Studies on the egg parasitoids of lineolaris (P. de B.) (:) in southwestern

by

Philemon Hakainda Sohati

A thesis submitted to the Faculty of Graduate Studies and Hesearch in partial fulfilment of the requi rements for the

degree of Master of Sc i ence

Department of Entomology Macdonald College of McGill University Montreal, Quebec CD July 1989 -...,

::: 6 6 f)H.l~:- /--1 S 1 7"2.' / /~ (\ \. ~ I)} ~ f- {- -< 1 \ ( , i- -/\ r' \ ,,' II ~ 1\

1-<1. t. 1 1'\.) c: 0 f- /+12 (5 ,/' / Î< '/ 0 ') 1\ l l..J \.../-~ ... " / Abstract

M. Sc. Philemon H. Sohati Entomo 1ogy

Studies on the egg parasitoids of Lygus lineolaris (P. de B.) (Hemiptera:Miridae) in southwestern Quebec

Four species of egg parasitoids of Lygus lineolaris (P. de B.) were found in southwestern Quebec in 1987 and 1988. They were Anaphes iole

Girault, frythmelus miridiphagus DOlier, Polynema pratensiphagum Walley and a Telenomus sp. belonging to the T. 1arieis Walker group of species.

The maximum level of parasitism ()f L. lineolaris eggs by these, was 15.4, 53.8, 70.0 and 17.8%, respeclively. The parasitoids were reared from eggs of L. 1ineolans inserted in stems of Amaranthus retroflexus L.,

Chenopodium album L., Coronilla varra l., Rumex obtusifolius L. and

Solanum tuberosum L. Erythmelus miridiphagus and P. pratensiphagum were the most abundant para~itoid species recorded.

Pre-pupae of A. iole were stored for 4, 6, 8, and 10 weeks at 1 and

5°C. There was no significant difference in parasitoid survival between the two temperatures, but there was significant differences among storage times. There was a negative linear relationship between survival and storage of A. iole pre-pupae at both temperatures investigated. Thus sur­ vival of A. Iole pre-pupae tended to decrease with increase in storag~ time. After 10 weeks in storage, the survival rate of pre-pupae of A. iole decreased approximately 50% at 1 and 5°C. The best survival was ob­ tained after 4 weeks of storage at SoC where an average of 82.4 + 10.4%

11 of A. iole pre-pupae emerged. Anaphes iole is more capable of slI,'vivin9

cold tempe ratures , that is 1 and 5°C, as a pre-pupae than as fit'st in­

star 1arvae.

iii Résumé

M. Sc. Philemon H. Sohati Entomologie

EtuJes de parasites des oeufs de Lygus 1ineolaris (P. de B.) (Hemiptera: Miridae) dans le sud-ouest du Québec

Quatre espèces de parasito'des des oeufs de Lygus lineolans (P. de B.) ont été trouvées au sud-ouest du Québec en 1987 et 1988. Ces espèces, Anaphes iole Girault, Erythmelus miridiphagus Dazier, Polynema pratensiphagum Walley ainsi qu'une espèce du genre Telenomus, font partie du groupe d'espèces T. laricis Walker. Le niveau maximum de parasitisme atleint, des oeufs de L. lineolaris, par ces espèces étaient de 15.4,

53.B, 70.0 et 17.B % respectivement. Les parasito'des ont été élévés à partir d oeufs de L. lineolaris, insérés dans des tiges de d'Amaranthus retroflexus l., Chenopodium album l., Coroni11a varia l.,

Rumex obtuSJfolius l. et Solanum tuberosum L. Les espèces Erythmelus mi rid1 phagus et P. pra tens iphagum ont été retrouvées plus abondammen t.

Des pré-pupes d' A. tole ont été entreposées pendant 4, 6, B et 10 semaines à des températures de 1 et 5°C. Aucunfl différence significative s'est dégagée entre le taux de survie du parasito1de et les deux niveaux de temprérature étudiés; par contre, une différence significative a été discernée entre le taux de survie et les durées d entreposage. On a con­ staté une relation 1 inéaire positive entre la survire! et l entreposage des

IV pré-pupes d"A. joIe aux deux niveaux de températm'e choisis. Donc, la survie des pré-pupes d'A. iole a une tendance à diminuer avec ulle aUylllen­ tation du temp5 d"entreposage. Après 10 semaines sous conditions d'entreposage, le taux de survie des pré-pupes d'A. iole a diminué ap­ proximativement de 50 % aux températures de l et SOL le mei lIeur taux de survie fut obtenu après 4 semaines d'entreposage à SoC ou 82.4 -f 10.4

% des pré-pupes, en moyenne, ont émergées. Anaphes iole peut mieux rOI1l­ battre l es basses températures ex. 1 et 5°C, au stade de pré -pupe QU au premier stade l arvai re.

v Suggested Short Title:

Egg parasitoid complex of Lygus 1ineolaris (P. de B.)

Ph il emon Il. Sohat i

V1 Acknowl~dgments

1 wi sh to express my si ncere gratitude to my thes i s superv i sor, Dl'. R. K. Stewart (Macdonald Collge of McGill University, Departmenl of

Entomology), and my co-supervisor, Dr. G. Boivin (Agriculture C=tll

Agriculture Canada, ottawa, , for the identification of Anaphes iole Girault; Dr. M. E. Schauff, Systematic Entomology Laboratory, I\RS­

USDA, Washington, OC, for the identification of Polynema prail~nslpha9um

Walley and frythmelus miridiphagus Dozier; Dr. P. M. Marsh, also of Sys­ tematics Entomology Laboratory; Dr. Norman F. Johnson, Ohio State Unlvpr­ sity, Ohio, for the identification of Telenomus sp. as weil as ln '''r.

Andt'~ Larochelle and Ms. Marie-Claude Lanviere for the identification of mirids. 1 am also indebted to Dr. C. Glen Jackson, Biological Control of Laboratory, USOA-ARS, Tucson, Arizona, for supplying A. ,ole and his help on the rear;ng and handling of the parasitolds. 1 am most grate­ ful to Dr. Walker A. JOlIes for his valuable suggestions on the ovrrwin­ tering strategies of A. iole. Thanks are extended to summer assistants, Messrs. Don Andersen and Robert Paul, for their active participation in field work. 1 am deeply indebted to my beloved and understanding wife, ,Joyc.e, and chil dren, Lweendo and Luyando, for the i r mora l support, enc.ouragem{~nt

vli and prayers which enab1ed me to complete my studies. 1 a1so thank Joyce for her assistance in typing the manuscript. Many thanks to Ms. Mary Curwell, Ms. Theodorine Ryan and the Hart1ey family for their moral sup­ port and source of inspiration and happiness to my family and me while in Canada. 1 am most grateful to a11 members of the Department of Entomo1ogy for their encouragement. Thanks to Mr. Pierre G. Langlois and Mrs. Ann Grainger for their technica1 assistance. Special thanks to Hélène Chias­ son, who kindly translated the abstracto 1 wish to thank the Ste-Clotilde, Agriculture Canada, staff for a1- lowi ng me to conduct part of my field work at the station. Many thanks are extended to the Macdonald College farm staff for their assistance and co-operation in several aspects of my research.

1 would 11 ke to thank the Government of the Republ le of Zambi a for awat-ding me the Canadian Commonwealth Scholarship and Fellowship Plan and for granting me study leave.

Lastly,I give praises and glory to God for taking care of my fami 1 y dnd me throughout my study.

vi ii Tabl e of contents

ABSTRACT ...... ~ ...... ii RÉSUMÉ ...... iv

SHORT TIlLE •...•••••.....•••...••..... ~ • • . . . . • • ...... • ...... vi

ACKNOWLEDGMENTS. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • . . . vii

LIST OF TABLES...... •...... xii LIST OF FIGURES ...... xiii

Chapter

1. General Introduction...... 1 2. Literature Review...... •...... 6 2.1 of A. foIe ...... 7

2.2 Geographical distribution of A. iole...... 9

2.3 Biology of A. iole...... 10

2 • 4 Ho s t s 0 fA. i ole...... 13 2.5 Success as a biological control agent...... 14

2.6 Natural enemies of Lygus spp. other

than A. iole...... 16

2.6.1 Egg paras i toids of Lygus spp. other

than A. iole...... 16

2.6.2 Nymphal parasitoids of Lygus spp...... 16

2.6.3 Parasitoids of Lygus spp. adults...... 19

2.6.4 Predators of Lygus spp...... 20

2.6.5 Pathogens and nematodes of Lygus spp...... 24

ix 2.7 Taxonomy and geographical distribution of L. lineolaris ...... 25 2.8 Biology of L. lineolaris ...... 26 2.8.1 Overwintering of L. lineolaris ...... 26 2.8.2 Life cycle of L. lineolaris ...... 27 2.8.3 Rearing of L. 1ineolaris ...... 30

2.9 Host plants of L. lineo7aris ., ...... 31

2.10 References ...... 33 3. Eg9 parasitoid complex in eggs of Lygus 7ineolaris associated with Coronil1a varia L., Solanum tuberosum l., and associated in southwestern Quebec •••••••••••••• 53

3.1 Introduction ...... 54 3.2 Materials amd Methods ...... 55 3.2.1 Egg parasitoid complex of L. 7ineolaris 55 3.2.2 Seasonal variation of L. lineolaris popul at ion ...... 57 3.2.3 Level of parasitism of L. 7ineo7aris

eggs ...... 58 3.3 Results and Discussion...... 60 3.3.1 Egg parasitoid complex of L. 7ineo7aris 60 3.3.2 Seasonal variation of L. 7ineolaris population...... 61 3.3.3 Level of parasitism of L. 7ineo7aris eggs .. "...... 62 3.4 Potential for biological control...... 66

x 3.5 Conclusion 68

3.6 References 70

3.7 Tables ...... , ..... , ...... 75

3.8 Figures 77

3.9 Connecting text ...... 87 4. The effect of cold temperature and storage on survival of A. joIe pre-pupae in the laboratory •••••••••••...•••••. 88

4.1 Introduction ...... 89 4.2 Materials and Methods ...... 90

4.3 Results and Discussion ...... 91

4.4 Conclusion 93 4.5 References 94

4.6 Tables ...... 95

4.7 Figures • • ...... 97 5. General Discussion and Conclusion ••.•.••••..•••....••.••. 99

xi List of Tables

l able Page

1. Predators of Lygus spp. 20 2. Pathogens and nematodes of Lygus spp ...... 24 3. Percentage parasitism of Lygus lineolaris eggs collected from Amaranthus retroflexus in southwestern Quebec, 1987 75 4. Effect of temperature and duration of storage on the survival of pre-pupae of Anaphes joIe in the laboratory ...... 96

xii Li st of Fi gures figure Page 1. Adults of Anaphes iole Girault (Hymenoptera:Mymaridae) left=Female, Right==Male ...... 77 2. Adults of Polynema pratensiphagum Walley (Hymenoptera:Mymaridae) Left=Female, Right==Male ...... 77 3. Adults of Erythmelus miridiphagus (Hymenoptera:Mymaridae) Left==Female, Right==Male ...... 78 4. Adults of Telenomus sp. (Hymenoptera:Scelionidae) Left=Female, Right==Male ...... 78 5. Seasonal variations in density of nymphs and adults of Lygus lineolaris in crown vetch and habitats ...... 79 6. Level of parasitism and number of Lygus lineolaris eggs in Amaranthus retroflexus at Ste-Anne-de-Bellevue, 1988 ...... 80 7. Level of parasitism and number of Lygus lineolarls eggs in Rumex obtusifolius at Ste-Anne-de-Bellevue, 1988 ...... 81 8. level of parasitism and number of Lygus 7ineolaris eggs in Solanum tuberosum at Ste-Anne-de-Bellevue, 1988 ...... 82 9. level of parasitism and number of Lygus lineolaris eggs in Chenopodium album at Ste-Anne-de-Bellevue, 1988 ...... 83 10. Level of parasitism and number of Lygus 17neo1aris eggs in Coronil1a varia at Ste-Anne-de-Bellevue, 1988 ...... 84 Il. Level of parasitism and number of Lygus lineolaris eggs exposed to parasitoids species in Coroni1la varIa at Ste-Anne-de

-Bellevue, 1988 ...... 85

xi 11 12. Relationship between duration of storage and survival of Anaphes io7e pre-pupae at temperatures l (A) and SoC (B) in the l aboratory ...... 98

xiv 1. General Introduction

1 The , Lygus lineolaris (Pa1isot de Beauvois), is a cosmopolitan of many horticultura1 and agronomie crops. It is dis­ tributed throughout (Kelton 1975) and has a host range of more than 300 species (Young 1986, Scott 1987). However, a succession of plants in the reproductlve stage through the spring and summer is re­ quired to develop damaglng populations (Domek 1982). A1ternative1y, host sources such as alfalfa or carrot, which flower continuously once b100m is initlated, serve as a substitute for the host sequencing (Domek 1982,

Cleveland 1982, Anderson and Schuster 1983).

At present, the only method of control for L. 7ineo7aris in Quebec is by chemical applied as foliar sprays to control the nymphs and adults. Martel et al. (1986) found that adult tarnished plant bugs were highly susceptible to carbamates and moderately susceptible to pyrethroids in laboratory tests. They also reported that malathion was least persistent and dimethoate and carbofuran were most persistent in the fleld.

Pesticides are environmentally hazardous and many pests have developed resistance to some of the insecticides, requiring heavier dosages and more frequent appl i cat ions. In response to a 11 these problems, integrated pest management programmes have been established, which dictate a nUlllber of changes in pest control practices, including reintl'oduclng beneficlal insects and reducing the use of synthetic or­ ganic insecticides. Attempts in the biological control of Lygus spp. by the use of introduced nymphal parasitoids (classica1 bio1ogical control)

2 have been conducted in Canadian Prairies (Craig and Loan 1984, 1987) and in the United States (Coulson 1987; Schuster 1987; Day 1987), but 110 ~ur cessful control programmes have been achieved. Early work on tlH' hrdrollH! parasitoids of lygus bugs were conducted in EUt'ope (Bilewiul\lwin ... ka

1969, 19:4, 1977; Drea et al. 1973). Populations of irnported SpPl ip<; of the genus Peristenus (formerly Leiophron) were released ln alfalfa sl'ed fields in Saskatchewan between 1978 and 1981 ln an attC'lllpl to (onlrol

Lygus spp. infestation. In 1980, indivlduals of only the illdlql'fl(HIS euphorine species, Peristenus palllpes (Curtis), were recaptured; no In­ troduced species have been recovered (CraIg and Loan 1984, 1987). Several other workers carried out research on biologlcal conlrol of l. 11neolaris using P. pa77ipes and P. pseudopallipes (Loan) (Llm and Stewart 1976a,l>,

Lim 1974) and using Peristenus styglCUS Loan (Broadbent 1976) in south­ western Quebec. Species of Peristenus and its c.lo~ely relaled yenus

Leiophron make up the majority of the known nymphal parasitoids of lygus spp., while all known egg parasitoids of Lygus spp. are Mymaridae in thp genera Anaphes , Erythmelus, and Polynema (CIBC 1979).

Phytophagous mirids have been included in lntegrated pest manaqe­ ment programmes on apples and vegetables. Visual traps have been used to monitor L. lineolaris (Prokopy et al. 1978, Boivin et al. 1982) and

economic thresholds for L. lineolaris plant bug have been determinpd on

apples (Prokopy et al 1982, Michaud 1986) and on celpry (Boivin dlld

Brodeur 1989). Slaymaker and Tugwell (1984) developed a trap for l.

7ineolaris that uses live virgin female L. 11neolans as bail at ray{!l­

teville, Arkansas and males of Adelphocoris 11neolatus (Goele) and

3 Stenotus binotatus (F.) were also captured in the traps. Bostanian and Coulombe (1986) developed an integrated pest management programme ta con­ trol Venturia irJaequalis (Cke.) Wint., L. lineolaris, Conotrache7us nenuphar (Herbst), and Rhagoletis pomone17a (Walsh), the annual key pests of apple orchards in southwestern Quebec. According ta their results, the programme reduced the cast of pesticide treatments by 34% when compared with pest control practices currently used by commercial growers in Quebec.

