GEOGRAPHICAL VARIATION IN ENCAPSULATION ABILITY OF DROSOPHILA-MELANOGASTER LARVAE AND EVIDENCE FOR PARASITOID-SPECIFIC COMPONENTS

The ability of Drosophila melanogaster larvae in Europe to encapsulate the eggs of their most important parasitoids, Asobara tabida and Leptopilina boulardi, shows a large amount of geographical variation. Interestingly, encapsulation ability against A. tabida is not correlated with encapsulation ability against L. boulardi. This indicates that the encapsulation system of D. melanogaster larvae has parasitoid-specific components. The variation in encapsulation ability can only partly be explained by the incidence of parasitism on the larvae. This means that factors other than the two parasitoid species must be selection pressures on the encapsulation ability of D. melanogaster larvae.