperature between the three habitats measured, tree 22.1°C,
H-strip 226°C, and grass 22.1°C, but relative humidity was more than 12%
higher in the grass than other habitats; tree 78.7%, H-strip 79.5%, and grass
92%.

77

INTRODUCTION

The studies reported here summarize a two-year investigation of the
location of codling moth males and females in apple orchards during daylight
hours, 09:00 - 18:00. It is widely understood that codling moth is behaviorally
active during evening twilight hours, approximately the hours of 19:00 — 22:00
(Castrovillo and Cardé 1979, Geier 1963, Witzgall et al. 1998). Very little is
reported in the literature regarding codling moth behavior and habitat selection
during periods of biological inactivity, and it is largely assumed that adult moths
conﬁne themselves within the tree canopy during inactive periods (Geier 1963).

However, direct sampling of tree canopies during the hours of 09:00 —
18:00 by Epstein et al. (2005, unpublished, chapter 3 of this dissertation) located
only eight moths in 576 samples of tree bark and foliage over four dates in 2005.
By comparison, evening twilight samples located 94 moths on tree bark and
foliage in 576 samples over four dates (Epstein unpublished, chapter 3 of this
dissertation). Additionally, direct visual observations of codling moths emerging
from orchard drive-row grass during evening twilight hours, 19:00 - 20:00
(Epstein, unpublished), raised questions as to whether codling moth adults leave
the tree canopy after periods of twilight biological activity.

Improved knowledge of codling moth bionomics, including diel behavior
patterns and the affects of factors such as age and prevailing climatic conditions
on female behavior, could lead to improved control of this key tortricid pest. In
particular, the long-term aim of this work is to improve the effectiveness of

codling moth mating disruption based on a greater understanding of diel patterns

78

of moth activity.
MATERIALS AND METHODS

Vacuum: A 10 horsepower (Briggs & Stratton lntek engine) leaf blower
(MacKissic lnc., PA, USA) with a 346m diameter impeller and 322KPH air
velocity, was converted into a vacuum powerful enough to remove codling moth
adults from sampled surfaces. A 2m length of 156m diameter reinforced rubber
air hose (Cathey Co, Lansing, MI) was attached to the leaf blower air intake
opening. The open end of the rubber hose was attached to a 2m long wand
constructed of 156m diameter heat duct sheet metal. A handle constructed of 1m
long, 2.5cm diameter metal was attached to the wand with hose clamps. Four
3.56m long bolts were attached at 90-degree spacing 2.5 cm from the end of the
sheet metal wand. Moths were collected from trees into a 19-Iiter nylon mesh
paint strainer bag (Master Craft, El Monte, CA, USA) inserted into the wand,
folded back over the bolts, and secured with rubber bands to prevent the bag
from being suctioned into the impeller. A 90-degree sheet metal register box was
attached to the wand and for vacuuming ground surfaces. Collection bags for
ground collections were made from ﬁberglass window screening tapered to 106m
at the closed end to avoid clogging the airﬂow through the wand.

Screen Tents: Four tents measuring 3m high, 5.5m wide, and 6.5m long
were constructed at the Trevor Nichols Research Complex, Fennville, Ml
(42°35'38.10"N, 86°06'05.92"W). The tent structure was covered with mosquito
netting walls and ceiling, sewn together to slip over the tent structure as one

piece (Quality Awning Shops, lnc., Lansing, MI). Mosquito netting walls were

79

staked into the ground with tent stakes to minimize open space where the tents
met the ground. The tents were erected over single apple trees, encompassing
drive row grass. Trees were 2.75m high Red Delicious, spaced 3X6m. Data
loggers (Hobo Pro series, Onset Computer Corporation, Bourne, MA, USA) were
placed in the tree and in the herbicide strip and grass at soil level to record daily
temperature and relative humidity levels from 9 June to 29 August.

Release / recaptures. Release I recaptures of marked moths were
conducted in 2006 and 2007 in screened tents to identify daytime (09:00-18:00)
habitats for adult moths within the orchard. Moths were recaptured with the
vacuum 16 hours post release in 2006 (15 releases), and 40 hours (13 releases,
6 dates) and 64 hours (17 releases, 7 dates) post release in 2007. Adult C.
pomonella were reared from pupae purchased from Benzon Research Inc.,
Carlisle PA. Females and males were sorted in the pupal stage and placed into
50-ml plastic cages containing 5% sucrose in plastic cups with cotton dental wick
protruding from the lids. Releases with wild type moths, collected as cocooned
larvae from the ﬁrst generation and reared to adulthood on corrugated cardboard
in 50-ml plastic cages in the laboratory, were also conducted in 2006 (1 release,
30 ea, male and female) and 2007 (2 releases, 40 females and 20 males on 8
August, and 40 females and 25 males on 9 August).

Moths were marked by placing 20 male and or female individuals at a time
into 13cm Petri dishes coated with differing colors of 0.49 luminescent powder
(Bioquip Inc., CA, USA) for easy differentiation of gender upon recapture. The

moths accumulated powder after several minutes of movement in the dish. Moths

80

were released into tents within two days of pupal emergence between 18:00-
19:00 hours and recaptured at 16 hours, 40 hours, and 64 hours post release,
between the hours 10:00 to 14:00.

Release cages consisted of two 50-ml plastic containers with two 5cm X
10cm windows cut from each, so that the two containers could be oriented with

windows non-aligned for transport, and aligned for moth release (Figure 13).

 

Figure 13. Release cages used in moth release I recapture trials.

Moths were released by placing 2 open release containers, one with 20 males
and one with 20 females, within the tree canopy. Male and female moths were
released in equal numbers and were segregated into separate release containers
prior to all releases. All tree, herbicide strip and grass habitats were

systematically vacuumed without time limit to recapture moths. Contents of mesh

81

vacuum collection bags were transferred into 4L freezer bags for transport to the
laboratory for identiﬁcation.

Statistics. All statistical analyses were performed using version 2.10.0 of
the R computing language (R Development Core Team, 2009, R Foundation for
Statistical Computing, Vienna, Austria, http:I/www.R-project.org). Spearrnan's
rank correlation tests were performed to assess the level of correlation between
percent moth recapture, after non-recovered moths were removed, in each
possible habitat category (tree, drive-row grass, herbicide strip) by either Julian
date, hours between release and recapture, and by average daily temperature,
respectively. Furthermore, a 4 + 4 ANOVA modeling proportion recapture, after
non-recovered moths were removed, by block and habitat was performed with
post-hoc multiple comparisons made using the Tukey Honest Signiﬁcant
Difference method. For the latter analysis, proportion recapture was normalized

using the arcsin transformation.

RESULTS
Fifteen release I recapture trials in screened tents in 2006 resulted in

47.7% of 596 released moths being recovered from one of ﬁve habitats after 16
h. Of recovered moths, 29.2% were found in the tree, 5.3% in the grass, 8.8% in
the herbicide strip, 32.4% on the tent screen surface and 24.3% did not leave the
release cage (Table 14). In 2007, 25.3% of released moths were recovered after
40 h (13 releases) and 45.7% were recovered after 64 hours (17 releases) (Table
14). Signiﬁcantly more moths were recovered from the tree than either the grass

or the herbicide strip (Table 15). No statistically signiﬁcant correlation was found

82

between percent moth recapture in varying habitats and Julian date, hours
between release and recapture or ambient temperature.

Although not statistically signiﬁcant, higher percentages of female moths
were consistently collected from drive-row grass and weeds under the trees than
male moths, 14.6% of females and 13.5 % of males after 16 hours, 17.4% of
females and 3.4% of males after 40 hours, and 16.9% of females and 7.8% of
males after 64 hours (Table 14). When analyzed temporally, no male moths were
found in the grass or herbicide strip in June, 3.7% of males were recovered from
the ground in July and 11.7% from the ground in August (Table 16). Seven
percent of female moths were recovered from ground surfaces in June, 11% in

July and 22.6% in August (Table 16).

83

Table 14. Percent male and female codling moth adults recovered in ﬁve habitats
in release I recapture trials in 2006-2007 (* = release cage).

 

Moth Recovery 16, 40 and 64 Hrs Post Release in 2006 - 2007 Trials

 

Mean % % Males % Females

 

16 Hrs Male Female Total Recovered Recovered Recovered
Tree 31 52 83 29.2 24.6 32.9
Grass 6 9 15 5.3 4.8 5.7
H-strip 11 14 25 8.8 8.7 8.9
Screen 49 43 92 32.4 38.9 27.2
Rel. cage* 29 40 69 24.3 23.0 25.3
Recovered 126 158 284

# Released 291 29_9 Q6;

:12_H_r§

Tree 34 26 60 32.1 38.2 26.5
Grass 2 12 14 7.5 2.3 12.3
H-strip 1 5 6 3.2 1.1 5.1
Screen 31 19 50 26.7 34.8 19.4
Rel. Cage* 21 36 57 30.5 23.6 36.7
Recovered 89 98 187

# Released 329 310 210

Quits

Tree 26 27 53 19.3 25.5 15.7
Grass 6 18 24 8.8 5.9 10.5
H-strip 2 11 13 4.7 1.9 6.4
Screen 17 15 32 11.7 16.7 8.7
Rel. Cage* 51 101 152 55.5 50.0 58.7
Recovered 102 172 274

# Released 309 Q9 @

 

Table 15. Tukey multiple comparison of the means of percent moth recapture in
varying habitats (H = Herbicide Strip, G = Grass; T = Tree; * indicates signiﬁcant
p value @ alpha = 0.05).

 

 

Comparisons Difference Lower Upper p adj
H-G 0.1697 -0.7557 1.0951 0. 5718
T-G 2.1459 1.2205 3.0712 0.0110*
T-H 1.9762 1.0508 2.9015 0.0003*

 

Table 16. Percent moths recovered from grass plus herbicide strip habitats over
three months of release I recapture trials in 2006-2007.

 

 

June July August
Male Female Male Female Male Female
16 Hrs 0.0 0.0 0.0 0.0 12.5 14.7
40 Hrs 0.0 6.3 0.0 3.7 8.8 35.9
64 Hrs 0.0 7.5 11.1 29.3 13.9 17.3
Mean 0.0 6.9 3.7 11.0 11.7 22.6

 

Data loggers (Hobo Pro series, Onset Computer Corporation, Bourne, MA,
USA) placed in the tree and in the grass at soil level showed that the mean
temperature in the 2 microclimates did not vary over a 3-month period (tree 22.1,
grass 22.1), but that mean relative humidity varied by 13.3% between the tree
(78.7%) and the grass (92.0%).

Release I recapture of wild type moths was conducted one time in 2006
(Recovery 16 hrs post release) and on two dates in 2007 (Recovery 64 hrs post
release). Twenty-four percent of wild type moths released were recovered 16 hrs
post release, and 16% of moths were recovered 64 hrs post release. All male

moths that left the release cage in 2006 were recovered 16 hrs post release from

85

the III
(Table
were

heibli

Table
relea:

_

M
We
Gias
H-stl
Scre
Rel.
Reci
it Re

ﬂ
Tree
Gras
H-sl;
Scre
Rel.
R601
# Re

\

dUHns
80”].

and fl

the tree (43%), while the lone female moth recovered was found in the grass
(Table 17). Twenty-ﬁve percent of female wild type moths recovered after 64 hrs
were recovered from the drive-row grass, 18.8% from the tree and 6.3% from the
herbicide strip (Table 17).

Table 17. Recovery of wild type moths in ﬁve habitats 16 and 64 hours post
release in release I recapture trials in 2006-2007 (* = release cage).

 

Mean % % Males % Females

 

 

16 Hrs Male Female Total Recovered Recovered Recovered
Tree 6 0 6 20.7 42.86 0.00
Grass 0 1 1 3.4 0.00 6.67
H-strip 0 0 0 0.0 0.00 0.00
Screen 0 2 2 6.9 0.00 13.33
Rel. cage* 8 12 20 69.0 57.14 80.00
Recovered 14 15 29
# Released 60 60 120
64 Hrs
Tree 2 3 5 25.0 50.00 18.75
Grass 0 4 4 20.0 0.00 25.00
H-strip 1 1 2 10.0 25.00 6.25
Screen 1 5 6 30.0 25.00 31.25
Rel. cage* 0 3 3 15.0 0.00 18.75
Recovered 4 16 20
# Released 45 80 125

DISCUSSION

This study provides evidence that adult codling moths do leave the tree
canopy in apple orchards to inhabit drive-row grass and herbicide strip vegetation
during daytime periods of inactivity. Signiﬁcantly more moths were recovered
from the tree than either the grass or the herbicide strip (Table 15), but both male

and female lab-reared moths were recovered from the grass and herbicide strip

86

at all recovery time periods, 16,40 and 64 hrs post release (Table 14). Vlﬁld type
females (6.7%) were recovered from the grass after 16 hrs, and wild type males
(25%) and females (31.3%) were recovered from ground habitats (combined
grass and herbicide) after 64 hrs (Table 17).

Although not statistically signiﬁcant, a numerical trend was seen with
recovery of 6.9% of female moths from ground habitats in June, 11% in July and
22.6% in August (Table 16). Males were also recovered in higher percentages
from ground habitats as the summer months progressed, 0% in June, 3.7% in
July and 11.7% in August (Table 16).