Most growers prevent L. lineo7aris damage to celery by applying up ta eight sprays, generally as a mix with fungicide (Soivin et al. 1989). With the development of an integrated pest management programme on celery, the average number of sprays per growing season decreased From 8 to 4.5 in fields where such an integrated pest management programme has been implemented (Boivin and Brodeur 1989). Most of the biological control work that has been conducted in

Quebec and Canada dealt with the parasitism of L. lineolaris nymphs by the Braconidae. The only report on egg parasitoids of Lygus spp. is that of Walley (1929), in which Polynema pratensiphaga (=pratensiphagum) Wal­ ley was found in Lygus pratensis l. eggs oviposited in common mullein,

Verbascum thapsus L. Quant Hat ive work i s 1ack i ng on the ra 1e of egg parasitoids as bio'ogical control agents against L. lineolaris in Canada.

Eggs of Lygus are extremely difficult ta locate in the field, which is perhaps why egg parasitoids are not commonly reported from Canada.

4 The objectives of this study are: 1) To determine the composition of the egg parasitoid complex of L. 7ineo7ans and estimate the percent age egg parasitism in crown vetch, Coron777a vana L., and assoclatrd weed hasts. 2) Clarify the field biology of Anaphes Jale Girault in southwestern Quebec with emphasis on synchrony wlth L. lineolans. 2) Ihe effect of cold temperature on survival of Anaphes JoIe pre-pupae and their ability to withstand lengthy storage periods in the laboratory.

This thesis is arranged in the form of original papers and requit'es the following to be cited in full:

"The candidate has the optlon" subject to the approval of th Department, of including as part of the thesis the text, or dupl icatpd published text (see below), of an original paper, or papprs. In thls (J'le the thesis must still conform to aIl other requirernpnt<; expldllled in Guidelines Concerning Thesis Preparation. AdditlOnal matenal (proledural and design data as well as descriptions of equipment) must be providpd in sufficient detail (e.g. in appendices) to allow a clear and pr('( Ic,e Judy ment ta be made of the importance and origInal ity of the rt\(;(~anh reported. The thesis should be more than a mere collection of manuslnpts published or to be published. Il must include a general abstract, full introduction and literature review and a final overall conclusIon. lon­ necting texts which provide logical bridges between different manustripts are usually desirable in the interests of cohesion. It is acceptable for theses ta include as chaplers authentic topies of papers already published, provided theses are duplicated clearly on regulation thesis stationery and bound as an integral part of the the~is.

5 cases, it is in the Candidate's interest to make the responsibilities of authors perfectly clear. Candidates fOllowing this option must inform the Department before it submits the thesis for review. The text of the above sha 11 be c ited in full in the i ntroductory sections of any theses ta which it applies. 2. Literature Review

6 2.1 Taxonomy of Anaphes foIe

Comprehensive works on the taxonomy of the family Mymaridae are few, and for many years these minute parasitoids of eggs were con­ sidered to be a rather small group of minor importance when compared to sorne of the larger families of the chalcids (Schauff 1984). However, more attention has recently been put in the study of mymarids, perhaps because of their role as important biological control agents of several key in­ sect pests.

Girault (1911) described Anaphes joIe Girault as a new species From a single female specimen captured at Urbana, Illinois. Later, Crosby and

Leonard (1914b) described Anagrus ovjjentatus Crosby and Leonard, an egg

parasitoid of Lygus pratensis which emerged from eggs found on flower

heads of daisy fleabane, Erigeron ramosus L. in . They pointed

out that Anagrus ovijentatus was simil ar to Anaphes saga Gi rault and provided a brief key for the two species. Girault (1916, 1929) described

Anaphes perdublus Girault as a distinct sppcies and, later, Anaphes

anomocerus Girault as a distinct variety of Iole mainly because of the difference in proportions of F3 (= Funicle article number) and F4.

Girault (1929) proposed the synonymy of ovijentatus and perdubius with

Iole and provided a key to Anaphes species. In 1925 8akkendorf correctly

referred ovijentatus to the genus Anaphes (Romney and Cassidy 1945).

Muesebeck et a7. (1951) listed Mymar ovijentatus (Crosby and Leonard) as

a new combination and a synonym of Anagrus ovijentatus. Krombein and

Burks (1967) suggested that the genus Anaphes requi red subst itut i on for

7 genus Mymar Curtis. Burks (1979) 1 isted several species of Anaphes. amOIl~l them were A. joIe, A. ovjjentatus, and A. perdubius A. anomocerus was

synonymized with A. joIe anomocerus. Girault (1929) provided a key of

eight species of Anaphes and joIe was synonymized with pcrdubJus and

ovijentatus. Huber and Rajakulendran (1988) redescribed A. iole based 011 the host-induced antennal variations From specimens reared From L.

hesperus and PseudatomosceUs seriatus (Reuter). Anaphes anomocerus, A.

oVijentatus, and A. perdubius were synonymized with A. joIe. Schauff

(1984) reported that phylogenetically Anaphes and Erythmelus diverge from the same point on the tree and are apparently closely related, cvrll though they are quite distinct From one another. He also gave a key to

the holarctic species of Mymaridae. Summary of the classification 1S as

fo11 ows ~ Order: Hymenoptera Superfamily: Chalcidoidea Family: Mymaridae Subfamily: Mymarinae Tribe: Anaphini

Genus: Anaphes Haliday

Species: joIe Girault The synonyms are:

Anagrus ovijentatus Crosby and Leonard. 1914a. 46: 181

Anaphes perdubjus Girault. 1916. Ent. News 27: 6

Anaphes ovijentatus (Crosby and Leonard). Bakkendorf 1925 (cited by Romney and Cassidy 1945. J. econ. Ent. 38: 497

8 Anaphes iole anomoeerus Girault. 1929. North Am. Hymen. Mymaridae, p. 13

Anaphes anomoeerus Girault. Burks. Family Mymaridae, p. 1029

Mymar ovijentatus (Crosby and Leonard). Gahan 1949. J. Wash. Acad. Sei. 39: 205.

The name is now Anaphes iole Girault. H1lber and Rajakulendran 1988.

Canad. Ent. 120: 894.

2.2 Geographical Distribution of A. iole

The paucity of information concerning the distribution of A. iole can be attributed largely to the very small size of these insects. Anaphes iole is distributed throughout the continent of North America, from Alaska and the Northwest Territories to southern Mexico (Oaxaca)

(llubet' and Rajakulendran 1988). Its geographical distribution agrees with that of L. lineo7aris. It has been collected from four provinces and one territory of Canada: , Alberta, Ontario and Quebec, and the Norlhwest Territories. Anaphe:; ioTe specimens have been collected From June to October in Canada, whil e i t has been coll ected throughout the year in the United States. They have been collected up to 3,600 m

(Nt. Evans, Co. U.S.A.).

9 2 • 3 Biol 0 gy 0 fA. j ole

Anaphes jale Girault is the most common species of Anaphes in museum collections (Huber and Rajaku1endran 1988). This is because it is

one of the few species of Anaphes that occurs principally in the her­ baceous layer of vegetation where its mirid hosts are found and is thet'e­ fore easily collected by sweeping. Its biology has becn we11 <;tlldicd by several workers. Crosby and Leonard (1914b) reported that a nl'W species,

Anagrus ovij2ntatus Crosby and Leonard (=Anaphes iale Giraul t), an eqg

parasitoid of L. praten~is (probably L. 1ineolaris), emerged froll1 eggs

found on flower heads of daisy fleabane, Erigeran ramosus L., in New

York. Glick (1939) collected A. joIe at an altitude of 1,524 m (5,000 ft) by airplane at Tallulah, Louisiana. In California, Romney and la<;<;Hly

(1945) found between 10 and 70% Lygus hesperus Knight eggs parasltizl'd by

A. iole in guayule, Parthenium argentatum Gray, flowers c.ollectpd from

fields near Salinas during the month of August, with high percentaqes of parasitism being found in the latter half of the month.

Clancy and Pierce (1966) found that eggs of L. hesperus in alfalfa

were commonly attacked by A. io7e in California. They also demonstratrd

that A. iole will develop readily in eggs of L. elisus van [)U7P(~, 1.

hesperus, Nabi s americoferus Carayon and N. al ternatus Par<;h lr~y depo<; llf!d in green beans in laboratory. They illustrated that the minimum life

cycle of A. jale was 15 days at a laboratory temperature of 750 r

(23.9°C). Bryan et al. (1969) described the rearing techniques of

insect parasitoids in the laboratory. A. iole was among them. Sloner and

10 Surber (1969) presented a method for rearing A. joIe in the laboratory.

They also observed numerous A. iole in the green beans infested with lygus eggs and hung on stakes in al falfa fields, but only one specimen was recorded from green beans hung on stakes in cotton fields in the Tuc­ son area, Anzona.

The development of A. foIe eggs took from 10 days at 30°C to 35 days at lSoC while the longevity of adult A. ioTe was about 4 days at

300 e wi th moderate rel ative humidity (RH) (ca 50%) (Stoner and Surber 1971). Scales (1973) provided a list of host plants and parasitoids of L. lineolaris, in Mississippi. Sillings (1971) and Sillings and Broersma

(1974) reported that Leiophron pa77ipes (Curtis), A7ophore17a fumosa

(Coq.), A. aeneoventris (Williston), Alophore71a sp. and several

Tachinldae parasitized adult L. 7ineo7aris. On the other hand, Euphoriana uniformis (Gahan) and A. iole parasitized nymphs and eggs of L.

1ineolaris, respectively. Anaphes foIe parasitized up to 85% of Lygus eggs in alfalfa fields in Indiana. Deitz et al. (1976) recorded A. iole as a parasitoid of the three cornered alfalfa hopper, Spissistilus fes­ tinus (Say), a major insect pest of soybean in North Carol ina.

Graham and Jackson (1982) showed that in the field, A. iole preferred Lygus spp. eggs to those of Nabis spp. and S. festinus. They al so observed that of the Lygus eggs oviposited in London rocket and al­ falfa, 34 and 9%, respectively, were parasitized by the parasitoid. The eggs of the four species of Lygus (L. hesperus, L. 1ineo7aris, L. elisus and L. desertinus Knight) that are important agricultural pests in the

United States were all heavily parasitized by A. iole in Arizona (Jackson

11 and Graham 1983). They listed Nabis spp., S. festinus, Po7ymerus basa/IS

(Reuter), Taedi a marmoratus (Uhl er) and Deraeocon 5 b,.ev 7 s (Uh 1el') il'> potential hosts of A. iole. More mymarid adults (A. iole and Polyl1cma spp.), and Lygus spp., Nabis spp. and S. festinus nymphs wer(l rollüctl'd by dropping the head of the O-vacR sampler vertically aver th~ plants than sweeping it through the tops of the pl ants, whi le the revel'se wa<; true for adults of the respective species (Graham et al. 1984). Jackson and Cohen (1984) demonstrated that the U 50S (the Ume requlrecl for 50% of each population to die from desiccation) for the free l ivinq A. Iole females were higher (20.63 hr) than those of male wasps (14.68 hr) and first instar L. hesperus nymphs (7.07 hr) at 30°C with an RH of 1ess than

5%. They also observed that adult A. iole proved ta be more lo1erant tu higher temperatures and more resistant to desiccalion than die! lhe firsl instar Lygus.

Graham et al. (1986) observed that A. iole was the mo<;!. commoll parasitoid found in agricultural areas of southern Arizona, wilh monlh1y averages of up to 100% parasitism. Jackson (I986) showed thal, in the laboratory, A. iole survival in storage, post-storage longevity, and progeny product i on in L. hesperus eggs tended to decrease wi t h h lqhr.r temperatures and longer storage t imes. Anaphes i 07 e, deve l oped from f'qg to adult in L. hesperus eggs at a constant temperatUYè of 12.80C and al. variable regimes based on conditions in January, February, and ,)Urlfl vlith means of 10.6, 12.8, and 32.80 C respectively in the laboratory (,Jack<,on

1987). He concluded that the extreme summer conditions viere more detrimental to A. iole adults and L. hesperus nymphs th an ta L. hesp~rus

12 eggs or the immature stages of the wasp in Ari zona. Gordon et al. (l987) recorded A. iole in survey of the insect parasitoids from alfalfa and as­ sociated weeds in Mesi11a Valley, New Mexico.

2.4 Hasts of A. iole

Species of Anaphes used in biological control projects have been reared from four separate orders (Hemiptera, Homoptera, Coleoptera, and Diptera) and at least 8 families (Miridae, Gerridae, Cicadell idae, Cur­ culionidae, Byrrhidae, Chrysomalidae, Ephydridae, and Tephritidae)

(Schauff }984). The host range of A. iole consists of 3 families.

Miridae: Halticus bractatus (Say), L. hesperus, L. elisus, L. desertfnus,

L. lineolaris, P. basa1is, P. seriatus, and T. marmoratus. Membracidae:

S. festlnus. Nabidae: N. alternatus, and N. americoferus (Huber and

Rajakul endran 1988). Anaphes foIe have been reared from host eggs found on various herbaceous plants such as Amaranthus, Rumex, Medfcago

(alfalfa), Coroni17a, Po7ygonum, Chenopodium, Conyza (horseweed),

Atrip7ex, Sa7so7a (Russian thistle), Sisymbrium, Solanum (bittersweet and potata), Monarda (horsemint), Erigeron, Encelia, Grindelia,

Petrose 11 num( parsl ey), Parthenium (guayul e), Brassica (mustard), Beta

(sugarbeet), Braccharis, and Phaseolus (common beans) (Huber and

Rajakulendran 1988).

13 ------

2.5 Success as a biological control agent

Mymarids have rarely been used deliberately in biological ('onlt'ol programmes, although they evidently exert a considerable degr(lc of

natural control (Huber 1986). However, studies in the United Stal(ls "tiC!

gest sorne potential for the manipulption of A. iole in biolo~lical or 111-

tegrated control programme for the eggs of Lygus spp. in the fwld. In

California, Romney and Cassidy (l945) found between 10 and 70% parasJt lSlIl

of A. foIe on L. hesperus eggs in guayule flowers al Salinas, with hlqh percentages of parasitism being found in the latter half of the rnonth.

Again, in California, Clancy and Pierce (1966) recorded that the penpnt

age parasitism of A. JoIe on L. hesperus eg9s ranged from 43.6 to 51.4%

from July through October, wi th an ove ra 11 averagp of 46.6%. 1 hey al so

showed that, in the laboratory, A. foIe successfully parasitl1ed eCI of

L. hesperus and also the predators N. alternatus and N. amcncofcrus and

suspected that they might have a detrimental effect on the<;p bpnpf I( lill

insects in the field. However, Graham and Jackson (1982) dP!llf)W,!tdtpd

that, in the field, A. foIe preferred Lygus spp. egys to those of Nab, ')

spp. and S. festinus and concluded that it would not have an adverse et fects on the predators.

Anaph~s foIe was the most common parasitoid of Lygus spp. found in

the agricultural areas of southern Arizona with monthly average,> of up tn

100% parasitism (Graham et al. 1986). It has been sho~1Il that this parasitoid i s present throughout the year in warm regions s inte the specimens have been collected in every month of the year (Huber and

14 Rajakulendran 1988). The wasps can parasitize up to 60 percent of the lygus bugs eggs in alfalfa grown for . However, many times, too few wasps are present and lygus bug populations soar out of control (Senft 1987). (onsequently, a rearing system was developed to produce thousand parasitoids per day by utilizing the oviposition packets for L. hesperus which were descnbed by Patana and Debolt (1985). The Agricultural Research Services (ARS) and the University of California Riverside scientists developed the rubidium-tracking technique to demonstrale dispersal abilities in 1972 and successfully used it on a number of insects including A. foIe (Senft 1987). Graham and Jackson studied the dlspersal of A. foIe reared on eggs of L. hesperus which were fed on a dlet containing RbCl. They demonstrated that, in the field, A.

Iole had dlspersed 30 metres 36 hrs after release. Others were collected between 20 and 30 metres distance 84 hrs after release (unpublished report 1985). Jackson et al. (1988) developed a labelling technique for

A. foIe using the element rubidium (Rb). They also demonstrated that A.

iole was marked with Rb concentrations above laboratory and field en­ dogenous levels when reared From labelled eggs of L. hesperus adults fed dlets containing 500 and 1,000 ppm rubidium chloride (RbCl). The rubidium-tracklng technique was used to study movement and dispersal of the wasps and to distinquish released parasitoids from indigenous ones.

Gt'aham and colleagues began sorne prel iminary parasitoid release studies at Yuma, Anzona, but no success on the establ ishment of the parasitoids

(unpubl ished report 1983).

