L‘AL ““‘LJAA AA‘A - EVALUATEQN OF METH CD 9' GE CHEMMAL CQE‘éTfiC-L OF THE CEREAL LEAF BEETLE (@ULEMfi MELANCE’US, L.) WtTH MEEEE’CT TO AN [HTEGEATED ELAN must-s for “to Dwm (if M. 5. MECHEGM STATE UNIVERSE” Marcus Tully Weils, 31'. £967 THESIS LIBRARY Michigan State University - ‘-D~»-dDF~O‘OM-—-fi ‘ ABSTRACT EVALUATION OF METHODS OF CHEMICAL CONTROL OF THE CEREAL LEAF BEETLE (Oulema melanopus, L.) WITH RESPECT TO AN INTEGRATED PLAN By Marcus Tully Wells, Jr. In the spring of 1966, chemical control techniques, with respect to an integrated plan, suitable to reduce and maintain the cereal leaf beetle at a non—economic level were evaluated. Also four insecticides (malathion, Baygon, lindane, dieldrin) were tested to determine their relative effectiveness and to evaluate their potential for the possible use in an integrated control program. Winter wheat fields were selected in a given area of heavy beetle infestation and treated with four known cereal leaf beetle insecticides. This was done early in the spring after the emergence of overwintering adults, but before many eggs had been laid. By treating the fields when the majority of beetles were in the wheat, it was possible to effectively reduce the egg laying population. The premise was that spring grain fields may not need treatments if the beetle is eliminated in the winter grain fields. An experiment was also conducted to evaluate the effectiveness of a single suppression spray of malathion as compared to an eradica— tion oriented application of four malathion treatments. The four Marcus Tully Wells, Jr. treatments in the eradication area allowed a significantly higher suppression of cereal leaf beetles, but beneficial predators and associated insects were kept at a much lower level after four sprays than after a single application. EVALUATION OF METHODS OF CHEMICAL CONTROL OF THE CEREAL LEAF BEETLE (Oulema melanopus, L.) WITH RESPECT TO AN INTEGRATED PLAN By Marcus Tully Wells, Jr. A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Entomology 1967 / }/l M a ’0 ”3’3” ACKNOWLEDGEMENTS I wish to express my deepest appreciation to Dr. Gordon E. Guyer, Chairman of the Department of Entomology, for making this study possible, for his constant encouragement and for serving on my guidance committee. Special thanks are expressed to the author's major advisor, Dr. Dean L. Haynes, for his constant encouragement, suggestions and criticisms. Sincere appreciation is also extended to Dr. Orlo K. Jantz for his untiring help, guidance and enthusiasm throughout the period of study, and to Mr. Richard V. Connin, Dr. Frederick W. Stehr and Dr. Everett H. Everson for valuable suggestions and criticism of the manuscript. Finally I am greatly indebted to my wife, Linda, for her continually encouraging attitude and enthusiasm throughout the period of investigation. ii TABLE OF CONTENTS Page INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1 LITERATURE REVIEW . . . . . . . . . . . . . . . . . . . . . . . 3 METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . l4 Experiment I . . . . . . . . . . . . . . . . . . . . . . . l4 Experiment II . . . . . . . . . . . . . . . . . . . . . . 18 Experiment III . . . . . . . . . . . . . . . . . . . . . . 22 Experiment IV . . . . . . . . . . . . . . . . . . . . . . 23 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Experiment I . . . . . . . . . . . . . . . . . . . . . . . 27 Experiment II . . . . . . . . . . . . . . . . . . . . . . 32 Experiment III . . . . . . . . . . . . . . . . . . . . . . 39 Experiment IV . . . . . . . . . . . . . . . . . . . . . . 40 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Experiment I . . . . . . . . . . . . . . . . . . . . . . . 44 Experiment II . . . . . . . . . . . . . . . . . . . . . . 45 Experiment III . . . . . . . . . . . . . . . . . . . . . . 46 Experiment IV . . . . . . . . . . . . . . . . . . . . . . 47 SUMMARY AND CONCLUSION . . . . . . . . . . . . . . . . . . . . . 48 LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . . . 51 iii LIST OF TABLES Table Page 1. Time of day, temperature, moisture and wind con— ditions for aerial spray applications of selected winter—grain fields in Berrien County, Michigan — 1966 . . . . . . . . . . . . . . . . . . . . . . . . . l9 2. Dosage, acres sprayed and application rates of four insecticides applied to selected winter—grain fields in Berrien County, Michigan . . . . . . . . . . 20 3. Ground applied insecticide rates, dates, dosages, and weather conditions for two fields treated with four insecticides near Galien, Michigan - 1966 . . . . . . . 