Oecologia

, Volume 160, Issue 2, pp 387–398

Multifaceted determinants of host specificity in an aphid parasitoid

Authors

    • Department of EntomologyUniversity of Minnesota
    • Unité de Recherches Intégrées en Horticulture, INRA
  • Ruth J. Barta
    • Department of EntomologyUniversity of Minnesota
  • Kim A. Hoelmer
    • Beneficial Insect Introductions Research Unit, USDA-ARS
  • Keith R. Hopper
    • Beneficial Insect Introductions Research Unit, USDA-ARS
  • George E. Heimpel
    • Department of EntomologyUniversity of Minnesota
Behavioral Ecology - Original Paper

DOI: 10.1007/s00442-009-1289-x

Cite this article as:
Desneux, N., Barta, R.J., Hoelmer, K.A. et al. Oecologia (2009) 160: 387. doi:10.1007/s00442-009-1289-x

Abstract

The host specificity of insect parasitoids and herbivores is thought to be shaped by a suite of traits that mediate host acceptance and host suitability. We conducted laboratory experiments to identify mechanisms shaping the host specificity of the aphid parasitoid Binodoxys communis. Twenty species of aphids were exposed to B. communis females in microcosms, and detailed observations and rearing studies of 15 of these species were done to determine whether patterns of host use resulted from variation in factors such as host acceptance or variation in host suitability. Six species of aphids exposed to B. communis showed no signs of parasitism. Four of these species were not recognized as hosts and two effectively defended themselves from attack by B. communis. Other aphid species into which parasitoids laid eggs had low suitability as hosts. Parasitoid mortality occurred in the egg or early larval stages for some of these hosts but for others it occurred in late larval stages. Two hypotheses explaining low suitability were investigated in separate experiments: the presence of endosymbiotic bacteria conferring resistance to parasitoids, and aphids feeding on toxic plants. An association between resistance and endosymbiont infection was found in one species (Aphis craccivora), and evidence for the toxic plant hypothesis was found for the milkweed aphids Aphis asclepiadis and Aphis nerii. This research highlights the multifaceted nature of factors determining host specificity in parasitoids.

Keywords

Host rangeSpecializationPreference-performance hypothesisOvipositionBinodoxys communis

Copyright information

© Springer-Verlag 2009