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THE NUTRITIONAL ECOLOGY OF A PARASITOID WASP, EPHEDRUS CALIFORNICUS BAKER (HYMENOPTERA: APHIDIIDAE)

Published online by Cambridge University Press:  31 May 2012

R. Sequeira
Affiliation:
Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
M. Mackauer*
Affiliation:
Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
*
1Author to whom reprint requests should be sent.

Abstract

We tested the hypothesis that the pattern of development and growth of a generalist parasitoid wasp varies in different hosts. We reared Ephedras californicus Baker (Hymenoptera: Aphidiidae), a solitary parasitoid of aphids, under controlled laboratory conditions on five kinds of hosts: nymphal instar 1 (24 h old), 2 (42 h), 3 (96 h), and 4 (144 h) of apterous virginoparae of Acyrthosiphon pisum (Harris), and nymphal instar 1 (24 h) of Macrosiphum creelii Davis (Homoptera: Aphididae). Parasitoid dry mass increased with the host instar at parasitization. Females were larger than males although the degree of sexual size dimorphism declined with increased host size. Development time from oviposition to adult eclosion varied non-linearly with the host instar at parasitization, and was shortest in first and fourth nymphal instars. Parasitoids developing in M. creelii gained more mass in less time than their counterparts developing in A. pisum of the same initial size. In low-quality hosts, parasitoids apparently trade off increased development time for a gain in adult mass. A possible explanation of sexual size dimorphism in E. californicus is that large females may be able to overcome aphid defensive behaviours better than small ones.

Résumé

Nous avons éprouvé l’hypothèse selon laquelle le développement et la croissance d’une guêpe parasitoïde généraliste varient en fonction de l’hôte. Nous avons élevé en laboratoire des Ephedrus californicus Baker (Hymenoptera : Aphidiidae), un parasitoïde solitaire des pucerons, dans des conditions expérimentales, sur cinq types d’hôtes, des larves de premier stade (âgées de 24 h), de deuxième stade (42 h), de troisième stade (96 h) et de quatrième stade (144 h) du puceron aptère virginipare Acyrthosiphon pisum (Harris) et sur des larves de premier stade (24 h) de Macrosiphum creelii Davis (Homoptera : Aphididae). La masse sèche des parasitoïdes augmentait en fonction du stade de l’hôte au moment de l’infestation. Les femelles étaient plus grosses que les mâles, mais l’importance de ce dimorphisme diminuait en fonction inverse de la taille de l’hôte. La durée du développement entre la ponte et l’éclosion des adultes variait selon une fonction non linéaire avec le stade de l’hôte au moment de l’infestation et le développement durait moins longtemps chez les hôtes de premier et de quatrième stades. Les parasitoïdes élevés sur des M. creelii ont subi un gain de masse plus rapide que ceux élevés sur des A. pisum de même taille initiale. Chez les hôtes de qualité moindre, les parasitoïdes semblent troquer le développement de longue durée contre l’acquisition d’une masse plus importante des adultes. Il est possible que les grosses femelles soient mieux armées que les petites contre les comportements de défense des pucerons, ce qui pourrait expliquer le dimorphisme sexuel quant à la taille observé chez E. californicus.

[Traduit par la rédaction]