22 4. Total number of cereal leaf beetles and associated insects in winter wheat, air sprayed with four insecticides near Galien, Michigan - 1966 . . . . . . . 28 5. Mean number of insects per 100 sweeps from fields air sprayed with four materials one day after treatment near Galien, Michigan - 1966 . . . . . . . . 29 6. Percent reduction of four insects associated with the cereal leaf beetle in winter wheat fields treated with four insecticides near Galien, Michigan - 1966 . . . . . . . . . . . . . . . . . . . . 31 7. Individual treatment effectiveness of application methods of four insecticides on the adult and larval cereal leaf beetle in winter wheat near Galien, Michigan - 1966 . . . . . . . . . . . . . . . . 33 8. Mean number of cereal leaf beetles from six fields treated with four insecticides in a paired plot design near Galien, Michigan - 1966 . . . . . . . . . . 34 9. Mean number of insects from evaluation fields treated with four insecticides indicating overall differences in treatment effects near Galien, Michigan - 1966 . . . 35 iv LIST OF TABLES—-Continued Table Page 10. Overall and individual treatment effectiveness of application methods of four insecticides on the associated insects of the cereal leaf beetle in winter wheat near Galien, Michigan - 1966 . . . . . . . 37 11. Total number of cereal leaf beetle eggs and larvae occurring in oats fields in treated and untreated areas - 1966 . . . . . . . . . . . . . . . . . . . . . 39 12. Mean number of insects per 1000 sweeps from wheat fields in an eradication spray area and a blanket spray area - 1966 . . . . . . . . . . . . . . . 42 13. Mean number of insects per 1000 sweeps from oats fields in an eradication spray area and a blanket suppression spray area - 1966 . . . . . . . . . 43 Figure LIST OF FIGURES Areas infested with the cereal leaf beetle in Michigan, Indiana and Ohio in 1963 Areas infested with the cereal leaf beetle in Michigan, Ohio, Indiana, Illinois and Pennsylvania in 1967 Location of experiment 1 study fields in Weesaw and Galien TWps. (Berrien Co., Michigan) . Weather chart showing precipitation, maximum and minimum temperatures at two-day intervals recorded at Eau Clare Station (January to July, 1966) Arrangement of insecticide applications in experiment 2 study fields near Galien, Michigan Location of experiment 4 study fields in Fillmore and Overisel TWps. (Allegan Co., Michigan). . . . . . . . . Log mean number of adult and larval cereal leaf beetles showing differences between single application and four applications of malathion vi Page 16 17 21 25 41 INTRODUCTION The cereal leaf beetle, Oulema melanopus (Linnaeus), is a significant pest of cereal crops in the Old World. Damage was recorded by Reaumur as early as 1737 (Kadocsa, undated). In the United States the beetle was first identified in Berrien County, Michigan in 1962 and control operations were begun by Ruppel and Wilson (1964). Feeding by adults and larvae cause damage to cereal crops. Oats are favored as a host over wheat, barley or rye (Janes and Ruppel, 1964). Since 1959 the beetle population has greatly increased and has infested large areas of spring grains. Surveys by the Plant Pest Con- trol Division of the United States Department of Agriculture indicate that the cereal leaf beetle spread from Berrien County, Michigan in 1962 to 225 counties in Michigan, Indiana, Ohio, Illinois and Pennsyl- vania in 1967 (Mbore, personal communication). However, severe damage has occurred only in southwestern Michigan and northwestern Indiana. Castro (1965) suggests that the rapid increase in population may be caused by the similarities in climatic conditions in the Great Lakes area and areas in eastern Europe that contain cereal leaf beetles in pest proportions, and that this U.S. location lacks the beetles' natural parasites and predators. Insecticide control was initiated in 1962 to check the infesta- tion of_Q. melanopus into new areas. Through the application of l 2 insecticides, the spread of the beetle to other grain producing areas has been slowed (USDA, 1963). The U.S. Department of Agriculture and involved states have developed cooperative control programs to suppress the pest. In 1966 alone spray programs in four states resulted in the application of low volume malathion to 1,616,807 acres. Suppressive spray programs in 1967 were reduced within the quarantine area and limited to areas on the perimeter of the quarantine zone. Several cooperating midwest universities are developing control methods in- volving natural enemies and plant