15 2.6 Natural enemies of Lygus spp. other than A. iole Girault

All stages of Lygus spp. populations are attackpd by different natural enemies either in the laboratory or in their natura1 habitats. They include parasitoids, predators, pathogens, and nematodes.

2.6.1 Egg paras i toi ds of Lygus spp. other than A. i ole

Walley (1929) described a new species of Mymaridae, Polynema pratensiphaga (=pratensiphagum). This egg parasitoid of L. pratensis was found by R. H. Painter from lygus eggs oviposited in common lllu11ein, V. thapsus. Two species of mymarid were recovered from Lygus sp. eggs in In donesia. One of them was identified as Erythme7us helopeltldis Gahan, and parasitized up to 55% of the eggs deposited in Amaranthus dublUS r1art. ex

Thell. (CIBC 1976) In the same report, Erythmelus sp. were parasitizlng eggs of Lygus gemel1dtus (H.-S.) in Pakistan.

2.6.2 Nymphal parasitoids of Lygus spp.

Pa inter (1929a) reported that undetermi ned hymenopterous 1arva(~ were found in nymphs of L. pratensis in Ontario. Frolll the disr.,e( tiOT!'> of the h 0 st, h e su 9 9 est e d t h a t the r e we r e t w0 9 e n e r a ti 0 nS 0 f tlJ(! parasitoid, one in the spring and the other in summer. Hill (1933) in western New York states found that the summer brood nyrnphs of L. pratcn-

16 sis were severely parasitized, but the third or fall brood was not so heav 11y paras it ized. No ident i fi cation of the paras itoids was carried out. Brindley (1939) gave a brief observation on the lite history of a nymphal parasitoid, Euphorus pal1ipes (Curtis), in England. The recorded hosts were nymphs of L. pratensis, Calocoris norvegicus Reut., Oncotylus viridifl avus (Goeze) and Poeci1 oscytus un ifasci atus (F abri. ). ln Uganda, hymenopterous paras itoids of the genus Euphorus paras it ized nymphs of

Lygus simonyi Reut. (Taylor 1945). Leston (l959) recorded that at least 24 species of Miridae nymphs are parasitized by the Braconidae in Britain, whether this parasitoid was a single Euphorine species or a group of species was unknown. Fi ft y one British mirids were reported from which unknown species of Euphorine larvae were found parasitizing nymphs of mirids by leston (1961), who gave a brief description of the develop­ ment of the parasitoids. Muesebeck (1963) listed the hosts of the paras itoids of tri be Euphorini and Euphorus Nees was recorded as a parasitoid of nymphs.

If! Pol and, braconids parasitized nymphs of mirids in different habitats (Bilewicz-Pawinska 1964). In early spring, L. pal1ipes parasitizes nymphs of Labops hirtus Knight, Leptopterna dolabrata (l.),

A. lineolatus, and A. rapidus Say. Lygus lineo7aris nymphs were parasitized in two distinct periods: one in June and the other in late

July, August, and September \Loan 1965). Clancy and Pierce (1966) sur­ veyed the natural enemies of lygus bugs in the ea!>tern Uni ted States, Canada, and western . Bi l ewi cz-Pawi nska (1968) des cri bed a method

17 for cul tu ri ng euphori ne adul ts from Lygus rugu 7i pf'nn i s Popp. and L. pratensis nymphs in the laboratory. A higher percf'ntage of L. l1fJl'olans

nymphs were para~itized by L. pal1ipes on Erigeron plants than on '\C'vPt'al

other plants (Streams et al. 1968). Stewart (1969) repot'ted pal'asitism of

L. rugulipennis nymphs by L. pa77ipes in Scotland. ln Poland, le/ophron

sp. parasitized L. rugulipennis and L. pratenslS primarily in hdbltats of cultivated fields, and the mean percentage of parasitisl11 of the firsl generation nymphs was about 30% while the maximum percentagC' of

parasitism found in a single sample was approximately 60% (Bilewicz

Pawinska (1970).

Loan {l970} noted that final instar larvae of L. pscudopal1/pcs

emerged from nymphs of L. lineo 1ari s wh il e those of L. pa 111 pes el11Pl'qed

from teneral adults. He concluded that l. pal1ipes i~ the most flPXlblp parasitoid as shown by its polyphagous parasitism and adaptat ion ln dif­

ferent ecosystems. Lim (1974) compiled a 1i5t of the pa r a5itoids of L.

7ineo7aris and ather Lygus spp. Lim and Stewart (1976a) stl/dipd thr

development of P. pa77ipes and P. pseudopal1ipes using nyrnphs of 1.

7ineo7aris in the laboratory as well as their life c.ycles in an alfdlfa field in southern Quebec (Lim and Stewart 1976b). Broadbpnt (1976) con

ducted laboratory studies on the biology of an irnported parasitold, P.

stygicus, using L. 7ineo7aris nymphs as a host. Horrnc.han (1977) reporU!d

4 - 24% parasitism by P. pal1ipes of L. I1neolans nymphs, dUr1ny a the

single generation in eastern Mississippi. limited 5amples Viere also takr~n

in Mississippi River Delta, but parasitoid effectiveness was no better

18 than in eastern Mississippi. Leiophron uniformis (Gahan), a braconid parasitoid of the nymphs of Lygus spp., was found in all agricultural areas surveyed in Arizona.

2.6.3 Parasitoids of Lygus spp. adults

An undetermined hymenopterous larvae were found in adults of L. pratensis in Ontario (Painter 1929a). Leston (1959) recorded that at least 24 species of mirid adults are parasitized by the Braconidae in Britain. Fifty one British mirids were reported from which unknown species of Euphorine larvae were found parasitizing the adults (Lestan 1961). Muesebeck (l963) listed the hasts of the parasitoids of tribe

Euphorini, and Euphorus was recarded as an occasional parasitoid adult mirids. Two species of tachinid f1 ies, Oedematopteryx pulverea (Coq.) and A. aeneoventris (Will.), parasitized L. Tineo/aris in Wisconsin (Medler 1961). Scales (1973) listed the host plants and parasitoids of L.

Uneolaris in the Mississippi Delta. He found that the adult plant bugs were parasitized by L. pa77ipes with parasitism sometimes reaching 62% in weed fields. The tachinid Alophorel1a sp. emerged in small numbers from adults of Lygus spp. col1ected at Tucson and Benson (Graham et al. 1986).

19 2.6.4 Predators of Lygus spp.

The known predators of Lygus spp. belong to seven ot'ders: Acari, Anura, Araneae, Dermaptera, Hem; ptera-Heteroptera and Jlymenoptera (1 ab 1e

1). The order Hemiptera-Heteroptera constitute the most importallt predators of Lygus spp. The predators mainly prey on nymphal and adult stages of Lygus spp. and occasionally on eggs.

Table 1. Predators of Lygus spp.

Predator Stage Specles Loca i Hy - k i nd of 21hd Pt'PIlU! of preyl of Lygus observation ACARI Erythraei dae

Lasioerythraeus N 1 ineolaris Mi ss. ,USA F Young & johnstoni Wel. Wrlbourn & Young 1987 ARANEAE Oxyopidae

Oxyopes salticus Hentz A lineolaris Que.,Canada L Arnoldi 1987 N lineolaris Miss.,USA L Young & Lock 1ey 1986 Ph il odromi dae

Phi lodromus praelustris Key. A lineolaris Que.,Canada L Arno 1d 1 1987 Thomi sidae

Xysticus punctatus Key. A lineolaris Que.,Canada L Arnoldi 1987 iStage of prey: E=egg, N=nymp~:adult 2Kind of observation: F=field, L=laboratory

20 '. Table 1. Continued

Preda tor Stagë- Species Local i ty Kind of 2Reference of prey1 of Lygus observat ion COLlOP IlRA

Carabidae ground beet les A pratensis Me., USA F Patch 1907 Slaphyl in; dae

rove beell es A pratensis Me., USA F Patch 1907 Malachiidae

Co 11 ops vittatus (Say) Lygus spp. Az., USA F Tel ford & Hopkins 1957 C. bipunctatus (Say)N Lygus spp. Ut., USA L Ouayogode & Davi s 1981 Cocci nell idae

CoccinC!17a t ranversoguttat a (Faldermann) N Lygus spp. Ut., USA l Ouayogode & Davis 1981 Co 7eomegil 7a maculata OeGeer 7ineo7aris Mich.,USA Romera 1972 Hippodaml a convergens (Guerin}N Lygus spp. Ut., USA l Ouayogode & Davi s 1981 IJEHMAPHRA

rorfi cul idae Forflcula auricularia l. N Lygus spp. Ut., USA l Ouayogode & Davis 1981 I\[MIPl ERA-IIE1EROPTERA

Anlhocol'idae I1nthoco1'1s spp. Lygus spp. Az., USA F Telford & Hopkins 1957 Orius spp. " Il Il lStage of prey:-t;'-ëgg, N=nymph, A=adult 2Kind of observation: F=field, L=laboratory

21 Table 1. Continued

Predator Stage Spec i es LocalHy-Kind of 2Refrrenrp of preyl of Lygus observa t i 011 -Geocoridae Geocods spp. N Lygus spp. Calif., USA L Chow et al. 1983 E, N hesperus Calif., USA L Clancy & Piercr 1966 G. atricolor Montd. Lygus spp. Al., USA F Telforo& Hopk i ns 1957 G. cadnatus McAtee Il fi Il " G. pa lIens Stal Il " " " G. punctipes sonoraens 1 s van Ouz. Lygus spp. Al., USA F " G. punctipes (Say) N, A lineo7aris Ver., USA L, r Wha 1on & Parker 1978 G. ul iginosus (Say) N, A .. " " " Mi ridae

Deraeocori s sp. N simonyi Uganda F laylor 1945

Nabi dae

Nabis spp. N hesperus Ca 1if., USA L Clan(y & Pi prcp 1966 N Lygus spp. Ut., USA L Ouay 0 90dp & Davie; 1981 E, N If Ca 1if., USA r Dunbar & Bac-ol1 1972 N Il Mich., USA L lhow et al. 1983 N. a lternatus Par. N, A elisus, hesperus Ut., USA F laylor 1949 N, A " " " Knowltoll 1949 N hesperus Al., USA L Pf~rk1n':. & Wdt<,on 1912 Lygus spp. Al., USA r rpl ford & Hopkin<, J957 N elisus, hesperus Wash., USA L, r Gllpt a ct al. 1980 N. Ferus (Linn.) Lygus spp. Az., USA F lelford & lIopk ifle; 1957 -}------Stage of prey: E=egg, N=nymph, A= adu lt 2Kin d of observation: F=field, L=laboratory

22 Table 1. Continued

------;0-- Predator Stage Species Locality Kind of 2Reference of preyl of Lygus observat; on

------N, A 7ineo7aris Ver., USA L, F Whalon & Parker 1978 N. roselpennis Reut.N 7ineo 7ari s Nadgauda & Pitre 1986 Pentatomidae Apateticus bracteatus Fitch N, A 7ineolaris Ver., USA L, F Whalon & Parker 1978 Phyrnat idae Phymata macu7iventris (Say) N, A 1ineolaris Ver. , USA L, F Whalon & Parker 1978 A 7ineo7aris Que. , Canada L Arnold; 1987 P. pennys7vanica Hdndl.A 7ineolaris Que. , Canada L Arnoldi 1987 P. wolfii (Skol) N, A 7ineolaris Que. , Canada L Arnoldi 1987 Reduvi idae

S. diadema (r. ) N, A pratensis Ark., USA L, F Readi 0 1924 A lineolaris Que. , Canada L Arnoldi 1987 N, A lineolaris Ver. , USA L, F Wha l on & Parker 1978 lelus socius Uhler A 1ineolaris Que. , Canada L Arnoldi 1987 HYMENOP1ERA Sphecidae Anacrabro ocellatus oce17atus Packard A 7ineolaris N. Y., USA F Kurczews k i & Peckham 1970 Plenoculus davisi Fox N, A lineolaris Kans. ,N.Y.,USA F Evans 1961 N, A 1ineo7aris Kans., USA F Kurczewsk i 1968 ANUHA Bufonidae Bufo amerlcarus Hol. A 7ineo7aris Mich., USA F Romera 1972 iStage of pr'ey:- E=egg~- N,;,n.imph~~aduît 2K1nd of observation: F=field, L=laboratory

23 2.6.5 Entomopathogenic fung; and nematodes of Lygus spp.

Little information is available on entomopathogenic fungl infectirlq Lygus spp. and also true of nematodes. Perhaps this may be altributable

Table 2. Pathogens and nematodes of Lygus spp.

Prey Stage1 Species Locdlity Kind of Rpfprencu '1 of Lygus observa t i on'-

------_.. __ .-.-- . NEMATODA Mermithidae Hexamermi s sp. A pratensis Ont.,Canada F Painler 1929b N rugulipennis Scotland r Stewart 1969 Paramermi s sp.? A 7ineo 1ad s Quebec F Stpwarl & Khoury 1976 PATHOGEN ZYGOMYCOTINA Entomophthora sp. A pratensis Ken., USA F Crosby & (=Empusa Cohn) Leonar'd 1914b DEUTEROMYCOT l NA Hyphomycetes unidentified fungus A rugu7ipennis 5cotland F Stewart 1969 Beauveria bassiana (Bals.) Vuill. A rugu7ipennis Pol and F Bajar. & Blle­

wicl-Pawin~ka 1971 Hyphomycete fungus A 7ineo7aris Mich., USA r Ramera 1972

lStage of prey: N=nymph, A=adultj 2Kind of observation: F=fif!ld

24 to the behaviour of Lygus spp. They rarely occur in the same habitats as the nematodes a~d pathogens. Nematodes prey on both adults and nymphs of

Lygus spp. (Table 2). On the other hand, entohiopathogenîc fungi have beeil reported infecting the adults of Lygus spp. (Table 2) in the field. The entomopathogenic fungi of Lygus spp. reported 50 far all belong to the

5ubdivision Deuterom.ycotina (=Fungi Imperfecti based (111 classification by

Hawksworth et a 7. 1983) dnd cl ass Hyphomycetes.

2.7 Taxonomy and Geographical Distribution of L. lineolaris

The common name tarnist.êd plant bug WëlS first used by Riley (1870).

This mirid wa3 first described From North America as Capsus ob7ineatus by

Palisot de Beauvols i~ 1818. He named the species 7ineolaris and referred il tentatively tù the genus Coreus. Say (1832) unknowin~ly redescribed it a~ Capsus oblinc:atlJs. Ha,rris (1841) noted the idemtity of the species described by Say and Palisot de BE'auvois and adopted the name given by the l.ltter but placing the spl~cies in the genus Phytocoris. Uhler (18 72) was the first to use the currently dtcepted name for the tarnished plant bug, Lygus 1ineolaris (P. df~ B.). Unfol'tunately, in 1886, Uhler then decided that L lineolaris WlS mereJy a North Arnerican population of the [uropean L. pratensfs (L.) (Young 1986). knight (1917) provided the first comprehensive review of the North American Lygus spp. In 1917, Kl1ight com~\romised by Llsillg the name L pratensis var. oblineatus, which prevailed for many years. Slater and Davis (1952) clarified the situation by demonstrating that the proper name sh.ou1d be L. 1ineo7aris. However,

25 Kelton (1955) then placed it in a new genus, Liocoris. This placeml'nt Il,, ... not been generally accepted, particularly after Carvalho's (1959) wOl'ld catalog of the Miridae agreed with the placement of Slalet' and Dav;".

Kelton (1975) revised the genus Lygus Hahn and rpferred to th(' tdl'ni~h('d plant bug as L. 7ineo7aris. In the early American economlc litel'atut'P, therefore, the tarnished plant bug WdS referred te as Capsus obI incatus

and Phytocoris 7ineo7aris or P. 7inearis (Crosby and Leonal'd 1914b). 11

is now referred to as the tarnished plant bu~, Lygus 7ineolaris (Palisot de Beauvois) (Hemiptera: Miridaej.

LygU5 7inr::07aris is the most widely distribuled nllrid lhrollghout

North America from Alaska to Labrador down tn Mexico (Kelton 1975). Il 15

found ~n all agricultural regions from low to relatively hl~Jh allitlld(~<;

(Kelton 1975).