Data loggers maintained over the duration of the study showed that mean
relative humidity varied by 13.3% between the tree (78.7%) and the grass
(92.0%). The higher availability of moisture found in the grass could provide an
explanation for why moths may seek shelter in this habitat during hot, dry
summer days.

Adult codling moth behavior during the hours of 09:00 and 18:00 has
received little study and is not well understood. Researchers investigating
behavioral management tactics should consider the impact of moth behavior
during periods of inactivity to better understand any potential impacts on control.
For example, adult moth behavior that physically removes the adult from the tree
canopy could affect efforts to manage codling moth with pheromone mediated
mating disruption. Should mating disruption operate, at any level, by
desensitization from long-term exposure to high pheromone concentrations, moth

displacement to habitats away from dispensers placed in the tree canopy might

87

inﬂuence di

We thank ll

research.

inﬂuence disruption efﬁcacy.

ACKNOWLEDGEMENTS

We thank the Michigan Apple Research Committee for funds supporting this

research.

88

CHAPTER SIX
Efﬁcacy and optimum use patterns of CM Granulosis virus [family Baculoviridae,
genus Granulovirus] formulations for control of Codling Moth, Cydia pomonella

(L.), in Michigan apple

89

ABSTRACT
Commercial on-farm trials performed as part of this project show that
codling moth (CM) granulosis virus (Cva) is an effective, biologically based
control option for CM in Michigan. Three commercially available formulations of

CP“, were evaluated over the 2005 and

CpGV, Carpovirusine, Cyd-X and Virosoft
2006 growing seasons in small plot trials to evaluate application rates and
frequency, and in larger on-farm trials to evaluate efﬁcacy of all three
formulations as supplements for codling moth control. Frequent applications of a
low rate of all three Cva formulations targeting ﬁrst and I or second-generation
larval populations consistently yielded excellent and economical control of CM.
The average number of second-generation larvae recovered in cardboard bands
and fruit injury at harvest was substantially reduced in all virus-treated plots

compared to plots not treated with virus. There was no statistically signiﬁcant

difference in efﬁcacy between the three formulations tested.

90

and I
leC
CpG
noni
(Gin
acth

lnco

hesi

(Art

for n

INTRODUCTION

Since it was ﬁrst collected in Mexico over 40 years ago (Tanada, 1964)
and undenrvent its initial orchard trials in the 1960’s, codling moth granulosis virus
(CpGV) has been investigated as a codling moth control (Falcon et al., 1968).
CpGV is highly speciﬁc, infecting CM and a few closely related species, and is
noninfectious toward beneﬁcial insects, ﬁsh, wildlife, livestock, and humans
(Groner 1986). Although laboratory bioassays conﬁrmed CpGV to be highly
active against neonate larvae (Jaques et al. 1987), effectiveness in the ﬁeld was
inconsistent (Huber and Dickler, 1977; Laing and Jaques, 1980; Jaques et al.,
1987; Vail et al., 1991; Charmillot, 1993; Rashid et al., 2001), resulting in
hesitancy by fruit growers to incorporate CpGV products into their IPM programs
(Arthurs et al., 2005).

Two factors limiting ﬁeld performance are the rapid breakdown of the virus
by UV radiation, and the lack of consistent quality of virus products (Lacey and
Shapiro-llan, 2003). Recent efforts to reforrnulate Granulosis virus products in
Europe, Canada and New Zealand have resulted in reports of consistently good
codling moth control, and CpGV products are now applied on more than 100,000
ha of sustainable codling moth control programs in combination with mating
disruption in Europe (Charmillot et al. 1998; Lacey and Shapiro-llan 2003; Eberle
and Jehle 2006). The entrance of these products into the market provides a
renewed opportunity to develop effective and economically viable use patterns

for this promising biopesticide.

91

Three commercial Cva formulations are available in Michigan,
Carpovirusine (Arysta LifeScience, Cary, NC), Cyd-X (Celtis USA, Columbia,
MD), and Virosoftcp‘ (BioTepp, Canada). All formulations of the virus have short
residual activity in the ﬁeld, resulting from viral inactivation from exposure to
ultraviolet radiation and high temperatures (Lacey and Shapiro-llan, 2003).
Researchers are currently investigating CpGV use patterns comparing the
efﬁcacy of frequent applications (5-7 day re-application intervals) of virus at low
rates vs. higher rates at 14-21 day application intervals, efﬁcacy against different
codling moth generations, and vertical transmission of CpGV between
generations (Epstein et al. 2006; Hull and Krawczyk 2005; Quénin and Laur
2006).

Here we report on ﬁeld trials at an MSU research station and on
commercial farms conducted 2005 and 2006, to evaluate application rates,
frequency of application and efﬁcacy of the three commercially available
formulations.

MATERIALS AND METHODS

Small Plot Trials to Evaluate Application Rates and Frequency: Three
Carpovirusine spray programs for CM control were evaluated in an experimental
apple block in Southwest Michigan located at the MSU Trevor Nichols Research
and Extension Center (42°35'38.10"N, 86°06'05.92"W). The experimental design
was a randomized block (blocked from North to South) with 4 replicates for each
treatment. A 1.4 ha block of Smoothee apples was subdivided into 12-tree plots

each measuring 0.03 ha. One or two tree buffers were established between

92

péol:

Iota
Iota
gen
The
dec

M

an

trea
we

Se:

plots. Each block was randomly assigned one of the following four treatments: 1)
application of 325 mL I ha of Carpovirusine (1013 viral particles I liter) weekly for a
total of 6 sprays per generation 2) application of 650 mL / ha every 14 days for a
total of 3 sprays per generation, 3) application of 975 mL I ha twice per
generation with a 21 day interval between sprays, and 4) an untreated control.
The ﬁrst application in the virus plots was timed for the start of egg hatch, 100
degree-days after bioﬁx, base 11°C. All virus treatments were applied with an
airblast sprayer at a rate of 950 LIha.

Fruit injury and larval survival were used to evaluate the effectiveness of
treatments in controlling CM. Fruit damage assessments on 100 fruit per plot
were conducted at the end of the ﬁrst and second CM generations (July 21 and
September 7). Banding of trees with corrugated cardboard strips (Uline Inc.,
Waukegan IL) and counting the number of healthy and infected larvae that enter
the bands to pupate was used to estimate larval densities and mortality from viral
infection. Bands (6-7 cm wide) were placed on each of the 12 trees per plot prior
to larvae exiting the fruit. Bands were removed after infestation and examined in
the lab for the number and health of larvae present. Banding was only done at
the end of the ﬁrst generation. Fruit injury data was analyzed using ANOVA and
mean separation with Fishers LSD for multiple comparisons.

Small-plot experiment to compare Carpovirusine and Virosoft: A small plot
experiment to compare two codling moth granulovirus (CpGV) materials was
conducted in apple blocks at the Trevor Nichols Research Complex in southwest

Michigan. Two Carpovirusine spray programs were compared to one Virosoft

93

spray program and an untreated control. The experimental design was a
randomized block with 4 replicates for each treatment. Each plot consisted of
twelve trees, primarily of the Red Delicious variety, and was randomly assigned
one of the following four treatments: 1) application of Virosoft (4 x 1013 viral
particles I liter) at the rate of 150 mL I ha weekly for a total of 5 sprays per
generation 2) application of Carpovirusine (1013 viral particles / liter) at 630 mL/
ha weekly for a total of 5 sprays per generation, 3) application of Carpovirusine at
975 mL I ha every 12 days for a total of 3 sprays per generation, and 4) an
untreated control. The ﬁrst application in the virus plots was timed for the start of
egg hatch, 100 degree-days base 11°C after bioﬁx. All virus treatments were
applied with an airblast sprayer at a rate of 950 L / ha.

Fruit injury and larval survival were the measures of effectiveness of
treatments in controlling CM. Fruit damage assessments on 150 fruit per plot
were conducted at the end of the ﬁrst and second CM generations, July 10 and
September 14, respectively. For each entry hole it was determined whether it
was a shallow “sting”, just breaking through the skin of the apple, or deep entry
hole penetrating into the ﬂesh. Apples were cut open to follow tunnels and larvae
were removed and identiﬁed. Banding of trees with corrugated cardboard strips
and counting the number of healthy and infected larvae that enter the bands to
pupate was used to estimate larval densities and mortality from viral infection.
Two bands (6-7 cm wide) were placed on each of four trees per plot prior to
larvae exiting the fruit. Each banded tree had the trunk and a major scaffold limb

banded. Bands were removed after infestation and examined in the lab for the

94

number and health of larvae present. Fruit injury data were analyzed using
ANOVA and means separated using the Tukey-Kramer HSD method for multiple
comparisons.

Large On-Farm Plot Trials to Evaluate Eﬂ‘icacy: Trials were conducted in
2005 and again in 2006 in Kent and Ottawa counties, Michigan. The overall
experimental design in 2005 was a direct comparison of the effectiveness of CM
pest management programs that included multiple applications of CM granulosis
virus with a grower standard program that did not include virus. In most cases the
standard plot at each site was treated with organophosphorous (OP) insecticides
such as Guthion (Azinphosmethyl) and lmidan (Phosmet), synthetic pyrethroids
(SP) such as Asana (Esfenvalerate) and Pounce (Perrnethrin), or Provado
(lmidacloprid).

VII'US formulations tested were Carpovirusine (Arysta LifeScience, Cary,
NC, 1013 viral particles / liter), Cyd-X (Certis USA, Columbia, MD, 3 x 1013 viral
particles l liter), and Virosoft‘3P4 (BioTepp, Canada, 4 x 1013 viral particles I liter).
Each formulation was tested on three to four farms. Granulosis virus products
were applied three times per generation at the following low label rates: 450 mL I
ha for Carpovirusine, 150 mL I ha for Cyd-X, or 130 mL / ha for ViroSoftCP‘.

Supplemental insecticides were applied at the discretion of the grower and
may have included one or more of the following insecticides: Calypso
(T hiacloprid), Rimon (Novaluron), Assail (Acetamiprid) and Intrepid (Acetamiprid).
Levels of fruit injury and larval survival were used to evaluate the effectiveness of

treatments in controlling CM. Fruit damage assessments on 600 fruit per plot, 30

95

from each of 20 trees, were conducted at the end of the first and second CM
generations. Banding of trees with corrugated cardboard strips and counting the
number of healthy and infected larvae that enter the bands to pupate was used to
estimate larval densities and mortality from viral infection. Corrugated cardboard
bands (6-7 cm wide) were placed around the trunk or major scaffold limbs of 20
trees in each treatment at mid-season and prior to harvest. Bands were removed
after infestation and examined in the lab for the number and health of larvae
present.

In 2006, Cyd-X and Carpovirusine were directly compared at four sites;
ViroSoft was included at three sites. In all cases, virus was applied on an
alternating basis with a Calypso (T hiacloprid) or Rimon (Novaluron) treatment.
Two virus applications and 1-2 applications of Calypso or Rimon were made
against each of the two CM generations at the following rates: 450 mL I ha for
Carpovirusine, 150 mL / ha for Cyd-X, or 130 mL / ha for \flroSoftCP‘. Fruit
damage assessments on 600 fruit per plot, 30 from each of 20 trees, were
conducted at the end of the ﬁrst and second CM generations. Banding of trees
with corrugated cardboard strips and counting the number of healthy and infected
larvae that enter the bands to pupate was used to estimate larval densities and
mortality from viral infection. Corrugated cardboard bands (6-7 cm wide) were
placed around the trunk or major scaffold limbs of 20 trees in each treatment at
mid-season and prior to harvest. Bands were removed after infestation and

examined in the lab for the number and health of larvae present.

96

RESULTS

Small Plot Tn'als to Evaluate Application Rates and Frequency: First
Generation Results: Densities of internal feeders were high in the plots, as
indicated by the nearly 50% injury recorded in the untreated check (Table 18).
Additionally, an average of ca. 14 larvae were recovered in tree bands placed in
the untreated plots (Table 19). Under this level of pest pressure, the three virus
treatments signiﬁcantly reduced the occurrence of deep entries (Table 18). They
also reduced by ca. 80% the number of larvae completing development and
spinning up in bands placed around the tree trunks (Table 19). Adults emerging
from most of the injured fruit were OFM. Only 15% of the individuals completing
development in the untreated check were CM. The only virus treatment in which
CM were recovered was the 975 mL rate applied only twice.
Table 18. Mid season codling moth (CM) or Oriental fruit moth (OFM) fruit injury

in small plots treated with Carpovirusine (Virus) at the indicated rate or untreated
(Means followed by the same letter do not differ signiﬁcantly, p = 0.05).

 

Mean entries Larvae in apples (%)

 

 

(%)
Rate Codling Oriental
Treatment (m Uha) Shallow Deep Moth Fruit Moth
Untreated na 2.0 45.6a 1 5 85
\ﬁrus 325 2.0 13.0b O 100
Virus 650 3.0 16.0b 0 100
Virus 975 3.0 12.6b 20 80

 

97

in 1
rec
dal
the

ire

0f.”

hig

Table 19. Density and health status of larvae recovered in cardboard bands
placed at base of trees in small plots treated with Carpovirusine (Virus) at the
indicated rate or untreated (Means followed by the same letter do not differ
signiﬁcantly, p = 0.05).