resistance (USDA, 1966). This study is part of a cereal leaf beetle investigation pro— ject being carried on cooperatively between the Entomology Research Division, Agriculture Research Service, USDA and the Michigan State University Department of Entomology. The purpose was to investigate chemical control techniques suitable to reduce and maintain the cereal leaf beetle at a non—economic level and to observe the effects on the beetle and certain associated insects. By using insecticides specifically designed for the cereal leaf beetle, and applying them while the adult beetle is concentrated in winter wheat it may be possible to develop a practical method of control directed at the spring adult. LITERATURE REVIEW The cereal leaf beetle adult usually emerges from diapause and engages in active feeding by the first week of April (Castro, 1965). The spring adults feed, mate and begin to oviposit on available winter grains. As soon as spring planted grains germinate, the beetles begin to appear on this newer growth. Castro (1965) reported the heaviest feeding and egg laying on spring grains. Eggs hatch in four to 23 days depending on the temperature (Knechtel and Manolache, 1936). In three weeks the larvae feed heavily on plant leaves and pass through four instars; the last becoming the prepupae. Pupation in the soil takes one to three weeks depending on temperature and humidity (Castro, 1965; Yun, unpublished data). The newly Emerged summer adults feed for about two weeks on grain, grass and corn leaves before going into a quiescent period or diapause until the following spring (Balachowsky and Mesnil, 1935; Castro, 1965; Hodson, 1929; Kadocsa, undated; Masnil, 1931; venturi, 1942). Castro and Venturi have outlined complete diagnostic character- istics for all stages of the cereal leaf beetle and should be con- sulted for specific information (Castro, 1965; Venturi, 1942). Since 1831 the cereal leaf beetle has caused serious periodic damage in certain parts of Europe, in particular the interior grain areas of Hungary (Kadocsa, 1916). However, the cereal leaf beetle is found throughout Europe, extending from north Africa to Norway and 3 4 England to Siberia. In the Mediterranean basin the beetle causes little if any significant crop reduction (Venturi, 1942). Population buildup and damage has been sporadic since the 1880's, buildups occurring every several years with an eventual gradual tapering off. Kadocsa (undated) suggested this phenomenon may be due in part to adverse climatic factors reducing the numbers of natural enemies for a number of years, and then eventually attaining a gradual recovery. It is not known exactly how the cereal leaf beetle arrived in the United States, although beetles were discovered in cargos at ports of entry in New Jersey and Detroit in 1961 (USDA, 1962). In 1962 the insect was positively identified by specialists of the U. S. Department of Agriculture and became recognized as a cereal crop pest in the United States. A cooperative survey between the Michigan Department of Agriculture, Entomology Department of Michigan State University and the Plant Pest Control Division, Agriculture Research Service, USDA, showed that parts of southwestern Michigan and northern Indiana were infested with cereal leaf beetles in 1962 (Figure l; USDA, 1963). Between 1962 and 1967 the beetle population has increased enormously. Shade and Wilson (1964) indicated a ten—fold increase in infestation of an area in northern Indiana between 1962 and 1963, and showed that infestations fit a calculated wind-rose so closely as to suggest that wind may be a major dispersion-influencing factor. The winds prevailed in a northeasterly direction during the major flight season. The beetle has continued to move to the north, east and south of the initial infestation in Berrien County, Michigan. It has pro- ceeded to infest the majority of Michigan and Indiana, and portions of MICHIGAN -—- —o_o—-—-—o—o—’—- —- — ' II. Ild. .fll‘.|llu . _ _ .. .(liJr A“UV _ .I.I.I.IJ... )(xi... _ .J .\ nl‘l‘la Q \ . x . . . .r " OJ. . ‘1 "L I OHIO , . . . an... 53.... Tu. po-o—n— all no“ ,u, 4' mE‘Efi’éi-» \ h.» I an. . unit. 172. A». . 3., v... . 3 .. k f’""'”'| 1 h— c—.—-o- J INDIANA -.l"' f L-.- ‘-—'-a —.j leaf beetle in fasted with the cereal In Michigan, Indiana and Ohio in I963. Fig. I.