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A STUDY 0F THE SPECIES OF AGRILUS
COLEDPTERA INFESTING
MICHIGAN RASPBEBRIES

THESIS FEB THE BEGBEE OF M. S.

R‘ D. SIMMONS *
1933

 

A serum: or mm 3230133 or mun: (Gomormn
mmmme nIcHIGu manna

EHESIS
Submitted to the tacﬁlty of 111911ng
State College for the partial tal-

ﬂllnent of tho’ degree of
M. 8.

R. D. imman-
1933

THE‘ES

 

ACKNOWLEDGEMENTS

The writer wishes at this
time to acknowledge the guidance
of Prefessors B. Hutson and B. I.
McDaniel, and to express his ‘
thanks for their kindly advice.

1034.97

(1)
Introduction.

Raspberry plants have suffered severely from.attaoks
by the larvae of a beetle known as Aggilus ruficollis for
at least 40 years. This has been considered the only imp
portant species of Agrilus attacking raspberries. New
blackberry, dewberry, and raspberry canes are favorite
host plants. _

Recently it has been thought that possibly Aggilus
communis ab. rubicola Abeille de Perrin, may infest rasp-
berry plants. 45. communis is commonly known as the "Rose
Stem-girdler."

The work of the two species is almost identical. In
the larval stages 5. communis and _A_. ruficollis resemble
each other very closely. In the adult stage they can be
distinguished without much trouble.

The study presented in this thesis aims to do two
things: (1) to present all the available material concern-
ing the species of Aggilus either infesting raspberries
or thought to infest raspberries to date, and (2) by
breeding to determine which species of Aggilus attack
Michigan raspberry plants. Ihe latter will be determined
from.observations made on material gathered from the
entomological experimental patch at Michigan State college
and from plantings in the vicinity of East Lansing.

(2)
Synonomy.

Aggilus ruficollis Fabricius 1787 (10,22)1 is also
known as 33);; podagra Riley (15,17). Commonly, it is
called redanecked cane-borer (1,7,14,16,18,21), red-
necked blackberry-borer (11,20), and red-necked Agrilus
(11), and its work is sometimes known as gouty gall

(15,16,17,20).
Early'History.

‘5. ruficollis is a native insect that has been found
infecting raspberries, blackberries, and dewberries (7,15,
16)., This beetle was first described in the year 1787.
Not much was known about it, however, until about 59 years
later. It became known as an injurious pest in 1846, but
was not considered as an.extreme1y serious pest until 1870
(22).

It is probable that the original food plants of,;.
ruficollis were wild raspberries and wild blackberries
(7), for at the present time they serve as host plants
for it. When.cultivated berry bushes are planted in prox-
imity to infested wild ones it would seem an easy matter
for the beetles to change over from the wild bushes to the

cultivated ones.

(3)
Distribution.

Distribution reports indicate that‘g. ruficollis is
confined to the eastern part of the United States.2

Iood Plants.

5, ruficollis has been found infesting raspberry,
blackberry, and dewberry bushes. It attacks both the
wild and cultivated varieties of raspberry and black-
berry plants (l,2,3,7,13,14,15,l6,l7,18,21). There
have been three doubtful reports of its infesting rose
(3).

Injury and Losses.

The most characteristic part of the injury is the
gall. These galls are formed by the stimulation of
cambium.growth, due to the presence of larval burrows
(1,6,10,12,15,16,l7,l9). One shoot may have one to
many galls on it (3,16). They are generally found near
the base of the shoots at first. Later they may be
found on the upper part of the shoots and even on the
lateral (3,19,22). The galls measure anywhere from
1 to 3 inches in length (7,18,19). After develoPment

 

1. Figures in parenthesis refer to references.
2. See map on page following,” 1!.

 

--——--P-

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Distribution of A. communis, as determined

by distribution maps obtained from J. A. hyslop, insect

Pest Survey, bureau of Entomology, Washington, D. U., and

records in the m. S. C. Department of Entomology.

(4)

and enlargement, the bark splits longitudinally over
the galls (6,7,10,12,13,15,16,l7,18,21).

The shape of the tunnel is characteristic of those
made by all flat-headed borers, being of flattened cross
section to permit passage of the enlarged prothorax.

- Infested shoots may start to leaf out, but the
foliage will not have its characteristic healthy appear-
ance. The infested shoots have generally been found un-
able to mature fruit (1,15,16,19,20). These shoots may
die prematurely, depending on the seriousness of the
girdle (15,14,15,16,18). A heavy wind or snow storm
will break the shoots off at the girdled places (13).
In.fact some of them will snap off when only lightly
touched with the hand.

The beetles have been known.to feed upon the upper
surfaces of young, bright green leaves. They either
notch or out little round holes in the leaves, and leave
excrement on its upper surface. The leaves wither and
die. ‘Unlike most buprestids these beetles feed on the
foliage in either shade or sunlight (5,7,19).

In time a whole bramble patch or plantation may be

ruined by'ép ruficollis.

(5)
Description of the Various Stages.

A. ruficollis adults range anywhere from 1/4 to
1/5 inches in length (1,4,5,7,11,13,14,l5,16,18,21).
The elytra are black and have a dull bluish reflection
(1,2,4,5,7,11,12,13,14,l5,16,l7,18). The thorax is
reddish or brassy, and this is how it came to be call-
ed the red-necked cane-borer (1,2,7,ll,12,15,14,15,16,
17,18). The head is black and has metallic reflections
on the front(4,5,11,18). The antennae and legs are black.
The ventral surface of the beetle is also black (11,17).
The adult larva is yellowish-white, slender, and
has a flattened anterior and due to the enlargement of
the prothorax (7,11,15,16,l7,18,21). It has black Jaws
and a brown head (11,16,17,18,21). Two brown hooks
are found on the tip of the abdomen (7,11,15,16,l7,18).
There are three blunt teeth on their inner edges (11,17).
Not much is known about the egg to date as no
literature has been published on it.

Life history and Habits.

The adults emerge aroundthe last of May or the first of
June. Eggs are laid in June and July in young shoots.
These eggs are deposited at the bases of the leaves (7,8,
11,13,14,l5,16,l7,18,21,22).

(6)

The larvae emerge in late June and July. They
burrow toward the tips of the shoots (7,15,16,18). Sever-
al larvae may be in one shoot (13,21). In traveling up
the shoots the larvae go around and around in the sapwood.
Some go to the right and some to the left (19). This is
called spiral burrowing. These spirals go around the
shoot anywhere from two to five or six times and galls
appear as a result of their interference with the trans
location of food in the plant (13,14,18,19).

This interference with the translocation of food in
the plant is what causes girdling to take place, because
the food supply is cut off (14,18). The bark splits
longitudinally over the galls on blackberry and dewberry
shoots. It also does this some on raspberry shoots (7,15,
15,17,1a,21). ’

After completing two to six spirals in the sapwood
the larvae enter the pith and continue up the shoot. At
frequent intervals they go to the edge of the pith and
feed on the sapwood (15,16). Slender white larvae are
found above the galls at distances varying from 1 to 6
inches.

The galls will start to show up in early'August.
Occasionally the injury does not form a gall. In this
case the larvae will be found in the pith (15,16).

(7)

Late in the fall the larvae are found in the pith
above the galls. here they pass the winter months (13,15,
16,18,21,22). They molt in.March and form shorter larvae,
which are called prepupal larvae. They molt again and
change to pupae in April. This stage lasts about 7 to 10
days (3). As has been said before, the adults emerge in
late May and June.

Number of Generations.

So far only one generation of;é. ruficollis has been
found (3,7,13). There may be another generation in the
southern.most range of these beetles, but this has not

been determined as yet.
Hibernation.