 

Mean larvae recovered per 12 trees

 

 

Rate
Treatment (mUha) Healthy Unhealthy
Untreated na 14.3a 0
Virus 325 1 .5b 0.3
Virus 650 2.0b 0
Wrus 975 3.8b

 

Second generation results. Second generation fruit injury exceeded 57%
in the untreated check (T able 20). All of the virus treatments again signiﬁcantly
reduced the occurrence of deep entries (Table 20). However, signiﬁcantly more
damage occurred in the plot treated twice at a high rate of 13.2 oz/acre than in
the plot treated frequently at the low rate of 4.4 oz/acre. The high rate / low
frequency virus application also allowed for a relatively high survival of CM, as
compared to frequent applications of a low rate of virus (Table 20). The majority
of adults emerging from infested fruit in plots managed under the more effective,

higher application frequency, virus programs were OFM.

98

Table 20. Pre-harvest codling moth (CM) or Oriental fruit moth (OFM) in small
plot trials treated with Carpovirusine (Virus) at the indicated rate or untreated
(Means followed by the same letter do not differ signiﬁcantly, p = 0.05).

 

Mean entries (%) Larvae in apples (%)

 

Codling Oriental
Shallow Deep Moth Fruit Moth

 

Rate
Treatment (m L/ha)
Untreated na
Virus 325
Virus 650
Virus 975

4.0 53.6a 25 75
8.0 8.6b O 100
8.0 13.0bc 1O 90
10.0 20.60 40 60

 

Small-plot experiment to compare Carpovirusine and Virosoft: First

generation results: The density of internal feeders was high, as indicated by the

mean percentage of infested fruit in the untreated plots (Table 21). Shallow

entries, or stings, were numerically higher in the virus treated plots but not

statistically different than in the untreated plots. All of the virus treatments

signiﬁcantly reduced the number of deep entries into the fruit. There was no

statistically signiﬁcant difference in the number of deep entries between the

products or application intervals. Although not statistically signiﬁcant, the

majority of larvae found in the injured fruit were codling moth in all cases except

in the Carpovirusine treatment at 8.5 ounces applied weekly where the proportion

of oriental fruit moth larvae was higher. The number of healthy and unhealthy

99

Mme
plots.
l‘0-'
(0 M

ima
UTm
VllOE
Carp
Cam

TaMe
cmdb
same

COdll'n
hiGlier

inban

Table 21. Evaluation of 1St generation fruit injury in virus treated and untreated
plots. Means followed by the same letter do not differ signiﬁcantly, Tukey’s HSD,
p = 0.05. (Carpovirusine (Carpo-V); codling moth (CM); Oriental fruit moth
(OFM).

 

Mean Entries (%) Larvae in Apple (%)

 

Rate Frequency
Treatment (mUha) (days) Shallow Deep CM OFM

 

Untreated nla nla 8.8 33.5a 93.6 6.4
Vll'OSOft 150 7 11.2 11.2b 64.2 35.8
Carpo—V 630 7 15.5 12.0b 37.5 62.5
Carpo—V 975 12 10.0 10.5b 58.9 41.1

 

Table 22. The health status of 1St generation CM larvae recovered from
cardboard bands in virus treated and untreated plots (Means followed by the
same letter do not differ signiﬁcantly, Tukey’s HSD, p = 0.05)

 

Mean larvae recovered

 

 

from bands
Rate Frequency
Treatment (oz/A) (days) Healthy Unhealthy
Untreated na na 8.8a 2.3 a
\ﬁrosoft 150 7 0.5 b 0.3 b
Carpovirusine 630 7 0.0 b 0.0 b
Carpovirusine 975 12 0.0 b 0.0 b

 

codling moth larvae recovered from bands in untreated plots was signiﬁcantly
higher than in the virus treated plots (Table 22). The number of unhealthy larvae

in bands did not differ statistically among virus treatments.

100

Small-plot experiment to compare Carpo virusine and Virosoft: Second
generation results: The infestation level for the second generation of codling
moth was high as shown by the percentage of injured fruit in the untreated plots
(Table 23). Like the data for the ﬁrst generation injury ratings, all virus
treatments signiﬁcantly reduced the number of deep entries. The 630 mL / ha
Carpovirusine treatment applied every seven days had the fewest deep entries
but not signiﬁcantly fewer than the number of entries in the other two virus
treatments. The percentage of shallow entries (stings) on the fruit was lowest in
the untreated plots and highest in plots treated with CM virus. Signiﬁcantly more
stings were found on fruit in the treatment consisting of Carpovirusine at the 630
mL I ha rate applied on a 7-day interval compared to the others. The majority of
the larvae recovered from injured fruit were identiﬁed as oriental fruit moths in the
virus treated plots while the opposite was true in the untreated plots. Only the
630 mL I ha Carpovirusine treatment had a signiﬁcantly lower proportion of
codling moth larvae in the fruit. The number of healthy and unhealthy codling
moth larvae recovered from bands in untreated plots was signiﬁcantly higher than

in the virus treated plots (Table 24).

101

Table 23. Evaluation of 2nd generation fruit injury in virus treated and untreated
plots (Means followed by the same letter do not differ signiﬁcantly, Tukey’s HSD,
p = 0.05).

 

Mean entries Larvae in apples (%)

 

 

(%)
Rate Frequency Codling Oriental
Treatment (oz/A) (days) Shallow Deep Moth Fruit Moth
Untreated na na 30.0b 50.2a 61 .1a 38.9b
Wrosoft 150 7 39.0ab 11.7b 26.1ab 73.9ab
Carpovirusine 630 7 47.5a 5.7b 3.6b 96.4a
Carpovirusine 975 12 42.0ab 10.8b 25.0ab 75.0ab

 

Table 24. The health status of 2nd generation CM larvae recovered from
cardboard bands in virus treated and untreated plots (Means followed by the
same letter do not differ signiﬁcantly, Tukey’s HSD, p = 0.05).

 

Mean CM recovered

 

 

from bands
Treatment Rate Frequency Healthy Unhealthy
(oz./A) (days)
Untreated na na 11.3 a 0.8
Virosoft 2 7 1.3 b 0
Carpovirusine 8.5 7 1.0 b 0
Carpovirusine 13 12 1.5 b 0

 

102

24

an

pl:

Large On-Fann Plot Trials to Evaluate Efﬁcacy: Results: The extent to
which the virus program contributed to CM control varied by site in 2005 (Tables
24-26). No ﬁrst generation fruit damage was recorded in the Carpovirusine plot,
and second-generation fruit protection was equivalent in the virus and no virus
plots (Table 25). The best summer fruit protection was recorded at the site with
the highest CM densities (Tables 25-27, site 1). Fruit injury at harvest was 0.3 %
and 39.3% in the Carpovirusine and no-virus treated orchards, respectively, 0.3
% and 49.7% in the ViroSoft and no-virus treated orchards, respectively, and 7.2
% and 57.7% in the Cyd-X and no-virus treated orchards, respectively. At sites 2
and 4, little or no fruit damage was recorded prior to harvest in the ViroSoft
treated plots (Table 26). Similar levels of fruit injury were recorded in the ViroSoft
and no virus plots at site 3. Fruit damage prior to harvest was higher in the Cyd-X
plots at sites 2 and 3, compared to the no virus plots (Table 27). The number of
CM larvae recovered in tree bands was substantially lower in all three of the virus
treatments than the no virus plots. Although fruit were damaged, larval survival

was low.

103

Table 25. Codling moth (CM) fruit injury and larval densities in plots treated with
Carpovirusine (Carpo-V) or not treated with virus (standard) at four sites.

 

 

 

 

 

 

Total Larvae
Percent Injury in Bands
Site Treatment 1St gen. 2nd gen. 1srgen. 2nd gen.
1 Carpo-V 0.3
Standard 39.3
2 Carpo-V 0.7 6.5 2 1
Standard 1.9 8.0 18 59
3 Carpo-V 0.4 12 5 1
Standard 0.2 0 18 1
4 Carpo-V 0 0.5 1 0
Standard 0.7 0.5 0 0

 

Table 26. Codling moth (CM) fruit injury and larval densities in plots treated with

ViroSoft or not treated with virus (standard) at four sites.

 

 

 

 

 

 

Total Larvae
Percent Injury in Bands
l—éite Treatment 1St gen. 2nd gen. 1st gen. 2nd gen.
1 Vi roSoft 1 .2 0.3 36 8
Standard 1 .5 49.7 17 503
2 ViroSoft 0 0 5 1
Standard 0.7 0.5 18 1
3 ViroSoft 0.4 10
Standard 0.2 0.8
4 ViroSoft 0.2 0 3 0
Standard 0.2 0.8

 

104

Table 27. Codling moth (CM) fruit injury and larval densities in plots treated with
Cyd-X or not treated with virus (standard) at three sites.

 

Total Larvae

Percent Injury in Bands

 

Site Treatment 1St gen. 2nd gen. 1St gen. 2nd gen.

 

 

 

1 Cyd-X 2.0 7.2 57 17
Standard 1 .3 57.7 57 92
2 Cyd-X 0.7 1 .7 3 1
Standard 0.3 0 0 0
3 Cyd-X 0.4
Standard 0

 

Table 28. Codling moth (CM) larval densities in plots treated with one of three
granulosis virus formulations compared to plots not treated with virus (standard)
based on tree banding.

 

Mean CM larvae recovered

 

 

 

 

Treatment 15t gen. 2"" gen. Season
Carpovirusine 2.7 0.7 1.7
Standard 12.0 20.0 16.0
Cyd-X 30.0 9.0 19.5
Standard 28.5 46.0 37.3
ViroSoftCP‘ 14.7 3.0 8.8
Standard 12.3 167.7 90.0

 

In on—farm trials in 2006, the average number of second-generation larvae
recovered in cardboard bands was substantially reduced in all virus—treated plots

compared to plots not treated with virus (Table 28). The three management

105

programs that included virus also substantially reduced fruit injury at harvest
(Figure 14). Fruit injury at harvest was 9 % and 1.5% in the virus vs. no-virus
treated orchards. To a large extent, however, this difference in damage could be
attributed to a single comparison for each virus formulation. Speciﬁcally, at three
sites, fruit injury was extremely high in the no virus, standard block. Differences
in fruit injury in the no virus compared to virus plots at the three sites were as
follows: 39.3% vs. 0.3% using Carpovirusine, 57.7% vs. 7.2% using Cyd-X, and

39.7% vs. 0.3% using ViroSoftCP4 (Figure13).

 

 

 

25 I Mid Season
Harvest
20‘: . .
5‘ 5 D Full Season
.+: 15 ‘; T
h ' f 3
w ‘: . : 1_
C . ’ = r’ ;.
an 10‘; .-r N 4 ? ‘
O i E :« i l
h ‘ ' . .......
(D N=4 '“ E l N=3 ,
G. 3, j...l I
5 “ ’ ‘
-th—rﬂji

 

O
M- ~ -]
.4
“’7‘“?
L. ‘

 

 

 

 

 

Carpo-V No Virus Cyd-X No Virus ViroSoft No Virus
Figure 14. On-farm comparison of CM control in plots treated or not treated with

one of three Cva virus formulations: Carpovirusine (Carpo-V), Cyd-X, or
ViroSoftCP” (ViroSoft). N = Number of farms trials conducted on. represented by

106

DISCUSSION

Small plot trials conducted to determine optimum application rates and
frequency of application of Cva formulations show that a tactic of frequent
application of low rates of all three commercially available formulations yielded
the best results, as measured by levels of codling moth injury to fruit and
numbers of larvae recovered from bands in treated and untreated plots (Tables
18-20). There were fewer codling moth deep entries into the fruit and fewer
healthy larvae recovered in the low rate frequent application plots for both ﬁrst
and second generation larvae as compared to both the untreated plot and plots
receiving less frequent applications of a higher virus rate.

Frequent application addresses concerns of viral inactivation of Cva
from exposure to ultraviolet radiation and high temperatures (Lacey and Shapiro-
llan, 2003). Lacey and Shapiro-lllan (2008) state that Cva has a relatively rapid
speed of kill, and that the LD50 has been estimated as low as 1.2—5 granules per
larva, indicating that a strategy that maintains a low rate of material through
frequent applications to prevent product breakdown can be effective.

Frequent application of low rates of virus should also prove to be the most
economical program for Michigan apple producers. Three applications of
products, such as Carpovirusine, are equal in the price of product used to one
application of the high rate. In temperate climates, growers are weekly applying
fungicides and or insecticides during codling moth ﬁrst generation, so the
addition of Cva formulations to the spray tank does not incur additional

expenses in time and tractor use. All Cva formulations tested using the low rate

107

frequent application strategy in our on-farm trials substantially reduced fruit injury
at harvest (Table 27, Figure 14). These data are supported by evidence from
multi-year programs combining CpGV and mating disruption in Europe, New
Zealand and the United States where a noted pattern of initially high numbers of
codling moth adults and high percentages of partial larval entries into fruit
declined over 2-4 year period resulting in reduced pest densities and reduced

injury to fruit (Charmillot et al. 1998; Wearing et al. 1994).