2.8 Biology of L. 7ineo7aris

2.8.1 Overwintering of L. 7ineolari s

L. 7ineo7aris overwinters in the adult stage under dead leav(~<;,

refuse in woodlots, beneath hedges and stones, and any deep ground-lover

(Brittain and Saunder"s 1917, Haseman 1918, Crosby and Leonard 1914b,

Painter 1929a). The earl iest record of overwinlered adult5 ln rh~w York

State was 20 March (Crosby and Leonard 1914b). Lygus /Inco/ans OVf!r­

winters in the adult stage in equal numbers of males and feraale<; arld

overwintering bugs in woodlots increase from early Oclober to mid-

26 November (Painter 1929a). Overwintered adults emerge from their hiber­ nacula during the first warm days in early April (Prakapy et al. 1978) and in late April in Quebec (Stewart and Khoury 1976, Salvin 1981) at a tempe rature as low as 80C (Painter 1929a).

2.8.2 Life cycle of L. lineolaris

The ovipositian of L. 7ineolaris on different host plants has been described by Chittenden and Marsh (1910), Ridgway and Gyrisco (1960a) and

Painter (1926). The eggs of L. 7ineolaris are inserted in a vêlriety uf places on host plants which make it difficult to generalize any definite location at which they may be found (Painter 1929a). Taksdal (1961,

1963), however, demonstrdted that oviposit ion site~ differ lr different hast plants, but generally seems to be confined tD the flowers or flower buds. According to Bariola (1969), the most preferred oviposition site on cotton was the enlarged portions of petioles. The eggs are generally inserted completely into the pldnt tissue with only the opercula exposed

(Pdinter 1926), or protruding almost on their entire length (Porter

1926). Ücc&slonally, eggs are found to be inserted loosely in a leaf fold si ogly or in groups of two or three, one above the other. Graham and

Jackson (1982) showed that in the field the eggs of Lygus spp. (L. hesperus , L. lineo7aris , and L. desert/nus) wefe mostly depo:;ited in the aplcal 30 cm of alfalfa stems. On the other hand, the oviposition of

27 LJ'gus spp. in London rocket, Sisymbrium irio L., was simi1ar to that on alfalfa when plants were young and succulent, whereas on mature plants more eggs were found on the lower parts of the stems. The nymphs are very similar in forlll and all al'e green in colom'.

They pass through five developmental instars before becoming adults. lh~y start feeding on the succulent parts of the host plants saon after halrh­ ing. From the third stage L. lineolaris nymphs present five black dols: four are 10catE:'d on the alary buds and thorax and the firth on the third abdominal segment (Boivin 1982). The lpngth of egg incubation, duration of nymphal development, fecundity, and longevlty of males, in relation to variolls telllperatllt·(!~ have been studied by many authors (Crosby and Leonard 1914b, Painter

1926, Ridgway and Gyrisco 1960b, Bariola 1969, Khattat and St~ 1977,

Khattat and Stewart 1980). Ma and Ramaswamy (1987) in their sludy of lhe histologlcal changes during ovarian maturation in L. 1ineolaris round that each oocyte goes through a gonotrophic cycle that lasts about 7 days during which 3 distinct stages are observed: previtellogenic, vilel­ logenic, and choriogenic.

The eggs, nymphs, and adults of L. IJneolaris have been described by several workers (Crosby and Leonard 1914b, Brittain and Saunders 1917,

Painter 1926). Painter (1929a) presented a key to the nymphal instars, and Knight (1941) described the male and female adults with illustrations of the male genitalia.

28 The egg laying period of overwintered adults of L. 1ineo7aris i5 very long (Boivin 1981). This results in an overlapping of generations which makes it difficult to determine the exact number of generations ppr annum. This is not definite a~d may vary from one area to another depend­

ing upon various cl imatic conditions. Lygus lineo7aris has two genera­ tions in eastern Ontario and simil ar resul ts wen~ found by Hauschild and Parker (1976) in Vermont. However, other authors 5ugges ted that at l east a partial third generation occurs in the northern United States each year (Knight 1941, Ridgway and Gyrisco 1960a). Day (1987) suggested of a fourth generation in northeastern United States alfalfa-grass fields.

Stewart and Khoury (1976) rpported two generat i (In s and a part i al th i rd generation on pigweed and alfalfa in Quebec (Khattat and Stewart 1980). In Ontario, Phillips (1958) reported that there are at least three gener­ ations per annum of L. 7ined::jrjs on clover and weeds. As a general rule, it is believed that L. lineo7aris is univoltine in northern latitudes and bivoltine south of about 51 0 (Craig and Loan 1984). Nympha 1 survivorship, fecundity, and adult longevity have been es­ timated for cohorts on beans, cotton, and other hosts (such as potato shoots, bean sprouts, broccoli, etc.) for laboratory rearing (Bariola

1969, Khattat and Stewart 1977, Fleischer and Gaylor 1987). Lygus lineolaris populations are densest on weedy hosts, but under appropriate condltions, the insect may move onto a wide variety of cultivated crops (lugwell et al. 1976, Soivin et al 1981, Cleveland 1982, Anderson and

Schuster 1983, Fleischer and Gaylor 1987). On agronomie erops, L. l7l7eo7aris is perceived as a pest at densities much lower than on weed

29 hosts (Stewart and Khattat 1980. Smith et al. 1982). Lygus lincolan's rnay switch hosts in the field, moving as adults from senescing hosts ta those entering a reproductive growth stage (Fleischer and Gaylor 1987).

2.8.3 Rearing of L. lineolaris

In the l aboratory, most of the reari ng methods for L. 1 j nco 1a/'; 5 recommend green beans as food ~ource and oviposition medium (Walers 1943,

Ridgway and Gyrisco 1960b, l3eards and leigh 1960, Bottger 1966, Parrolt et al. 1975, Oebolt 1987) or a combinations of green beans wi th olher foods such a~ heat-killed larvae of the beet armyworm, Spodoptera eXIgua

(Hubner) (Bryan et al. 1976). Curtis and McCoy (1964) demonstralpd lhat,

in the laboratol"'Y, L. 7ineolaris preferred celery or carr"ot to the ~p'el'n

bean, both as a food source and as ovipositlOn sile, allhou~Jh adult

fecundity and nymphal survival were greatly superior wllh beans. lhp fOO(1

plant influenced the duration of nymphal developmenl and tl1(' ralr. of dev~lopment was lower for nymphs confined on colton plants as lomparrd 10

those reared on green beans (Bariola 1969).

Vanderzant (1967) developed an artificial diet for lygus bugs (on taining alfalfa meal and other nutrients. She was able to rear threr. grn erations of L. Uneolaris and b/o generations of L. hesperus on il hprb diet. The survival rate of L. lineolaris adults in captlvity incn!ac;ed with the presence of aphids (Lindquist and Sorenson (1970). It wac; lalr>r

reported that sorouting potatoes were preferred to green beans and prr­ mitted a better survival of nymphs and adults (Khattat and Stewart 1977,

30 Hatfield et al. 1982, Slaymaker and Tugwell 1982). Only recently has Oebolt (1982) reported the first artificial diet suitable for continuous reari ng of any Lygus sp. Improvements in reari ng and feedi ng techn i ques

(Patana 1982, Oebolt and Pat ana 1985) have allowed greatly increased production of L. hesperus nymphs and eggs for A. iole production.

2.9 Host plants of L. lineolaris

Lygus lineolaris feeds on a great variety of host plants throughout the growing season. The literature concerning the host plants of L.

1ineolaris is volt.. minous. Host plants of L. lineolaris were reported in New York (Crosby and Leonard 1914b), the Yakima Valley and Columbia Basin in Washington (Fye 1980), southwestern and central Arizona Graham et al. 1982), the Mississippi River Oelta (Cleveland 1982, Snodgrass et al.

1984), and in the Northern Blackland Prairies of Texas (Womack and

Schuster 1987). Taksdal (1963) compiled a list of 120 plant species belonging to 30 r1ant families as host plants of L. iineo7aris. Lygus lineolaris has a host range of more than 300 species (Young 1986). It has been suggested that populations of this insect do not stay or breed on one plant species for a long time (Painter 1929a, Woodside 1946, Taksdal 1961, 1963). Lygus lineo7aris pre fers to feed on plants near the flower­ ing stage probably related to the need for protein, and its selection of hosts, therefore, follows a seasonal succession (Painter 1929a, Taksdal 1963, Lelgh 1963, Strong 1968, Pack and Tugwell 1976). Although highly polyphagous, L. lineolaris pl'efers to feed on sorne hast plants more than

31 ethers (Taksdal 1963, Curtis and MeCey 1964). Chemosensory eues from the hest are generally considered to be the principal factors in host seIN' tian and feeding behaviaur in phytophagous insects (Schoonhoven 1972,

Chapman 1974). Hatfield et al. (1982) indicated, indirectly, that ehemosensory input from epi pharyngea 1 chemosens i 11 ae regul at ed the f eed ing respense of L. 7ineo7aris.

32 2.10 References

Anderson, R. A., and M. F. Schuster. 1983. Phenology of the tarnished plant bug on natural hast plants in relation ta populations in cot­ ton. Southwest. [nt. 8 : 131 - 136.

Arnoldi, D. 1987. Predation studies of mirids (Hemiptera: Miridae) in apple orchard in southwestern Quebec. M. Sc. Thesis, McGill Univer­ sity. 293 pp.

Bajan, C., and 1. Bilewicz-Pawinska. 1971. Preliminary studies on the role of 8eauveria bassiana (Bals.) Vuill. in reduction of Lygus rugu1jpennis Popp. Eka1. Pol. Ser. A. 19: 35 - 46.

Bariola, L. A. 1969. The biology of the tarnished plant bug Lygus 7ineo7aris (Beauvois), and its nature of damage and control on cot­

ton. Ph. D. Dissertation. Texas A & M University, College Station. 102 pp.

Beards, G. W., and 1. F. Leigh. 1960. A laboratory rearing method for Lygus hesperus Knight. J. ecan. [nt. 53 : 327 - 328. Bilewicz-Pawinska, 1. 1964. Role of braconids (Hymenoptera: Braconidae) in reduction of field bugs (Heteroptera). Pol. Plsmo. ent. Ser. B. ent. Stosow. 29 : 261 - 264. Bilewicz-Pawinska, T. 1968. Laboratory culture of Euphorinae-parasites of Lygus sp. Ekol. Pol. Ser.B, 14 : 231 - 236. Bilewicz-Pawlnska, T. 1969. Natural limitation of Lygus rugu1ipennis

Popp. by a group of Leiophron pal1ipes Curtis on the rye crop fields. Ekol. Pol., Ser. A, 17 : 811 - 825.

33 Bilewicz-Pawinska. T. 1970. Studies on the natural limitation of sOllle

Lygus bugs in ecosystems of cultivated fields. Roc? Nank. NaIn.

Ser. E. 1 : 93 - 204.

Bilewicz-Pawinska, 1. 1974. Observations of introduction of Perrstcflus

rubrieolUs Thomson under laboratory conditions. Bul. Acad. Pol.

Sei. 22 : 681 - 684.

Bilewicz-Pawinska, T. 1977. Occurrence and rolt:! of the parasitic genll~

Peristcnus roer~tpr (Hymenoptera: Braconidae) in the fields uf ry(~.

Pol. Pismo Ent. 47 : 123 - 125.

Boivin, G. 1981. Bionomics of five species of phytophaqous mirids

(llemiptera: Miridae) in an apple orc.hard Ifl soulhwe~tern (}lIebpl.

Ph. O. Thesis. McGill Unlverslty. 269 pp.

Boivin, G. 1982. Les punaises phytophages du pommier. Allas des in<;pll{~\

[-4. Que. Min. Agr. Pech. AlIment Dir. Nech. Sei. Tech. Cah. Inf.

B-507. 4 pp.

Boivin, G., and L. Brodeur. 1989. Réseau de lutte intégrée en soh or­

ganiques: fonctionement et résultats. Naturaliste Cano 115 : ~uh

mitted.

Soivin, G, J.-P. R. LeBlanc, and J. A. Adams. 1989. Spatidl di')pl~r,>ion

and sequential sampling plan for the tarnished pIanI. b\lU, Iygus

lineofaris (P. de B.) (lIemlptera: Miridae), on c.elery: "iuhmiUpd.

Buivin, G., R. K. Stewart, and 1. Rivard. 1982. Stilky Irape; for ITHHlllor ing phytopha90us miflds (Hemiptera: Mifldae) in dpple orchanj<) in

southwestern Quebec. [nvlron. Ent. 11 : 1067 - 1070.

34 Soivin, G., G. Mailloux, R. O. Paradis, and J.-G., Pilon. 1981. La punaise terne, Lygus line07aris (P. de B.) (Hemiptera: Miridae), dans le sud-ouest du Québec. II. Fluctuations saisonnières des

populations sur certaines mauvai~es herbes. Ann. Soc. ent. Que. 26 : 159 - 169. Bostanîan, N. J.! and L. J. Coulombe. 1986. An IPM program for apple or­ chards in southwestern Quebec. Càn. [nt. 118 : 1131 - 1142. BoUger, G. T. 1966. Lygus bugs, p.425-427. In C. N. Smith [ed.], Insect colonization and mass production. Academic Press, New York. 618 pp.

Brindley, M. D. 1939. Observations on the life-history of [uphorus pal­ lipes (Curtis) (Hymenoptera: Braconidae), a parasite of Hemiptera­

Heteroptera. Proc. R. ent. Soc. Land. (A) 14 : 51 - 56.

Brillaln, W. IL, and L. G. Saunders, 1917. Notes on the biology of Lygus

pratensis Linn., in Nova Scotia. Proc. ent. Soc. Nova Scotia 3 : 85

- 91.

Broadbent, A. B. 1976. Laboratory studies on the biology of Peristenus stygicus Loan (Hymenoptera: Braconidae), a parasitoid of Lygus lineolaris (P. de B.) (Hemiptera: Miridae). M. Sc. Thesis, McGill University. 73 pp.

Bryan, D. E., C. G. Jackson, and A. Stoner. 1969. Rearing cotton insect parasites in the laboratory. Prod. Res. Rep. USDA No. 109. 13 pp.

Bryan, D. E., C. G. Jackson, R. L. Carranza, and E. G. Neeman. 1976. Lygus hesperus: Production and development in the laboratory. J. econ. [nt. 69 : 127 - 129.

35 Burks, B. D. 1979. Family Mymaridae, pp. 1022 - 1033. ln K. V. Kromlwin,

P. D. Hurd Jr., D. R. Smith, and B. D. Burks [eds.], Catalo~l of

Hymenoptera in America north of Mexico, vol. 1. Smi thsOll1an In

stitution Press, Washington, OC. 1198 pp.

Carvalho, J. C. M. 1959. Cata10'Jue of the Miridae of the wot'ld. Arch.

Mus. Nac., Rio de Jenairo 48 1 - 384. Chapman, R. F. 1974. The chemical inhibition of feeding by phytophagous

insects: A review. Bull. ente Res. 64 : 339 - 363.

Chittenden, F. H., and H. O. Marsh. 1910. Note on the oviposition of the tarnished plant bug. J. econ. Ent. 3 : 477 - 479.

Chow, T., G. E. Long, and G. Tamaki. 1983. Effects of ternperature dllel hunger on the functional response of Geocoris bullatus (Say) (Hemiptera: Lygaeidae) ta Lygus spp. (Hemiptera: Minuaü) densJty. Environ. Ent. 12 : 1332 - 1338.

Commonwealth Institute of Biological Control (CIBC). 1976. Investigations on the natural enemies of Lygus spp. and other bugs (Miridae). Ann. Rep. Commonw. Inst. Biol. Control, Pakistan Statlon.

CISC. 1979. Possibilities for the biological control of lygu') bugs

(Hemiptera, Miridae). Commonw. Inst. Biol. Status Paper tlo. 15. 7

pp. Clancy, D. W., and H. D. Pierce. 1966. Natural enemies of saille lyljuS

bugs. J. econ. Ent. 59 : 833 - 858. Cleveland, T. C. 1982. Hibernation and hast plant sequence studie') of

tarnished plant bugs, Lygus 7ineolaris, in the Mis~issippi Uelta.

Environ. Ent. 11 : 1049 - 1052.

36 C.oulson, J. R. 1987. Studies on the biological control of plant bugs (Heteroptera: Miridae): An introduction and history, 1961-83, pp.

1-12. In R. C. Hedlund, and H. M. Graham, [eds.], Economie impor­

tance and biological control of Lygus and Ade7phocoris in North America. USOA, ARS, ARS-64. 95 pp.