--Araas 6 Illinois, Ohio and Pennsylvania. In 1967 it was reported to be within miles of the Kentucky border. The heaviest infested areas and areas threatened with significant damage problems are located, in the south— west and northern portions of Michigan and Indiana, respectively. Figure 2 indicates the entire area, as of September, 1967, of infesta- tion for the cereal leaf beetle; a total of 68,759,040 acres, including 225 counties in five states (Mbore, personal communications). The cereal leaf beetle has encountered little environmental resistance in the United States. It has virtually no natural para- sites and few predators in this country. This, along with a suitable climate and ample food supply, is probably why the beetle has increased in number and spread so rapidly. The steady spread and the threat of substantial economic loses to small grains has necessitated some con- trol measures. The first record of chemical control was in 1831, when a Hungarian suggested soaking the grain seeds in water containing several handfuls of garlic for 24 hours; the results indicated little control (Kadocsa, undated). Early attempts to control the pest led to the development of several tobacco extracts and nicotine combinations. Tharton, a nicotine extract, proved successful but expensive in Hungary (Kadocsa, 1916), and nicotine sulphate gave varying control in the Soviet Union (Vassiliev, 1913); nicotine however, was used to no avail in Spain (Urquijo, 1940). Tobacco extracts combined with Pyrethrum were noted as effective in France (Mesnil, 1931). Pyrethrum alone was ineffective in Hungary, but effective in England 30 years later (Hodson, 1929; Kadocsa, 1916). Fig.2." Areas infested with the cereal leaf beetle in Michigan. Indiana, Ohio, Illinois and Pennsylvania in I967. 8 Inorganic compounds produced little control and proved awkward, troublesome and expensive to apply (Balachowsky and Mesnil, 1935; Kadocsa, 1916; Vassiliev, 1913; Venturi, 1942), the exception being lead arsenate which was reported to be an effective control agent (Urquijo, 1940). In 1963, Yun and Ruppel (1965) at Michigan State University, began a program of laboratory screening of organic insecticides known to be effective on other insedt pests and chrysomelids. Several of the more promising chemicals including carbaryl, malathion, Guthion (0,0-dimethyl-Sf(4—oxo-1,2,3,—benzotriazinyl-3—methyl) phosphoro— dithioate) and Baygon (gfisopropoxy phenol methylcarbamate) were later field tested against the cereal leaf beetle by aerial application in southwestern Michigan (Ruppel and Wilson, 1964). In their work carbaryl was found more effective against adults than malathion, while Guthion was highly effective as a larvacide. In 1964 Ruppel and Yun (1965) field tested carbaryl, dieldrin, endrin, Guthion, lindane and malathion by ground application and reported that all gave good control except malathion (Ruppel and Yun, 1965). Biological tests showed malathion to have an immediate kill with a short two to three day residual effectiveness (Ruppel and Wilson, 1964; Wilson, Ruppel and Treece, 1965). Yun (1964) also found that malathion was not as toxic to several insects associated with the cereal leaf beetle as other materials tested. On the basis of these results malathion was registered in 1962 and has been the most popular insecticide for the control of the cereal leaf beetle for the past four years. In 1966, 1,616,807 infested acres in Michigan, Illinois 9 and Indiana were treated with low volume malathion under the coopera- tive control program of the states involved and the Plant Pest Control Division, U. S. Department of Agriculture (Janes and Ruppel, 1964; USDA, 1966). Frequently, chemical control alone can be more detrimental than beneficial in controlling a pest species. In Canada, as a precautionary measure, apple orchards were often sprayed before pests appeared. The chemical used removed parasites and predators of the pest as well as the pest itself. By selecting a pesticide and dosage that spared the pest's natural enemies, and treating only severe outbreaks, insecticide costs were lowered and crop yield was as good or better than before (Pickett,_g£_§l,, 1946; Pickett and Patterson, 1953). Side effects often follow the use of many pesticides, such as residue problems, resistant pest populations and the destruCtion of natural enemies of the pest controlled and of other pests (Briggs, 1965; Smith and Hagen, 1959). Almost every example of strict chemical control has shown a harmful influence of the chemical on the ecosystem and resulted in inadequate results that are temporary and uneconomical (Hagen and Smith, 1958). Chemical control agents can be responsible for the destruction of environmental resistance which often results in increases in pest numbers (DeBach, 1964). Insecticides should be fitted into an ecosystem, not imposed upon it (Laird, 1963; Stern, e£_al:, 1959). Through effectively applying and integrating ecological concepts and methods to the problems of economic entomology, alternative and complementary methods of chemical control are being developed for use on insect pest problems (Pickett, 35,313, 1946; Smith and Hagen, 1959). 