A? ruficollis hibernates as a larva. The hibernation
period is passed in the pith of the host plant (11,15,16,
18,21).

Natural Enemies.

The following insects are thought to be parasitic on
.5. ruficollis: (1).Microbracon xanthostigmus Cresson, and
(2) Charitopus maggificus Ashmead (3,8,22). “hese para-

sites are small, wasp-like, and have four wings.

(8)
Birds may be natural enemies of the species in the
adult and larval stages. This is especially true of the

larvae that may be in or just above the galls when the

canes are first broken off.
control Measures.

The common practice of pruning and burning berry
canes checks the spread of the A, ruficollis beetle, if
applied diligently every year.

Por'é. ruficollis the following measures should be
applied:

1. but and burn all infested canes in the fall, winter,
or early spring (1,2,3,4,5,6,7,10,12,13,14,15,16,l7,18,
20,21).

2. out and burn any wild berry bushes nearby that might
be infested (2,7,14,15,16,18,21).

3. Cut off all new shoots at the surface of the ground.
This should be done about the last of June (12,20).

4. Spray canes with lead arsenate (2% 1bs./100 gals. of

water), (7).

1.

2.
3.

4.

5.

6.

7.
8.

~9.

10.

12.

~(9)
References.

For _A_. ruficollis:
Baldwin, 0. 3., 1914-15 Eighth Annual Report of the
State Entomologist of Indiana, p. 158.
Blatchley, W. 3., 1910 Coleeptera of Indiana, p. 798.
Chittenden, r. H., 1922 U.S.D.A., Farmers' Bull. 1286,
pp. 1-5.

Oomstock, J. M., 1924 An Introduction to Entomology,
3rd. Ed., p. 503.

Ommstock, J. M1, 1930 A Manual for the Study of Insects,
Rev. Ed., p. 149.

Gossard, H.A., 1911 Ohio Agr. Exp. Sta., Bull. 233,
p. 146.
Herrick, G. W., 1925 Injurious Insects, pp. 205-206.
Hopkins, A. D., 1891 W. Vir. Agr. Exp. St., Bull. 15,
pp. 81-84.
Hutson, 3., 1932 Quarterly Bull. (May), vol. 14, no. 4,
pp. 267-269.
Lintner, J. A., 1890 43rd. Rept. I. York State luseum
Nat. Hist., pp. 123-125, fig. 13.
Lochhead, W., 1919 Economic Entomology, p. 301.
Lugger, 0., 1899 Minn. Agr. Exp. Sta., Bull. 66, pp.
142-145, figs., 65-66.

13.

14.
15.

16.

17.

18.

19.

20.

22.

(10)

Metcalf, O. L. and Flint, T. P., 1928 Destructive and
Useful Insects, pp. 639-640.

O'Kane, W. 0., 1912 Injurious Insects, p. 244.
Sanderson, E. 0., 1912 Insect Beats of Farm, Garden,
and Orchard, pp. 466-468.

Sanderson, E. D. and Peairs, L. H., 1921 Insect Pests
of Fens, Garden, and Orchard, p. 409.

Saunders, W.,183 Insects Injurious to fruits, pp. 307-
309.

Slingerland,JM.‘V., and Crosby, O. R., 1914 Manual of
Fruit Insects, pp. 332-333.

Smith, J. B., 1891 N. Jersey Agr. Exp. Sta., Spec. Bull.
n. pp. 373-378.

Smith, J. 5., 1906 Economic Entomology, pp. 186-187.
Washburn, P. L., 1925 Injurious Insects and Useful
Birds, pp. 139-140. '

Webster, F. H., 1892 Ohio Agr. Exp. Sta., Bull. 45, pp.
191-193.

4

 

(11)
Synonomy.

Aggilus communis variety rubicola Abeille de Perrin,
1897 (3) is also known as A. viridis variety fagi
Hatzeburg, 1839 (3) and as‘é. politus Say, 1825 (3).

commonly, it is called the "Bose stem-girdler".
Early History.

A, communis is native to Europe (2,6). It was found
in the United States in 1913, in the state of New Jersey.
This insect is a serious pest on rose bushes in Eur0pe
(6). It is spreading very fast in the United States, and
has caused considerable trouble in the east (6,7).

It was‘collected from.raspberry in 1932 and bred from
raspberry in 1933. It is thought that possibly this
buprestid may become a serious pest of berry bushes as
well as rose bushes, because the species of Agrilus have
so much in common, and because both the rose and the berry

belong to the family "Rosaceae".
Distribution.

Ah communis has been found only in northeastern
i

United States according to distribution reports (2,6,7,8).

1" See map followingmAeE 3.

 

 

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, as determined

 

Distribution of A. ruficollis

by distribution maps obtained.from.d. A. Hyslop, Insect

and

Pest Survey, Bureau of Entomology, Washington, D. 0.,

records in the M. S. C. Department of Entomology.

(12)
Food Plants.

The only previously reported food plants for A.
communis are different varieties of rose bushes such as
the following: _H_o_s_a_ blanda, Ii. nitida, g. seti era,

3. multiflora japonica, g. hugonis, g. rubrafolia, g.
rugosa, and‘g. carolina (wild rose), (3,5,6,7,8). This
buprestid beetle has been found to be most serious on.§gg§

rugosa stock (2,3,6).
Injury and Losses.

The injury caused by A. cogunis is similar to that
caused by A. ruficollis. The galls are the most character-
istic part of the injury. These galls differ from those
caused by the work of _A_. ruficollis, in that they are found
any place on the shoot (4). They are formed, as on rasp-
berry shoots, by the stimulation of the cambium due to the
presence of the larval tunnels. More than one gall may be
found on a shoot (6). After the gall enlarges the bark
splits longitudinally over it (1,2,6,7,8). Girdled shoots
break quite easily (2,6).

A shoot with one or more galls will not show charac-
teristic healthy foliage. The leaves turn yellow and die
(2,6,7).

(13)
Description of the Various Stages.

The adult A, communis varies from.3/l6 to 114 inch
in length. It has brassy-colored elytra with metallic
reflections (1,2,3). The head, thorax, and legs are also
of the same color.) The ventral surface of the body has
a very decided metallic coloration. Even the antennas are
of a brassy hue (3).

The larva of _A_. communis is similar to that of A.
gagicollis. It is 5/8 to 3/4 inches long and has about
the same colorations (6). .

The shortest diameter of the egg is 1/25 of an inch.
_ It is oval in shape and looks like a scale insect (4).

Life History and Habits.

The adults begin to emerge about June 1st. (6).
The eggs hatch in the latter part of June and in early
July. The larvae make spiral burrows around the rose
shoots much the same as the A. ruficollis larvae do A-
round the raspberry shoots (6). These burrows are l to

2 1/2 inches long and are close together (2,6).
Hibernation.

_A_. communis hibernates as a larva in the pith of the canes.

 

 

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Fm.- -a

r-—_— — nc— -—

 

PLATE I

e“ I

Fig. l.—-Adu1t of Imported Rose Stem-girdler
(Enlarged)

 

 

 

 

 

 

 

Fig. 2.—Eggs of new pest on raspberry canes
(Enlarged)

 

 

 

 

 

Fig. 3.—-Cane injury caused by new pest

 

h- -n —— - I.-

PLATE. II

 

 

 

 

 

Fig. 4.—Work of Imported Rose Stem-girdler. Upper twig shows character-
istic gall. lower twig the spiral tunnel.

 

 

 

 

 

 

Fig. 5.—Bark removed to show the tunnels of the Imported Rose
Stem-girdler

 

 

 

 

 

Fig. 6.—-Gouty gall on dewberry

(14)
Natural Enemies.

