Behavioral and Reproductive Variation of the Males of Nasonia (Hymenoptera: Pteromalidae)

Abstract

Behavioral and Reproductive variation of the males of Nasonia (Hymenoptera: Pteromalidae). The Pteromalid parasitoid wasp Nasonia is the focus of numerous genetic and evolutionary studies, particularly sex-ratio evolution, courtship behavior, and genetics of speciation. This genus consists of four closely related species: N. vitripennis, N. longicornis, N. giraulti, and N. oneida. In this dissertation, using high-speed video and biological assays, the mating behavior of Nasonia was examined to comprehend the variables that may affect a male’s mating success. The four species differ significantly in their courtship behaviors despite sharing a lot of morphological similarities. The results demonstrated that courting differences can be used to discriminate between closely related species. Further to identify the individual components which can make a male acceptable to a female during courtship, an analysis of successful and unsuccessful mating videos for each species was conducted. The results showed that a courting male behaves very differently in successful and unsuccessful mating. I also examined the olfactory cues (chemical cues from male) to evaluate their chemical divergence and explore how they function as species-specific cues for sexual signaling. I manipulated the olfactory cues to explore their role in male acceptance by females. The acceptance of heterospecific males, by two species, was significantly greater than that of the other two. As the morphological and ultrastructural properties of the reproductive systems offer significant evidence for the research of taxonomy, reproductive biology, and speciation, I examined the morphological differences in addition to the ultrastructure of the aedeagus and the general morphology of the sperm and attempted to find out whether these variations are related to their behavioral uniqueness.