Genetic variability of host-parasite relationship traits: utilization of isofemale lines in a Drosophila simulans parasitic wasp

Abstract

We investigated genetic variability of traits involved in the successful parasitization of larvae of Drosophila melanogaster and D. simulans by the hymenopteran parasite Leptopilina boulardi. Characters studied were: the rate of infestation, overall developmental success, ability to escape host encapsulation, developmental success after eclosion, and physiological incompatibility between the 2 partners. These investigations were performed over 3 generations (G1, G2 and G4) using 14 isofemale lines of L. boulardi collected in Tunisia. The host was D. simulans. For the first 4 traits, the mean values were relatively constant from 1 generation to another. Comparisons of variability within and between isofemale lines of the same generation, and correlations between generations, indicate a genetic component for 2 traits: overall developmental success and ability to evade encapsulation.