Up to the present time no parasites have been found

infesting‘é, communis. Birds may be a natural enemy to

the larvae and to the adults.

Control Measures.

For‘é. communis the following measures should be

applied:

1.

2.

1.

2.

3.

4.

Prune out infested rose canes and burn before spring
sets in (2,6).

Cut and burn any wild rose bushes nearby that might
be infested.

References.

For .A_. communis:
Britton, W. E. 1926 Conn. Agr. Exp. Sta., Bull. 275,
p. 325, pl. 9, fig. 3.
Felt, E. P. 1924 Manual of Tree and Shrub Insects,
pp. 64-65.
Fisher, W. 3. 1928 A.Revision of the North American
Species of Buprestid Beetles Belonging to the Genus
Agrilus, U. 8. Nat. Museum, Bull. 145, pp. 209-215.
Hutson, R. 1932 A. New Pest On Raspberry, Quarterly
Bull. (Nov.), vol. 15, no. 2, pp. 68-70.

(15)

5. .Inull, J. H. 1922 Canadian Entomologist, v01. 54,
pp. 85-86.

6. Me Daniel, E. I. 1931 Quarterly Bull. (Nov.), vol.
14, no. 2, pp. 89-91.

7. Weiss, H. B. 1914 Journal of Economic Entomology,
vol. 7, pp. 439-440.

8. Weiss, H. B. 1915 Journal of Economic Entomology,
vol. 8, p. 134.

Experimental Work.

The experimental work was planned to clarify the
question suggested by the second part of this study as
stated in paragraph 4, on page 1.

Methods, Apparatus, and.Procedure.

Material was gathered from five different sources:
(1) raspberry canes from the entomological experimental
patch, (2) raspberry canes from the horticultural "50"
patch, (3) raspberry canes from the east horticultural
patch, (4) rose canes from.the Botanical Gardens, and (5)
wild blackberry canes from the railroad track alongside
of the entomological experimental patch. This material
was put in separate bell jars in a hatchery at a constant
temperature of 75-80 degrees F. A thermostat regulated
this constant temperature in the hatchery.

(16)

Data were collected from this material and put in
tabular form.under the following headings: (1) number of
canes, (2) number of infested canes, (3) per cent of infes-
ted canes, (4) number of broken canes, (5) per cent of
broken canes, (6) number of galls in each bell jar, (7)
emergence of beetles, (8) emergence of parasites, (9) per
cent of emergence of beetles, (10) distance from.exit hole
to the gall, (11) length of tunnel, (12) distance the beetle
came back down the tunnel (those that did), and (13) size
of exit hole (long and short diameters).

The principal experimental material was taken frmm the
entomological experimental patch. The two horticulture
patches were used as checks. The wild blackberry and rose
canes collected, were also used as checks.

The entomological experimental patch consists of one
row of red raspberries, which is approximately 66 paces
long. This was divided up into 11 plots of‘6 paces each.
Six of these were used for experimental work (l,3,5,7,9,11),
After figures were obtained from these plots the other five
were averaged in.

The horticultural "50" patch consists of 7 rows of
red raspberries. Each rowaverages about 54 paces in
length. Three of these rows (1,4,7) were divided into
9 plots of 6 paces each. In these rows (1,4,7) were

(17)

divided into 9 plots of 6 paces each. In these 9 plots
data were taken from 5 of them. The other 4 plots in

the three rows were then averaged in. Then the remain-
ing four rows were averaged in with the three rows used.

In the horticultural patch of red raspberries east
ofthe horticulture building the red raspberry canes
are planted in hills. This patch is made up of 4 rows
of berry bushes, each row having about 44 hills. Two
rows were used (1,3). These rows were split up into
half rows of 22 hills each. Data were collected from
one half or 22 hills in rows 1 and 3. Then the other
half of these rows were averaged in. Finally, the re-
maining two rows (2,4) were averaged in.

Material was gathered from.the‘wild patch of black-
berry canes alongside of the entomological experimental
patch, but no special dimensions were taken on the size
of the patch or on the number of canes.

This was also true of the rose canes taken from the

Botanical Gardens.
Data.

The following data is indicative of the damage done
by the Agrilus species from the entomological experimental

patch:

I .00 0: 08.1163.
(1)
(2)

62 canes.

70

(3) 117

(4)
(ﬁlms.

canes in 11 plots.

77

440

ll
7'
N

(18)

" in 5 plots. 440 times 11/5 equal 968

The average number of canes per plot is 88. .The

lowest number is in plot (1) with 62 canes. Plot (3)

has the highest with 117 canes.

II lo. of Infested Canes.

(1)
(2)
(3)
(4)
(5)

25 canes infested.

34
40
27
33
159

 

ﬂ

3 in 5 plots. 159 times 11/5 equal

349.8 canes infested in 11 plots.

The average number of infested canes per plot is

31.8. Plot (1) has the lowest number with 25 infested

canes. The highest is 40 in plot (3).

(19)

III Per cent of Infested canes.

349.8
=---- times 11 equals 36. per cent infestation in

968

the entire patch.

Dividing the number of infested canes by the total

number of canes gives approximately 36 per cent infest-

ation for the entire patch.

I? no. of Broken Canes.

(l)
(2)
(3)
(4)
(5)

20 canes.

28 "

27 "

l7 '
_§Q_ i

112 3 broken in 5 plots. 112 times 11/5

equals 246.4 canes broken in 11 plots.

The average number of broken canes per plot is 22.4.

The lowest number is in plot 4, which has 17 broken ones.

The highest is in plot (2) with 28 broken ones.

7 Per cent of Broken canes.

246.4
- times 100 equals 70 per cent infested canes

349.8 broken in 11 plots.

Dividing the number of broken canes by the number of

infested canes gives the per cent of breakage. This is

approximately 70 per cent for the entire patch.

(20)

The following data shows the damage done by the

Aggilus species in the horticultural "50" patch, which

3|.

was used as one of the checks.

I Total No. of Canes.

(1) Bo. lo

(a)
(b)
(a)
(d)
(e)

370 times 915
equals 666 canes
1n 9 PlOtle

555 plus 667.8 plus 720 equals 2 053.8
2,053.8 times 7/3 equals 4,792.8

88 canes.

91
56
65

.Jﬂl.

370

I!

in 7 rows.

(2)
(a)
(b)
(o)
(d)
(e)
in

5 PlOtIe

Row’4.
76 canes.
54 '
81 *
58 "
_§§_ .
371 * in
5 plots.

371 times 9/5

equals 667.8

(3)
(a)
(b)
(o)
(d)
(e)

ROW 7e

92 canes.

89
74
79

66

400

7 in
5 Platae

400 times 9/5
equals 720 canes
canes in 9 plots. in 9 plots.

7 total no. of canes

The average number of canes per plot in row 1 is 74,

in row 4 it is 74.2, and in row 7 it is 80.

The average

number of canes per plot in the entire 7 rows is 76.1.

The lowest number of canes in row 1 is found in plot (a)
which has 55, and the highest is in plot (b) with 91.
The lowest number in.row 4 is in plot (b) with 64 and the

highest is in plot (0) with 82, The lowest figures in

row 7 are found in plot (e) with 66, and the highest in

plot (a) with 92.

(21)

II No. of Infested Canes.
‘ ‘1) 30"1.

