Relative effect of different host feeding site on long-range host location and electroantennogram response in the parasitoid Cotesia glomerata (Hymenoptera: Braconidae).

Abstract

The effect of host feeding site on the potential host-finding success of the parasitoid Cotesia glomerata was investigated in the tritrophic system Brassica oleracea L. - Pieris brassicae L. (Lep., Pieridae) - Cotesia glomerata L. (Hym., Braconidae). The parasitoids were found to be most attracted to plants with herbivores feeding on upper foliage, less attracted by mid-plant herbivory and incapable of distinguishing between control plants and plants with herbivory on the lowest leaves. In EAG tests there was no difference in response with respect to volatiles from damage at different levels on the plant. The possible ecological significance of these results are discussed in relation to predicted models of wound-induced defence and olfactory neurological coding.