Craig, C. H. 1963. The alfalfa plant bug, Ade7phocoris 7ineolatus (Goeze)

in northern Saskatchewan. Can. Ent. 95 : 6 - 13.

Craig, C. H., and C. C. Loan. 1984. Lygus spp., Plant bugs (Heteroptera:

Miridae), pp. 45 - 47. ln J. S. Kelleher, and M. A. Hulme [eds.], Biological control programmes against insects and weeds in Canada 1969-1980. 410 pp. Commonw. Agric. Bureaux., Farnham Royal, England.

Craig, C. H., and C. C. Loan. 1984. 1987. Biological control efforts in Miridae in Canada, pp. 48 - 53. In R. C. Hedlund, and H. M. Graham,

[eds.], Economie importance and biolo2ical control of Lygus and

Ade7phocoris in North America. USDA, ARS, ARS-64. 95 pp.

Crosby, C. R., and M. D. Leonard. 1914a. An egg-parasite of the tarnished

plant bug, Lygus pratensis L. Cano Ent. 46 : 181 - 182.

Crosby, C. R., and M. D. Leonard. 1914b. The tarnished plant bug. Corne77

Agr. Expt. Stn. Bu 17 . 346 : 463 - 526.

Curtis, C. t., and C. E. McCoy. 1964. Sorne host-plant preferences shown

by Lygus 1ineo7aris (Hemiptera: Miridae) in the laboratory. Ann.

ent. Soc. Am. 57 : 511 - 513.

37 Day, W. H. 1987. Biological control effects against Lygus and Ade]­

phocoris spp. infesting alfalfa in the United States, with Ilotps on

other associated mirid species, pp 20 - 39. In R. C. Hedlullu, and

H. M. Graham [eds.J, Economic importance and BlOloyical control of

Lygus and Ade7phocoris in North America. USDA, ARS, AHS-64. 95 pp.

Debolt, J. W. 1982. Meridic diet for rearing successive yenct'at iOIl of

Lygus hesperus. Ann. ente Soc. Am. 75 : 119 - 122.

Oebolt, J. W. 1987. Augmentation: Rearing, release, and evalualioll of

plant bug parasites, pp 82 - 87. In R. C. Hedlun(l, and II. M. Graham

[eds.], Economie importance and biological control of Lygus and

Ade7phocoris in North America. USDA, ARS, ARS-64. 95 pp.

Oebolt, J. '1'1., and R. Patana. 1985. Lygus h'2sperus. In R. r. Maorr, clnd

P. Singh, teds.], Handbook of illsect reariny, vol. 1. 488 pp. 1I­

sevier Science Publishers, Amsterdam, The Netherland<;.

Deitz, L. L., J. W. van Duyn, J. R. Bradley, Jr., IL L. Habb, W. M.

Brooks, and R. E. Stinner. 1976. A guide ta the Identification ,111<1

biology of soybean in North Carolina. North Caro/Ina

Agr. Expt. Stn. Tech. Bull. No. 238. 264 pp.

Domek, J. M. 1982. Plant hasts of species of Lygus Hahn (Helllipt!!ra:

Miridae) in the Lewiston-Moscow area of Idaho. M. Sc. lhesis, Univ.

Idaho, Moscow.

Oomek, J. M., and D. R. Scott. 1985. Species of the genus Lygus Hahn and

their hast plants in the Lewiston-I~oscow area of Idaho (H(!nlil.pra:

Miridae). Entomography 3 : 75 - 105.

38 Doutt, R. L. 1949. The genus Erythmelus in California (Hymenoptera, Mymaridae). Pan-Pacifie [nt. 25 : 77 - 81. Dozier, H. L. 1937. Descriptionc; of miscellaneous chalcidoid parasites From Puerto Rico. (Hymenoptera). J. Agrie. Univ. Puerto Rico 21 :

121 - 135.

Drea, J. J., Jr., L. Dureseau, and E. Rivet. 1973. 8io10gy of Peristenus

stygi eus from Turkey, a potent i al natura l enemy of 1ygus bugs in

North Amer i ca. Env 1 ron. [nt. 2 : 278 - 280. Dunbar, D. M., and O. G. Bacon. 1972. Feeding development of Geoeoris

puncti pes (Heteroptera: Lygaeidae) on e i ght di ets. Ann. ent. Soe.

Am. 65 : 892 - 895.

[vans, H. E. 1961. Notes on the nesting of Plenoculus davisi Fox

(Hymenoptera: Sphecidae). [nt. News 72 : 225 - 228. f Jeischer, S. J., and M. J. Gaylor. 1987. Seasonal abundance of Lygus lineolaris (Heteroptera: Miridae) and selected predators in early

season uncultivated hosts: implications for managing movement into

cotton. Environ. [nt. 16 : 379 - 389.

Iye, R. E. 1980. Weed sources of Lygus bugs in the Yakima Valley and

Columbia Basin in Washington. J. eeon. [nt. 73 : 469 - 473.

Gahan, A. B. 1949. The status of the genus Mymar Curtis (Hymenoptera: Mymaridae). J. Wash. Acad. Sei. 39 : 204 - 205.

Glt'ault, A. A. 1911. Descriptions of North American Mymaridae with

synonymie and other notes on described genera and species. Trans.

Am. ent. Soc. 37 : 253·324.

39 Girault, A. A. 1916. Notes on North American Mymaridae and h'icho~ll'am­

matidae (Hymenopter'a). Ent. News 26 : 4 - 8.

Girault, A. A. 1929. North American Hymenoplera Myll1arida(~ pp. 1 - 27. Ad-

dendum "New insects mostly Australian", pp. 28 - 29. Pl'iv,ltely printed papers.

Glick, P. A. 1939. The distribution of insects, spider'), and mites in ttH'

air, USDA Tech. Bul,. 673: 1 - 150.

Gordon, R., J. Ellington, G. F. Faubion, and H. Graham. 1987. A survey of

the insect parasitoids from alfalfa and associated weeds in Nf'W

Mexico. Southwest. Ent. 12 : 335 - 348.

Graham, H. M., and C. G. Jackson. 1982. DistributIon of e9Ys of lygus

spp. (Hemiptera: Miridae), Nabis spp. (llemiptera: Nabiuap), and

Spissistilus festinus (Say) (Homoplera: Membracidae) on pIanI

stems. Ann. ent. Soc. Am. 75 : 56 - 60.

Graham, H. M., C. G. Jackson, and C. D. Butler, Jr. 1982. lOlllpo'>lllon of

Lygus complex in sorne crop and weed habitats of Arizona. 50uthwest.

Ent. 7 : 105 - 110.

Graham, H. M., C. G. Jackson, alld J. W. Oebolt. 1986. Lygus ')pp.

(Hemiptera: Miridae) and their parasites ln agricultural arC~dS of

southern Arizona. Environ. Ent. 15 : 132 - 142.

Graham, H. M., C. G. Jackson, and K. R. Lakin. 1984. lomparison of Iwo

methods of using the O-vac ta sample mymarids and thelr hw.t<. III

a lf al fa. Sou t hw est. En t. 9 : 249 - 252 .

40 Gupta, R. K., G. Tamaki, and C. A. Johansen. 1980. Lygus bug damage, predator-prey interaction and pest management implications on al­

falfa grown for seed. Wash. State Agri. Res. Ctr. Tech. Bu77. 0092

18 pp. Harris, T. W. 1841. A report on the insects of Massachusetts injurious to

vegetation, pp 161 - 164. Cambridge.

Ilasernan, L. 1918. The tarnished plant bug and its in jury to nursery

stock. Mon. Agr. Expt. Stn. Res. Bull. 29 : 1 - 26.

Hatfield, L. D., J. l. Frazier, and J. Ferreira. 1982. Gustatory dis­ crimination of sugars, amine acids, and selected allelochemicals by

the tarnished plant bug, Lygus lineolaris. Physiol. Ent. 7 : 15 - 23.

Ilauschlld, K. 1., and B. L. Parker. 1976. Seasonal development of the

tarnished plant bug on apple in Vermont. Environ. [nt. 5 : 675 -

679. lIawksworth, D. L., B. C. Sutton, and G. C. Ains'l'Iorth. 1983. Ains"wrth and Bisoy's dictionary of the fungi. Commonw. Mycological Institute.

Kew, Surrey. 445 pp.

11111, L. L. 1933. Further studies of tarnished plant bug injury to

celery. J. econ. Ent. 26 : 148 - 150.

Hormchan, P. 1977. Biology of three exotic species, and role of native

species of the genus Peristenus-parasites of tarnished plant bug,

Lygus 11neolans, in Mississippi. Ph. D. Dissertation, Mississippi

State Univ .• 74 pp.

41 Huber, J. T. 1986. Systematics, biology, and hasts of thl' Mym.tridae ilnd

Mymarommatidae (Insecta: Hymenoptera): 1758 - 1984. Entomogt'aphy 4

: 185 - 283.

Huber, J. T., and V. K. Rajakulendran. 1988. Redescription of and host

induced antennal variation in Anaphes foIe Girault (lIynll'noptera'

Mymaridae), an egg parasite of Miridae (Hemiplera) in North

America. Cano Ent. 120 : 893 - 901.

Jackson, C. G. 1986. Effects of cold storage of adult Anaphes oVIJcntatus

on survival, longevity, and oviposition. Southwest. Ent. Il : 149

153.

Jackson, C. G. 1987. Biology of Anaphes oviJentatus (lIyIllPlJoplpra'

Mymaridae) and its hast, Lygus hesperus (Hemiptera: Mindap), al

low and high temperatures. Ann. ent. Soc. Am. 80 : 367 - 372.

Jackson, C. G., and A. C. Cohen. 1984. Temperature and waler telation., of

a parasitic wasp in its free-living adult ~l(lyp and il.,>

phytophagous hast. Comp. Biochem. PhySl01. 78 A : 437 440

Jackson, C. G., and H. M. Graham. 1983. Parasilisrn uf four sp('( 11''> of

Lygus (Hemiptera: Miridae) by Anaphes oVIJentatus (lIynlPnoptl!tïl:

Mymaridae) and an evaluatlOn of other posslble hosts. Ann. ent.

SOC. Am. 76 : 77 2 - 77 5 .

Jackson, C. G., A. C. Cohen, and C. L. Verdugo. 1988. Labf~llng Anaphes

ovijentatus (Hymenoptera:Mym-3rldae), an egg parasIte of Lygus spp.

(Hemiptera:Miridae), with rubIdium. Ann. ent. Soc. Am. 81 : 919 -

922.

T l

42 Kelton, L. A. 1955. Species of Lygus, Liocoris and their allies in the

prairie provinces of Canada (Hemiptera: Miridae). Cano Ent. 87: 531 - 556.

Kelton, L. A. 1975. The lygus bugs (Genus Lygus Hahn) of North America

(Ileteroptera: Miridae). Mem. ent. Soc. Cano 95 : 1 - 101. Khattat, A. R., and R. K. Stewart. 1977. Devebpment and survival of

Lygus lineolaris exposed to different laboratory rearing condi­

tions. Ann. ent. Soc. Am. 70 : 274 - 278. Khattat, A. R., and R. K. Stewart. 1980. Population fluctuations and in­

terplant movements of Lygus lineolaris. Ann. ent. Soc. Am. 73 : 282 - 287.

Knight, H. H. 1917. A revision of the genus Lygus as it occurs in America north of Mexico, wlth biological data on the species From New York.

Camell Univ. Agr. Expt. Stn. Bull. 391 : 555 - 645.

Knlght, H. H. 1941. The plant bugs, or Miridae of Illinois. Bu7l. 117.

Stn. Nat. Hist. Surv. No. 22.234 pp.

Krolllbein, K. V., and B. D. Burks. 1967. Hymenoptera of America North of Mexico. Synoptic catalog. USDA Monogr. 2. Secol1d Suppl. 584 pp.

Klll'czewski, F. E. 1968. Nesting behaviour of Plenocu7us davisi

(llyrnenoptera: Sphecidae, Larrinae). J. Kans. eot. Soc. 41 : 179-

207.

Klll'CZewskl, F. E., and D. J. Peckham. 1970. Nesting behaviour of

Anacrabro oce71atus oce17atus (Hymenoptera: Sphecidae). Ann. ent.

Soc. Am . 63 : 14 19 - 14 24 .

43 Leigh, T. F. 1963. Life history of Lygus hesperus in the labm'atory. Anf).

ent. Soc. Am. 56 : 865 - 867.

Leston, D. 1959. The mirid (Hemiptera) hosts of Braconidae (IIYIl1Pllopterd)

in Britain. [nt. Mon. Mag. 95 : 97 - 100.

Leston, D. 1961. Observations on the mirid (lIpllliptera) host~ of

Braconidae (Hymenoptera) in Britain. Ent. Mon. Mag. 97 : 65 - 71.

Lim, K. P. 1974. Field and laboratory studles of LClophron pal11pc~

(Curtis) and L. pseudopall1pes Loan (HYll1enoptera: I3raCUIlIUJe),

parasitoids of the tarnished plant bug, Lygus 71neolaris (P. de 13.)

(Hemiptera: Miridae), with ell1phasis on seasonal parasltislll Hl t.wo

habitats. M. Sc. Thesis. McGill University. 140 pp.

Lim, K. P. and R. K. Stewart. 1976a. Laboralory sluJles of PCrlstCf)US

pa71ipes and P. pseudopal1ipes (Hyrnenopterd: BraroniddP),

parasitoids of the tarnished plant bug, Lygus lincolarls

(Hemiptera: Miridae). Cano [nt. 108 : 815 - 821.

Lim, K. P. and R. K. Stewart. 1976b. Parasltism of the tarrllsllPd plan!

bug, Lygus lineo7aris (Hemiptera: Mirldae), by Penstenus pal/Ipes

and P. pseudopa771pes (Hymenoptera: Braconidae). Cano Lnt. 108 :

601 - 608.

Lindquist, R. K., and E. L. Sorenson. 1970. Intf!r-relatlonshlps i.tnlorl

aphids, tarnished plant bug and alfalfa. J. econ. Ent. 63 : 192

195.

Loan, C. C. 1965. Life cycle and development of Leiophron pallipes Curtl',

(Hymenoptera: Braconidae, Euphorianae) in five mlrld ho)!s Irl thr>

Belleville district. Proc. ent. Soc. Ont. 95 : 115 - 121.

44 Loan, C. C. 1970. The new paras ites of the tarn i shed plant bug in On­

tario: Leiophron pseudopallipes and Euphoriana lygivora

(Ilyrnenoptera: Braconidae, Euphorianae). Proc. ent. Soc. Ont. 100 :

188 - 195.

Ma. W. K., and S. B. Ramaswamy. 1987. Histological changes duriny ovarian

maturation in the tarnished plant bug, Lygus 7ineo7aris (Palisot de

Beauvois) (Hemiptera: Miridae). Int. J. Insect Morph. & Embryol. 16 309 - 322.

Martel, P., G. Soivin, and J. Belcourt. 1986. Efficiency and persistence

of different lnsecticides against the tarnished plant bug, Lygus

I/neolans (Ileteroptera: Miridae), on a season-long host plant,

Coron/7la var/a. J. econ. [nt. 79 : 721 - 725.

Medler, J. T. 1961. A new record of parasitism of Lygus 7ineo7aris (P. de

B.) (Hemlptera) by Tachnidae (Oiptera). Proc. ent. Soc. Wash. 63 :

101 - 102.

Michalld, O. 1986. The establ i shment 0,' economic thresholds for the green

apple bug, Lygocons communis Knight and the tarnished plant bug,

Lygus 71neoJaris (P. de B.) (Hemiptera: Miridae) in apple orchar'ds

ln sOllthwestern Quebec. M. Sc. Thesis. McGill University. 277 pp.

Mucsebeck, C. F. W., K. V. Krombein, and H. K. Townes. 1951. Hymenoptera

of America north of Mexico. Synoptic catalog. Monogr. 2 Second

Suppl. 584 pp.

~'uesebeck, C. F. W. 1963. Host relationships of the Euphorini

(Ilymenoptera: Braconidae). Proc. ent. Soc. Wash. 65 : 306.

45 Nadgauda, D., and H. N. Pitre. 1986. fffects of temperallwe and ferdinq.

development, fecundity, and longevity of Nabis roselpenfllS

(Hemiptera: Nabidae) fed on tobacco blldwot'm (Lepidol('t'd: Noc: lu id,ll') larvae and tarnished plant bug (Hemiptera: Miridae). Environ. Ent.