(s) (a) (a)
24 canes infested. .18 canes infested. 25 canes in-

 

fested.
(b) (b) (b)
31 N I! 44 I 9' 31 I I!
(o) a (c) (o)
7 29 77 77 19 ﬂ 7' 40 I! 7!
(d) (d) (d)
31 I! 77 35 I! I! 37 ﬂ 7'
(e) (a) (e)
A 34 - II N 43 II I! 35 3! I!
149 ' ' " 159 " ' 168 ' "
in 5 plots. in95 plots. in 5 plots.
149 times 9/5 159 times 9/5 158 times 9/5
equals 268.2 ‘ equals 286.2 equals 302.4
canes infested in canes infested in canes infested
9 plots. 9 plots. in 9 plots.

268.2 plus 286.2 plus 302.4 equals 856.8

856.8 times 7/3 equals 1,999.2 total no. of infested

canes in 7 rows. ,

In row 1 the average number of canes is 29.8, in row
4 it is 31.8, while in row 7 it is 33.8. The average
number of infested canes per plot in the entire patch is
31.7. The lowest number of infested canes found in row 1
is 24 in plot (a), and the highest is 34 in plot (e). The
lowest number in row 4 is 18 in plot (a), while the high-
est is 44 in plot (b). In row 7 the lowest number of in-
fested canes is found in plot (a) with 25, while plot (0)

has 40 infested canes for the highest number.

(22)

III Total per cent of Infestation in the entire patch.

1,999.2

------- times 100 equals 41.7 or 42 per cent total
4,792.87 infestation.

Divide the total number of infested canes in the

entire patch by the total number of canes in order to get

the per cent. This is 42. per cent for the entire patch.

IV No. of Broken Canes.

(1) Row 1.
(a) 19 broken.
(b) 14 broken.

(0) l5 "
(d) 17 '
(e)_§Q_ "
’ 85 7 in
5 plots.
85 times 9/5

equals 153 brok-
en canes in 9
plots

(2) HOW 4e

(a) 14 broken.

(b) 12 "

(o) 26 "

(d) 24 .

(elgﬂ1_ '1

104 5 in

5 plots.

104 times 9/5

equals 187.2

broken canes in
9 plots.

(3) ROW 7e

(a) 16 broken.
(b) 18 "
(c) 20 7
(d) 25 .
(e)_;§_ "

94 7'
1n 5 PIOtSe

94 times 9/5
equals 169s2
broken canes in
9 PIOtBe

153 plus 187.2 plus 169.2 equals 509.4
509.4 times 7/3 equals 1,188.6 total number of
broken canes in the 7 rows.

The average number of broken canes in row 1 is 17, in

row 4 it is 20.8, while in row 7 it is 18.8. The average

per plot for the 7 rows is 18.9.

The lowest number of

broken canes in row 1 is 14 in.plot (b), while the highest

is 20 in plot (e). The lowest number in row 4 is 12 in

(25)

plot (b), while plot (e) is the highest with 28. In row
7 the lowest is 15 in plot (e) and the highest is 25 in

p10t (Q’s

v Total per cent of .Broken Came in the Entire Patch.

1188.6

------ times 100 equals 59 per cent broken canes.

1999.2

By dividing the total number of broken canes in the

7 rows by the total number of infested canes in these

rows, the per cent of broken canes was found to be 59 for

the entire patch.

The following data is taken from.the east horti-

cultural patch, which was also used as a check.

"I Total No. of Canes.

1. BO' 10

(1)
(2)
(3)
(4)
(5)
(5)
(7)
(8)

20 canes.

18 canes.

17
19
15
18
16
17

(9)
(10)
(11)
(12)
(13)
(14)
(15)
(15)

15 canes.

18
16
2O
22
23
21
25

(17) 22 canes.
(18) 24 7
(19) 23 "
(20) 25 "
(21l'22 "
(22)_2_4_ "
440 ”

440 times 2 equals
880 canes in the
row.

2. Row III.

(1) 18 canes.

(2) 17
(3) 15
(4) 18
(5)‘16
(5) 21
(7) 22
(8) 21

(24)

(9) 21 canes.

(10) 22
(11) 18
(12) 17
(13) 18
(14) 18
(15) 20
(15) 18

(17) 21 canes.

(18) 20 7
(19) 25 n
(20) 21 "
(21) 15 .
(22)_2_l_ "

423 '

423 times 2 equals
846 canes in the
row.

3. 880 plus 846 equals 1,726 canes in rows I and III.
1,726 times 2 equals 3,452 canes in the entire patch.

The average number of canes per hill in row I is 20,

and in row III it is 19.2,
the entire patch is 19.6.

The average number per hill in

The lowest number of canes in

row I is found in hills (5) and (9), with 15 canes each.

The highest is in hills (16) and (20), with 25 canes each.

The lowest number in row III is found in hills (3) and
(21) with 15 each, while hill (19) has the highest with 25

canes.

II Total 50. of Infested Canes.

' 1. not 1.

(1) 3 infested.

(2) 5
(3) 4

(4) 5 infested.
(5) 5
(6) 6

(7) 5 infested.
(8) 5 '
(9) 4 '

(10) 5 infested.

(11) 4
(12) 9
(l3) 7
(l4) 8

2e BOW IIIe

(1) 6 infested.

(2) 5
(3) 3
(4) 4
(5) 4
(6) 7
(7) 5
(8) 4

(25)-

(15) 7 infested.

(16) 7
(17) 5
(18) 7
(19) 6

(9) 3
(10) 5
(11) 4
(12) 5
(l3) 7
(14) 8
(15) 7
(15) e

infested.

(20) 8 infested.

(21) 7 7
(22) 8 7
132 7

132 times 2 equals
264 infested canes
in the row.

(17) 5 infested.
(18) 7 7
(19) 6 7
(20) 5 7
(21) 8 '
(22)_2_ 7

125 7

125 times 2.equa1s
250 infested canes
in thﬁ row.

3. 254 plus 250 equals 514 infested canes in.rows I and

III.

514 times 2 equals 1,028 infested canes in the en-

tire patch.

In row I the average number of infested.canes is 6,
while in row III it is 5.7.
age is 5.8. Hill (1) has 3 infested canes for the lowest
number in row I, while the highest number is 9 in hill (12).
In row III the lowest number is in hills (3) and (9) with

In the entire patch the aver-

3 infested canes, while the highest is 9 as found in hill

(22).

(26)

III Total per cent Infestation in the Entire Patch.
‘7 1,028 « 7
----- times 100 equals approximately 30 per cent
3,452 total infestation.
This was feund to be 30 per cent, approximately.
The figure was arrived at by dividing the total number
of infested canes in the 4 rows by the total number of

canes in these rows.

IV Total No. of Broken Canes.

(1) Row 1.

7(1) 2 broken. (9) 4 broken. (17) 4 broken.
(2) 3 broken. (lo) 4 7 (18) 5 7

(3) 3 7 (11) 3 7 (19) 3 7

(4) 2 7 (12) 5 7 (20) 5 7

(5) 4 7 (13) 3 7 (21) 4 7
(5)4 7 (14) 4 7 (22_L(_3__ 7

(7) 3 7 (15) 5 7 84 7

(8) 3 7 (15) 5 7 iécttiﬁieﬁ 5333:.

. in the row.

(2).Rew III.

(1) 3 broken. (7) 4 broken. (13) 5 broken.
(2) 4 7 (8) 3 7 (14) 5 7

(3) 5 7 (9) 5 7 (15) 4 7

(4) 3 7 (10) 3 7 (15) 5 7

(5) 2 7 (11) 2 7 (17) 4 '-

(5) 4 7 (12) 3 7 (18) 4 7

(27)

(19) 3 Broken. (21) 5 Broken. 82 times 2 equals
164 broken canes
(20) 4 7 (22) 5 7 in the row.
82 '

(3) 168 plus 164 equals 332 broken canes in rows I
and III. .
332 thmes 2 equals 664 broken.canes in the en-
tire patch.

