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LARVAL AND PUPAL PARASITISM OF THE FOREST TENT CATERPILLAR, MALACOSOMA DISSTRIA HÜBNER (LEPIDOPTERA: LASIOCAMPIDAE), IN ALBERTA, CANADA

Published online by Cambridge University Press:  31 May 2012

Dylan Parry
Affiliation:
Department of Entomology, University of Alberta, Edmonton, Alberta, Canada T6G 2E9

Abstract

Larval and pupal parasitoids were studied from collections made in endemic, outbreak, and post-outbreak populations of forest tent caterpillar (FTC), Malacosoma disstria, at 21 sites in Alberta, Canada, from 1989 to 1994. The parasitoid complex included 18 identified species. Aleiodes malacosomatos (Mason) (Hymenoptera: Braconidae) was common in low density populations and was the only species to attack FTC larvae prior to the fourth instar. Leschenaultia exul (Townsend) (Diptera: Tachinidae) was the most abundant larval parasitoid in endemic populations and after the 2nd year of outbreak. Although prevalent early in outbreaks, Patelloa pachypyga (Aldrich and Webber) (Diptera: Tachinidae) declined in older outbreaks possibly because it completes larval development later than other tachinids, leaving it vulnerable to competition from aggressive pupal parasitoids. I hypothesize that early initiation of oviposition allows L. exul to be more successful than P. pachypyga in low density populations because caterpillars have dispersed before the latter species initiates oviposition. I recorded lower pupal parasitism by Arachnidomyia aldrichi (Parker) (Diptera: Sarcophagidae) in Alberta than has been recorded in other regions, although it was still the most abundant parasitoid reared in this study. Parasitism by A. aldrichi was significantly higher in cocoons collected from undergrowth vegetation than from the forest canopy. Other pupal parasitoids contributed relatively little to FTC mortality.

Résumé

Les parasitoïdes des larves et des nymphes ont été étudiés à partir d’échantillons prélevés dans des populations endémiques, épidémiques et post-épidémiques de Livrées des forêts, Malacosoma disstria, à 21 endroits en Alberta, Canada, de 1989 à 1994. Le complexe des parasitoïdes contenait 18 espèces identifiables. Aleiodes malacosomatos (Mason) (Hymenoptera : Braconidae) était répandue dans les populations de faible densité et c’était là la seule espèce qui s’attaquait aux larves de la Livrée avant leur quatrième stade. Leschenaultia exul (Townsend) (Diptera : Tachinidae) était le seul. parasitoïde larvaire chez les populations endémiques et le seul présent après la 2ème année d’épidémie. Bien qu’abondant au début des épidémies, le parasitoïde Patelloa pachypyga (Aldrich and Webber) (Diptera : Tachinidae) le devenait moins plus tard au cours des épidémies, probablement parce que cette espèce termine son développement larvaire plus tard que les autres tachinides et est probablement supplantée par des parasitoïdes des nymphes, plus aggressifs. Je crois que la pont hâtive de L. exul assure son succès au sein des populations de faible densité parce que les chenilles se dispersent avant que P. pachypyga n’ait le temps de commencer à pondre. Le parasitisme des nymphes par Arachnidomyia aldrichi (Parker) (Diptera : Sarcophagidae) s’est avéré moins important en Alberta qu’en d’autres régions, bien qu’il s’agisse là du parasitoïde le plus abondant dans les élevages faits au cours de cette étude. Le parasitisme d’A. aldrichi était plus important dans les cocons récoltés dans la végétation du sol que dans le feuillage des arbres. Les autres parasitoïdes des nymphes ont contribué relativement peu à la mortalité des livrées.

[Traduit par la Rédaction]