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1993

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References

Benson, J.F. 1973. Intraspecific competition in the population dynamics of Bracon hebetor Say (Hymenoptera: Braconidae). Journal of Animal Ecology 42: 105124.Google Scholar
Berry, J.F., and Shine, R.. 1980. Sexual size dimorphism and sexual selection in turtles (Order Chelonia). Oecologia 44: 185191.Google Scholar
Charnov, E.L. 1982. The Theory of Sex Allocation. Princeton University Press, Princeton, NJ. 355 pp.Google Scholar
Charnov, E.L., Los-den Hartogh, R.L., Jones, W.T., and van den Assem, J.. 1981. Sex ratio evolution in a variable environment. Nature 289: 2733.Google Scholar
Chow, F.J., and Mackauer, M.. 1986. Host discrimination and larval competition in the aphid parasite Ephedrus californicus. Entomologia Experimentalis et Applicata 41: 243254.Google Scholar
Cloutier, C., Lévesque, C.A., Eaves, D.M., and Mackauer, M.. 1991. Maternal adjustment of sex ratio in response to host size in the aphid parasitoid Ephedrus californicus. Canadian Journal of Zoology 69: 14891495.Google Scholar
Cohen, M.B., and Mackauer, M.. 1987. Intrinsic rate of increase and temperature coefficients of the aphid parasite Ephedrus californicus Baker (Hymenoptera: Aphidiidae). The Canadian Entomologist 119: 231237.Google Scholar
Cornuet, J.M. 1982. Représentation graphique des populations multinormales par des ellipses de confiance. Apidologie 13: 1520.Google Scholar
Gerling, D., Roitberg, B.D., and Mackauer, M.. 1990. Instar-specific defense of the pea aphid, Acyrthosiphon pisum: Influence on oviposition success of the parasite Aphelinus asychis (Hymenoptera: Aphelinidae). Journal of Insect Behavior 3: 501514.Google Scholar
Gilbert, J.J., and Williamson, C.E.. 1983. Sexual dimorphism in zooplankton (Copepoda, Cladocera, and Rotifera). Annual Review of Ecology and Systematics 14: 133.Google Scholar
Gilbert, N., and Gutierrez, A.P.. 1973. A plant–aphid–parasite relationship. Journal of Animal Ecology 42: 323340.Google Scholar
Hughes, A.L., and Hughes, M.K.. 1986. Paternal investment and sexual size dimorphism in North American passerines. Oikos 46: 171175.Google Scholar
Hurlbutt, B. 1987. Sexual size dimorphism in parasitoid wasps. Biological Journal of the Linnean Society 30: 6389.Google Scholar
Irvine, M.T. 1991. Preference of Ephedrus californicus for Different Instars of the Pea Aphid and its Relationship to Parasitoid Fitness. Master of Pest Management Professional Paper, Simon Fraser University, Burnaby, B.C.90 pp.Google Scholar
Kouamé, K.L., and Mackauer, M.. 1991. Influence of aphid size, age and behaviour on host choice by the parasitoid wasp Ephedrus californicus: A test of host-size models. Oecologia 88: 197203.Google Scholar
Lawrence, P.O. 1981. Interference competition and optimal host selection in the parasitic wasp, Biosteres longicaudatus. Annals of the Entomological Society of America 74: 540544.Google Scholar
Mackauer, M. 1983. Quantitative assessment of Aphidius smithi (Hymenoptera: Aphidiidae): Fecundity, intrinsic rate of increase, and functional response. The Canadian Entomologist 115: 399415.Google Scholar
Mackauer, M., and Finlayson, T.. 1967. The hymenopterous parasites (Hymenoptera: Aphidiidae et Aphelinidae) of the pea aphid in eastern North America. The Canadian Entomologist 99: 10511082.Google Scholar
Mackauer, M., and Sequeira, R.. 1993. Patterns of development in insect parasites. In Beckage, N.E., Thompson, S.N., and Federici, B.A. (Eds.), Parasites and Pathogens of Insects. Vol. I. Academic Press, Orlando, FL. In press.Google Scholar
Nealis, V.G., Jones, R.E., and Wellington, W.G.. 1984. Temperature and development in host–parasite relationships. Oecologia 61: 224229.Google Scholar
Opp, S.B., and Luck, R.F.. 1986. Effects of host size on selected fitness components of Aphytis melinus and A. lingnanensis (Hymenoptera: Aphelinidae). Annals of the Entomological Society of America 79: 700704.Google Scholar
Sandlan, K. 1979. Sex ratio regulation in Coccygomimus turionella Linnaeus (Hymenoptera: Ichneumonidae) and its ecological implications. Ecological Entomology 4: 365378.Google Scholar
Sequeira, R., and Mackauer, M.. 1992 a. Nutritional ecology of an insect host–parasite association: The pea aphid – Aphidius ervi system. Ecology 73: 183189.Google Scholar
Sequeira, R., and Mackauer, M.. 1992 b. Covariance of adult size and development time in the parasitoid wasp Aphidius ervi in relation to the size of its host, Acyrthosiphon pisum. Evolutionary Ecology 6: 3444.Google Scholar
Shine, R. 1988. The evolution of large body size in females: A critique of Darwin's “fecundity advantage” model. American Naturalist 131: 124131.Google Scholar
Sokal, R.R., and Rohlf, F.J.. 1981. Biometry, 2nd ed. W.H. Freeman, San Francisco, CA. 859 pp.Google Scholar
SPSS. 1983. SPSS, User's Guide. SPSS Inc., Chicago, IL. 806 pp.Google Scholar
Takagi, M. 1985. The reproductive strategy of the gregarious parasitoid, Pteromalus puparum (Hymenoptera: Pteromalidae). I. Optimal number of eggs in a single host. Oecologia 68: 16.Google Scholar
van den Assem, J. 1971. Some experiments on sex ratio and sex regulation in the pteromalid Lariophagus distinguendus. Netherlands Journal of Zoology 21: 373402.Google Scholar
Waage, J.K., and Godfray, H.J.C.. 1985. Reproductive strategies and population ecology of insect parasitoids. pp. 449470in Sibly, R.M., and Smith, R.H. (Eds.), Behavioural Ecology. Ecological Consequences of Adaptive Behaviour. Blackwell Scientific, Oxford.Google Scholar
Waage, J.K., and Ng, S.M.. 1984. The reproductive strategy of a parasitic wasp. I. Optimal progeny and sex allocation in Trichogramma evanescens. Journal of Animal Ecology 53: 401416.Google Scholar
Werren, J.H., and Simbolotti, G.. 1989. Combined effects of host quality and local mate competition on sex allocation in Lariophagus distinguendus. Evolutionary Ecology 3: 203213.Google Scholar