There is an average of 3.8 broken canes in row I, and

3.7 in row III. The entire patch.has an average of 3.8

broken canes per hill. how I has the lowest number of

broken canes in hills (1) and (4), each having only 2.

The highest number of broken canes is found in hill (22),

which has 6. Bow III has 2 broken canes in.hills (5) and

(11) for the lowest number, and 5 in hill (15) for the

highest.

7

Total per cent of Broken canes in.the Entire Patch.
664

----- times 100 equals 65 per cent broken.canes.
1,028

By dividing the total number of broken canes in the

entire patch by the total number of infested canes, it

appears that approximately 65 per cent of the infested

canes break.

(28)

Number of galls gathered and put in hell jars.
1. Approximately 244 galls on the red raspberry canes
from the experimental patch.
2. Approximately 70 galls on the rose canes from the
Botanical.Gardens.
3. Approximately 96 galls on the red raspberry canes
from the east horticultural patch.
4. Approximately 85 galls on the red raspberry canes
from the horticultural "50" patch.
5. Approximately 336 galls on the wild blackberry canes
from the railroad track along side of the experimental
patch.

.The following data show the time, the number, and
the kind of mugged“ as they emerged from the canes
in the bell jars.

44.1..
h (This bell jar contained raspberry canes from the

entomological experimental patch.

Series A. (Beetles).

Emerged March 20, 1933.
£2!-

1. A. w. 2. A. gommunig. 3. A. comunis.
Emerged March 21, 1933.

4.
5.
6.
7.
8.
9.
10.
11.

8111131.

A. communis.

U 7'
w .
e w
I! 77
I! l7
.. w
I! II

(29)-

Emerged March 22, 1933.

112;,
25.
27.
28.
29.
30.
31.
32.
33.

A. communis.

I ll
77 I!
7' 77
N 77
7' 7'
ﬂ 7!
I! '7

Emerged March 23, 193g.

99;.
48.
49.
50.
51.

A. amis-
II 7'
l7 H
I! ll

12. A. semis.
13. 7 7
14. 7 7
l5. 7 7
15. 7 7
17. 7 "
18. 7 7
19. 7 7
34. A. ogmun g.
35. 7 7
35. 7 7
37. 7 7
38. 7 7
39. 7 7
40. 7 7
41. 7 7
52. A. 9.9913241:-
53. 7 7
54. 7 7
55. 7 "

20.
21.
22.
23.
24.
25.

43.
44.
45.
46.
47.
48.

56.
57.

A. communis.

I N
ﬂ 7'
N 77
I! N
77 77

A. communis.

.4. summin-

” M10 Olliﬂe

(30)

Emepged March 24, 1933.
Nos.

58. A. communis. 60. A. gommunis.

62s As rg 1001;18e

59. ' n 61. " rufiCOlliBeéze n ”

Emelged March 25, 1933.

Nos.

64. A. gogunig. 66. A. Lug-1001118.“. A. ruficollis.

55. 7 7 57. 7 7
Emerggd narch 27, 1933.
B08.

69. A. comunig. 71. A. Micollisﬂa A. ruficollis.
70. . IglcollABJIZJ' I 74. 7! 77

Sub I.
75. A. ruficollAs.
76. " "
Emerggd March 2;, 1933.
Dog.
7". As coma-n12.
78. " "

Serieg B. (Parasites).

1! one emerged.

March 20 three A. communis emerged.

March 21 the

emergence rate jumped and 22 A. communis emerged. Again

on March 22 there were 22 A. comunis in the bell jar.

(31)

On March 23 the rate of emergence dropped, as only 9 A.
communis and A. ruficollis were found. This one specimen
of A. ruficollis was the first to make its appearance.
Three A. oomunis and three Agrilus ruficollis were found

 

on March 24. Two A. communis and three A. ruficollis em-
erged March 25. Only one A. communis emerged March 27,
as compared to 7 A. ruficollis. The last beetles emerged
March 28, and these were two specimens of A. communis.
There were 19 dead beetles in the canes that crumb-
led up when touched. Some of’then had their head partial-
ly sticking out of the exit holes. Both species of
Aggilug were represented.

lo parasites emerged from this material.

Sub II.
(This bell jar had rose canes in it from the Botanical

Gardens .

§eries A.(Beetles).
Emerged March 21, 1933. Enlarged £17011 22, 1933.

Roe. Nos.
7 l. A. communis. 3. A. gmunis.
2. II I 4. I! n

Merged March 23, 1933.

(32)

NOIe
1. A. communig. 2. A. communis. 3. A. communis.

sub.III. ,
Emerged March 24, 1933.

£12.
4. A. communig. 6. A. gommun g.
5. n w 7. w w
Emerged March 25, 1933.
Egg.

8. A. communis.
Emerged March 27, 1933.

ﬁgs.
9. 5e COMQAQ. 120 A. comma-n18. 15e.ée MiGOlliBe
11. 7 7 14. 7 ppgicollis.

Emerged March 30, 1933.
508.

16. A. comunis. 17. A. ruficollig.
Emerggd llarch 31, 1933.
£33.
18. A. ruficollis.
Series B (Parasites).
Emerged March 21, 1933.
Egg.

1. Braconidae. 2. Braconidae.

(33)

On March 23 the first three beetles emerged. They
were A. comunis. March 24 there were four A. communis
that had merged. The rate fell off March 25, as only
one A. communig merged. On March 27 the rate jumped up
again, as five A. comunig and two A. ruficollis emerged.
The first appearance of an A. ruficollis beetle in this
bell jar was four days later than in bell jar Sub I.
March 30 only one A. communis and one A. ruficollis emerg-
ed. The 1ast beetle to emerge was a single A. ruficollis
specimen on March 31.

There were 12 dead beetles in the canes in this bell
jar. They were both A. gommunis and A. guficollis.

Two parasites emerged on March 21. They were
Braconids. These were the only parasites found in the
different batches of material.

Sub. .
This bell jar had raspberry canes from the horticultur-

al "50" patch.
Series A (Beetles).
arsed March 27, 1933.

“030

l. A. communis. 2. A. ruficollis.

Emerged March 29, 1933.

(34)‘

Gas

50 _A_e Comma-Illae 4s A. ruf1001118e

Emerged March 30, 1933. Emerged April 8. 1933.

 

Nos. Nos.
5. A. communis. 6. A. communis.

march 27 anlA. communis and an A. ruficollis both
emerged. The same thing happened on March.29. On March
30 a single A, communig beetle emerged. Then after a
lapse of eight days another.A. communis beetle emerged
on April 8.
‘ There were five dead beetles in the canes and these
five consisted of both species of Aggilus.
Series B.(Parasites).

None emerged.

Sub. V.
The material in this bell jar consisted of wild black-
berry canes.
Series A.(BegpAg§).
Emepged March 24, 1933.
Egg.

1. ‘A. ruficollis. 3. .A. ruficollis. 5. .A. ruficollis-

 

 

 

2. I! H 4. I! 77 6. ﬂ 7'

(35):

Merged March 25, 1933.

Ros.

7e As M1001113e
Emerged Algroh 27, 1933.

Has.
8e ée ruficolAig. 12. A. ruficollAs. 16. ée guild 01113e
9. w 7 13. w 7 17. " "
lo. 7 7 14. 7 7 18. 7 7

11. 7 7 15. 7 7 19. 7 7
Energed March 28, 1933. I 7

H
O
u
e

20. A. ﬂicolAis. 22. A. ruficolAis. 24. A- ruficollAs.

21. 7 7 23. 7 7
Emerged March 29, 1933. pperggd.narch 31, 1933.
Egg. App.