15 : 536 - 539.

Ouayogode, B. V., and D. W. Davis. 1981. Feeding by selecled preddtor<, on

alfalfa weevil larvae. Environ. Ent. 10 : 62 - 64. Pack, T. M., and P. Tugwell. 1976. Clouded and tarnished plant bugs on cotton: comparison on in jury symptoms and damage on fruIt parls.

Ark. Agr. Expt. Stn. Rep. Ser. 226 : 1 - 17.

Painter, R. H. 1926. Some notes on the oviposilion habits uf tllP tiB'

nished plant bug, Lygus pratensls Linn., with a lisl of ho')t

plants. Ent. Soc. Ont. Annu. Rep. 57 : 44 - 46.

Painter, R. H. 1929a. The tarnished plant bug, Lygus pratensis L.: fi.

progress report. Annu. Rep. Ont. ent. Soc. 60 : 102 -107.

Painter, R. H. 1929b. A brief note on the occurrence of a nlPtllllllll

parasite genus Hexamermis, in the tarnished plant bug, Iygus

pratens i s L. Que. Soc. Prot. Plants Rep. 21 : 53 - 55.

Parrott, W. L., J. N. Jenkins, F. G. Maxwell, and M. L. Bostic..k. 1975.

Improved techn i ques for reari ng the tarn i s/1ed plan t buq, LY9U!> 1 n

vHus (Palisot de Beauvols). Tech. Bull. USUA, AH), Bollweevll Hp')

labo Miss. Agr. For. Ex.pt. Stn. Tech. 8ull. t~o. 77. 8 (Jp.

Patana, R. 1982. Disposlble diet packet for feedlny and OViPO',l1.10rl of

Lygus hesperus (He~iptera: Miridae). J. econ. tnt. 75 : 668 - 669.

46 Patana, R., and J. W. Debolt. 1985. Rearing Lygus hesperus in the laboratory. USDA, ARS, ARS-45. 9 pp.

Patch, E. M. 1907. Insect notes for 1907. Haine Agr. Expt. Stn. Bu7l. 148 : 257 - 285.

Perkins, P. V., and T. F. Watson. 1972a. Nabis a7ternatus as a predator

of Lygus hesperus. Ann. ent. Soc. Am. 65: 625 - 629.

Perkins, P. V., and T. F. Watson. 1972b. Biology of Nabis alternatus

(Parshley) (Hemiptera: Heteroptera). Ann. ent. Soc. Am. 65 : 54 -

57.

Phlllips, J. H. H. 1958. The tarnished plant bug, Uocoris lineolaris (Beauv.) (Hemlptera: Miridae), as a pest of peach in Ontario: a

progress report. [nt. Soc. Ont. Annu. Rep. 88 : 44 - 48.

Porler, B. A. 1926. The tarnished plant bug as a peach fruit pest. J.

econ. Ent. 19 : 43 - 47.

Prokopy, R. J., K. 1. Hauschild, and R. G. Adams. 1978. Tarnished plant

bug on apple: damage and monitoring traps. Fruit notes 43 : 10 -

14.

Prokopy, R. J., G. L. Hubell, R. G. Adams, and K. 1. Hauschild. 1982.

Visual monitoring trap for tarnished plant bug adults on appl~. EfI­

viron. Ent. 11 : 200 - 203.

HeJuio. P. A. 1924. Notes on the life history of a beneficial reduviid,

51nea diadema (Fabri .), Heteroptera. J. econ. Ent. 17 : 80 - 86.

l~ldgway. R. L., and G. G. Gyrisco. 1960a. Stuàies on the biology of the

tarnished plant bug, Lygus 7ineo7aris (P. de B.). J. econ. Ent. 53

.., : 1063 - 1065 .

47 Ridgway, R. L., and G. G. Gyrisco. 1960b. Effect of tel11peraturc on thp

rate of development of Lygus lineolaris (Hemiptel'a: Miriddc). AII/J.

ent. Soc. Am. 53 : 691 - 694.

Riley, C. V. 1870. The tarnished plant bug Capsus oblineatus Say.

Ma. State ent. Annu. Rep. 2 : 113 - 115. Romero, J. 1. Sr. 1972. Relationship between tarnished plant bug and al

falfa plant bug, (Hemiptera: Miridae) on alfalfa in . Ph.

D. Thesis, Michigan State University.

Romney, V. L, and T. P. Cassidy. 1945. Anaphes ovijentatus, an egg­

parasite of Lygus hesperus. J. econ. Ent. 38 : 497 - 498.

Say, T. 1832. Descriptions of new species of heteropterolls lIemiptera of

North America. New Harmony. Indiana. 39 pp.

Scales, A. L. 1973. The parasites of the tarnished plant bug in the Mie,

sissippi Delta. Environ. [nt. 2 : 304 - 306.

Schauff, M. L 1984. The holarctic genera of Mymaridae of (IIYl11pnoptpra:

Chalcidoidea). Mem. ent. Soc. Wash. No. 12. 67 pp.

Schoonnoven, L. M. 1972. Secondary plant substancec; and 1nc;ects, pp. 197

- 224. In V. C. Runeckless [ed.], Structural and funllional ae,pPlt<;

of phytochemistry. Academic Press, New York. 350 pp.

Schuster, M. F. 1987. 8iological control of plant bugs in collon, pp.

13-19. In R. C. Hedlund, and H. M. Graham [eds.], Economie 1l11por­

tance and biological control of Lygus and Adelphocons in florlh

America. USDA, ARS, ARS-64. 95 pp.

48 Scott, D. R. 1987. Biologieal control of lygus bugs on vegetables and fruit crops, pp. 40 - 47. In R. C. Hedlund, and H. M. Graham

[eds.), Economie importance and biological control of Lygus and

Adelphocoris in North America. USDA, ARS, ARS-64. 95 pp.

Senft, O. 1987. Tracking wa5ps with Rubidium. U. S. Dept. Agrie., A. R.

S., Agric. Res. 35: 4.

5i11ing5, J. O. 1971. The parasites of the tarnished plant bug, Lygus

lineolarls, in Indiana. Proc. North Central Branch, ent. Soc. Am. 26 : 105.

5il1ing5, J. O., and D. B. Broersma. 1974. The parasites of the tarnished

plant bug, Lygus lineolaris, in Indiana. Proc. North Central

Branch, ent. Soc. Am. 29 : 120 - 125.

Slater, J. A.• and N. T. Oavh. 1952. The scientific name of the tar~­

nished plant bug (Hemlptera: Miridae). Proc. ent. Soc. Wash. 54 :

194 - 198.

5layrnaker, P. H., and N. P. Tugwell. 1982. Low-labor method for rearing

the tarnished plant bug (Hemiptera: Miridae). J. econ. [nt. 75 :

487 - 488.

Slayrnaker, P. H., and N. P. Tugwell. 1984. Inexpensive female-baited trap

for the tarnished plant bug (Hemiptera: Miridae). J. econ. Ent. 77

: 1062 - 1063.

Smith, R. H., B. Freeman, G. B. Worley, and M. J. Gaylor. 1982. Guide for cotton insect management. Alabama Cooperative Extn. Sev. Circular

ANR-S.

49 Snodgrass~ G. L., W. P. St:ott, and J. W. Smith. 1984. Host plant~ and seasonal distt'ibution of the tarnished plant bug (Hel11iptHa:

~1iridae) in the dp,lta of Arkansas, Louisiana, and MississIppi. 111-

viron. fnt. 13 : 110 - 116.

Stewart, R. K. 1969. The biology of Ljigus rugt/7ipet1l1is Poppius

(Hemiptera: r1iridae) in Scotland. Trans. R. ent. Soc. Lond. 120 :

437 - 453.

Stewart, R. K., and A. R. Khattat. 1980. Economie in jury level of lhe

tarnished plant bug, Lygus 1ineolaris (Hemiptera (Hele'roptrra):

Mi ri dae) on green beans in Quebee. Can. fnt. 112 : '306 - 310.

Stewart, R. K., and H. Khoury. 1976. The biolo9Y of Lygus l/neolans

(Palisot de Beauvois) (Hemiptera: Miridae) in Queuec. Ann. Soc.

ent. Que. 21 : 52 - 63.

Stoner, A., and D. E. Surber. 1969. Note on the bioloyy and redring of

Anaphes ovijentatus, a new parasite or lygus hesperus in Ay'izuna.

J. econ. [nt. 62 : 501 - 502.

Stoner, A., and D. E. Surber. 1971. Development of Anaphes oviJentatus,

an egg parasite of Lygus hesperus, in relation to ternprraturr.. J.

econ. Ent. 64 : 1566 - 1567.

Streams, F. A., M. Shahjahan, and H. G. LeMasurier. 1968. Infl1JenCf~ of

plants on the parasitization of the tarnlshed plant bug by

Leiophron pal1ipes. J. econ. Ent. 61 : 996 - 999.

Strong, F. E. 1968. The selective advantage accrulng to lygus bugs that

cause blasting of floral parts. J. econ. fnt. 61 : 315 - 316.

50 raksdal, G. 1961. Eco10gy of plant resistance ta the tarnished plant bug,

Lygus lineolaris (P. de B.). M. Sc. Thesis, Cornell Univ., Ithaca, N. Y. 94 pp.

Taksdal, G. 1963. E(010gy of plant resistance ta the tarnished plant bug,

Lygus 11neolaris (P. de B.). Ann. ent. Soc. Am. 56 : 69 - 74. laylor, T. IL C. 1945. Lygus simonyi Reut., as a cotton pest in Uganda.

Bull. ent. Res. 36: 121 - 148.

Taylor, E. J. 1949. A life history study of Nabis alternatus. J. eC01.

Ent. 42 : 991 felford, A. D., and L. Hopkins. 1957. Arizona cotton insects. Arizona

Agr. fxpt. 5tn. Bull. 286. 60 pp. lugwell, P., S. C. Young, Jr., B. A. Dumas, and J. R. Phillips. 1976.

Plant bugs in cotton: importance of infestation time, types of cot­

ton ln jury, and significance of wild hosts near cotton. Univ.

Arkansas Agr. Expt. Stn. Rep. 227. 24 pp.

Uh 1cr, P. R. 1872. No t i ces of the Hemi ptera of the western territori es of

the United States, chiefly from the surveys of Dr .. V. Hayden, pp.

392 - 423. ln F. V. Hayden, Preliminary Report: U. S. Geological

Survey, Montana.

VdlHlerlant, [. S. 1967. Hearing Lygus on artificial diet. J. econ. Ent.

60 : 813 - 816.

Wdlley, G. S. 1929. Descriptions of new canadian parasitic Hymenoptera.

Cano Ent. 61 : 190 - 191.

51 Waters, H. A. 1943. Rearing inseets that attack plants: TarllisllC'd pl.mt

bug, pp 3 - 28. In F. L. Campbell, and F. IL Moulton, leds.l. Laboratory procedures in studies of the chernical control of III

sects. Am. Assoc. Adv. Sei. Pub 7. 20. 206 pp.

Whalon, M. E., and B. L. Parker. 1978. Immunological identifHdLIOIl of tarnished plant bug predators. Ann. ent. Soc. Am. 71 : 453 - 456.

Womaek, C. L., and M. F. Schuster. 1987. Host planl~ of Lhl' LH'nhhpd

plant bug (Hetet'optera: Miridae) in the Northern Blac..kland Prairl!'''

of lexds. Environ. [nt. 16 : 1266 - 1272.

Woodside, A. M. 1946. Cat-faclng and dlmpl ing ln peaches. J. econ. (nt.

39 : 158 - 160.

Young, O. P. 1986. Host plants of the tarnlshed plant 1>1I~J, Iygus 77ne07aris (Heteroptera: Miridae). Ann. ent. Soc. Am. 79 : 747 -

762.

Young, O. P., and T. C. Loekley. 1986. Predation of striped lynx spldp{',

Oxyopes sa7ticus (Araneae: Oxyopidae), on tarnished plant IJlI~I, Lygus lineo7ans (Heteroptera: Mlridae): a laboratory evaludtloll.

A~n. ent. Soc. Am. 79 : 879 - 883.

Young, 0 P., and Welbourn, W. C. 1987. Biology of lasloerythraeu)

johnstoni (Aeari: Erythraeidae), ectoparas i t le and pn!dau!(JlJ') on

the tarnished plant bug, Lygus 17neolaris (Herniptera: Mlrldap), dllrJ

other arthropods. Ann. ent. Soc. Am. 80 : 243 - 250.

52 3. [gg parasitoid complex of Lygus 7ineolaris associated with

Coroni17a varia L. , ~o7anum tuberosum L., and host weeds in southwestern Quebec

53 3.1 Introduction

The tarnished plant bug, Lygus 7ineo7aris (P. de B.), is thl' dominant mirid in crops grown in eastern North America (Strollq 19G8;

Bariola 1969). Lygus 1ineolaris in an ubiquitous spec ies found 011 a wld" range of wild plants and cultivated crops (Knight 1941).

All previously known egg parasitoids of Lygus spp. were rnyl11ill'1d\ 111 the genera Anaphes, frythmelus and Polynema (CII3C 1979). lhp mymal'ld,

Anaphes foIe (=ovjjentatus) Girault, is the prinl1pal eq9 pal'a~ll()1d of

Lygus spp. in the United States. Anaphes Iole was flrst reportpd a~ .111 egg parasitoid of Lygus pratensis L. in New York (Crosby alld leOl1clrd

1914a), and of Lygus hesperus Knight in Califorllia (HOJ1HlPy alld Ca';<'ldy

1945). This parasitold has been recorded ln LOUlsiana, 1\r1/0Ila, 11j<,<"1<, sippi and Indiana (Glick 1939; Stoner and Surber 1969; SillllHj') 1971;

Scales 1973; Sillings and Broersma 1974; Graham and Jackson 1982; Grahclfl1 et al. 1986). Recently, it has been recorded in a <;urvey of para<,itold<, from alfalfa and associated weeds in New MexIco (Gordon et al. 1987), II has been reported from four provinces and one tCfntory of LUlrl(Li:

British Columbia, Alberta, Ontano and Quebec, and the North Wpc;t Illf ritories, respectively (Huber and RaJakulendran 1988).

Wall e y (1 9 2 9) des cri b e dan e w s pee i e s 0 f 11 Yrn a r i d a e! Po/ Y Tl e ni rl pratensiphagum Walley, from L. pratensis eggs inserted in lorl1lTlOn Hlull p ln,

Verbascum thapsus L., in Ontario. Dozier (1937) reporf.ed Erythme/us mfridfphagus Dozier from the eggs of a mirld, Polymeru5 caneatus 01~tant!

54 collected from a pure stand of Amaranthus at the edge of a cane field at lIormigueros, Puerto Rico. Erythmelus miridlphagus was collected along rl par 1 an areas in northern Ca l iforn i a (Dout t 1949). 1his research was l!ndertaken ta integrate a biological component lnt.o ung01rlg control programmes for the tarr.ished plant bug ln south­ western Quebec. Recently, emphasls has been on the devr>lopment of an in­ tegrat.ed pest management programme for L. 7ineo7ans in Quebec. The ob­

Ject.ives of UliS study were: 1) Ta estimate the per'centage of parasitism of L. 7/neolans eggs ln crown vetch, Coroni71a vana L., potato, 507anum tuberosum and associated weeds, 2) Ta determine the existence and com­ positIon of the egg parasitoid complex, ar.d 3) To investigate the parasite-hast synchrony in southwestern Quebec.

3.2 ~aterials and Hethods

3.2.1 [99 parasitoid complex of L. lineolaris

A crown vetch plot of 30 by 30 m was establ ished at the Macdonald

Colleyp Seed Farm at Ste-Anne-de-Bel1evue (450 35 1 N, 73 0 57'W) in 1987 and sl'eus were broadcast by hand on 8 May 1987. On 7 July 1987 25 Kg of

34-0-0 granula}' fertilizer (W. H. Perron, Laval) was applied by hand to pnhdflce the growth of crown vetch. The plot was pesticide-free and was weeùed by hanù. lhis forage crap was chosen because it can sustain the complete llfe cycle of all generations of L. 1ineolaris (Martel et al. 1986). In 1987, three bean plots (cv. Cantender) each 10 by la m were

55 planted adjacent to the crown vetch plot at two-week intervals wilh tlH' first plot planted on 27 May }Q87. ln 1988, in additlOn to bl'an'\, two

plots of potatoes (cv. Shepody) were planted on 23 May and 7 ,!tlfl!' wJth

intra-row and ;nter-row spaclngs of 0.45 m and 0.75 Ill, rl's~H'dlvply. llll' crown vetch plot was separated by a 1 m gap From bean and potalo plo\<'.