108

CHAPTER SEVEN
Quantifying the Beneﬁts of Areawide pheromone mating disruption programs

for codling moth (Lepidoptera: Tortricidae)

Portions of this chapter are being submitted for peer review to the American

Entomologist as:

McGhee, P.S., L.J. Gut, and BL. Epstein. Quantifying the Beneﬁts of Area-wide

pheromone mating disruption programs for codling moth (T ortricidae)

109

ABSTRACT

A four-year research and implementation project in Michigan apple
production demonstrated that deploying pheromone-mediated mating disruption
for codling moth in an areawide (AW-CMMD) program where mating disruption is
established on all apple producing acreage on individual and adjacent farms,
signiﬁcantly improved control of codling moth compared to mating disruption
applied to individual apple blocks (CMMD) on farms with other blocks not under
disruption, or apple blocks not treated with mating disruption (No-CMMD).
Pheromone-baited traps were deployed at 1 per ha over 850 ha of AW-CMMD,
20 ha CMMD, and 20 ha of No-MD. Average captures of CM in AW-CMMD
declined each season while they remained steady or increased, respectively, in
the CMMD and No-MD programs. Additionally, injury to fruit and the overall
number of insecticides targeting CM decreased each year in the AW-CMMD
program while injury levels remained similar with slight insecticide reductions
from year to year in CMMD orchards and injury increased signiﬁcantly while
insecticide use varied little from year to year in the No-MD orchards. Growers
implementing AW-CMMD realized a mean savings of $55 to $65 lha as

compared to orchards utilizing insecticide only programs.

110

INTRODUCTION

Codling moth (CM) (Cydia pomonella L.) is a primary internal feeder of
apples, and damage from this pest makes fruit unmarketable. Without effective
control, losses can range from 50 to 90% of the crop (Wise and Gut 2000, 2002).
Michigan apple orchards have a history of high CM pressure, and growers have
experienced increasing difﬁculty in controlling this key internal-feeding pest
(Howitt 1993, Epstein and Gut 2000, Epstein et al. 2002). As of 2002, infestation
levels in excess of 10% had occurred on MI farms, and reduced pack-outs and
load rejections due to the detection of infested fruit had become common.
Controlling this pest with one or more broad-spectrum compounds became
difﬁcult, with failures reported throughout the State of Michigan. CM resistance to
the organophosphorous insecticide, azinphos-methyl was reported at levels of
greater than 10 fold, compared to susceptible populations throughout major
apple growing regions in MI (Mota-Sanchez et al. 2008).

Areawide pest management aims to suppress the population levels of
mobile pest species over a large geographic range. This strategy relies less on
reactive population controls such as the application of insecticides after pest
populations reach treatment thresholds, and more on proactive measures (i.e.
pheromone-mediated mating disruption) designed to suppress pest populations
from ever reaching treatment thresholds. Pheromones are semiochemicals that
elicit intraspeciﬁc behavioral responses between members of a species (Gut et
al., 2004). The deployment of synthetic sex pheromone to interfere with mate

ﬁnding orientation and subsequent mating behavior is called mating disruption.

111

Areawide (AW) pheromone management promotes a cooperative effort by
neighboring growers with contiguous acreage to deploy mating disruption on all
of the acreage on their farms to directly address key concerns regarding the
immigration of mated females and lower pheromone concentrations in the
borders of smaller, individualized disruption programs (Gut and Brunner, 1998;
Knight, 1995). Deploying sex pheromones for AW pest management has been
utilized for various pests in diverse cropping systems around the world including:
South Africa, Italy, the Western U.S.A., Australia, and Argentina, (Barnes and
Blomeﬁeld, 1997; Staten et al., 1997; Jones and Casagrande, 2000; Calkins et
al., 2000; ll’ichev et al., 2002).

The objective of this four-year research project was to determine whether
the deployment of a pheromone based AW mating disruption (AW-CMMD)
program would be an effective management approach under Michigan apple
production conditions, speciﬁcally smaller farms (240 ha) often separated from
neighboring orchards by ﬁelds and woodlots. The project also was designed to
directly assess, for the ﬁrst time, the added beneﬁt of using pheromone on an
areawide basis versus on an individual block basis. Thus, we compared AW-
CMMD with mating disruption applied to smaller (<4 ha) individual orchards
(CMMD) and orchards not treated with MD (No-CMMD) in the same region.
Numbers of moths captured, levels of CM injury to apples, insecticide usage
targeting CM and control program economics were used to evaluate

management approaches.

112

METHODS AND MATERIALS

Experimental Layout. The Ml apple production region commonly referred
to as The Ridge is located 16 km northwest of Grand Rapids Michigan
(43”07’51.97”N; 85"46’46.65”W; 278m elevation). The Ridge was chosen for this
study due to recurring codling moth (CM) outbreaks and increased levels of fruit
injury, >5%, at harvest. Eight adjacent commercial apple orchards comprising an
area of 320 fruit bearing hectares were selected to implement an areawide CM
mating disruption (AW-CMMD) strategy in 2004. Four farms located closely to,
but distinctly outside of the immediate AW-CMMD region, deployed CM
pheromones to a single, 2-4 ha, apple block (CMMD). Each of these four farms
had a paired 2-4 ha apple block that was left untreated with pheromones (NO-
CMMD) as a negative control. Supplemental insecticides were used when
necessary throughout all farms and treatments to control codling moth
populations that exceeded economic treatment thresholds. Ten additional farms
joined the AW-CMMD project in 2005-2007 bringing the total area treated to 850
ha.

Pheromone Disruption. Growers participating in the AW-CMMD and CM-
MD orchards chose which hand-applied disruption product to deploy in their
orchards. All pheromone dispensers were placed in orchards prior to the start of
ﬁrst generation CM ﬂight, approximately May 10 — May 15, at label rates.
Products used included Isomate® C+ and CTT (Shin-Etsu Chemical Co., Tokyo,
Japan), Scentry NoMate® codling moth Spirals (Scentry Biologicals, Billings,
Montana), and CheckMate® codling moth XL 1000 (Suterra, Bend, OR).

113

Monitoring. Large Delta style traps (LPD Soenturian Guardpost, Suterra,
Bend, OR) baited with long life CM L2 lures (Trécé lnc., Adair, OK) and Biolure
CM 10x (Suterra Inc.) were used to monitor male adult activity throughout each
growing season. Traps were deployed at 1 trap per ha in each treatment. CM L2
and Biolure 10x baited traps were deployed so that they were arranged in an
alternating pattern with 1 each per 2 ha. The L2 lure, releases pheromone at a
rate similar to a female CM and was used to measure the effectiveness of the
pheromone MD treatments. The 10x lure releases pheromone at a much higher
rate, and captures in these traps measured relative CM density. Moth captures
were recorded each week throughout the growing season. Sticky liners were
replaced after cumulative captures exceeded 30 moths per trap or at the
beginning of each ﬂight. Pheromone lures were replaced at the onset of adult
emergence for each generation.

The location of each trap was recorded using a Garrnin etrex Wsta GPS
device (Garrnin, USA, Olathe, KS). Trap locations were plotted on USGS aerial
imagery using Terrabrowser V1 .5b3 (http://www.Chimosoft.com). Trap locations
were used to plot moth captures in each orchard in order to assist in the
assessment of CM populations and to facilitate management decisions. Mean
moth captures were calculated weekly for each 4 ha apple block and a
corresponding color coordinated map overlay was generated according to
assigned pest pressure: no moths, low (1-3 moths), medium (4-10 moths), or
high (11+ moths) catch using Omnigraffle Pro (Omni Development, Inc., Seattle,

WA). Each week participating apple growers were presented with a summary

114

report detailing the numbers and corresponding locations of moths captured on
their farms. A public information kiosk was established at the Fruit Ridge
Orchard Supply Store, Sparta, MI, located centrally within the AW-CMMD project
region. This kiosk provided a summary of moth captures for all farms and
treatments, while the color coordinated map indicating relative moth captures
illustrated the weekly trends in moth populations.

Evaluation of Control Programs: Fruit Injury. Fruit injury assessments
consisted of evaluating 600 fruit per block; 30 fruit from each of 20 trees (15 fruit
from high and 15 from low in the canopy) in each orchard. Each fruit was
inspected by hand on the tree for CM feeding. Fruit injury assessments were
conducted after 1"t CM ﬂight (ca. July 7) and just prior to harvest beginning in the
fall (Aug 21-Sept 14) of each year. Equal numbers of fruits were sampled from
the orchard perimeters and interiors. All damaged fruit was collected, cut open,
and any larvae found were identiﬁed as either oriental fruit moth (OF M) or codling
moth by presence (OFM) or absence (CM) of an anal comb. The total number of
injured fruits and larval species was recorded.

Evaluation of Control Programs: Chemical Control Programs. Records of
all pesticide applications were obtained from each grower. The number and
kinds of insecticides applied for CM control were summarized for each season.
The mean number of insecticide applications was directly compared for each
treatment.

Evaluation of Control Programs: Economics. A general economic analysis

was used to evaluate the economic impact of using AW-CMMD verses the

115

grower standard, NO-CMMD. The economic analysis assessed net cost or
savings of implementing MD relative to the grower's “standard comparison”
approach, based upon a ranging analyses (Connor and Epstein, unpublished).
This analysis used a ﬁve-year (1995-1999) average on prices received in
Michigan for fresh and processed apples. Costs considered were: 1) damage
cost - the revenue lost when damaged fruit cannot be sold or receives a lower
price, and 2) cost of arthropod pest control inputs including MD plus cost of MD
installation for orchards where MD programs were implemented. Costs for fuel
and labor to apply insecticides were not included as some control applications
regularly occur with tank mixes to control other pests and diseases present in the
orchard. The value of apples in each plot was estimated and presented within a
range depending on crop market destination, either for processing or the fresh
market. The Connor/ Epstein model (Unpublished) estimates that a 1%
reduction in injury from pests feeding internally on apples is equivalent to a range
of $17.50 per ha for orchards where 100% of fruit is destined for a processing
market to $52.50 per ha where 100% of fruit will be sold fresh.

Data analyses. We calculated the average and standard error of the
number of male CM captured in 1 mg pheromone-baited traps for each
generation in all treatments over the course of 4 years. Data were square root
transformed to meet the requirements of normality according to skewness and
kurtosis and then subjected to an analysis of variance (ANOVA). Means were

separated by Fischer’s protected least signiﬁcant difference (PLSD) (P = 0.05)

116

(StatView 5.0.1, SAS Institute). The untransformed means and standard errors
are presented in table 1.

Percentage data from fruit injury analysis were arcsine transformed to
stabilize variances and then subjected to analyses of variance (ANOVA). Means
were separated by Fisher’s protected least signiﬁcant difference (PLSD) (P =
0.05) (Systat 13, Systat Software, Inc., Chicago, Ill, www.syst§t.com). The

untransformed means and standard errors are presented in ﬁgure 1.

 

r“

The mean number of total insecticide applications as well as the number I
of organophosphorous insecticide applications targeting codling moth were
directly compared for all management programs and standard errors of the
means reported.

Product cost for pheromone ($108/ac), organophosphate insecticides
($15.37/ac/ application), and non-OP insecticides ($33.40/ac/applicaiton) were
calculated based on local insecticide prices obtained from a chemical distributer.
The average price for pheromones, and insecticides targeting CM was
determined for CMMD and No-CMMD blocks.

RESULTS

Moth Capture. Catch of male codling moth in 1x baited traps decreased
from 42 :t 12.5 to 1.5 i 0.8 in AW-CMMD orchards over four years. Reduced
moth captures were realized by the second generation in year one, with only an
average of 7.8 :I: 2.8 in moths captured. Captures of moths also were greatly
reduced from 28.7 :I: 11.8 to 7.7 :I: 3.5 in the Block-CMMD orchards by the 4th

year. Statistically the two mating disruption treatments only differed in the ﬁrst

117

generation of year 2 when 6x more moths were captured in the Block-CMMD
treatment compared to the AW-CMMD treatment (Tables 29—31). Overall moth
captures were signiﬁcantly lower in both AW-CMMD and Block-CMMD vs. No-
CMMD orchards. Moth catch was sustained at high levels over all four years in
the No-CMMD treatment with 59, 37, 99, and 25 males per trap during ﬁrst
generation for 2004-2007, respectively (Table 29). The same pattern of high

captures was observed during second generation each year. Weekly moth

 

captures in all pheromone treatments remained at consistently low levels.
Orchards employing AW-CMMD rarely saw captures over 2 moths per trap while
populations in Block-CMMD peaked near 5 moths per trap. In contrast, a pattern
of higher and more variable moth captures was observed over the course of each
season in the No-CMMD orchards with maximum weekly captures averaging as
high as 28 individuals per trap.

Table 29. Captures of male moths was signiﬁcantly lower in AW-CMMD vs. No-
CMMD for every generation in all 4 years, except for the 1st generation, 2004.

 

 

DF SS Mean Sq F-Value P-Value
1st gen. 2004 2 13.1 6.6 0.948 0.4126
20d gen. 2004 2 89.9 44.9 7.793 0.0060
1st gen. 2005 2 53.5 26.7 8.745 0.0045
20d gen. 2005 2 33.1 16.6 8.042 0.0061
1st gen. 2006 2 107.8 53.9 16.961 0.0003
20d gen. 2006 2 119.5 59.8 21.858 <0.0001
1st gen. 2007 2 35.1 17.5 10.862 0.0025
20d gen. 2007 2 52.6 26.3 11.542 0.0020

 

118

Table 30. Mean captures of 1St and 2nd generation male codling moth in AW-
CMMD, Block-CMMD, and No—CMMD apple orchards 2004-2007.

