RELATIVE EFFECT OF DIFFERENT HOST FEEDING SITE ON LONG-RANGE HOST LOCATION AND ELECTROANTENNOGRAM RESPONSE IN THE PARASITOID COTESIA-GLOMERATA (HYM., BRACONIDAE)

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) -Co tesia glomerata L. (Hym., Braconidae). The parasitoids were found to b e most attracted to plants with herbivores feeding on upper foliage, l ess attracted by mid-plant herbivory and incapable of distinguishing b etween control plants and plants with herbivory on the lowest leaves. In EAG tests there was no difference in response with respect to volat iles from damage at different levels on the plant. The possible ecolog ical significance of these results are discussed in relation to predic ted models of wound-induced defence and olfactory neurological coding.