Ouring July and August 1987, 750 (that i5 250 slpllls alld bl'alHhp\

per sample taken thrice per sampllng penod) stems and brall( Il!'\ of

pigweed, Amaranthus retroflexus l., a weed host of lygus spp., WPIP 1 ail

domly collected at Ste-Anne-de-Bellevue and at the Agricullul p ldllada (x

perimental Farm at Ste-Clotilde (45 0 10'N, 73° 39'W), QuelJf'C, in or dpI' 10

study the egg parasitoid complex of L. Ilneolans. The Stl'illS dlld bl'arHhp.)

of A. retroflexus were eut lllto 20 cm lengths and 50 weY'f' pla< pd IIJlo R fiv~ Tergal (Fabricville Co., Montreal) screelled caqps of '275 1 qld')')

jars, each with a ventilated metal caver. A f1l1e slt'l'l'n tprqal IJPlw(lpll

the jar top and caver prevented the parasitoids from escapllly. Ihp JiH', were maintained in incubators at 26 ± 1°C and a photopenod of 161 ·8D.

Lygus lineolaris nymphs or parasltoids ernerglng ft'om the (><1<)\ WPtP tp

corded daily. Due ta the dlfficulty ln locatlng J. Ilncolans Pqq') III

serted in plant stem tissues, the percent para<;ltlsm wa" bd<;pd on !hp emergence of first-instar L. lineolans and egg para<;rt()ld<;. Ihe pptcPlI1

parasitlsm was calculated by dividing the total number of pdra<;ltoHjc) by the sum of the total number of parasitoids plus L. Ilncolan s pymph', xIOO.

56 3.2.2 Seasonal variation of L. 1ineolaris population

Ta check the seasonal variation in the population density for adults and nymphs of L. 11neolaris, two weed and crawl! veteh habitats were sampled weekly using a standard sweepnet of 30 cm diameter. Fifty swe~ps Wère taken in weed habitats at Ste-Anne-de-Bellevue and Ste­

ClotIlde from mid-May to early November 1987. Twenty-flve sweeps were takpn 111 crown veteh habitat at Ste-Anne-de Bellevue from 22 July to early November 1987. The insects sampled were emptied in a plastic bag and lmmedlately taken to the laboratory for sorting and counting after llyhl1y anesthetiz Ing them wHh carbon dlOxide. The crown vetch and one w(!pd habItat were locdted at Macdonald College Seed Farm and the other wped habItat was located at Ste-Clotilde.

The w('ed habitat at Macdonald College Seed Farm was a mixture of al- falfa, f1cdTcago saUva L., red clover, Trifo17um pratense L., pigweed,

Amaranthus retroflexus L., dandelian, Taraxacum offic7nale Weber, lamb's

Cjllar·ter, Chenopod1um album L., ox-eye daisy, Chrysanthemum leucanthemum

1., tuftpd vrtch, ViCIa cracca L., Philadelphia fleabane, Etigeron phlladclph7CUS l., lady's thumb, Polygonum persicana L. and several

9rassps sllch as Bromus inermis Leyss., Kentucky blue grass, Poa pratensis

L., and quack grass, Agropyron repens (L.) Beauv. The weeds at Ste-

Clot i ld~~ were cornposed of A. retrof1~xus, C. album, C. leucanthemum, pu)'slane, Pol'tulaca oleracea L., T. officinale, T. pratense, V. cracca, and t llllothy grass, Phleum pratense L., A. repens and E. phi1adelphlcus

57 3.2.3 Level of parasitism of L. 77neo7aris eggs

To obtain eggs for this study, L. 7ineolans culture was st.ltlpd III mid-April 1987 using overwintering adults colleclE'd frum E'arly <"pnnq weed hosts such as dandelion, T. offIcinale and ttH' ShppIH',d'<; PlI'\!"

Capse77a bursa-pastoris L., at Ste-Anne-de-BellpvlIe, {JlIplwr. lyglJ~

7ineo7aris adults from the field were added ta thr culture tlllou911uut th!' season. ln 1988, overwintered L. 71neolans adults were Lollpcte

College Seed Farm. Adults of L. 71neolans were palred (i.r I1hllp ellHI fema1e) and p1aced in Tergal covered rearing cages (21 by 21 by 16 (Ill) and checked daily ta determine the condition of the inc,e(Is and lo

Six L. lineolans adults (3 females:3 males) lakpn flOIl1 IIH' (Idtlll!' were p1aced in five 500 ml glass jars contalnlng 4 grePII !)('an pooc, c,lHPd on one side ta allow ovipositlon for 24 hours. Anaphcs Iole lIspd Ifl IIIIc, experiment was from a culture slarled al Macdonald lollpge 1I',iny thl!'P

(l fema1e: 2 male) adu1t wasps that emerged from l. llncolans pqer, in serted in broad-leaved dock, Rumex obtuslfollus stems. lo f!rl-;Ure that 1111' adult A. io7e used in this experiment were mated, thf'y were palrpd (rllalp and female) at emergence and put in I-dram vials fLr 24 hOUfS lo nltltr.

The green bean pods with a known number of L. Il ne 17 an s {~qy<; Wf!Y'f' PX posed to two mated fema1es of A. iole 24 hours old for three day-;. The

58 parasitlzed eggs were kept in the incubator at 26 ± IDe and a photoperiod of 16L:80 for 21 days. The experiment was replicated three Urnes. Ernerg- ing pilrasltolds were recorded and after 21 days, the bean pods were dis­ sected ta count the dead larvae and pupae of A. Jale and dead eggs of L. l/neolans. The percent parasitism of L. lineolans eggs was calculated by the formula,

A + B A + B + e + D where A = number of emerged A. fole, B == number of dead larvae and pupae of A. Iole, e = number of hatched L. lineolaris nymphs, and D :: number of dead L. llneolaris eggs. A 95% confidence interval was calculated using the normal approxImation (Steel a~d Torrie 1980),

r - ---- " (1 _ pA) P ± Z0.05 (N orma 1) 1 .E<.P---'_~ __t!.4- __ 1 \ n " where p == observed proportion of parasitized eggs in the population,

10.05 = 1.96, and n = total number of observations in the samp1e.

10 determine the percent parasitism of L. lineo7an~ eggs in the field, ten pairs (10 males: 10 females) of L. llneo7aris adlllts were put in 4 cylindrical sleeve cages (15.0 diameter and 35 cm ~,igh) which were placed randomly over crown vetch plants. The top was covered '/nth tergal and the boltom was earthed to approximalely 5 cm. The cages were sup- ported by wooden slakes to prevent them from fa111ng. Sorne 1eaves of crown vetch stems and branches were removed to avoid too mllch evapo- transpirat10n lnside the cages. After 24 hours, the cages were removed to

59 expose the eggs to possible parasitism for three days. After three days. the stems and branches were cut into 20 cm lenglhs and put into (,l1lel~l'Il(!' cages" The number of L. lineolaris eggs was counted lIsing a dissert ill~1 microscope before putting the stems into 2.75 L Jars and the ell1('r~JPnce of parasitoids and L. 7ineo7aris nymphs was checked daily. lhe percC'llt parasitism was calculated as above.

3.3 Results and Discussion

3.3.1 E99 parasitoid c.omplex of L. lineo7aris

On 30 July 1987, parasitoids were observed emerging from 1.

7ineo7aris eggs inserted in A. retrof7exus slems and br'ancllPs lO!!P( lpd on July 15 (Table 3). Four species of egg parasitold~ L. l1neolans were retrieved by this method: Anaphes iole Girault (FIg. 1), Polynema praten siphagum Walley (Fig. 2), Erythmelus mlr1dlphagus OOllPr (ri~l. 3)

(Mymaridae) and a Telenomus sp. (Sceliortldae) be!onglng lo lhe Telenomu~

7aricis Walker group of species (Fig. 4). 1h15 is the flrsl y'e({)rd of d scelionid parasitizing L. lineolans eggs. t~ale para5Jtcnd'> (>fII(!rlJPd first. A similar pattern of emergence has been ob5erved wilh Anaphes sor didatus (Gi rault) emergi ng from eggs of the carrot weev il, il st ronotus oregonensis (Le Conte) (Guy Boivin pers. comm. 1).

1Research Station, Agriculture Canada

Saint-Jean-sur-Richelieu, Québec, Canada J3B 6Z8

60 In 1988, samples were collected only at Ste-Anne-de-Bellevue and the same egg parasitoid species were retrieved From stems and branches of broad-leaved dock, crown vetch, lamb's quarter, pigweed and patata. Based on the level of parasitism, Erythme7us miridiphagus and P. pratenslphagum were the most abundant parasitoids recorded. However, all four parasitoids were present throughout the season.

3.3.2 Seasonal variation of L. lineo7aris population

The seasonal variation of the population density of L. 7ineolaris is shown in Fig. 5. The results From the two weed habitats are similar. Overwlntering adults were found on both habllals in May 1987. By the beginning of June, the nymph population increased in the two habitats and reached a high density by late June at Ste-Anne-de-Bel1evue (Fig. SB) and mid-July at Ste-Clolllde (Fig. SC). The adult L. linealaris population reached a peak late June at both locations and decreased thereafter. The crown vetch harboured more L. l1nealans adults and nymphs (Flg. SA) con·­ firmlng the fact that crown vetch is highly attractive to L. 71neo7aris and harbours substantial populations throughout the season. They are a1so compatible with the seasanal developments found on alfalfa (Khattat and

Stewart 1980), apple (Baivin and Stewart 1983a), crawn vetch (~lartel et al. 1986), strawberries (Boivin et al. 1981a), and various species of weeds (Baivin et al. 1981b; Boivin and Stewart 1983b; Fleischer and Gay10r 19B?).

61 3.3.3 Level of parasitism of L. Uneolaris eggs

Field parasitism by A. iole, E. miridjphagus, P. pratenslphagum and

Te7enomus sp. on eggs of L. lineolaris was first observed frolll A. retrof7exus stems and branches collected at Ste-Clotilde and Stf' 1\1l1l1' de-Bellevue in 1987 (Table 3). In 1988, percent parasitlSIl1 of the f01l1' parasitoids on eggs of L. lineolans retneved from A. retroflexus stplIl'" and branches at Ste-Anne-de-Bellevue \'Iere recorded (Flg. 61\, B). ~IlJ. 6( shows the number of L. linealaris eggs inserted in A. retrof7cxus ... tpllI~) and branches. This weed attracted more L. l1neolaris adulte- and Ilymph,> at the t ime wh en the spri ng weeds were senesc i ng in 1a te ,Julie.

The level of parasitlsm of L. 17nea7ads eggs by P. pratcnslphayul11 increased to a peak (61.8%) in late August and uecreased thereafter (1 iq.

6A). Parasitism of E. miridiphagus remalned below 40% for rno"t of thp time except in late October when it reached 53.8% (rlg. 61\). Ihl' ppneflt

parasitism of A. iale and Telenomus sp. on L. 7incolans P~q<; wa ... Ip,>c,

than 20% throughout the season (Fig. 68). lhe resu1t<; of the 11IJIII!Jr>r of 1.

7ineolaris eggs laid in A. retroflexus stems and brt:ndlf><; were rpconlpd

(F~g. 6e). Based on the percent parasltism, lelenomus sp. found Hl A. retroflexus were in synchrony with eggs laid by first generatiol1 adults

of L. lineolaris. The number of eggs increased to a peak in mid I\llqw,t

and decreased until the end of the season.

The pe r c e n t par a s it 1 sm 0 f L. li ne a l a ri 5 e9 g s i Il S (! r t f~ d i ri IL 0 b

tusifolius by A. iole, E. mlr1dlphagus and Telenomus sp. were bplow 10'10

whereas the raLe of parasitism P. pratens;phagum reached 25% (f ig. 71\,

62 B). The pattern of parasitism of L. lineolaris eggs by E. miridiphagus and Telenomus sp. were similar and increased to a peak in late June (Fig.

7B). It is more likely that the parasitoids retrieved from R. ob­ tusifolius stems and branches were parasitizing eggs laid by the overwin­ tering adults of L. lineolaris. Sampling was stopped early July because the plants were senescing. Fig. BA and B show the percent parasitism of the four parasitoids on L. lineolaris eggs laid in S. tuberosum. The level of parasitism of L. lineolaris eggs by P. pratensiphagum reached a peak (47.9%) in mid-July

(Fig. BA). Erythmelus miridiphagus reached a peak parasitism of 23.4% early August (Fig. 8A) when the number of L. 71neolaris eggs was on its ebb (fig. 8C). Based on the rate of parasitlsm of the four parasitoids obtamed in S. tuberosum and the phenological data of L. lineolaris (Stewart and Khoury 1976; Khattat and Stewart 1976, Boivin et al. 1983b),

E. miridlphagus and P. pratensiphagum were in synchrony with the second and Unrd adult generations of L. Uneolaris. However, no synchrony was observed with Telenomus sp. Parasitism of A. Iole on L. I1neolaris eggs reached a peak in late July and decreased thereafter (Fig. 8B). On the contrat'y, parasitism of L. lineolaris eggs by Telenomus sp. was high at the beginning and end of the sampl ing period corresponding to low L. Tineolaris eggs (Fig. 8C). The levels of parasitism of E. mirldiphagus and P. pratensiphagum on L. 17neolaris eggs retrieved from C. album reached a peak in mid­

August and early August, respectively (Fig. 9A). The egg number of L.

71neolaris was low (Fig. 9C) when E. mlridiphagus and P. pt'atensiphagum

63 were at their peak parasitisme Parasitism of L. 1ineolaris eggs by A. iole in C. album never exceeded 5% throughout the season (1 ig. 9B). However, parasitism of L. lineolaris eggs by Telenomus sp. was high at the end of the season (Fig. 9B).

The level of parasitism of f. miridiphagus on L. lineolar'is e~ms inserted in C. varia reaehed its peak in early September (Fig. 101\) tllld that of P. pratensiphagum was recorded in E'drly October (rig. 101\).

Parasitism of A. iale and Telenarnus sp. (Fig. lOB) on L. 71neolans eggs laid in erown veteh was more fluetuating than those of E. m/ddlphagus and P. pratensiphagum. The egg number reaehed its peak in early I\ugust.

In addition to L. lineolaris, eleven Lygus vanduzeei Knight and riqht

Nabis spp. hatched from the eggs retrip.ved from C. vana betwern lB ,July and 29 August. No Nabis spp. nymphs were reared from eggs colledrd be tween September and October despite the presence of the adul ts 111 C. vari a.

Parasitism of L. lineolaris eggs exposed to paraC:;iloid sppries in

C. varia revealed the pre5enCE' of the fOLlr egg parac,itolds (Ii~l. II): Il. iole, f. miridiphagus, P. pratenslphagum and 7elenomus sr.· Ih~se n"!'i.ults demonstrated that peaks of paras it i sm of E. mi ri dl phaglJs and P. pratcn­ siphagum on L. lineolaris eggs weY"e reached in Inld-September and mid­

August, respectively (Fig. liA). However, peak parasitism of A. joie WélS reached in early September when the lel/els of parasitism of the othp.r parasitoids were at their lowest.

64 The level of parasitism of 341 eggc; of L. 7ineolaris by A. iole in

the l aboratory was 49.9 ± 5.3% (% ± C.1.). These resul ts were lower than those found by Stoner and Surber (1969) for the same species parasitizing

eggs of L hesperus in Arizona. Stoner and Surber (1969) recorded 82.7%

pdras i t i sm of L. hesperus eggs in the 1 abora tory.