 

 

st nd
Year Treatment 1 gen :I: SEM 2 gen :I: SEM
2004 AW-CMMD 42.0 :I: 12.5a 7.8 :l: 2.8a

 

Block-CMMD 28.7 :I: 11.88 7.9 :l: 1.6a
No—CMMD 58.9 :I: 13.1a 78.3 :I: 42.0b

 

2005 AW-CMMD 4.3 :I: 2.6a 7.2 :I: 3.3a

 

Block-CMMD 26.7 :I: 10.5b 12.5 :I: 3.3a
No—CMMD 36.8 :I: 21 .0b 37.8 :I: 24.0b

 

2006 AW-CMMD 16.7 :t 4.13 9.0 :I: 2.4a
Block-CMMD 15.8 :I: 8.93 10.3 :I: 2.1a
No-CMMD 99.3 :I: 21 .4b 92.6 :1: 29.6b

 

2007 AW-CMMD 1.5 :I: 0.8a 2.2 :I: 1.23
Block-CMMD 7.7 :I: 3.5a 9.9 i 4.7a
No—CMMD 24.5 :I: 7.0b 36.7 :I: 10.9b

119

Table 31. Fishers PLSD table for effect of treatment on male moth capture in
pheromone-baited traps. Signiﬁcantly different P values, alpha = 0.05, are bolded
and marked with the symbol, * (AW = AW-CMMD, NoMD = no disruption, Block
= Block-CMMD).

 

 

Comparison Year Gen. Mean Diff. Crit. Diff. P-Value
AW - NoMD 2004 1st -1.708 3.479 0.3082
AW — Block 2004 1st 0.764 3.479 0.6429
NoMD - Block 2004 lst 2.472 4.017 0.2065
AW — NoMD 2004 2nd -5.579 3.176 0.0022*
AW - Block 2004 2nd -0.347 3.176 0.8174
NoMD - Block 2004 2nd 5.232 3.668 0.0087*
AW — NoMD 2005 1st -4.197 2.388 0.0024*
AW - Block 2005 1 st -3.240 2.388 0.01 20*
NoMD - Block 2005 1st 0.957 2.694 0.4536
AW — NoMD 2005 2nd -3.602 1.960 0.001 8*
AW — Block 2005 2nd -1 .105 1 .960 0.2431
NoMD - Block 2005 2nd 2.497 2.212 0.0300*
AW - NO-MD 2006 1st 5959 2.435 0.0002*
AW — Block 2006 1st 0.273 2.435 0.81 15
NoMD - Block 2006 1st 6.231 2.747 0.0003*
AW — NoMD 2006 2nd -6.501 2.258 <0.0001*
AW - Block 2006 2nd -0.347 2.258 0.7434
NoMD - Block 2006 2nd 6.154 2.547 0.0002*
AW — NoMD 2007 1st -3.720 1 .768 0.0007*
AW — Block 2007 1st -1 .455 1 .876 0.1 158
NoMD - Block 2007 1st 2.265 1.876 0.0223*
AW — NoMD 2007 2nd -4.541 2.100 0.0006*
AW — Block 2007 2nd -1 .675 2.228 0.1262
NoMD - Block 2007 2nd 2.866 2.228 0.0163*

 

120

 

Fruit Injury. Immediate reductions in CM injured fruit were observed in
orchards deploying AW-CMMD compared to Block-CMMD and No-CMMD
orchards. In 2004, CM injury to fruit in AW-CMMD was 0.7% and 1.0%,
signiﬁcantly less than either the Block or No-CMMD programs (Figure 15). The
AW-CMMD program had signiﬁcantly less injury due to CM feeding than No-
CMMD orchard blocks for every CM generation in all four years (Figure 15 and

Table 32). Block-CMMD had signiﬁcantly less injury due to CM feeding than No-

 

CMMD orchard blocks for both CM generations in 2005 and 2007, and for ﬁrst i
CM generation in 2006 (Figure 15 and Table 33). The AW-CMMD program had
signiﬁcantly less injury due to CM feeding than Block-CMMD both CM
generations in 2004, and for all four years at harvest (Figure 15 and Table 33).
Injury in orchards treated with pheromone gradually decreased over 4
years of pheromone usage while there was a steady increase in injury levels in
the NO-CMMD orchards, with ﬁnal harvest injury above 3% in 2007. In the fourth
season, CM injury to fruit in the AW-CMMD was 0.6% and 3.1% less than Block
and No—CMMD orchards, respectively. Fruit protection was also realized in the
Block-CMMD orchards with a total reduction of about 0.5% over 4 years. On

average, CM injury on AW-CMMD farms was virtually undetectable by year 4.

121

Table 32. Fruit injury from CM was signiﬁcantly lower in AW-CMMD vs. No-
CMMD for every generation in all 4 years.

 

DF SS Mean Sq F-Value P-Value

 

1$t gen. 2004 2 0.02 0.008 21.959 <0.0001
20d gen. 2004 2 .015 .008 6.824 .0078
1St gen. 2005 2 .032 .016 14.123 <0.0001

20d gen. 2005 2 .085 .043 18.600 <0.0001

1St gen. 2006 2 .041 .021 7.868 .0014
20d gen. 2006 2 .041 .020 12.275 <0.0001
1St gen. 2007 2 .051 .026 12.250 .0003
20d gen. 2007 2 .091 .046 29.634 <0.0001

 

122

Table 33. Fishers PLSD table for effect of treatment on injury to fruit from CM
feeding. Signiﬁcantly different P values, alpha = 0.05, are marked with the
symbol, * (AW = AW-CMMD, NoMD = no disruption, Block = Block-CMMD).

 

 

Comparison Year Gen. Mean Diff. Crit. Diff. P-Value
AW - NoMD 2004 1st -0.052 0.023 0.0003*
AW — Block 2004 1 st 0067 0.023 <0.0001*
NoMD - Block 2004 1st 0.015 0.026 0.2237
AW — NoMD 2004 2nd -0.064 0.041 0.0043*
AW — Block 2004 2nd 0052 0.041 0.0161*
NoMD - Block 2004 2nd 0.012 0.045 0.5664
AW — NoMD 2005 1 st -0.073 0.028 <0.0001*
AW - Block 2005 1st -0.010 0.032 0.5104
NoMD - Block 2005 1st 0.063 0.037 0.0015*
AW - NoMD 2005 2nd 0119 0.040 <0.0001*
AW - Block 2005 2nd 0053 0.045 0.0214*
NoMD - Block 2005 2nd 0.066 0.053 0.0161*
AW — NO-MD 2006 1st 0069 0.037 0.0005*
AW — Block 2006 1st 0.004 0.056 0.8740
NoMD - Block 2006 1st 0.074 0.060 0.0171*
AW — NoMD 2006 2nd 0069 0.029 <0.0001*
AW — Block 2006 2nd 0048 0.045 0.0349*
NoMD - Block 2006 2nd 0.021 0.048 0.3739
AW — NoMD 2007 lst -0.114 0.049 <0.0001*
AW - Block 2007 1st -0.049 0.053 0.0692
NoMD - Block 2007 1st 0.065 0.064 0.0446*
AW — NoMD 2007 2nd 0152 0.042 <0.0001*
AW — Block 2007 2nd 0066 0.045 0.0067*
NoMD - Block 2007 2nd 0.087 0.055 0.0033*

 

123

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

   

 

 

 

 

4 - i: Midseason 2004
3 I Preharvest
a
2 .
b a a a
0 ___..— - i— -
AW-CMMD Block-CMMD No-CMMD
4 . Cl Midseason 2005 a
4.. 3 - Preharvest
a ‘ a
LL 2 ﬁ
8
‘5 1 . b °
E 0 ._ﬂ
5 AW-CMMD Block-CMMD No—CMMD
E, 4 E ii Midseason 2006
g I Preharvest
0’ a
D. 2 a
C b b a l
(D b j
0)
2 o ._;.i. , I , I l
AW-CMMD Block-CMMD No—CMMD
- a
4 i ” Midseason 2007 a
3 ' Preharvest
2 i '
i
1 d b c i
o -l..__.._L - t I I
AW-CMMD Block-CMMD No-CMMD

Figure 15. AW-CMMD was signiﬁcantly better at protecting fruit from injury by
CM larvae than both Block-CMMD and No-CMMD in all four years, 2004-2007.

124

Chemical control programs. Insecticide management regimes were
similar across all programs, beginning in 2004, and relied primarily on
organophosphorous compounds averaging 5 of the 6 seasonal sprays applied.
Both the AW-CMMD and Block-CMMD programs saw decreased insecticide
usage in the 2nd — 4th years, while the overall numbers of applications remained
the same in the No-CMMD program orchards (Figure 15). AW-CMMD
insecticide applications were reduced by at least 1 spray from each of the
previous years over the duration of the project. There were only 3 targeted

sprays in the AW-CMMD in 2007, of which only 1 spray was an OP. A similar

      

 

 

 

 

 

 

 

 

 

2004 2005 2006 2007 2004 2005 2006 2007

I i l I : I

8‘:

g 7 {j UAW-CMMD
% E (I. DBLOCKCMMD
\. 6. a; r}. INOCMMD
t, 5 l ‘ ﬁ-
.5 l j:

“a“: 4': ‘ .
1.8 5 Is:
!a 34' If
.8 : l, :1
.“5 2*; I: j": i
:3 1a I; .. j. l
EgOE Eu} in: u

C

C

(U

(D

2

g All (CM) Insecticides i OP’s

Figure 16. Number of insecticide applications for farms under areawide disruption
(AW-CMMD), disruption in individual orchard blocks (Block-CMMD) and no
disruption (No-CMMD) over the years 2004-2007.

125

insecticide applications was realized in the Block-CMMD programs, but with
fewer reductions in total seasonal and OP sprays, 5 and 3 respectively.

Economics. Costs: Dispenser input costs ranged between $200 and $275
/ ha depending on product chosen and rate of dispensers deployed per ha. Labor
costs for applying dispensers ranged from $37.50 and $50.00 / ha. Labor costs
for monitoring traps ranged from $75 to $100 / ha.

Economics: Retums: Insecticides: Average cost for application of an
insecticide spray targeting CM control was $87.50 / ha. AW growers realized a
mean reduction of 50% in CM insecticides over 4 years (7 applications in 2004 to
3.5 applications in 2007). The reduction from 7 to 3.5 CM insecticide applications
represented a savings of $306.25 / ha.

Fruit Injury: After 4 years of AW-CMMD injury to fruit from CM feeding was
a mean of 3.1% less than in insecticide only programs. Based on a 1% reduction
in internal injury to apples being valued at a range of $17.50 per ha for orchards
where 100% of fruit is destined for a processing market to $52.50 per ha where
100% of fruit will beEsold fresh, AW-CMMD growers received an average range
of $61.25 I ha to $183.75 / ha additional income compared to growers using
insecticide only.

The cost of purchasing pheromone dispensers, labor for applying
dispensers and for monitoring pheromone-baited traps ranged between $312.50 /
ha and $425 / ha. Mean savings realized from implementing AW-CMMD by year
four of the project ranged between $367.50 I ha to $490 / ha, meaning that

growers implementing AW-CMMD realized a mean savings of $55 to $65 Iha.

126

DISCUSSION

Although CM mating disruption has been practiced in apple orchards
around the world for nearly 2 decades, many practical and economical concerns
with the approach have slowed its widespread adoption. In apple growing regions
like Michigan, challenges of incorporating pheromone disruption into pest
management programs include costs for managing a multitude of insect and
disease pests, availability of labor for hanging pheromone dispensers, and a
farmland topography in which orchards are interspersed with other crop or non-
crop habitats. Indeed, MI orchards are often surrounded by woodlots and
neglected blocks that support populations of pest insects. Our results show that
mating disruption is both effective and economical under Michigan conditions,
especially when applied on a whole-farm basis.

It is well documented that great successes with mating disruption can be
achieved where large, contiguous areas are treated with pheromone. (ll’ichev et
al., 2002; Barnes and Blomeﬁeld, 1997; Calkins et al., 2000; Brunner et al.,
2001). Growers in the Michigan areawide project were rewarded with a similar
level of success. Overall the results have been impressive, with pest densities,
as measured by moth captures in pheromone traps and fruit injury at harvest,
declining to very low levels following implementation of an area-wide approach.
In addition, direct comparisons with conventional programs outside the project
area have revealed dramatic reductions in the number of insecticides applied for

control of the targeted pest. However, each of the areawide projects cited above

127

has fallen short of demonstrating superior efﬁcacy of mating disruption applied on
an areawide versus an individual block basis.

This Michigan areawide project marks the ﬁrst time that the efﬁcacy of
mating disruption deployed in an areawide fashion (AW-CMMD) was measured
against mating disruption deployed in individual farm plots (Block-CMMD).
Results show that an areawide approach further improved upon the beneﬁts of
deploying mating disruption in individual blocks within a larger orchard in terms of
both fruit protection from CM injury and reductions in insecticide applications for
CM control (Table 33 and Figures 15 and 16).