25. A. ruficollis. 25. 4.. ruficpllis.
2124.1.
Emergpd April 3, 1933.
£25.

27. A. ruficollis. 28. A. ruficolAis. 29. A. Micollis.
Eerged April 5, 1933.

Nos.

30. A. ruficolAis. 31. A. ruficollis. 32. A. ruficollis.

(36)

Merged April 8. 1933.

A23.
33. A. puficollis.

The first six specimens of‘A. ruficollis emerged
March 24. Only one A. ruficollis emerged March 25. On
March 27 twelve A. ruficollis beetles emerged. March 28
five A. ruficollis beetles were found. On larch 29 the
rate fall of! and only a single‘A. ruficollis emerged.
The same thing happened on March 31. On April 3 three
specimens of the same kind emerged. The same thing
happened April 5. The last specimen emerged April 8.
All the beetles taken from this bell Jar were A. $3;-
sense-

There were 15 dead beetles in the wild blackberry
canes in this bell Jar.

§eries B.(Parasites).

N one emerged.

The following data were taken to learn‘the per cent

of emergence of the beetles.

Sub, A.

1. Red Raspberrz canes frgm the mepimental patch.
a. 244 galls.

b. 78 beetles emerged.

c. 32 per cent emergence.

(57)

Sub. II.
1. ‘Rose canes from the Botanical Gardens.
a. 70 galls.
b. 13 beetles emerged.
c. 19 per cent emergence.
Sub. III.
1. Bed raspbergl_canes from.the east horticultural
me-
a. 93 galls.
b. 18 beetles emerged.
c. 19 per cent emergence.
Sub. IV.
1.. Red raspberrz canes from the horticultural "50"
name.
a. 85 galls.
b. 6 beetles emerged.

c. 7 per cent emergence.

Suba V.
1. Wild blackberpz canes from along the railrgad track

b1 the espergental patch.
a». 336 881130

b. 33 beetles emerged.

c. 10 per cent emergence.

(as)

The following measurements were taken in order to
learn further the characteristics of the Agrilus species.
Sub. .

Distance i’gm exit hole to the ggll.

1. 18.8mm. 10. 109.4mm. 20. 103.1mm.
2. 43.8mm. 11. 87.5mm. 21. 215.6mm.
5. 3.1mm. 12. 43.8mm. 22. 121.9mm.
4. 115.6mm. 13. 112.5mm. 23. 109.4mm.
5. 31.3m. 14. 15.6mm. 24. 128.4m.
6. 68.8mm. 15. 125.0mm. 25. 40.6mm.
7. 109.4m. 16. 193.8mm.
8. 3.1mm. l7. 140.6mm.
9. 40.6mm. 18. 60.0mm.

The average distance is 82.5mm. This distance was
measured from the top of the gall to the nearest edge of
the sit hole. The minimum distance is 3.1mm. The
maximum distance is 215.6nun.

Lepgth of the mnnel.

1. 18.8m. 6. 78.1m. ll. 87.5m.
2. 43.8m. 7. 109.4mm. 12. 57.8m.
3. 3.1mm. 8. 9.41m. 13. 112.5mm.
4. 134.4mm. 9. 48.4m. 14. 15.6mm.

50 39e1Me 100 117.2“e 15. 125eOEMe

16. 218.8nﬂb
17. 1.3.9...
50.0mm.
35.9mm.

18.
19.

(39)

20. 107.8mn.
21. 226.6mn.
22. 184.8mm.
25. 128.1mn.

24¢ 155e1ﬂle

25.

40 0 6mm.

The average length of the tunnel is 91.7mm. These

measurements on the length of the tunnel were taken from

the tsp of the gall on the inside of the cans, to the

end or the tunnel, which in some cases ran beyond the

exit

hole. The minimum length is 3.1mm. and the maximum

18 2260 6“.

Distance the beetle came back down the cane.

1.
2.
3.
4.
5.
6.
7.
8.
9.

back down the cane before mmerging.

IBeBMe
7e8“.

9.4m.

6e3Me

7e8“e

10.
11.
12.
13.
14.
15.
16.
17.
18.

7.8mm.
7.8M.
1401“.

25eOMe

603m.

19.
20.
21.
22.
23.
24.
25.

This means the distance some of the

4.7mm.
4.7mm.
10.9mm.
62.5mm.
18.8mm.
25.0mm.

beetles came

Some of the beetles

made their exit hole from.the end of the tunnel, while

others made a short tunnel back down the cane before

(40)

making an exit hole. The average length of this short

tunnel down to the exit hole is 15.3mm. The minimum
' length is 4.7mm. and the maximum is 62.5mm. both species
of Aggilus came back down the tunnel.

The beetles that came back down the tunnel emerged

bottom side up.

§ise 0; exit ho;eg (lgng and sharp dAgetezs).

Long ‘ Short Long Short
1. 2.5m. 1.5mm. 14. 1.5mm. 1.5m.
2. 2.0mm. l.5m. 15. 2.0mm. 1.5mm.
3. 2.5mm. 1.5mm. l6. 2.0mm. 1.5mm.
4. 2.01m. 1.5m. 1"]. 2.01m. 1.511111.
5. 2.01m. 1.5mm. 18. 2.0mm. 2.0mm.
6. 2.0m. 1.5mm. l9. 2.0m. 1.5mm.
'7. 2.0mm. 1.5mm. 20. 2.0mm. 1.5m.
8. 2.01m. 1.5mm. 21. 2.0mm. 1.5m.
9. 2.5mm. 1.5mm. 22. 1.5mm. 1.0mm.
lO. 2.0mm. 1. 5mm. 23. 2. 5mm. 1. 5mm.
11. 2.0mm. 1.5mm. 24. 2.0mm. 1.5mm.
12. 2.0mm. 1.5mm. 25. 1.5mm. 1.5mm.
13. 2.0mm. 1.5mm.

The average long diameter of the exit hole is 2mm.
and the average short diameter is 1.5mm. The minimum

long diameter is 1.5mm. and the maximum long diameter is

L41)

is 2.5mm. The minimum short diameter is 1mm, and the

maximum short diameter is 21m.

 

Sub. l.
Distance from exit hole to the gag.
1. 75.0m. .4. 15.6m. 7. 43.8m.
2. 28.1m. 5. 15.6m. 8. 37.5m.
3. 25.0m. 6. 37.5m. 9. 7.8mm.
' 10. 14.1mm.

The average distance is 30mm. The minimum is 7.8m.
and the maximum is 75.0mm.

Length of the tunnel.

1. 75.0mm 4. 28.1mm. 7. 53.1mm.
2. 28.1mm. ' 5. 34.4mm. e. 40.6mm.
3. 25.0mm. a. 37.5mm. 9. 7.8mm.

10. 7 23.4.

The average length of the tunnel is 35.3mm. The
minimum is 7.8mm. and the maximum is 75mm.

Distance the beetle came back down the cane.

l. 4. 12.5m. 7. 9.4mm.
2. 5. 1808mm. 8. 5.1m.
3. 6. 9.

lOe 9.4m.

(42)

The average distance some of the beetles burrowed
back.down the cane is 10.6mm. The minimum distance is
3.1mm. and the maximum is 18.8mm. The A. communis.
beetles came back down the tunnel, here. No‘A, ruficollig.
beetles emerged in this bell Jar.

Size pf exit hples (A023 and Short diameters).

