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PARASITISM OF THE ARMY CUTWORM, EUXOA AUXILIARIS (GRT.) (LEPIDOPTERA: NOCTUIDAE), BY COPIDOSOMA BAKERI (HOWARD) (HYMENOPTERA: ENCYRTIDAE) AND EFFECT ON CROP DAMAGE1

Published online by Cambridge University Press:  31 May 2012

J.R. Byers ,
D.S. Yu  and
J.W. Jones
J.R. Byers
Affiliation:
Agriculture Canada Research Station, PO Box 3000, Main, Lethbridge, Alberta, Canada T1J 4B1
D.S. Yu
Affiliation:
Agriculture Canada Research Station, PO Box 3000, Main, Lethbridge, Alberta, Canada T1J 4B1
J.W. Jones
Affiliation:
Alberta Special Crops and Horticulture Research Station, SS4, Brooks, Alberta, Canada T1R 1E6
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Abstract

During an outbreak of army cutworm in southern Alberta in the spring of 1990, the overall incidence of parasitism by the polyembryonic parasitoid, Copidosoma bakeri (Howard), was 61% in samples from seven fields. The incidence of parasitism in samples of army cutworms collected on five dates from a single location, during the spring of 1991, increased from about 20% in the early samples to about 50% in the later samples. Cutworms parasitized by C. bakeri feed for a longer time than unparasitized ones; therefore estimates of the incidence of parasitism by C. bakeri, based on samples of late-instar cutworms, are misleadingly high. Parasitized cutworms also grow considerably larger than unparasitized ones and may have a supernumerary instar. Larger hosts support larger broods of C. bakeri and apparently a successful strategy of C. bakeri is to prolong host development so as to maximize an acquired resource. Because cutworms parasitized by C. bakeri feed more and longer than unparasitized cutworms, a high rate of parasitism can exacerbate crop damage and complicate control recommendations. The life cycles of army cutworm and C. bakeri are asynchronous and it is likely that high rates of parasitism are dependent on the presence of intermediary hosts.

Résumé

Au cours d’une infestation de Légionnaires grises dans le sud de l’Alberta au printemps de 1990, le taux de parasitisme par le parasitoïde polyembryonnaire Copidosoma bakeri (Howard) a été évalué à 61% dans des échantillons provenant de sept champs. Au cours d’un programme d’échantillonnage effectué en un endroit au printemps de 1991, l’incidence du parasitisme a augmenté d’environ 20% dans les premiers échantillons à environ 50% dans les échantillons recueillis plus tard. Les légionnaires parasitées par C. bakeri se nourrissent plus longtemps que les légionnaires saines, et les estimations de l’importance de l’infection basées uniquement sur les échantillons de légionnaires de dernier stade sont beaucoup trop élevées. Les légionnaires parasitées atteignent également une taille beaucoup plus grande que les légionnaires non parasitées et subissent peut-être une mue supplémentaire. Les hôtes les plus gros supportent des fardeaux de parasites plus grands et il semble que le parasite utilise une stratégie avantageuse en prolongeant le développement de l’hôte, maximisant ainsi la durée de son utilité. Comme les légionnaires parasitées par C. bakeri se nourrissent plus abondamment et plus longtemps que les légionnaires saines, un taux élevé de parasitisme peut exacerber les dommages aux récoltes et complexifier les problèmes de contrôle. Les cycles biologiques de la légionnaire et du parasite sont asynchrones et il est fort possible que des taux élevés de parasitisme soient reliés à la présence d’hôtes intermédiaires.

[Traduit par la rédaction]

Type
Articles
Information
The Canadian Entomologist , Volume 125 , Issue 2 , April 1993 , pp. 329 - 335
Copyright
Copyright © Entomological Society of Canada 1993