Researchers have established that the success of mating disruption
programs is strongly inﬂuenced by moth density and the ability to detect moth
immigration into disrupted orchards (Carde' and Minks 1995, Knight and Light
2005, Miller et al. 2006a). A key contributor to the success or failure of mating
disruption is the program for monitoring pest populations, and a portion of the
success of areawide mating disruption projects has often been attributed to the
more intensive monitoring programs that are implemented (Calkins et al., 2000;
Brunner et al., 2001). Inadequate monitoring can result in undetected CM
populations exceeding damage thresholds and ultimately crop loss at harvest
due to infested fruit. Growers in the Michigan areawide project relied on traps
baited with standard or high-load pheromone lures and were encouraged to
place traps at a density of one trap per hectare. Damage was kept to a minimum
and decisions to not treat based on moth captures allowed growers to reduce the

number of insecticide applications.

128

Still, monitoring of CM in disrupted orchards is limited using codlemone-
baited traps. The codlemone lure is attractive to males, only, leaving half the
moth population unmonitored. Another limiting factor is the ability of the
monitoring trap, baited with the same sex pheromone as is found in dispensers,
to outcompete both dispensers and calling females.

The recent identiﬁcation of ethyl (E, Z)-2,4-decadienoate (pear ester) as a
CM lure provides a new tool to improve CM monitoring and the timing of
insecticide applications in mating disrupted orchards (Light at al. 2001). Current
research is undenivay investigating the use of pear ester alone and in
combination with codlemone to better measure moth activity. The possible
advantages of the pear ester-based lures over the sex pheromone lure are 1)
they attract females and thus moth catch is more directly linked to egg laying and
the potential for worms in the fruit, and 2) attraction does not appear to be
impeded or suppressed by pheromone-based mating disruption. As orchard
production systems move toward greater reliance on pheromones and narrow-
spectrum and relatively expensive insecticides, more precise trapping systems
are required to monitor CM activity and aid in making cost-effective management
decisions.

The cost of purchasing pheromone dispensers, labor for applying
dispensers and for monitoring pheromone-baited traps ranged between $312.50 /
ha and $425 / ha. Mean savings realized from implementing AW-CMMD by year
four of the project ranged between $367.50 / ha to $490 / ha, meaning that

growers implementing AW-CMMD realized a mean savings of $55 to $65 Iha,

129

demonstrating that AW-CMMD is a cost efﬁcient management approach.
Following the success of the AW-CMMD program established in the Fruit
Ridge, additional AW-CMMD programs were established on apple farms in four
additional Ml counties (11 farms on approximately 400 ha). After two years, these
AW programs were yielding similar results to those seen on the Fruit Ridge
(Epstein, unpublished). These areawide programs are continuing in 5 counties
after completion of the MSU organized research project, with growers hiring
private concerns to maintain the intensive monitoring program. The Ml areawide
project has had a major impact in advancing the adoption of mating disruption by
apple producers in the state of Michigan. Combining both pheromones and a few
well-timed sprays using these compounds is effective and economical and has

proven to maintain CM populations at low levels year after year.

ACKNOWLEDGEMENTS

Heidi Noordijk, Jessica Suschil, Leah Rasch, David Chase, Amy lrish- Brown,

Jim Miller, William Shane and Nikki Rothwell

130

 

SUMMARY AND CONCLUSIONS

Pest control for Michigan apple growers is currently a major challenge,
and is likely to become more difﬁcult in the foreseeable future due to loss of
compounds through us. Environmental Protection Agency (EPA) regulatory
restrictions to protect citizens from the harmful effects of pesticides in food, air,
and water (Food Quality Protection Act, 1996, HR. 1627), the development of
pest resistance to currently used pesticides, and a shortage of economic and
effective alternatives. The overall aim of this thesis research was to develop and
deliver effective and economical biopesticide-based management programs for
codling moth (CM) and Oriental fruit moth (OFM) control that rely on
management tactics generally considered to be sustainable into the foreseeable
future: mating disruption, granulosis virus, and the judicious use of reduced-risk
or conventional insecticides.

My initial studies (chapters 1 and 2 of this dissertation) addressed
deployment strategies for hand-applied reservoir dispensers for mating disruption
of CM and OFM. Some researchers (Shorey and Gerber 1996, Knight 2004)
reported that efﬁcacy of disruption performance was maintained while reducing
the density of release sites, if overall release rate of pheromone per ha was
maintained or increased, thereby providing the grower savings in labor for
pheromone deployment (Knight 2004). My results contradicted these ﬁndings,
instead showing that the highest density of pheromone-dispenser release sites
yielded the best orientational disruption of male CM to traps and lowest fruit

injury. These results are in agreement with Miller et al. (2006 a and b) who

131

 

argues that competitive attraction is the predominant mechanism of disruption,
and identiﬁes practical implications for improving application of mating disruption
as 1) dispenser attractiveness should be competitive with females, 2) dispenser
density should be high, and 3) distribution of pheromone dispensers should be
uniform rather than clumped.

Should competitive attraction be the predominant mechanism in mating

disruption, a factor to consider in point source distribution of reservoir pheromone

 

dispensers is location of dispensers within the tree canopy to compete with
calling females. Previous research with pheromone baited traps showing male
activity to be greater in the upper than lower portion of the tree canopy resulted in
the standard recommendation that dispensers be applied within the top meter of
the tree (Barret 1995, Knight 2000, McNally and Barnes 1980). However, there
was little in the literature directly investigating male distribution without use of
behavioral stimuli inducing ﬂight, and the distribution of CM females within the
tree canopy was unknown. I developed a vacuum system for sampling male and
female moths directly from the tree canopy that revealed adults to be distributed
throughout all parts of the tree during evening periods when female calling and
male searching activity is occurring. In fact, higher numbers of moths were
captured at mid-tree canopy than in either the top 1I3 canopy or low 1I3 canopy,
with signiﬁcantly more moths captured in the combined lower 2I3 than in the top
1I3 of the tree canopy (Chapter 3, table 3). In plots under pheromone mating
disruption, female moths were captured in approximately equal numbers from the

top 1/3 and mid 1/3 of tree canopies (Chapter 3, tables 5 and 6).

132

Discovering that the presence of female moths was equally distributed
between the top and middle portions of the tree canopy led me to investigate the
effects of pheromone dispenser placement at different heights within the tree
canopy. If competitive attraction is a primary mechanism in pheromone-mediated
disruption of codling moth, it follows that a distribution of female moths
throughout the tree canopy calls for a similar distribution of dispensers in the
upper and mid canopy levels to reduce CM mating. The results showed that a
distribution of pheromone dispensers in the upper and mid canopies of trees did,
indeed, result in reduced overall mating of tethered female moths, and suggests
that recommendations for placement of pheromone ties should be revisited
based on recent ﬁndings of moth distribution and mechanism of codling moth
pheromone disruption (Chapter 4).

Studies investigating the canopy distribution of adult moths provided me
with another question regarding moth behavior. Vacuum samples during daytime
hours, 09:00 to 18:00, when adults are typically inactive, yielded a few moths.
Coupled with visual observations of moths emerging from orchard drive-row
grass at twilight, these ﬁndings initiated adult moth release I recapture studies to
investigate the possibility that moths were leaving the tree canopy after twilight
activity periods to rest on the orchard ﬂoor. This potentially removes adults from
the inﬂuence of pheromone sources in the tree for up to 12 hours per day. The
release I recapture investigation showed that signiﬁcantly more moths were
recaptured from the tree canopy, but also provided evidence that adult codling

moths do leave the tree canopy in apple orchards to inhabit drive-row grass and

133

 

 

herbicide strip vegetation during daytime periods of inactivity (Chapter 5). The
importance of this behavior, if any, to optimizing mating disruption efﬁcacy is yet
to be determined.

Positive reports of multi-year programs combining reformulated Granulosis
virus products and mating disruption in Europe and New Zealand encouraged me
to investigate efﬁcacy and use patterns for this biopesticide under Michigan
conditions beginning in 2005 (Charmillot et al. 1998; Wearing et al. 1994). Small
plot trials at research stations and larger on-farm experiments established that
frequent applications of a low rate of all three Cva formulations available in
Michigan targeting ﬁrst and / or second-generation larval populations consistently
yielded excellent and economical control of CM. The low rate frequent application
strategy of Cva use should prove to be the most economical program for
Michigan apple producers, since three applications of Cva products are equal
in price of product used to one application of the high rate. In temperate climates,
growers are weekly applying fungicides and or insecticides during codling moth
ﬁrst generation, so the addition of Cva formulations to the spray tank does not
incur additional expenses in time and tractor use. Virus used in combination with
mating disruption has been shown to be effective at reducing high CM
populations and resulting larval entries into fruit over a 2-4 year period
(Charmillot et al. 1998; Wearing et al. 1994). The combined use of these two
biopesticides allows growers to control two different CM life stages, mating

disruption targeting adults and Cva targeting neonate larvae.

134

 

Codling moth Granulosis virus products were incorporated into control
programs on several farms in Michigan as part of a four-year areawide (AW) CM
mating disruption project from 2004 to 2007. Participating growers deployed a
uniform distribution of high densities of pheromone-dispensers across 800 ha of
contiguous apple plantings in Sparta, MI, and used Cva and other insecticides
to gain control of CM populations that had been increasingly difﬁcult to control in

years leading up to the start of the AW project. Results showed that an AW

 

approach further improved upon the beneﬁts of deploying mating disruption in
individual blocks within a larger orchard in terms of both fruit protection from CM '
injury and reductions in insecticide applications for CM control (Chapter 7, Table
5 and Figures 15 and 16).
The above investigations show that biopesticide-based management
programs for CM and OF M control in Michigan apple production are both
effective and economical. As products and delivery strategies have been
developed and their efﬁcay demonstrated, growers have embraced their use.
Commercial use of codling moth pheromone-mediated mating disruption
products for CM, alone, has grown in Michigan from 50 to 100 ha in the year
2000 to over 3200 ha in 2010 (D. Thomson, Paciﬁc BioControl Corp., Seattle,
WA, personal communication). Researchers will continue to further develop and
reﬁne current use protocols for biopesticide-based products as additional
investigations reveal relationships between insect behavior / physiology and

product development and use.

135

LITERATURE CITED

Alford, A. R., and P. J. Silk. 1983. Effect of pheromone-releaser distribution and
release rate on the mating success of spruce budworrn (Lepidoptera:
Tortricidae). J. Econ. Entomol. J. Econ. Entomol. 76: 774-778.

Alway, T. 2002. Codling Moth Mating Disruption Revisited in 2002, Orchard IPM
Update newsletter, WA State Univ. Tree Fruit Research and Extension
Center. 4: 1-5.

Asser-Kaiser, S., E. Fritsch, K. Undorf-Spahn, J. Kienzle, K. E. Eberle, N. A.
Gund, A. Reineke, C. P. W. Zebitz, D. G. Heckel, J. Huber, J. A. Jehle.
2007. Rapid Emergence of Baculovirus Resistance in Codling Moth Due to
Dominant, Sex-Linked Inheritance, Science: 317: 1916-1918, September.

Atterholt, C.A., M.J. Delwiche, R. E. Rice, and J.M. Krochta. 1998. Study of
biopolymers and parafﬁn as potential controlled-release carriers for insect
pheromones, J. Agric. Food Chem. 46: 4429-4434.

Audemard, H., C. Leblon, U. Neumann, and G. Marboutie. 1989. Bilan de sept
années d'essais de lutte contre la Tordeuse orientale du pécher Cydia

molesta Busck (Lep., Tortricidae) par confusion sexuelle des males. J.
Appl. Ent. 108:191-207.

Arthurs, S. P., L. A. Lacey and R. Fritts, Jr. 2005. Optimizing Use of Codling
Moth Granulovirus: Effects of Application Rate and Spraying Frequency on
Control of Codling Moth Larvae in Paciﬁc Northwest Apple Orchards, J.
Econ. Entomol. 98(5): 1459-1468

Barnes, B.N. and TL Blomeﬁeld. 1997. Goading growers towards mating
disruption: the South African experience with Grapholita molesta and Cydia
pomonella (Lepidoptera: Tortricidae). IOBC WPRS Bulletin 20: 45-56.

Barret, BA. 1995. Effect of synthetic pheromone permeation on captures of male
codling moth (Lepidoptera: Tortricidae) in pheromone and virgin female
moth-baited traps at different tree heights in small orchard blocks. Environ.
Entomol. 24(5): 1201-1206.

Bartell, R.J. 1982. Mechanisms of communication disruption by pheromone in the
control of Lepidoptera: a review. Physiological Entomology 7: 353-364.

Borror, J.B., C.A. Triplehom and NF. Johnson, 1989. An introduction to the study
of insects. Sixth Edition, Saunders College Publishing, Fort Worth, TX, 875

PP-
Brunner, J., S., Welter, C., Calkins, R., Hilton, E., Beers, J., Dunley, T., Unruh,

136

A., Knight, R. VanSteenwyk and P., Van Buskirk. 2001. Mating disruption
of codling moth: a perspective from the Western United States. IOBC
WPRS Bulletin 25: 207-215.

Calkins, C.O., A.L., Knight, G. Richardson, and K.A. Bloem. 2000. Area-wide
population suppression of codling moth. In: Tan, K-H. (ed) Area-wide
Control of Fruit Flies and Other Insect Pests, Peneritg Universiti Sains
Malaysia, Pulau Pinang, pp. 215-219.

