Development, preimaginal phases and adult sensillar equipment in Aganaspis parasitoids (Hymenoptera: Figitidae) of fruit flies

Abstract

Aganaspis daci and Aganaspis pelleranoi (Hymenoptera: Figitidae) are important parasitoids of fruit flies. Here we studied, with light and scanning electron microscopy, aspects of their morphology that could help with plans to mass rear and thus contribute to improved pest control (preimaginal phases) and to shed light on parasitoid-pest relationships (sensillar equipment). The two species present a stalked egg, eucoiliform first and second-instar larvae and hymenopteriform third instar and mature larvae. The first instar presents tegumental differentiations in the mesoma and first metasomal segment in A. daci, but not in A. pelleranoi, while unlike other figitids, neither species displays setae in the mesosomal processes. Second and third instar and mature larvae present tegumental differentiations in A. daci, but not in A. pelleranoi. The moniliform (female) and filiform (male) antennae of A. daci and A. pelleranoi harbor seven types of sensilla, four of them (sensilla campaniformia, sensilla coeloconica type II, and two types of sensilla trichoidea) described here for the first time in Cynipoidea. The largest sensilla were the multiporous placoid sensilla, which were smaller and more numerous in A. pelleranoi. Species also differed to some extent in morphology of sensilla coeloconica. Observations on the ovipositor revealed the presence of coeloconic sensilla on Valva I in both species.