Long Short Long Short
1. 2.0mm. 1.6mm. 6. 2.0mm. 1.5mm.
2. 2.0mm. 1.5mm. 7. 2.0mm. 1.5mm.
3. 2.0mm. 1.5mm. 8. 2.0mm. 1.5mm.
4. 1.5mm. 1.5mm. 9. 1.5mm. 1.0mm.
5. 2.0mm. 1.5mm. lO. 1.5mm. 1.5mm.

The long diameter average is l.9mm., while the
short diameter average is 1.5mm. The minimum.long di-
ameter 1.5mm. and the maximum is 2mm. The minimum.
short diameter is 1mm. and the maximum is 1.5mm.

SHb: IIIe
Distance from exit hole to the gpll.

1. 112.5mm. 6. 145.8mm. 11. 87.5mm.
2. 93.8mm. 7. 162.5mn. 12. 125.0mm.
3. 106.3mm. . 8. 131.3mm. 15. 115.6nm.
4. 171.9mm. 9. 121.9lm. 14. 146.9MM.'
5. 56.3mm. 10. 121.9mm. 15. 128.1mm.

The average length is 124mm. The minimum length is
56.3mm. and the maximum length is 171.9mm.

(43)

Distance the beetle came back down the cane.

1. 34.4mm. 6. 11.
2. 7. 12.
3. s. 13.
4. 9. 90.6mm. 14.
3. 10. 15. 31.3mm.

The average distance is 52.1mm. The minimum dis-
tance is 31.3mm. and the maximum is 90.6mm. Both
species came back down the tunnel. Those that did come
back down.emerged upside down.

Size of exit holes (long and short diameters).

'Long Short Long Short
1. 2.0mm. 1.5mm. 9. 1.5mm. 1.0mm.
2. 2.0mm. 1.5mm. 10. 2.0mm. 1.5mm.
3. 2.5mm. 1.5mm. ll. 2.0mm. 1.5mm.
4. 2.0mm. 1.5mm. 12. 2.0mm. 1.5mm.
5. 2.0mm. 1.5mm. l3. 1.5mm. 1.5mm.
6. 1.5mm. 1.5mm. l4. 2.0mm. 1.5mm.
7. 2.0mm. 1.5mm. l5. 2.0mm. 1.5mm.
8. 2.0mm. 1.5mm.

The average length of the long diameter is 1.9mm.
and the average length of the short diameter is 1.5mm.
The minimum length of the long diameter is 1.5mm. and
the maximum is 2.5mm. The short diameter has a minimum

length of 1mm. and a maximum of 1.5mm.

.(44)

Sub. IV.
Distance from exp; hole to the gall.

lo 460%. 3e 81.3m. 5. 31.3m.
2. 121.9“. 4. 12.5”. 6. lOéezm.
The length averages 66.7mm. -The minimum is 12.5mm.

and the maximum is 121.9mm.

Length of the tunnel.
1. 60.9m. 3. 81.3mm. 5. 40.6m.

2e 121e9Me 4. 12.5m. 6e 106.5“.
The average length ofthe tunnel is 70.6mm. The
minimum length is 12.5mm. The maximum length is 121.9mm.

Distange the beetle came back down the cane.
1. 14.1m. 3. 5. 9.4mm.
2. . ' 4. 6.
The average distance is 11.8mm. The minimum is
9.4mm. and the maximum is 14.1mm. both an A. ruficollis
and an A. communis were observed coming back down the

cane, and they emerged upside down.

Size of exit holes (long and short diameters).

Long Short Long Short
1. 2.0mm. 1.5mm. 4. 2.0mm. 1.5mm.
2. 2e5mIRo 1.5“. 5. 2.0m. 1.5m.

3. 2.0m. 1.5mm. 6. 2.0mm. 2.0mm.

(45)

The average long diameter is 2.1mm. and the average
short diameter is 1.6mm. The minimum long diameter is
2mm. and the maximum is 2.5m. The short diameter has a

minimum of 1.5mm. and a maximum or 2mm.

Sub. Y.
Distance from exit hole to the gall.

1. 118.8mm. 1o. 62.5mm. 19. 12.5mm.
2. 51. 6mm. 11. 18.8mm. 20. 8?. 5m.
3. 75.0mm. 12. 6.3mm. 21. 43.8mm.
4. 12.5mm. 13. 43.8mm. 22. 62.5mm.
5. 46.9mm. 14. 65.6mm. 23. 34.4mm.
6. 115.6mm. 15. 15.6mm. 24. 87.6mm.
7. 21.9mm. 15. 34.4mm. 25. 50.0mm.
s. 93.8mm. 17. 43.8mm.

9. 12.5mm. 18. 96.9mm.

The average distance is 52.6mm. The minimum is
6.3mm. and the maximum is 118.8mm.

Dengjh of the tunnel.

1. 118.8mm. 5. 115.6mm. 11. 68.8mm.
I 2. 71.9mm. 7. 59.4mm. 12. 46.9mm.
3. 75.0mm. e. 104.7mm. 13. 43.8mm.
4. 57.8mm. 9. 31.3mm. 14. 90.6mm.

5.0 46.9“. 10. 840m. 150 15e6Me

(46)

15. 34.4mm. 20. 87.5mm. 24. 87. 5mm.
17. 43.8mm. 21. 43.8mm. 25. 57.8mm.
18. 95.9m. 22. 62.5mm.
19. 35. 95:1. 23. 34.4m.

The average length is 64.6mm. The minimum.is
15e6ﬂe The mm 18 118e8Me

Distance the beetle came bacdeown the cane.

l. 10. 21.9mm. 18.

2. 20.3mm. ll. 50.0mm. 19. 23.4mm.
3. 12. 40.6mm. 20.

4. 45.3mm. 13. 21.

5. l4. 25.0ll. 23.

6. 15. 24.

7. 37.5mm. 16. 25. 23.4mm.
8. 10.9mm. 17. ‘

The average distance here is 28.8mm. The minimum
is 10.9mm. and the maximum is 50m. Only A. ruficollis
emerged here. They'came back.down the tunnel in some

cases, and emerged upside down.

Size of exit holes 10 and short diameters).
Long Short Long Short
1. zoom. 1e 5“. 3e 2e 5”. 105Me

2o 2.0mm. 1.5mm. 4. 2.5mm. 1.5mm.

(47)

Long Short Long Short
5. 1.5mm. 1.0mm. l7. 2.5mm. 1.5mm.
6. 2.0mm. 1.5mm. 18.‘ 2.0mm. 1.5mm.
7. 2.0mm. 1.5mm. l9. 2.0mm. 1.5mm.
8. 2.0mm. 1.5mm. 20. 2.0mm. 1.5mm.
9. 2.0mm. 1.5mm. 21. 2.5mm. 1.5mm.
lO. 2.0mm. 1.5mm. 22. 2.0mm. 1.5mm.
ll. 2.5mm. 1.5mm. 23. 2.0mm. 1.5mm.
12. 2.0mm. 1.5mm. 24. 2.0mm. 1.5mm.
l3. 2.0mm. 1. 5mm. 25. 1.5mm. 1. 5mm.
14. 2.5mm. 1.5mm.
l5. 1.5mm. 1.5mm.
16. 2.0mm. 1.5mm.

The average long diameter is 2mm. and.the average
short one is 1.5mm. The long diameter has a minimum.o£
1.5mm. and a maximum.of 2.5mm. The minimum.short

diameter is 1mm. and the maximum.is 1.5mm.

(48)
General Discussion.

In the entomological experimental patch there is an
average of eighty-eight canes per plot. In the horti-
cultural "50" patch this average is a little lower, as
there are approximately seventy-six canes per plot. The
east horticultural patch can not be accurately compared
with the experimental patch or the horticultural ”50”
patch as to average number of canes, because the canes
are planted in hills. The average per hill is approx-
imately twenty canes.