10 Few control methods involving only chemical or only biological factors alone have been able to adequately subdue pest species (Wigglesworth, 1965). All suitable methods of pest population reduction must be con- sidered and integrated into a functional control approach (Pickett, 1959; van Emden and Wearing, 1965). Kennedy (1965) suggests that the idea of integrated control should consider such factors as plant cul— ture, cultivation, resistance and breeding and should look at the pos— sibilities of manipulating the delicate ecosystem. Briggs (1965) stated that these approaches have probably been overlooked because we lack the essential information on how the ecosystem itself is integrated. The ecological, physiological and systematic relationships of the fauna must be understood, but cannot be applied without a working knowledge of the principles that underlie the fluctuations in the populations concerned (Glen, 1954; Stern £5 31., 1959). For instance, methods utilizing parasites, predators, or pathogens to control pest species (biological control) cannot be devised without at least basic information on the ecosystems involved (Pickett, 1959). Thus the main approach to the successful control of pest populations must include the interaction or integration of every feasible control method available (Chant, 1966). Natural control of the cereal leaf beetle must occur in Europe since the population increase is limited and more or less stabilized by environmental factors. When introduced insects meet a favorable climate in the absence of their natural enemies they often increase in numbers to pest proportions (DeBach, 1958). One of the best means of modifying the environment to lower a pest's population permanently is 11 through the use of its natural enemies (DeBach, 1964; Turnbull and Chant, 1961). Several parasites and predators of_0._melanopus are known to exist in Europe (Hilterhaus, 1966). As of May, 1967, 16 parasites and one predator that directly and/or indirectly affect the pest have been reported to occur in Europe (Sailer, unpublished report). Since 1963, research programs have investigated the feasibility of using the cereal leaf beetle's natural enemies in biological control in the United States (USDA, 1966). Laboratories in France, Yugoslavia and Poland find, investigate and send the potentially useful natural enemies to the U. S. for further study or release in infested areas. Presently, research programs are underway at Michigan State University, Ohio State University, Purdue University and the Univer— sity of Wisconsin to investigate all aspects of the cereal leaf beetle. In addition, a laboratory in Niles, Michigan organized by the Plant Pest Control Division, Agriculture Research Service, USDA, has initiated a program to mass produce and distribute cereal leaf beetle parasites. To date the parasite, Anaphes flavipes Foerster, is the only one that has been produced and released in large numbers. In 1967, an egg parasite, Trichogramma minutum Riley, was re- corded from cereal leaf beetle eggs in Berrien County, Michigan. In- vestigations are presently being carried out at Niles, Michigan on the general biology of this parasite (Stehr, personal communication). Also in 1967, 20,000 cereal leaf beetle larvae collected from Michigan fields were examined in a continuous survey for natural parasites; however, no parasites were found. The most recently discovered 12 parasite, Hylalomyodes triangulifera Loew., parasitizes the summer adult beetle. Parasitized beetles have been found in Berrien County, Michigan. Studies are being conducted at Michigan State University concerning the nature of the insect's relationship to the cereal leaf beetle (Wellso, personal communication). One native predator, the spotted lady beetle, Coleomegilla maculata lengi Timberlake, has been found in Michigan (Castro, 1965). It overwinters as an adult appearing in the field at approximately the same time as the cereal leaf beetle. Coleomegilla maculata is normally an aphid and pollen feeder, but has been reported to cause ten to fifty percent mortality in cereal leaf beetle eggs (Castro, 1965). The spotted lady beetle will readily feed on 9: