Communication ecology of webbing clothes moth: 2. Identification of semiochemicals mediating attraction of adults to larval habitat

Our objective was to identify the semiochemicals that mediate attraction of the webbing clothes moth (WCM), Tineola bisselliella (Lepidoptera: Tineida e), to suitable larval habitat. Coupled gas chromatographic-electroantennog raphic detection (GC-EAD) analyses of Porapak Q-captured bioactive volatile s from horseshoe crab, and dried but untanned vertebrate pelts revealed num erous EAD-active volatiles. These volatiles were identified by comparative GC-mass spectrometry and GC-EAD analyses of natural and synthetic compounds . A blend of 28 synthetic candidate semiochemicals attracted both male and female WCM. Experiments deleting various components determined that saturat ed aldehydes-but not unsaturated aldehydes, saturated hydrocarbons, saturat ed alcohols, or ketones-were essential for blend attractiveness. A blend of nonanal, the single most attractive aldehyde, in combination with geranyla cetone was more attractive to WCM than the 28-component blend or dried, unt anned animal pelt. Selection of larval habitat resides more with male than female WCM, as indicated by stronger EAD responses from male than female an tennae to habitat-derived semiochemicals, and more selective and early resp onse to habitat cues by males than females. Exploitation of nonanal and ger anylacetone as resource-derived semiochemicals by both adult WCM and its la rval parasitoid, Apanteles carpatus, is an example of convergent semiochemi cal parsimony.