The average number of infested canes per plot in the
experimental patch is about thirty-two, in round numbers.
This compares exactly with the average in the horticul-u
tural "50' patch, as it also has thirtybtwo infested canes.
The east horticultural patch has an.average of about six
canes per hill.i '

The experimental patch has an average infestation of
36 per cent. This is not as high as the infestation in the
horticultural ”50' patch, as it has 42 per cent. The low-
est per cent of infestation is in the east horticultural
patch, it being 30 percent. This is peculiar in that the
36 per cent infestation of the experimental patch is equal-
1y distant from the 42 per cent infestation of the horti-
cultural "50" patch and from.the 30 per cent infestation of

(49)

the east horticultural patch.

There is an average of twenty-two broken canes per
plot in the experimental patch. The average for the
horticultural '50 patch is somewhat lower, with nineteen
broken canes. ~The east horticultural patch has an aver-
age of four broken canes per hill.

The experimental patch has an average of about 70
per cent broken canes. The horticultural ”50" patch is
considerably lower in that it has an average breakage of
about 59 per cent. The east horticultural patch compares
more favorably with the experimental patch, as it has an
average of approximately 65 per cent broken.canes.

The raspberry canes in Sub I are from the entomolo-
gical experimental patch. Seventy-eight beetles were
taken from the raspberry canes in Sub I. Of these seventy-
eight only fourteen of them.were:A. ruficollis. The other
sixty-four were A, communis. This was verified by send-
ing several specimens to washington.D. 0. They were des-
cribed as Agrilus communig ab. rubicola Abeille de Perrin,

 

by W. S. Fisher, Associate Entomologist in the Bureau of
Entomology at Washington D. C. No parasites emerged from
this material.

Hose canes in Sub II are from the Botanical Gardens.

Thirteen beetles were taken from the rose canes in Sub II.

(50)

These were all A. communis. No parasites emerged from
this material, either.

Sub III contains raspberry canes from the east
horticultural patch. Eighteen specimens emerged from
this material. Of these eighteen beetles, four were A.
ruficollis and the remaining fourteen were A. communis.
Two parasites emerged from this material. They were
Braconids.

Raspberry canes from the horticultural "50" patch
were put in Sub 17. tour A. communis and two A. 21;;-
colAAs emerged. No parasites were found.

Wild blackberry canes from along the railroad track
by the experimental patch, were put in Sub 7. Thirty-
three beetles emerged and they were all A. ruficollis.
Not a single specimen of A. communis was found. A. commun-
is has not been bred from black berry canes, as yet. No
parasites emerged.

About sixty beetles were found dead in the canes.
Some had their heads sticking part way out of the exit
hole, while others had no head at all. The specimens all
crumbled up when touched. Either the bedes were too
weak to burrow their way entirely out of the thicker canes,
or there is some disease that kills them off.

The per cent of emergence in Sub I is approximately
32 per cent. In Sub II it is 19 per cent. Sub III has a

(51)

19 per cent emergence also. In Sub IV it is only 7 per
cent. Sub V has a low per cent, it being about 10.

There is a considerable variation in the distance
from the exit hole to the gall. Sub I has an average
distance of 82.5mm. Sub II averages 30mm. Sub III has
an average of 113.6mm. The average for Sub IV is 66.7mm.
The average is 52.6mm. for Sub V. Adding the averages
of Subs I, III, and IV gives an average of 87.6mm. for
all the raspberry material. In the raspberry material of
Sub I the average distance from the exit hole to the gall
is very close to the average of Subs I, III, and IV.

.neasurements were taken on the actual length of some
of the tunnels. The average for Sub I is 91.7mm., for
Sub II it is 35.3mm., for Sub III it is 124mm., for Sub
IV 1'. is 70.6mm., and for Sub 7 it is 64.6mm. The averages
of Subs I, III, and IV average 95.4mm. for the length of
the tunnels in all the raspberry material. Again, the
average of Sub I is very near the average of Subs I, III,
and IV. '

Some of the beetles turned around and tunneled back
down the pith before emerging. Both species of Agrilus
did this. When they emerged, after coming back down the
pith, they did it upside down. Not only were the flat or
short diameters on the bottom part of the exit holes, but

some of the beetles were actually observed upside down.

(52).

This was done by splitting a.few canes open that had
beetles all read to emerge. In the material in Sub I

the average distance down is 16.4mm. In Sub II it is
10.6mm. Sub III has an.average distance of 52.1mm.

for the highest average. Sub IV averages 11.8mm. The
average is 28.8mm. in Sub V. Subs I, III, and IV average
26.8mm. for all the raspberry material gathered.

Two averages were taken on the size of the exit
holes. They were the long and short diameter measure-
ments. The material in Sub I has a long diameter average
of 2mm. and a short on of 1.5mm. The diameter averages
are the same for the material in Subs II and III, as the
long diameters average 1.9mm. and the short ones average
1.5mm. The largest average diameter, both long and short,
is found in the material of Sub IV. This-is 2.1mm. for
the average long diameter and 1.6mm. for the average
short diameter. Sub V has an.average of 2mm. for the
long diameter and 1.5 for the short one. These figures
are the same as those found in Sub I.

There is an apparently larger infestation of rasp-
berries by A. conununis than by A. ruficolAis. This is
shown by the emergence records of Subs I, III, and IV.

In Sub I the rate of emergence of A. communis to A. £111;-
collis is 4.6 to 1. In Sub III it is 3.5 to 1. Sub IV

has a rate of 2 to 1. The average rate of emergence of

(.53)

the three batches of material is 3.4 to 1.

SUMMARY.

1. A. communis infests Michigan raspberries as does A.
ruficoIAis. In feet A. communis is more prevalent on
raspberries. .The ratio, as determined by three patches
around East Lansing, is 3.4 to 1. A

2. The total infestation of Michigan raspberry patches
may run anywhere from 30 to 42 per cent.

3. More than half of the infested canes break off. The
per cent varies anywhere from 59 to 70.

4. There may be some disease that kills the adults as
they are about to emerge. Many dead beetles were found
in the canes. The thickness of the canes may prevent some

of the beetles from emerging, however.

5. The per cent of emergence of both Agrilus species from

raspberry canes varies anywhere from 7 to 32 per cent.

(54)
From rose canes it is about 19 per cent, as determined
by rose material taken from the Botanical Gardens. It
is about 10 per cent for wild blackberry canes taken
from around the entomological experimental patch. Two
parasites emerged from hell Jar Sub III.
6. The average distance of the exit hole from the gall is
87.6mm. in the raspberry material. It is 30mm in the rose
material and 52.6mm. in the wild blackberry material.
7. The average length of the tunnel in the raspberry
material is 95.4mm. In the rose it is 35.3mm. and in the
wild blackberry it is64.6mm.
8. Both A. ruficollis and A. communis may turn around
in the pith of the cane and tunnel a short distance down-
ward before emerging. The average length of this tunnel
is 26.8mm. in the raspberry, 10.6mm. in the rose, and
28.8mm. in the wild blackberry. ‘When a beetle tunnels
down the cane it emerges upside down.
9. The long and short diameters of the exit holes vary
but a little bit. The average long diameter of the exit
hole in raspberry canes is 2mm. and the average short
diameter is 1.5mm. The average long diameter in the rose
canes is 1.9mm. and the short one is 1.5mm. The average
diameters in the wild blackberry canes are 2mm. and 1.5mm.,

respectively.

(55)

10. A. ruficollis seldom infests rose bushes.
11. A. communis does not appear to infest wild blackberry

canes.

 

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