Cardé, AM, TO Baker, and RT. Cardé . 1979. Identiﬁcation of a four-
component sex pheromone of the female Oriental fruit moth, Grapholitha
molesta (Lepidoptera: Tortricidae), Journal of Chemical Ecology: 5(3)

Cardé, RT. 1990. Principles of mating disruption. In Ridgeway, R.L. and RM.
Silverstein (eds) Behavior-modifying chemicals for pest management:
applications of pheromones and other attractants, pp. 47-71, New York,
Marcel Dekker.

 

Cardé, RT. and AK Minks. 1995. Control of moth pests by mating disruption:
successes and contraints. Annual Review of Entomology 40: 559-585.

Cardé, R.T., A. Mafra-Neto, R.T. Staten and L.P.S. Kuenen. 1997.
Understanding mating disruption in the pink bollworm moth. IOBC/WPRS
Bulletin 20: 191-201.

Cardé, R.T., R.T. Staten and A. Mafra-Neto. 1998. Behavior of pink bollworm
moths near high-dose, point sources of pheromone in ﬁeld wind tunnels:
insights into mechanisms of mating disruption. Entomol. Exp. et Appl. 89:
35-46.

Castrovillo, P.J. and RT. Carde. 1979. Environmental regulation of female calling
and male pheromone response periodicities in the codling moth
(Laspeyresia pomonella), Journal of Insect Physiology, 25(8): 659-667.

Charlton, C. E. and R. T. Cardé. 1981. Comparing the effectiveness of sexual
communication disruption in the oriental fruit moth (Grapholita molesta)
using different combinations and dosages of its pheromone blend. J.
Chem. Ecol. 7: 501- 508.

Charmillot P J, D . Pasquier, N.J. Alepaiz and M. Meiwald. 1993. A biological
preparation for control of the codling moth Cydia pomonella L.: the
granulosis virus. Revue Suisse Wtic Arboric Hortic 25: 225-231.

Charmillot, P.J., Pasquier, D., Scalco, A., and Hofer, D. 1998. Control of codling

moth Cydia pomonella L. by an attract and kill technique. Rev. Suisse Vitic.
Arboric. 29: 111-117.

137

de Lame, FM. 2003. Improving mating disruption programs for the oriental fruit
moth, Grapholita molesta (Brusck): efficacy of new wax-based formulations
and effects of dispenser application height and density. M.S. thesis,
Michigan State University, East Lansing.

de Lame, F. M., J. R. Miller, C. A. Atterholt, and L. J. Gut. 2007. Development
and evaluation of an emulsiﬁed paraffin wax dispenser for season-long
mating disruption of Grapholita molesta in commercial peach orchards. J.
Econ. Entomol. 100: 1316-1327.

Devotto, L. and M. Gerding. 2005. Control of the codling moth (Cydia pomonella)
using the area-wide approach in Chile. In Book of Abstracts, lntemational
Conference on Area-Wide Control of Insect Pests: Integrating the Sterile
Insect and Related Nuclear and Other Techniques. Food and Agriculture
Organization (FAO) and lntemational Atomic Energy Agency (IAEA), 9-13
de Mayo de 2005, Vienna, Austria.

Eberle, K. E. and J.A. Jehle. 2006. Field resistance of codling moth against Cydia
pomonella granulovirus (CpGV) is autosomal and incompletely dominant
inherited, J. of Invertebrate Pathology. 93: 201-206.

Eberle, K.E., S. Asser-Kaiser, S.M. Sayed, H.T. Nguyen, and J.A. Jehle. 2008.
Overcoming the resistance of codling moth against conventional Cydia
pomonella granulovirus (CpGV-M) by a new isolate CpGV-I12, Journal of
Invertebrate Pathology 98: 293—298.

Epstein, D. & L. Gut. 2000. A Pocket Guide for IPM Scouting in Michigan Apples.
Michigan State University Extension Bulletin E-2720, 72pp.

Epstein, D., L.J. Gut, A.L. Jones and K. Maxson-Stein. 2002. A Pocket Guide for
IPM Scouting in Stone Fruits. Extension Bulletin E-2840, East Lansing, MI,
Michigan State Univ., 83 p.

Epstein, D.L., D. Waldstein, and C. Edson. 2002b. Michigan Apple Integrated
Pest Management Implementation Project Final Narrative Report to the
Pew Charitable Trusts,
http:/Iwww.ipm.msu.edu/pdeMAIPMlPFinalReport.pdf

Epstein, D.L., L.J. Gut, and J. Wise. 2006. Early season codling moth
management decision-making, MI State University IPM Program Fruit Crop
Advisory Team Newsletter 21(6).

Falcon, L.A., W.R. Kane, and RS. Bethell. 1968. Preliminary evaluation of a

granulosis virus for control of codling moth. Journal of Economic
Entomology 61: 1208-1213

138

 

Food Quality Protection Act. 1996. HR. 1627
http:IIwww.epa.gov/pesticideslregulating/Iaws/fqpaI

F ritsch, E., Undorf-Spahn, K., Kienzle, J., Zebitz, C. P. W., Huber, J. 2005.
Codling moth granulovirus: Variations in the susceptibility of local codling
moth populations, Bulletin of the International Organization for Biological
and Integrated Control of Noxious Animals and Plants, West Palaearctic
Regional Section.

Fruit and Tree Nuts Situation and Outlook Yearbook. Market and Trade
economics Division, Economic Research Service, US. Department of
Agriculture, October 2008, FTS-2008.

Geier, PW. 1963. The life history of codling moth, (Cydia pomonella (L.)
Lepidoptera, Tortricidae) in the Australian capital territory, Aust. J. Zool.,
11, pp. 323-67.

Groner, A. 1986. Speciﬁcity and safety of baculoviruses, CRC Press, Publisher
Place, Boca Raton, Fla.

Gut, L. and J. Brunner. 1998. Pheromone-based management of codling moth
(Lepidoptera: Tortricidae) in Washington apple orchards. Journal of
Agricultural Entomology 15: 387-405.

Gut, L. J, J. Wise, J. Miller, R. Isaacs & P. McGhee. 2001. New insect controls
and pest management strategies. Proc. Mich. State Hort. Soc. 129: 66-75.

Gut, L.J., L.L. Stelinski, D.R. Thomson, and JR. Miller. 2004. Behavior-Modifying
Chemicals: Prospects and Constraints in IPM, p. 73-121, In: Integrated
pest management: potential, constraints and challenges, Koul, 0., GS.
Dhaliwal and G.W. Cuperus, (eds), CAB lntemational, Oxfordshire, UK: 73-
121.

Gut, L. & J. Wise. 2004. Increasing concern about codling moth resistance to
insecticides. Fruit CAT Alert 19(8): 1-2.

Gut, L.J., JR. Miller, L. L. Stelinski, and D. L. Epstein. 2007. Competitive
Attraction as a Primary Mechanism of Moth Mating Disruption in Tree Fruit
Crops, lOBC/wprs Bulletin, Vol. 30(4), ISBN 92-9067-199-6 [xii + 279 pp.].

Howitt, AH. 1993. Common Tree Fruit Pests. Michigan State University.
Michigan State University Extension Bulletin, NCR 63.

Huber, J. and E. Dickler. 1977. Codling moth granulosis virus: Its efﬁciency in the

ﬁeld in comparison with organophosphorus insecticides. J. Econ. Entomol.
70: 557-561

139

Hull, L. and G. Krawczyk. 2005. An Evaluation of Cyd-X(r) in Pennsylvania
Orchards for Codling Moth Control, Proceedings of the 76th Annual
Western Orchard Pest & Disease Management Conference, Portland, OR.

ll’ichev, A.L., L.J. Gut, D.G. Viﬁlliams, M.S. Hossain, P.H. Jerie. (2002). Area-
wide approach for improved control of oriental fruit moth Grapholita
molesta (Busck) (LepidopterazTortricidae) by mating disruption Gen. Appl.
Ent. 31, pp. 7-16.

ll'ichev, A.L., L.L. Stelinski, D.G. VIﬁlliams and L.J. Gut. 2006. Sprayable
microencapsulated sex pheromone formulation for mating disruption of
Oriental fruit moth (Lepidoptera: Tortricidae) in Australian peach and pear
orchards. J. Econ. Entomol. 99: 2048-2054.

Jaques, R. P., J. E. Laing, D. R. Laing, and D. S. K. Yu. 1987. Effectiveness and
persistence of the granulosis virus of the codling moth, Cydia pomonella
(L.) (Lepidoptera: Olethreutidae), on apple. The Canadian Entomologist
119(12): 1063-1067.

Jehle, J.A., S. Sayed and B. WahI-Ermel. 2006. What do we (need to) know
about low-susceptibility of codling moth against Cydia pomonella
granulovirus (Cva)! Proceedings of the Ecofruit 12th lntemational
Conference on Organic Fruit Growing, Weinsberg, Germany.

Jehle, J. A. 2008. The Future of Cydia pomonella Granulovirus in Biological
Control of Codling Moth. Ecofruit, In: Boos, Markus (Ed.) Ecofruit - 13th
International Conference on Cultivation Technique and Phytopathological
Problems in Organic Fruit-Growing: Proceedings to the Conference at
Weinsberg/Gerrnany, pp. 265-270.

Jones, OT. and ED. Casagrande. 2000. The use of semichemicaI-based
devices and formulations in area-wide programmes: A commercial
perspective. In: Tan, K-H. (ed) Area-wide Control of Fruit Flies and Other
Insect Pests, Peneritg Universiti Sains Malaysia, Pulau Pinang, pp. 285-
293.

Judd, G.J.R., M.G.T. Gardiner, N.C. DeLury and G. Karg. 2004. Reduced
antennal sensitivity, behavioural response, and attraction of male codling
moths, Cydia pomonella, to their pheromone (E,E)-8,10-dodecadien-1-ol
following various pre-exposure regimes, Entomologia Experimentalis et
Applicata: 114(1): 65-78.

Knight, AL. 1995. The impact of codling moth (Lepidoptera: Tortricidae) mating

disruption on apple pest management in Yakima Valley, Washington.
Journal of the Entomological Society of British Columbia 92: 29-38.

140

Knight, A. L.1995b. Evaluating pheromone emission rate and blend in disrupting
sexual communication of codling moth (Lepidoptera: Tortricidae). Environ.
Entomol. 24: 1396-1403.

Knight, A. 2000. Monitoring codling moth (Lepidoptera: Tortricidae) with passive
interception traps in sex pheromone-treated apple orchards. J. Econ.
Entomol. 93(6): 1744-1751.

Knight, A. L., and T. E. Larsen. 2004. Improved deposition and performance of a
microencapsulated sex pheromone formulation for codling moth
(Lepidoptera: Tortricidae) with a low volume application. J. Entomol. Soc.
B. C. 101: 79-86.

Knight, A. L. 2004. Managing codling moth (Lepidoptera: Tortricidae) with an
internal grid of either aerosol or dispenser clusters plus border applications
of individual dispensers. J. Entomol. Soc. Brit. Columbia. 101: 69-77.

Knight, A. L. and D. M. Light. 2005. Seasonal Flight Patterns of Codling Moth
(Lepidoptera: Tortricidae) Monitored with Pear Ester and Codlemone—
baited Traps in Sex Pheromone-Treated Apple Orchards, Environ.
Entomol. 34(5): 1028-1035.

Krupke, C. H., B. D. Roitberg, and G. J. R. Judd. 2002. Field and laboratory
responses of male codling moth (Lepidoptera: Tortricidae) to a pheromone-
based attract-and-kill strategy. J. Econ. Entomol. 31: 189-197.

Klihrt, U., J. Samietz and S. Dorn. 2005. Effect of plant architecture and hail nets
on temperature of codling moth habitats in apple orchards, Entomologia
Experimentalis et Applicata, 118(3): 245-259.

Lacey, LA. and DJ. Shapiro-llan. 2003. The potential role for microbial control of
orchard insect pests in sustainable agriculture, Food, Agriculture &
Environment 1(2): 326-331.

Lacey, LA. and DJ. Shapiro-llan. 2008. Microbial Control of Insect Pests in
Temperate Orchard Systems: Potential for Incorporation into IPM, Annu.
Rev. Entomol. 53: 121-44.

Laing, D.R., Jaques, RP, 1980. Codling moth: techniques for rearing larvae and
bioassaying granulosis virus. J. Econ. Entomol. 73, 851-853

Light, D. M., A. L. Knight, C. A. Henrick, D. Rajapaska, B. Lingren, J. C. Dickens,
K. M. Reynolds, R. G. Buttery, G. Merrill, J. Roitman, and B. C. Campbell.
2001. A pear-derived kairomone with pheromonal potency that attracts male
and female codling moth, Cydia pomonella (L.). Naturwissenschaften 88:

141

 

333-338.

McGhee, P., D.L. Epstein and L.J. Gut. 2009. Michigan Growers Successfully
Managing Codling Moth With Areawide Mating Disruption, Fruit Growers
News, March.

McNally, PS. and Barnes, MM. 1980. Inherent characteristics of codling moth
pheromone traps. Environ. Entomol. 9: 538-541.

McNeil, J.N. 1991. Behavioral Ecology of Pheromone-Mediated Communication
in Moths and its Importance in the Use of Pheromone Traps, Annu. Rev.
Entomol. 1991. 36:407-30.