melanopus eggs until the aphid population builds up later in the season. Other Coccinellidae observed in the field but not known to be predaceous on cereal leaf beetles are: Coccinella 9-notata Herbst, Hippodamia l3—punctata tibialis Say and Hippodamia convergens Guerin (Castro, 1964). Castro (1964) considered the spotted lady beetle to be the only predator important in cereal leaf beetle population reduction. Malathion is highly toxic to the spotted lady beetle (Harris and VOlcarce, 1955; Yun and Ruppel, 1964), while endrin and Baygon are slightly to moderately toxic (Campbell and Hutchins, 1953; Harris and volcarce, 1955; Yun and Ruppel, 1964). All of the above investi- gators agree that dieldrin in only slightly toxic to C: maculata. Bartlett (1963) tested insecticides on six coccinellids, but did not include the spotted lady beetle. His results showed that malathion was highly toxic to all six species, Recent work by Yun and Ruppel 13 (1964) agrees with Bartlett that dieldrin, endrin and lindane were slightly or non-toxic to the coccinellides tested. All the previous authors that have tested insecticides on E: maculata are in agreement that the chlorinated hydrocarbons were the least toxic. METHODS This study was initiated in 1966 to investigate the use of chemicals in an integrated control program. The main objective was to find the most effective material and method of exposing the cereal leaf beetle population to the toxic effects and still minimize con- tamination of the environment. The three controllable parameters were type of insecticide, timing and localization of treatment. By the first week of April the cereal leaf beetle emerges from overwintering sites and feeds primarily on winter-grains which are much more abundant than wild grasses. Castro (1965) has shown that more than ninety percent of the beetle population will infest winter grains before any desirable spring grains germinate, and that less than one percent of the eggs are laid by early April. In view of these facts it would appear possible to control the cereal leaf beetle by treating only those winter grain fields that are heavily infested by spring adults at this time. The premise is that spring grain fields may not need treatments if the beetle is eliminated in the winter grain fields. Experiment I Malathion, Baygon, lindane and dieldrin were selected based on studies of a large number of materials tested against the cereal leaf beetle in 1963 and 1964 (Ruppel and Yun, 1965; Ruppel and Wilson, 1964; Wilson, Ruppel and Treece, 1965; Yun and Ruppel, 1965). These 14 15 investigators reported good control of the pest with each of the four materials, and varying effects on other associated insects. Beetle migration to and from winter grain fields minimize its exposure to the insecticides and timing of the treatment becomes an important factor in addition to the residual effectiveness of a material. A material such as malathion controls the pest effectively for two or three days but provides no control of beetles migrating later into the winter grain fields. This exposes only a small portion of the population to the material. On the other hand a more persistent insecticide like dieldrin may have more lasting effects to the beetle and to other sus- ceptable organisms (Chant, 1966). Yun and Ruppel (1965) found Baygon and lindane to have about a ten day residual effect which is inter- mediate between malathion and dieldrin. The treatment area was located in four sections of Galien Township and the adjoining four sections of Weesaw Township, Berrien County, Michigan (Figure 3). Area selection was based on 1965 survey results indicating a high number of overwintering adult beetles in the Galien area (Gomulinski, unpublished data). Every fall-planted small- grain field within the area was treated. The forty-four fields ranged in size from three-fourths to forty—nine acres. The residue problem with dieldrin, lindane and Baygon prevented their use near dairy farms so these fields were treated with malathion. The remaining fields were randomly assigned one of the four insecticides. Above normal precipitation in April (Figure 4) prevented ground application so materials were applied by air. A Piper Pawnee spray plane calibrated for a swath thirty-five feet wide at an altitude of 4:322: .60 cotton. .3: 5:2. 9.; 333; E 2:»: :22” _.=oECoa.o 2 3233.273... 5.32:. ll :33: n .33; I 2:53; a (BF IU.J(G DIVIIAIIG .t’h ’(OUI’ NV $0 ['0 NI NOI1V1I4I33ld HDNI 32.1.32...egfizce...” 8.5 :3 I 3333 22:35 39.2.: .5 2:33:53 225...... u..