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1995

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References

Arnaud, P.H. Jr., 1978. A Host–Parasite Catalog of North American Tachinidae (Diptera). United States Department of Agriculture Miscellaneous Publication 1319: 860 pp.Google Scholar
Batzer, H.O. 1955. Some Effects of Defoliation of Aspen Populus tremuloides Michx., Stands in Northern Minnesota by the Forst Tent Caterpillar, Malacosoma disstria Hbn., with Notes on Parasitism of Cocoons by Sarcophaga aldrichi Park. and Cocooning Habits of the Host. M.Sc. thesis, University of Minnesota, St. Paul, MN. 66 pp.Google Scholar
Bess, H.A. 1936. The biology of Leschenaultia exul Townsend, a tachinid parasite of Malacosoma americana Fabricius and Malacosoma disstria Hübner. Annals of the Entomological Society of America 29: 593613.CrossRefGoogle Scholar
Brown, C.E., and Cumming, M.P.. 1953. Forest tent caterpillar. p. 113 in 1953 Annual Report of the Forest Insect and Disease Survey, Canada Department of Agriculture, Forest Biology Division. 158 pp.Google Scholar
Caesar, L. 1915. Insects of the season in Ontario. Annual Report of the Entomological Society of Ontario 45: 42.Google Scholar
Coppel, H.C., House, H.L., and Maw, M.G.. 1959. Studies on dipterous parasites of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae). VII. Agria affinis (Fall.) (Diptera: Sarcophagidae). Canadian Journal of Zoology 37: 817830.CrossRefGoogle Scholar
Cumming, M.P. 1954. Forest tent caterpillar egg survey. Canada Department of Forestry, Forest Entomology and Pathology Branch, Bi-monthly Progress Report 10 (3): 3.Google Scholar
de Gryse, J.J. 1924. The control of forest tent caterpillars in the prairie provinces. Canada Department of Agriculture, Entomology Branch Circular 19: 14.Google Scholar
Eggen, D.A. 1987. A Comparative Study of the Parasite Complexes of Gypsy Moth and Forest Tent Caterpillar in New York. Ph.D. thesis, University of New York, Syracuse, NY. 223 pp.Google Scholar
Elliot, K.R. 1961. Status of the forest tent caterpillar in Manitoba and Saskatchewan. Proceedings of the Entomological Society of Manitoba 17: 2831.Google Scholar
Emond, F.J., and Cerezke, H.F.. 1989. Forest Insect and Disease Conditions in Alberta, Saskatchewan, Manitoba, and the Northwest Territories in 1988 and Predictions for 1989. Forestry Canada, Northern Forestry Research Centre Information Report NOR–X–303: 29 pp.Google Scholar
Hildahl, V., and Reeks, W.A.. 1960. Outbreaks of the forest tent caterpillar and their effects on stands of trembling aspen in Manitoba and Saskatchewan. The Canadian Entomologist 92: 199209.CrossRefGoogle Scholar
Hodson, A.C. 1939. Sarcophaga aldrichi Parker as a parasite of Malacosoma disstria Hbn. Journal of Economic Entomology 32: 396401.CrossRefGoogle Scholar
Hodson, A.C. 1941. An Ecological Study of the Forest Tent Caterpillar, Malacosoma disstria Hbn. Minnesota Agricultural Experiment Station Technical Bulletin 148: 55 pp.Google Scholar
Hodson, A.C. 1977. Some aspects of forest tent caterpillar population dynamics. Minnesota Agricultural Experiment Station Technical Bulletin 310: 516.Google Scholar
Ives, W.G.H. 1971. The Forest Tent Caterpillar in Alberta. Environment Canada, Canadian Forest Service, Northern Forest Research Centre Internal Report NOR–4: 30 pp.Google Scholar
Ives, W.G.H. 1984. Malacosoma disstria Hübner, forest tent caterpillar (Lepidoptera: Lasiocampidae). pp. 311–319 in Biological Control Programmes Against Insects and Weeds in Canada 1969–1980. Commonwealth Institute of Biological Control Technical Committee. 410 pp.Google Scholar
Langston, R.L. 1957. A synopsis of hymenopterous parasites of Malacosoma in California (Lepidoptera: Lasiocampidae). University of California Publications in Entomology 14: 150.Google Scholar
Mason, W.R.M. 1979. A new Rogas (Hymenoptera: Braconidae) parasite of tent caterpillars (Malacosoma spp. Lepidoptera: Lasiocampidae) in Canada. The Canadian Entomologist 111: 783786.CrossRefGoogle Scholar
