Mating behaviour and alternative oviposition sites for male eggs in the heteronomous hyperparasitoid Coccophagus gurneyi Compere (Hymenoptera : Aphelinidae)

The aphelinid parasitoid Coccophagus gurneyi Compere has unusual sex-relate d host relationships. Females are diploid and develop internally within mea lybugs Pseudococcus calceolariae (Maskell). Males, in contrast, are haploid and hyperparasitic, developing on primary parasitoid larvae within the mea lybugs. Furthermore, males have been claimed to be capable of either intern al or external development, depending on the precise site of deposition of the haploid egg. This diversity of developmental pathways could indicate th e existence of a sibling-species complex. We therefore quantified the matin g and ovipositional behaviour of C. gurneyi, for comparison with that of an undescribed sibling species. We also checked whether the females deposit m ale eggs in alternative sites. The pattern of mating was found to be typica l of mating behaviour in Coccophagus spp. and was consistent among all mati ng pairs, suggesting that the colony comprised one species. Further, the ma ting behaviour was significantly different from that of the undescribed sib ling species. The site of male egg deposition varied and is apparently dict ated by two factors; whether the mealybug is parasitised and, if so, the si ze of the parasitoid it contains. If the mealybugs were unparasitised or if the parasitoids within the mealybugs were small (< 0.53 mm), male eggs wer e deposited within the mealybug haemocoel. If the parasitoids were large (> 1.05 mm), male eggs were deposited within the parasitoids. These results s upport the claim of alternate host relationships and developmental pathways within males of C. gurneyi.