- E:E...E £33233; 2:33: :23 3533--...2. .07 ._ a Wax“. u. :¢e( p 108(2 . . r... 1: 1:41 a _ _ _ ___ _ _ ___ __ ___ _ ___ o u _ "___ u u". 2... _ ___ n n _ _ _ ._ _ _ _ _ m u: _ “u _ n H" u .2 _ n __ _ _ __ u _ _ _ n _ h u _ A _ _ _ N. J _ _ _ u n n n n n a u u n u _ _ you n _ _I n 0.1 n n u M u “ _ non H m _ _ N. v.1 u a n m _ I h .2 .. _ I l m _ N n n _ Ton m _ _ _ 9 _ _ _ I _ _ _ I. _ _ 3 fl _ “ I00 5 . _ u _ H _ ton n u N _ H _ H _ Ion I. _ s. . " .:al " _ 100 . n o... H _ :— Ir 3. 100— 18 three to thirty feet was used to treat all fields in this experiment. The optimum spray date was April 15, but atmospheric conditions pre— vented treatments until May 2. Eggs were abundant at this time in the winter grains and beetles could be found in oat fields. Two hundred and sixty-five acres were sprayed on May 2 and the remaining one hundred and sixty—eight acres were treated on May 4. Time of day, temperature and wind conditions for the two spray dates are indicated in Table 1 while the dosages used are given in Table 2. An unsprayed check area was established for comparative pur— poses. This area, approximately one mile from the nearest treated field, contained twenty-two winter grain fields in an area of similar size (two miles by four miles) and beetle density. Samples were obtained using a standard 15 inch sweep net. Pre—treatment samples of 200 sweeps per field were taken on April 26. Post-spray samples were taken on May 5, May 24, June 2 and June 6, and consisted of 500 sweeps in each treated field. Samples in the check area consisting of 100 sweeps were taken on May 20, May 26 and June 7 in each of the twenty-two fields. Each field sample was placed in seventy percent ethyl alcohol, labelled and stored for analysis at a later date. Experiment II Malathion, Baygon, lindane and dieldrin were applied in a paired plot design in six fields (Figure 5). Application was made with ground equipment to two fields, and by air in four fields. The purpose of the experiment was to compare the effectiveness of the chemicals and methods of application. l9 asae has ommlam tango nae «Hue um canvases .a.« co Hanoo ca max 0 mama um: oomlms “mmao nae OHIA m coagumamz .a.m om mumm w an: m aEmU umB omalwm Hmmao 3&8 «:0 m Gowhmm .E.m oouwloauo mm: a mac has oooumm “mane nae Calm 3m-m cowmmm .e.m om Hauom ca an: m mama “as omm-ms ummao nae mum mm memecaa .s.m ooon- mum an: N mama ems omenme umuao nae o-q mm-m mameaaa .a.m maum-no N am: H mucmam Hwom .mEmH mxm huwoon> coHuomHHQ Hmfiumumz mEHH mumo wmoq whdumwoz @GHZ coma I amwfinofiz .muaaoo cowuuom a“ mpHon afimuwiuauaws wouomaom mo mewmwuam Hmwuom mom mcoHuwnaoo paw3 pan manomwoa .ouaumumaamu .mmp mo meHuI.H mgmwuo< .No pmuooaom ou wmflammm cmwwsowz .huasou cowuuom aw mvamfim :HmuwiumoaH3 mmpfiowuommcw know mo mmumu COwumoHHmam 6cm vohmuam mmuom .mwmmonii.m mqm<¢mm OZDO¢0 23.0.5.6 20.1h<4<¢am ¢_< 22 Each insecticide was randomly selected for one of the strips. These fields were located in the same area as those in experiment I. The air applications were also of the same dosages and applied on the same dates (May 2 and 4) as the first experiment (Table 2). Ground applications were made on May 4 and 5, with a John Bean sprayer cali- brated at 4.55 gallons per acre. Dosages, weather and application rates are shown in Table 3. TABLE 3.--Ground applied insecticide rates, dates, dosages, and weather conditions for two fields treated with four insecticides near Galien, Michigan — 1966' Oz. Active Wind Spray Ingredient Oz./ Material Date /Gal H20 Acre Temp. Direct. Veloc. Malathion 5 May 24 E.C.1 16 670 F SW .10-12mph Baygon 4 May 24 E.C. 6 590 S 8-12 Lindane 4 May 24 E. c. 3 55° 3 5-6 Dieldrin 5 May 24 E.C. 4 60° SW 0-1 1Emulsifiable concentrate Pre—spray samples of 200 sweeps per field were taken on April 26. Post-treatment samples of 500 sweeps per strip were taken on May 20, 23, 26 and June 2. Experiment III If a major portion of spring adult cereal leaf beetles could be eliminated early in the spring while concentrated in winter grains, then the pest's threat to oats, planted later in the season, would be lessened. This experiment represents a comparison of two groups of 23 oats fields; one group (14 fields), located within an area where all winter-grain fields were treated for beetles in the first week of May, and a second group (15 fields) located in an area where no control measures had been taken. Since winter—grains in the unsprayed area were not treated, oats fields in this area were susceptable to the pests migration from both outside areas and from beetles in the winter-grains. Oats in