McAlpine, J.F., Peterson, B.V., Shewell, G.E., Teskey, H.J., Vockeroth, J.R., and Wood, D.M.. 1981. Manual of Neararctic Diptera, Part 2. Agriculture Canada Research Branch Monograph 27: 674 pp.Google Scholar
McLeod, J.H., and Ayre, G.L.. 1956. Parasites of tent caterpillars (Lepidoptera: Lasiocampidae) in the lower Fraser valley of British Columbia, Canada. Proceedings of the 8th Pacific Science Congress 3A: 15471560.Google Scholar
Parry, D. 1994. The Impact of Predators and Parasitoids on Natural and Experimentally Created Populations of Forest Tent Caterpillar, Malacosoma disstria Hübner, (Lepidoptera: Lasiocampidae). M.Sc. thesis, University of Alberta, Edmonton, Alta.91 pp.Google Scholar
Peck, O. 1963. A Catalogue of Nearctic Chalcidoidea (Insecta: Hymenoptera). Supplement of the Entomological Society of Canada 30: 1092 pp.Google Scholar
Ross, D.A. 1953. Key to the puparia of the dipterous parasites of Malacosoma spp. in British Columbia. Proceedings of the Entomological Society of British Columbia 49: 1923.Google Scholar
Schmidt, J.M. 1993. A comparison of the sensory morphology of the cephalic region of first and third instar Arachnidomyia aldrichi (Parker) (Diptera: Sarcophagidae). The Canadian Entomologist 125: 101111.CrossRefGoogle Scholar
Sippell, W.L. 1957 a. A Study of the Forest Tent Caterpillar Malacosoma disstria Hbn. and its Parasite Complex in Ontario. Ph.D. thesis, University of Michigan, Ann Arbor, MI. 147 pp.Google Scholar
Sippell, W.L. 1957 b. A Study of the Forest Tent Caterpillar and its Parasite Complex in Ontario. Canada Department of Agriculture, Science Service, Forest Biology Division, Interim Report. 1956–1957. 147 pp.Google Scholar
Sippell, W.L. 1961. Key to the puparia of common dipterous parasites of the forest tent caterpillar, Malacosoma disstria Hbn., in Ontario. The Canadian Entomologist 93: 433436.CrossRefGoogle Scholar
Sippell, W.L. 1962. Outbreaks of the forest tent caterpillar, Malacosoma disstria Hbn., a periodic defoliator of broad leafed trees in Ontario. The Canadian Entomologist 94: 408416.CrossRefGoogle Scholar
Stairs, G.R. 1965. Artificial initiation of virus epizootics in forest tent caterpillar populations. The Canadian Entomologist 97: 10591062.CrossRefGoogle Scholar
Stehr, F.W., and Cook, E.F.. 1968. A Revision of the Genus Malacosoma Hübner in North America (Lepidoptera: Lasiocampidae): Systematics, Biology, Immatures and Parasites. United States National Museum Bulletin 276: 321 pp.Google Scholar
Thompson, W.R. 1953. The tachinid parasites of Archips cerasivorana Fitch (2). Eusisyropa blanda O. S. (Diptera). The Canadian Entomologist 85: 393404.CrossRefGoogle Scholar
Townes, H. 1969. Genera of Ichneumonidae, Part 1. Memoirs of the American Entomological Institute 11: 300 pp.Google Scholar
Volney, W.J.A. 1988. Insects and diseases of the mixedwood forest: Problems or opportunities? pp. 99–109 in Samoil, J.K. (Ed.), Management and Utilization of Northern Mixedwoods. Forestry Canada, Northern Forestry Research Centre Information Report NOR–X–296: 163 pp.Google Scholar
Williams, D.J.M., Parry, D., and Langor, D.W.. 1995. Sampling and Identification of Forest Tent Caterpillar Parasitoids in the Prairie Provinces. Natural Resources Canada, Canadian Forest Service, Northwest Region, Northern Forestry Centre Report NOR–X–345. In press.Google Scholar
Witter, J.A., and Kulman, H.M.. 1972. A Review of the Parasites and Predators of Tent Caterpillars (Malacosoma spp). in North America. Minnesota Agricultural Experiment Station Technical Bulletin 289: 48 pp.Google Scholar
Witter, J.A., and Kulman, H.M.. 1979. The parasite complex of the forest tent caterpillar in northern Minnesota. Environmental Entomology 8: 723731.CrossRefGoogle Scholar
Witter, J.A., Mattson, W.J., and Kulman, H.M.. 1975. Numerical analysis of a forest tent caterpillar (Lepidoptera: Lasiocampidae) outbreak in northern Minnesota. The Canadian Entomologist 107: 837854.CrossRefGoogle Scholar