Michigan Agricultural Statistics. 2009. url:
http:IIwww.nass.usda.gov/Statistics_by_State/Michigan/PublicationsIAnnual
_Statistical_BuIletinIstats09Ifru'rt.pdf

Millar, J. G. 1995. Degradation and stabilization of (E,E)-8,10-dodecadien-1-ol,
the major component of the sex pheromone of the codling moth
(Lepidoptera: Tortricidae). J. Econ. Entomol. 88: 1425-1432.

Miller, J. R. L. J. Gut, F. M. de Lame and L. L. Stelinski. 2006a. Differentiation of
Competitive vs. Non-competitive Mechanisms Mediating Disruption of Moth
Sexual Communication by Point Sources of Sex Pheromone (Part I):
Theory, J Chem Ecol, 32: 2089—21 14

Miller, J. R. L. J. Gut, F. M. de Lame and L. L. Stelinski. 2006b. Differentiation of
Competitive vs. Non-competitive Mechanisms Mediating Disruption of Moth
Sexual Communication by Point Sources of Sex Pheromone (Part II): Case
Studies, J Chem Ecol, 32: 2115—2143

Mota-Sanchez, D., J. C. Wise, R. Vander Poppen, L. Gut and RM.
Hollingsworth. 2008. Resistance of codling moth, Cydia pomonella (L.)
(Lepidoptera: Tortricidae) larvae in Michigan to different modes of action
causes reduced residual activity. Pest Manag. Sci: 64: 881-90.

Palaniswamy, P., R. J. Robs, W. D. Seebrook, G. C. Lonergan, C. J. Weisner, S.
H. Tan, and P. J. Silk. 1982. Mating suppression of caged spruce budworrn
(Lepidoptera: Tortricidae) moths in different pheromone atmospheres and
high population densities. J. Econ. Entomol. 75: 989-993.

Pfeiffer, D. G. and J. C. Killian. 1988. Disruption of olfactory communication in
oriental fruit moth and lesser appleworrn in a Virginia peach orchard. J.
Agric. Entomol. 5(4): 235-239.

Quénin, H. and P. Laur. 2006. Carpovirusine granulosis virus formulation: control
of resistant strain of codling moth and study of the vertical transmission of

142

 

the virus, Proceedings of the 77th Annual Western Orchard Pest & Disease
Management Conference, Portland, OR.

Rashid, T., D. T. Johnson, D. C. Steinkraus and C. R. Rom. 2001. Effects of
microbial, botanical, and synthetic insecticides on Red Delicious apple
arthropods in Arkansas. HortTechnology 11: 615-621

Riedl, H. A., S. A. Hoying, W.W. Barnett and J. E. Detar. 1979. Relationship of
Within-Tree Placement of the Pheromone Trap to Codling Moth Catches,
Environ. Entomol., 8(4): 765-769.

Riedl, H. A., A. Seaman & F. Henrie. 1985. Monitoring susceptibility to
azinphosmethyl in ﬁeld populations of the codling moth (Lepidoptera:
Tortricidae) with pheromone traps. J. Econ. Entomol. 78: 692-699.

Rodriguez-Saona, CR. and LL. Stelinski. 2009. Behavior-Modifying Strategies in
IPM: Theory and Practice, In: Integrated Pest Management: Innovation-
Development, R. Peshin, A.K. Dhawan (eds), Springer Netherlands, pp.
263-215.

Roelofs, W., A. Comeau, A. Hill, and G. Milicevic. 1971. Sex Attractant of the
Codling Moth: Characterization with Electroantennogram Technique,
Science, 15 October: 174 (4006), pp. 297-299

Rothschild, G. H. L. 1975. Control of oriental fruit moth (Cydia molesta (Busck)
(Lepidoptera, Tortricidae)) with synthetic female pheromone. Bull. Ent. Res.
65: 473-490.

Rothschild, G. H. L. 1979. A comparison of methods of dispensing synthetic sex
pheromone for the control of oriental fruit moth, Cydia molesta (Busck)
(Lepidoptera: Tortricidae), in Australia. Bull. Ent. Res. 69: 115-127.

Sanders, C.J. 1997. Mechanisms of mating disruption in moths, In: Insect
Pheromone Research, New Directions, Carde,R.T. and Minks, A.K. (eds),
Chapman and Hall, N.Y., pp. 333-346.

SAS Institute. 2000. SAS/STAT User’s Guide, version 6, 4th ed., vol. 1. SAS
Institute, Cary, NC.

Sexton, S. B. and A. L. Il'ichev. 2000. Pheromone mating disruption with
reference to oriental fruit moth Grapholita molesta (Busck) (Lepidoptera:
Tortricidae) literature review. Gen. Appl. Ent. 29: 63-68.

Shapiro-Ilan, D. l., R.F. Mizell Ill, T.E. Cottrell, and D. L. Horton. 2003. Measuring
ﬁeld efﬁcacy of Steinernema feltiae and Steinernema riobrave for
suppression of plum curculio, Conotrachelus nenuphar, larvae. Biological
Control 30 (2), June, 496-503.

143

Shorey, H. H. and R. G. Gerber. 1996. Use of puffers for disruption of sex
pheromone communication of codling moth (Lepidoptera: Tortricidae) in
walnut orchards. Environ. Entomol. 25: 1398-1400.

Staten, R. T.; H. M. Flint, R. C. Weddle, E. Quintero, R. E. Zarate, C. M. Finnell,
M. Hernandes, A. Yamamoto. 1987. Pink Bollworrn (Lepidoptera:
Gelechiidae): Large-Scale Field Trials with a High Rate Gossyplure
Formulation, J. Econ. Entomol., 80(6): 267-1271.

StatSoft. StatSoft. Inc., Tulsa, Oklahoma, USA, http:IIwww.etatsoftcom/contact—
usI

Stelinski, L. L., L. J. Gut, R. E. Mallinger, D.L. Epstein, T. P. Reed, J. R. Miller.
2005a. Small plot trials documenting effective mating disruption of Oriental
fruit Moth by using high densities of wax-drop pheromone dispensers, J.
Econ. Entomol., 98: 1267-1274.

Stelinski, L.L., L. J. Gut, D. Epstein and J. R. Miller. 2005b. Attraction of four
tortricid moth species to high dosage pheromone rope dispensers:
Observations implicating false plume following as an important factor in
mating disruption IOBC/wprs Bulletin 28(7): 313-317.

Stelinski L.L., L.J. Gut, K. C. Ketner and J. R. Miller. 2005. Orientational
disruption of codling moth, Cydia pomonella (L.) (Lep., Tortricidae), by
concentrated formulations of microencapsulated pheromone in ﬂight tunnel
assays. J. Appl. Entomol. 129: 481-488.

Stelinski, L. L., JR. Miller, R. Ledebuhr, and L.J. Gut. 2006. Mechanized
applicator for large-scale ﬁeld deployment of parafﬁn-wax dispensers of
pheromone for mating disruption in tree fruit, J. Econ. Entomol. 99(5): 1705-
171 0.

Stelinski, L.L., L.J. Gut, D. Epstein, P. McGhee and M. Haas. 2007. Evaluation of
aerosol devices for simultaneous disruption of sex pheromone
communication in Cydia pomonella and Grapholita molesta (Lepidoptera:
Tortricidae). J. Pest Sci. 80: 225-233.

Stelinski, L.L., P. McGhee, M. Haas, A. L. Il'ichev and L.J. Gut. 2007b. Sprayable
microencapsulated sex pheromone formulations for mating disruption of
four tortricid species: Effects of application height, rate, frequency, and
sticker adjuvant J. Econ. Entomol. 100: 1360-1369.

Stelinski, L.L., JR. Miller, R. Ledebuhr, P. Siegert and L.J. Gut. 2007c. Season-
Iong disruption of Grapholita molesta (LepidopterazTortricidae) by one

144

 

 

machine application of pheromone in wax drops (SPLAT-OFM). J. Pest
Sci. 80: 109-117.

Stelinski, L.L., P.McGhee, M. Grieshop, J. Brunner and L.J. Gut. 2008. Efﬁcacy
and mode of action of female equivalent dispensers of pheromone for
mating disruption of codling moth, Cydia pomonella (L). Agric. Forest
Entomol. 10: 389-97.

Stoeckli, S., K. Mody and S. Dorn. 2008. Inﬂuence of Canopy Aspect and Height
on Codling Moth (Lepidoptera: Tortricidae) Larval Infestation in Apple, and
Relationship between Infestation and Fruit Size, J. Econ. Entomol. 101(1):
81

Suckling, D. M., G. Karg, S. J. Bradley, and C. R. Howard. 1994. Field electro-
antennogram and behavioral responses of Epiphyas postvittana under low
pheromone and inhibitor concentration. J. Econ Entomol. 87: 1477-1487.

Suckling, D.M. and N.P.D. Angerilli. 1996. Point source distribution affects
pheromone spike frequency and communication disruption of Epiphyas
postvittana (Lepidoptera: Tortricidae), Environ. Entomol. 25: 1 01-1 08.

Swenson, D. W. and I. Weatherston. 1989. Hollow-ﬁber controlled-release
systems. In: A. R. Jutsum and R. F. S. Gordon (eds), Insect pheromones
in plant protection. Whiley, Chichester, UK, pp. 173-197.

Tanada, Y. (1964). A granulovirus of the codling moth, Carpocapsa pomonella L.
J Insect Pathol 6, 378-380.

Thomson, D. R., L. J. Gut, and J. W. Jenkins. 1999. Pheromones for insect
control: strategies and successes, pp. 385-412. In: F. R. Hall and J. J.
Menn (eds), Methods in Biotechnology, vol. 5: biopesticides: use and
delivery. Humana Press Inc., Totowa, NJ

Thomson, D., J. Brunner, L.J. Gut, G. Judd, and A. Knight. 2001. Ten years
implementing codling moth mating disruption in the orchards of Washington
and British Columbia: starting right and managing for success!
Pheromones for insect control in orchards and vineyards. IOBC/WPRS
Bull. 24: 23-30.

Unites States Environmental Protection Agency. 2006. What Are Biopesticides.
url: http:IIwww.epa.gov/pesticides/biopesticides/whatarebiopesticides.htm

Vail, P.V., J.S. Tebbets, D.C. Cowan, and K.E. Jenner. 1991. Efﬁcacy and
persistence of Granulosis virus against investations of Plodia interpunctella
(Hubner) (Lepidoptera: Pyralidae) on raisins, J. Stored Prod. Res. 27: 103-
107.

145

Vickers, R.A., Rothschild, G.H.L. and EL. Jones, 1985. Control of Oriental Fruit
moth at a district level by mating disruption with synthetic female
pheromone. BuII.Entomol.Res. 75: 625- 634.

Waldstein, D. W. and L. J. Gut. 2005. Effects of rain and sunlight on oriental fruit
moth (Lepidoptera: Tortricidae) microcapsules applied to apple foliage. J.
Agric. and Urban Entomol 21: 117-128.

Wearing, C.H., Walker, J.T.S., Thomas, W.P., Clearwater, J.R., Suckling, D.M.,
Charles, J.G., Shaw, P.W., White, V. and Burnip, GM. 1994. Pest control
for organic apple production in New Zealand, Proc. 43rd New Zealand
Weed and Pest Control Conference, The Horticulture and Food Research
Institute of New Zealand Ltd., Palmerston North, New Zealand.

Weeden, Shelton, Li, and Hoffman. 2007. Biological control: a guide to natural
enemies in North America, Cornell University, url:
http:IIwww.nysaes.cornell.eduIent/biocontrol/pathogenslbacuIoviruses.htrnl

Weissling, T. J. and A. L. Knight. 1995. Vertical distribution of codling moth adults
in pheromone-treated and untreated plots, Entomologia Experimentalis et
Applicata, 77(3): 271-275.

Welter, S., and F. Cave. 2005. Rapid Assessment of New Pheromone Mating
Disruption Devices Using an EAG. Proceedings of the Western Orchard
Pest and Disease Management Conference, 5-7 January 2005, Portland,
OR.

Welter, S.C., C. Pickel, J. Millar, F. Cave, R.A. Van Steenwyk, and J. Dunley.
2005. Pheromone mating disruption offers selective management options
for key pests, California Agriculture: 59 (1), p. 16.

Wilson, E. O. and W. H. Bossert. 1963. Chemical communication among
animals. Recent Progress in Hormone Research, 19, 673-716.

Wise, J. and L. Gut. 2000. Control of codling moth and Oriental fruit moth with
new insecticide chemistries, 1999: Arthropod Management Tests 25:40.

Wise, J. and L. Gut. 2002. Apple: season long control of Iepidopteran pests with
Intrepid, 2001: Arthropod Management Tests 27: A55.

Witzgall, P., Backman, A., Svensson, M., Koch, U. Rama, F., El-Sayed, A.,
Brauchli, J., Am, H., Bengtsson, M., and Lofqvist, J. 1998. Behavioral
observations of codling moth, Cydia pomonella, in orchards permeated with
synthetic pheromone. BioControl 44:2 11-237.

146

Witzgall, P., L. Stelinski, L. Gut and D. Thomson. 2008. Codling moth
management and chemical ecology. Ann. Rev. Entomol. 53: 503-22.

Zingg, D. 2008. Madex Plus and Madex l12 overcome virus resistance of codling
moth. In: FOEKO (Ed), Ecofruit—Proceedings of the 13th International
Conference on Cultivation Technique and Phytopathological Problems in
Organic Fruit-Growing, FOEKO, Weinsberg (Germany), pp. 256-260.

147