-rhe results bath from the retrieval of L. 7ineolaris eggs inserted

in varlOUS plant stems and branches and the exposure of the eggs ta pos­ sIble parasitoids in C. varia demonstrated that there were four egg parasitotJ species presenl both at Ste-Clotilde and Ste-Anne-de-Bel1evue.

frythmelus mindlphagus and P. pratenslphagum were ~he most abundanl egg

para~lloid ~pecies recorded. However, Palnter (1929) repoded that only

seven sp(!ClnIens of P. pratensiphagum were secured from egg collections of

L pratensls inset'ted in common mullein, V. thapsus, between July and

August ;n Ontario. 1he results also show that thec;e parasitoids are more active during the August through October period (Flg. 9). Amaranthus

retroflexus and 5. tuberosum harboured high numbers of L. 17neolaris eg~ls, pcrhaps because they are more succulent and could provide a better dl'veloprnent of the nymphs. High levels of parasitlsm were recorded on A.

retrofle)(u~ (flg. 6) and S. tuberosum (fig. 8). The level of parasitism of A. Iole on L. lineolaris eggs was lower than previously reported by

Slllings (1971) and Sillings and Broersma (1974) in Indiana. lhey re­ conled 85~~ parasitism of L. Uneolaris eggs in alfalfa fields.

65 3.4 Potential for biological control

The most successful families of egg parasitoids are Scelionidae and

Mymaridae (Greathead 1986). There are seant y reports of P. pratcn­ siphagum, E. miridiphagus and Telenomus sp. as egg parasilcllds of Iygus

spp. Nevertheless, it has been shown in thi s study that f. m,nd,phi/gus

and P. pratensiphagum had a high level of parasitlslll on L. ',nca1a,.,s

eggs in the field. The two parasitoid species should bp lOn~ldul'd potP1\ tial candidates for biological control in Quebrc. lIowpvPt·, thp !pvpl of

parasitism of L. 7ineolaris eggs is low during spring and parly ~llIllIllPt·

because the parasitoid population i5 still developing. Thuc;, il woulcl IH'

necessary to augment the parasitoid population la eff(lctlv(~!y maintal!l 1.

lineolaris population belaw the economic lhreshold tll"oll~n()l/t the ')Pd'.O!l.

A11 four paras i toid spec ies may be considered important morla 1i ty factors

against L. lineolaris population especially for the eggs laId by the

second generation during which the parasitoids are in abundaflce. If Ihat

is the case, then those crops that are g""own dUr1ny carly SlJIIIIIIPt' Illay sut

fer severe L. lineo7aris darilage when the parasih>1d populalio!l 1<, <,1111

too low ta control L. lineo7aris. These resulls woulri be l/<,f!ful 10 thp

r development of integrated pest management pr01jrdnllne -.

Suc ces s f u l a u9 men t a t ion 0 f the sep a r il silo 1 d s rj e p p nd s u Il () Il t 1H~

timely availabil Hy of adequate numbers of them. As a result an efff>C!pnt

and highly cost-efeClive methods are requlred ta merl. tll15 goal. IfH!

rearing methods should be improved and/or developed for tl1f~ para',ltoi(j<,

to be produced in mass numbers for re1ease. There are several problf~rn') in

66 reanny pilrasitaids of L. lineolaris using potata sprouts and green ueans. Maulding and drying of the substrates are the most serious problems in cultunng the parasitoids in the laboratary. The potataes and grt]en beans are expenSlVe during off-season and sometimes when avai1able are not of good quallty. Hns problem may be solved by deve10plng artifi­

Cld1 diels which are eff1clent and hlghly cost-effective. Patana and

Debolf. (1985) developed an artiflcial diet for L. hesperus. Perhaps a sI1Jl11ar kind of an arliflcial diet could be developed for other hasts of lh!!,>e paras 1 tOlds.

Sludles by Graham and Jackson (1982) and Graham et al. (1986) sug­ gest some potentlal for manipulation of A. joIe in a biological control or integrated control programme for Lygus spp. Anaphes iole can ki 11 up to 60 per cent of the lygus bug eggs 1 n alfa 1 fa grown for seed. However, many times, too few wasps are present and lygus bug populations soar out of control (Senft 1987). In Quebec, the level of parasitism of A. iole on

L. Ilneolaris was lower than 20% throughout the season. It is not a prollllsing candidate for biological control, unless by augmenting ils population. Nevertheless, that level of parasltism is still beneficial ta the growers because L. llneolans population would be reduced.

Lygus bugs are very mobile which implies that the timing of these bugs eggs in the field l'lOuld vary from crop to crop. Since they are oHen the source of infestation of Lygus to the adjacent crolJs, it would be nece!>sary to release these parasitoids in the weeds early in spring as soon as the bugs have started laying eggs to check their populatlOn before soaring out of control. Poston and Pedigo (1975) found L.

67 7ineo7aris adults and nymphs migrated from cut alfalfa to thr bon!p!'<; of soybean fields and Stewart and Khout,y (l976) indicaled A. rct"oflc\us as a source of infestatlon to celery. Khatlat and Stewart (1980) round lhdl the adults and nymph s of L. lineo 1ad 5 dl sperseJ lu (TOPS and wl'Plh in flower. To effectively use the se parasitoids ln biulogi(al (olltrol Wl' need to understand fully their biology.

3.5 Conclusions

Lygus 7ineolaris eggs in southwestern Queber are parasitl1Pd by four species of hymenopterous wasps: A. Jo/e, E. mlrldiphagus, and P. pratensiphAgum (Mymaridae), and Telenomus sp. (ScellOnldae). This jt, thl' first report of a Scelionldae parasltlzing L. l1neolans f'yq5. Ihp maxi mum level of parasltism of L. /lneo7ans eggs by these, was 15.4, 53.8,

70.0 and 17.8%, respectively, in the field.. The para~ltoid~ W{~t'f' retrieved from stems and branches of A. retrof7exus, C. album, C. varia,

R. obtusifolius and 5. tuberosum. Amaranthus retroflcxus and S. tuhrrosum sustained a large number of L. llneo/ans and CUy pardsltoid ')Ili'( IP'> perhaps because they are more succulent and could provlde a betlpY' <'IJY' vival for L. lineo7aris development. E. mindlphagus and P. pratcn siphagum were the mast abundanL egg parasltold species recoydf!(1

Anaphe<; lo/e has already shawn itself a polential can(JJdalp for augmentative release in Arizona where it l S successfully mass prodlJu~d on

L. hesperus eggs inserted in an artificial diet. Hm'/ever, E. mln'diphagus and P. pratensiphagum are the most potE:ntial candIdates for biolorJical

68 control of L. lineo7aris in southwestern Quebec. Further investigations are necessary ta determine their overwintering strategies and abil ity to withstand lengthy storage pedods in the laboratory before they can be used in release programmes. A study on the biology of F. miridiphagus, P. pratenslphagum and Telenomus sp. i~ necessary. Eventually, the se species could be used to augment mortality of L. 7ineolaris populations in in­ tegrated pest management programme~.

69 3.6 References

Bariola, L. A. 1969. The biology of the tarnished plant buq, /yyu~

7ineo7aris (P. de Beauvois), and its nature of damd~le drHI lOl\tlol

on cotton. Ph. D. Dissertation. Texas A & M UnIversIty, (olll'qp

Station. 102 pp.

Boivin, G. and R. K. Stewart. 1983a. Sampling techlllqup and <;pa"olldl

development of phytophagous mirids (llemipteta MIl'lddP) Oll ,)pplp

in south-western Quebec. Ann. ent. Soc. Am. 76 359 - 364.

Boivin, G. and R. K. Stewart. 1983b. Seasonal developlllent and Intl'lpLll1I

movements of phytophagous mlrids (Hemlptera : MIl'idiH') on dltptll,lIp

host plants in and around an apple orchal'd. Ann. ent. Soc. Am 76

776 - 780.

B0 i vin, G., G. Mai 1 1 0 u x, R. O. Par ad 1 s, and J. G. Il 1 1 (J n. 198 1 cl l ,\

punaise terne, Lygus lineolans (P. de B.) (IlPllllptPld. I~'t Idd!'),

dans le sud-ouest du Québec. I-InformatlOrl addlll011f1P]]p <,llt ',on

comportement dans les fraisieres et frambolsu:'re<;. Ann. Soc. l'nt.

Que. 26 : 131 - 141.

Boivin, G., G. Mailloux, R. O. Paradis, and J -G. P']OIl. 1981h Id

punaise terne, LY gus 71 ne a 1ans (P. de B.) ( Il f! m, p t p t' a' 11, y ,cl rl Il ) ,

dans le sud-ouest du Québec. II. rluctuatior1') ',ai ',Ollflll'YP', Il,,,,

populations sur certaines mauvaises herber; Ann. Sor. cnt (jU(l 26

: 159 - 169.

70 Commonwealth Institute of 8;010g;ca1 Control (CIBe). 1979. Possibilities

for the blological control of lygus bugs (Hemiptera, Miridae). Com­

rnonw. Inst. Biol. Status Paper No. 15. 7 pp.

Cru~lJy, l. R., and M. D. Leonard. 1914. An egg-parasite of the tarnished

plant lJug, Lygus pratensls L. Cano Ent. 46 : 181 - 182.

Debolt, J. W. 1987. Augmentation: Reanng, release, and evaluat;on of

plant bug parasites, pp 82 - 87. ln R. C. Hedlund, and H. M. Graham

leds.], EconomIe importance and biologlcal control of Lygus and

Adelphocor/s ln North America. USOA, ARS, ARS-64, 95 pp.

[)oult, H. L. 1949. 1he genus Erythmelus in California (Ilymenoptera,

MYlIlarldae). Pan-PacIfIe Ent. 25 : 77 - 81.

[)OllPt', H. L. 1937. Oescnptions of miscellaneous chalcidoid parasites

hum Pllet'to RIco. (llymenoptera). J. Agne. Univ. Puerto RIco 21 :

12J - 135.

f 11'1')(her, S. J., and M. J. Gaylor. 1987. Seasonal abundance of Lygus

lineolaris (Heieroptera: Mlrldae) and selected predators in early

~Pd~on llllcultivated hasts: lmplications for managing movement into

cottOl1 lnvlron. [nt. 16 : 379 - 389.

l,IIll<., P A. 1939. lhe dlstnbution of insects, spiders, and mites in the

aIr. U5LJA Tech. Bull. 673 : 1 - 150.

(;onlon, R , J. lllington, G. F. Faublon, and H. Graham. 1907. A survey of

UlP inspcl Pill'dSlloids froill alfalfa and associated weeds in New

~,pxico. 50uthwest. [nt. 12 : 335 - 348.

II Graham, H. M., and C. G. Jackson. 1982. Dlstribut ion of (199" of Iygus

spp. (Hemiptera: Miridae), Nabis spp. (Hrllllplera: Nabldap), ,lI1d

SpiSSlsti7us festinus (Say) (Homoptera: MembrdCiddP) on pltll1t

stems. Ann. ent. Soc. Am. 75 : 56 - 60.

Graham, H. M., C. G. Jackson, and J. W. Oeboll 1986. Iygu) "pp

(Hemiptera: Miridae) and their parasites in aqrHllltul'dl .111',\'> of

sOlJthern Arizona. EnvIron. Ent. 15 : 132 - 142.

Greathead, D. J. 1986. Parasltoids in classical bioloyi(al (ol1t)ol, pp

289 - 3 1 8 . 1 n J. Wa age and D. J. Gre a the ad l (' (h J,Ill '> l' ( 1

parasitoids 13th Symposium of the Royal [ntornu!otj1tal ~()( Il'Iy of

London 18 - 19 Seplember 1985, London. ACddpl11H Pt (><,'), IOIlt!OIl 1B9

pp.

Huber, J. T., and V. K. Rajakulendran. 1988. Rl!de~(r1pt 1011 of ,H1d hw,t

induced antennal variation ln Anaphes Iole GIrault (HyIlIPlloptl't

Mymaridae), an egg parasi te of MI ndae (Heml pt (lt il) III r~()I' Ir

America. Cano [nt. 120 : 893 - 901.

Khattat, A. R., and R. K. Stewart. 1977. Dpvelopmf'lll dlld ',lH Vlvrll of

Lygus 7ineo7an5 exposed ta differ'ent laboralory Yf'ilrtrHj (olldl

tians. Ann. ent. Soc. Am. 70 : 274 . 278.

Khattat, A. R., and R. K. Stewart. 1980. PopuldtloJl flu( tlJdlIOIl', dnrl III

terplant movements of Lygus 71neolans. Ann. cnt Soc /lm. 73 . ?Fl?

- 287.

Knight, H. H. 1941. lhe plant bugs, or Mlndae uf III trIUI',. liull III

Stn. Not. IIlst. Surv. No. 22. 234 pp.

72 t~artel, P., G Boivin, and J. Belcaurt. 1986. Efficiency and persistence

of different insecticides against the tarnished plant bug, Lygus

lineolans (Heteroptera: Miridae), on a season-long hast plant,

Coron/lia' ana. J. econ. [nt. 79 : 721 - 725.

Palnter, R IL 1929. lhe tarnishpd plant bug, Lygus pratensis L.: A

progress report. Ent. Soc. Ont. Annu. Rep. 60 : 102 - 107. Poston, r. L., and L. P. Pedigo. 1975. Migration of plant bugs and the

potato leafhopper in a soybean-alfalfa complex. Environ. Ent. 4: 8

10

Romney, V. L, and T. P. Cassidy. 1945. Anaphes oviJentatus, an egg­

paras i le of Lygus hesperus. J. econ. Ent. 38 : 497 - 498.

~cales, A. L. 1973. The parasites of the tarnished plant bug in the Mis­

sIssIppi Oelta. Envlron. Ent. 2 : 304 - 306.

~Pllft, IL 1987. Trading wasps with rubidium. U. S. Oept. of Agric.,

A.ILS., Agt'ic. Res. 35: 4.

Slllln~l<;, J. O. 1971. lhe parasites of the tarnished plant bug, Lygus

11 ne 0 1a ri 5 , i Il 1n d i ana. Pro c . North Ce nt ra l Br an ch, en t Soc. Am.

26 : 105.

~Illln~ls. J O., and D. B. Broersma. 1974. The parasites of the tarnished

plant bug. Lygus lineolaris, in Indiana. Proc. North Central

/iranch, ent. Soc. Am. 29 : 120 - 125.

Steel, G. D., and J. Il. Torrie. 1980. Principles and procedures of

<,tatistics: A blornetrical approach. 2nd. ed. McGraw-Hil1 Book Co.,

Nl'W York, 633 pp.

73 Stewart, R. K., and A. R. Khattat. 1980. Economie injury level of the

tarnished plant bug, Lygus lineolaris (llemiptera (Heteroptera):

Miridae) on green beans in Quebec. Cdn. Ent. 112 : 306 - 310.

Stewart, R. K., and H. Khoury. 1976. lhe blOlo9Y of Lygus l111eolal'ls

(Palisot de Beauvois) (Hemitltera: Miridae) III Quebec. Ann. Soc.

ent. Que. 21 : 52 - 63.

Stoner, A., and O. E. Surber. 1969. Note on the bio1ogy and rearllll) of

Anaphes ovijentatus, a new paras ite of Lygus hesperus l Il Ar i lona.

J. econ. [nt. 62 : 501 - 502.

Strong, F. E. 1968. The selective advantage accruing ta lygus bugs that

cause blasting of floral parts. J. econ. Ent. 61 : 315 - 316.

Walley, G. S. 1929. Descriptions of new canadian parasilic Hymrnoptpra

Cano [nt. 61 : 190 - 191.

J

74 3.7 Tables

75 Table 3. Percentage parasitism of Lygus lineolaris eggs collected from Amaranthus retraflexus in southwestern Quebec. 1987.

Parasitoid No. of No. of % f'ljq Date species hast eggs paras i toids parasitl\1li

Female Male

Ste-Anne-de-Bellevue 698 15.vii.1987 A. ia 1e 4 o 7 P. pratensiphagum 21 3 3 4 E. miridiphagus 28 5 4.1 Telenomus sp. 6 9 2 0

191 4.v;;,,1987 A. i a7 e 9 3 6.3 P. pra t en SI phagum 47 22 36 1 E. miridiphagus 28 6 17.8 Telenomus sp. 15 8 I? .0

------"

Ste-Clotilde 85 3.viii.1987 A. iole 2 6 9,4 P. pratens i phagum 9 7 J8 B E. ml ridiphagus 6 8 16 5 Te7enomus sp. 2 5 B.7

------

76 3.8 Figures

77 1 Fig. 1. Adults of Anaphes foIe Girault (Hymenoptera: r~Yll1arJdae)

Left = Female. Right ::: ~ldle

Fig. 2. Adults of Polynema pratensiphagulIJ ~~aney (Hymenoptera:

'~ymaridae) Left::. Female, Right = Male

1