Document Type

Article

Publication Date

2010

Journal or Book Title

Annals of the Entomological Society of America

Volume

103

Issue

3

First Page

371

Last Page

378

DOI

10.1603/AN09130

Abstract

Tritrophic interactions may include directly harmful effects of host plants on herbivores, and directly or indirectly harmful effects of host plants on the natural enemies of herbivores. Tritrophic interactions involving parasitoids and predators have received considerable attention but less is known about how host plants affect entomopathogens. We compared growth and resistance to entomopathogenic nematodes for “woolly bear” caterpillars, Grammia incorrupta(=geneura) (Hy. Edwards) (Lepidoptera: Arctiidae) fed lettuce, Lactuca sativa L. (Asteraceae), versus threadleaf groundsel, Senecio longilobus Benth. (Asteraceae). Both plants are members of the Asteraceae, but only S. longilobus contains pyrrolizidine alkaloids. Caterpillars gained more mass when fed L. sativa compared with S. longilobus; yet, in one of four cases studied, resistance to nematodes was higher when caterpillars ate S. longilobus.Caterpillar resistance to nematodes did not differ between host plants in the other cases. In addition, nematode reproduction was higher in cadavers of G. incorrupta that had been fed L.sativa instead of S. longilobus, suggesting that S. longilobus had indirectly detrimental effects on entomopathogenic nematodes. Our results illustrate how trade-offs may arise in tritrophic interactions involving entomopathogens, as the cost of decreased growth imposed by S.longilobus was accompanied by the benefit of greater resistance to entomopathogenic nematodes.

Comments

This article is from Annals of the Entomological Society of America 103 (2010): 371, doi:10.1603/AN09130. Posted with permission.

Rights

This article is the copyright property of the Entomological Society of America and may not be used for any commercial or other private purpose without specific permission of the Entomological Society of America.

Copyright Owner

Entomological Society of America

Language

en

File Format

application/pdf

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