Stephen J. TAKÁCS, Gerhard GRIES* and Regine GRIES
Chemical Ecology Research Group, Centre for Pest Management, Department of
Biological Sciences, Simon Fraser University, Burnaby, B.C. V5A 1S6, Canada
In Y-tube olfactometer bioassays, adult female Apanteles carpatus (Say). were attracted to beaver or rabbit pelts infested with larvae of the casemaking clothes moth (CCM), Tinea pellionella L. Porapak Q-captured volatiles from a CCM-infested beaver pelt were also very attractive, whereas isolated CCM larvae or larval faeces were not. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analysis of the Porapak Q volatile extract revealed two compounds that elicited responses by A. carpatus antennae. Coupled GC-mass spectrometry (MS) in electron impact and chemical ionization modes of these compounds indicated, and GC-MS and GC-EAD of authentic standards confirmed, that they were nonanal and geranylacetone. While each compound singly did not attract A. carpatus, a 1:1 blend of both compounds was as attractive as the volatile extract. Because these compounds are host-habitat derived, A. carpatus is a habitat- rather than host-specialist, responding to kairomonal indicators of localized and specific habitats, such as animal hair or feather. The tritrophic interaction between A. carpatus, its clothes moth hosts and their animalderived habitats is similar to the well-studied relationship between parasitoids of insect herbivores and their host-plant habitats.