the treated area would only be threatened by those beetles that were not stopped in the treated winter-grain fields. Accordingly, if the number of beetles in winter-grain of the treated area were signifi- cantly changed by insecticides, then the number of beetles eventually appearing in oats in the sprayed area should have changed in comparison to those in oats fields in the untreated area. Counts were made in oats fields on June 17, in both test and unsprayed areas. Eggs and second to fourth instar larvae were preva- lent in most of the fields. A random sample of twenty stems was col- lected from the central portion of each field, and the number of un- hatched cereal leaf beetle eggs and larvae were totaled and recorded as live units. Experiment IV Low-volume technical malathion has been shown to be a_practical method for suppression and control of cereal leaf beetle (Wilson, Ruppel and Treece, 1965). These investigators indicate that this treatment is highly effective against spring adults and should be equally effective against the summer adults. Ruppel (unpublished re- port) shows that near eradication of the beetle can be achieved if two 24 or more stages of the pest are controlled. Previous studies in Indiana have been conducted on the effectiveness of insecticides for suppression and also on block eradication trials (Ruppel and Wilson, 1964). In 1966 an experiment was carried out by the Plant Pest Control Division, USDA, to evaluate the feasibility of achieving an eradication of the cereal leaf beetle through the use of a properly timed insecti- cide applied for adult beetles. A sixteen square mile area was chosen in Fillmore Township in Allegan County, Michigan for the eradication experiment (Figure 6). This area was located near two natural barriers; Lake Michigan to the west and Allegan Forest to the south, and contained a light infesta- tion of cereal leaf beetles. These barriers helped to eliminate migration of the beetle into the test area. Therefore, the evaluation was over an area comparable to one with an isolated infestation where outside infestation was lacking. The Michigan Department of Agriculture also treated several thousand acres to the east and north of the eradication experiment area with a single blanket low-volume (4 ounce per acre) malathion treatment in an attempt to suppress the spread of the beetle from southern Michigan to central and northern Michigan. The eradication experiment area lay within this blanket treatment area. An eight square mile area within this blanket suppression area and about five miles from the eradication site was selected for evaluation and come parison with the eradication experiment. An aerial application of four ounces actual malathion per acre using a flight height of 125 feet was applied on May 4, to the blanket 4.33.35 :3 53.33.33 _eu_e>0 vco 0.08.2“. c. .30: xv...“ v .coECaaxo .0 ca_.0uo._ in.o .m: ‘9 * // » m>oH muafianmnoum Nm onu um uaouomman haucmoamaawwm boa mum umuuoa aoaaoo wcwumcm mammz m .GONumoHHamm mo poaumzm .m .e .N ha: "poaaaam moamBumouHH em.oms “n.0m mm.NA wm.HN .. -- -- -- canaamao am.mma am.amo mm.~a mo.ema -- -- -- -- newsman am.amm em.mom ww.moH mm.aa -- -- -- -- cowxmm am.maoH ao.mmwa wo.¢¢s mo.amm -- -- -- -- coaaumamz mm>umq am.om am.aa mm.oo~ m0.0m no.3Na oo.am mm.ma mo.oa canvases uo.mo uo.- mm.mo~ mo.am nm.¢m ao.~a mm.ms mo.oH assess; um.w~ mo.aa mm.mna mo.ms an.~o no.ao mo.HoH mm.om cowamm mo.mm um.ma mo.mma ao.wm aw.mma ao.oo an.mm mmn.na acaauaamz uaaea muommaH mo Hmnasz can: HH< padouo ua< panouw HH< vasono NHH< pasono Hamfiumumz mash N an: em hm: mm mm: ON ooaa i amwasofl: .amAHmu “no: umms3 paucas aw mauoob mama Hmouoo Hm>una new oaswm ago so mmpwofiuoomcw know no meoguma aofiumoaaaam mo mmmcm>wuoomwm ucmsuwauu Hmawfi>wvaHil.m mam<fi 34 TABLE 8.--Mean number of cereal leaf beetles from six fields treated with four insecticides in a paired plot design near Galien, Michigan - 1966 Cereal Leaf Beetle Date Material Adult Larvae 20 May Malathion 44.83 --1. Baygon 74.33 -— Lindane 33.69 -- Dieldrin 17.67 -- No insecticide 453.20 -- 23 May Malathion 113.17 -- Baygon 64.00 -- Lindane 77.00 -- Dieldrin 90.33 -- No insecticide **2 ** 26 May Malathion 114.67 404.67 Baygon 118.83 94.33 Lindane . ‘ 80.17 113.67 Dieldrin 81.00 55.33 No insecticide 229.30 47.10 2 June Malathion 27.50 1288.17 Baygon 24.50 428.17 Lindane 53.33 533.00 Dieldrin 63.67 319.00 No insecticide 8.10 1806.00 Spray dates: May 2, 4, 5. Dash indicates larval emergence had not occurred by these dates. 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