The ecological significance of differences in host detection behaviour in coexisting parasitoid species

Abstract

1. Six species of drosophilid parasitoids of the genus Leptopilina (Hymenoptera: Eucoilidae) exist in Europe. Laboratory experiments reveal that the fundamental niches for most of these species overlap. Field collections indicate that overlap in their realised niches is much smaller. 2. Here data are presented for the little known species Leptopilina longipes. Field and laboratory observations indicate that its niche overlaps with both that of L. clavipes and L. heterotoma . 3. The host detection behaviour of L. longipes is examined and it is shown that L. longipes uses vibrotaxis to detect its hosts. This behaviour of L. longipes is compared with that of L. heterotoma and L. clavipes , which both use the ovipositor in host detection. 4. The ways in which differences in host searching behaviour can contribute to niche segregation and coexistence of these species are discussed.