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References

Baehrecke, E.H., and Strand, M.R.. 1990. Embryonic morphology and growth of the polyembryonic parasitoid Copidosoma floridanum (Ashmead) (Hymenoptera: Encyrtidae). International Journal of Insect Morphology & Embryology 19: 165–175.Google Scholar
Beach, R.M., and Todd, J.W.. 1986. Foliage consumption and larval development of parasitized and unparasitized soybean looper, Pseudoplusia includens (Lepidoptera: Noctuidae), reared on a resistant soybean genotype and effects on an associated parasitoid, Copidosoma truncatellum (Hymenoptera: Encyrtidae). Entomophaga 31: 237–242.CrossRefGoogle Scholar
Burton, R.L., Starks, K.J., and Peters, D.C.. 1980. The army cutworm. Bulletin B–749, Agricultural Experiment Station, Oklahoma State University. 35 pp.Google Scholar
Cheng, H.H. 1977. Insect parasites of the darksided cutworm, Euxoa messoria (Lepidoptera: Noctuidae), in Ontario. The Canadian Entomologist 109: 137–142.CrossRefGoogle Scholar
Heinrich, G.H. 1960. Synopsis of Nearctic Ichneumoninae Stenopneusticae with particular reference to the northeastern region (Hymenoptera). Part II. Synopsis of the Ichneumonini: Genera Orgichneumon, Cratichneumon, Homotherus, Auclichneumon, Spilichneumon. The Canadian Entomologist, Supplement 18: 89–206.Google Scholar
Heinrich, G.H. 1969. Synopsis of Nearctic Ichneumoninae Stenopneusticae with particular reference to the northeastern region (Hymenoptera) — Supplement 1. Le Naturaliste Canadien 96: 935–963.Google Scholar
Hinks, C.F., and Byers, J.R.. 1976. Biosystematics of the genus Euxoa (Lepidoptera: Noctuidae). V. Rearing procedures, and life cycles of 36 species. The Canadian Entomologist 108: 1345–1357.CrossRefGoogle Scholar
Hunter, K.W., and Stoner, A.. 1975. Copidosoma truncatellum: Effect of parasitism on food consumption of larval Trichoplusia ni. Environmental Entomology 4: 381–382.Google Scholar
Ivanova-Kasas, O.M. 1972. Polyembryony in insects. pp. 243–271in Counce, S.J., and Waddington, C.H. (Eds.), Developmental Systems, Vol. 1. Academic Press, New York, NY.Google Scholar
Jones, D., Jones, G., van Steenwyk, R.A., and Hammock, B.D.. 1982. Effect of the parasite Copidosoma truncatellum on development of its host Trichoplusia ni. Annals of the Entomological Society of America 75: 7–11.CrossRefGoogle Scholar
Jones, J.W., Byers, J.R., Butts, R.A., Okuda, M., and Harrison, L.. 1990. Insects and related pests of cereal crops — Alberta. The Canadian Agricultural Insect Pest Review 68: 13–14.Google Scholar
King, K.M., and Atkinson, N.J.. 1928. The biological control factors of the immature stages of Euxoa ochrogaster Gn. (Lepidoptera, Phalaenidae) in Saskatchewan. Annals of the Entomological Society of America 21: 167–188.CrossRefGoogle Scholar
Mattson, D.J., Gillin, C.M., Benson, S.A., and Knight, R.R.. 1991. Bear feeding activity at insect aggregation sites in the Yellowstone ecosystem. Canadian Journal of Zoology 69: 2430–2435.Google Scholar
McMillan, E. 1930. A Preliminary Study of the Polyembryonic Cutworm Parasite, Berecyntus bakeri var. gemma Girault. M.Sc. thesis, University of Saskatchewan, Saskatoon, Sask. 243 pp.Google Scholar
Noyes, J.S. 1988. Copidosoma truncatellum (Dalman) and C. floridanum (Ashmead) (Hymenoptera, Encyrtidae), two frequently misidentified polyembryonic parasitoids of caterpillars (Lepidoptera). Systematic Entomology 13: 197–204.Google Scholar
Orr, D.B., and Boethel, D.J.. 1985. Comparative development of Copidosoma truncatellum (Hymenoptera: Encyrtidae) and its host, Pseudoplusia includens (Lepidoptera: Noctuidae) on resistant and susceptible soybean genotypes. Environmental Entomology 14: 612–616.Google Scholar
Roberts, L.I.N., and Cameron, P.J.. 1989. Chrysodeixis eriosoma (Doubleday), green looper (Lepidoptera: Noctuidae). pp. 67–72 in Cameron, P.J. et al. , (Eds.), A Review of Biological Control of Invertebrate Pests and Weeds in New Zealand 1874 to 1987. Commonwealth Agricultural Bureaux International Institute of Biological Control, Technical Communication No. 10.Google Scholar
Schaaf, A.C. 1972. The parasitoid complex of Euxoa ochrogaster (Guenee) (Lepidoptera: Noctuidae). Quaestiones Entomologicae 8: 81–120.Google Scholar
Seamans, H.L. 1929. The army cutworm. Pamphlet No. 102 — New Series, 8 pp. Department of Agriculture, Ottawa, Ont.Google Scholar
Slansky, F. 1978. Utilization of energy and nitrogen by larvae of the imported cabbageworm, Pieris rapae, as affected by parasitism by Apanteles glomeratus. Environmental Entomology 7: 179–185.CrossRefGoogle Scholar
Snow, S.J. 1925. Observations on the cutworm, Euxoa auxiliaris Grote, and its principal parasites. Journal of Economic Entomology 18: 602–609.Google Scholar
Steel, R.G.D., and Torrie, J.H.. 1980. Principles and Procedures of Statistics, 2nd ed. McGraw-Hill, New York, NY. 633 pp.Google Scholar
Strand, M.R. 1989 a. Development of the polyembryonic parasitoid Copidosoma floridanum in Trichoplusia ni. Entomologia Experimentalis et Applicata 50: 37–46.Google Scholar
Strand, M.R. 1989 b. Oviposition behavior and progeny allocation of the polyembryonic wasp Copidosoma floridanum (Hymenoptera: Encyrtidae). Journal of Insect Behavior 2: 355–369.CrossRefGoogle Scholar
Strand, M.R., Dover, B.A., and Johnson, J.A.. 1990. Alterations in the ecdysteroid and juvenile hormone esterase profiles of Trichoplusia ni parasitized by the polyembryonic wasp Copidosoma floridanum. Archives of Insect Biochemistry and Physiology 13: 41–51.Google Scholar
Townes, H., and Townes, M.. 1978. Ichneumon-Flies of America North of Mexico: 7. Subfamily Banchinae, Tribes Lissonotini and Banchini. Memoirs of the American Entomological Institute 26: 614 pp.Google Scholar
Van Driesche, R.G., Bellows, T.S., Elkinton, J.S., Gould, J.R., and Ferro, D.N.. 1991. The meaning of percentage parasitism revisited: Solutions to the problem of accurately estimating total losses from parasitism. Environmental Entomology 20: 1–7.CrossRefGoogle Scholar