Site-dependent aggression and mating behaviour in three species of Nasonia (Hymenoptera: Pteromalidae)

• Published in: Animal behaviour 2006-03, Vol.71 (3), p.641-647
• Main Authors: Leonard, Jason E., Boake, Christine R.B.
• Format: Article
• Language: English
• Subjects: Animal behavior; Animal ethology; Animal reproduction; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Insects; Nasonia; Protozoa. Invertebrata; Psychology. Psychoanalysis. Psychiatry; Pteromalidae
• ISSN: 0003-3472; 1095-8282
• DOI: 10.1016/j.anbehav.2005.07.010

We tested the hypothesis that changes in male reproductive tactics are often associated with female receptivity or female density. We used a phylogenetic context, comparing three species of the parasitoid wasp Nasonia. Females of these species may emerge from the host puparium as virgins or having already mated (called within-host mating, WHM). Males vary in their probability of aggressively defending the host puparium after they emerge. We used six lines of Nasonia, two from each species, to test whether male aggressive tendencies were higher in species in which females emerge as virgins. During adult emergence from the host puparia, we scored female WHM and male aggressive behaviour, site fidelity and dispersal. We found a positive association between male and female behaviour at the species level. First, male N. vitripennis were highly aggressive and did not disperse, and 95% of females emerged as virgins. In contrast, N. giraulti males showed little to no aggression and a high tendency to disperse after emerging from the host, and 100% of females mated prior to emergence. Finally, for N. longicornis, both male aggressive behaviour and WHM were variable. Based on the molecular phylogeny of Nasonia, we hypothesize that the behavioural differences between males of N. vitripennis and N. giraulti represent the ancestral and derived states, respectively, and that N. longicornis is in an early stage of divergence from N. vitripennis. We suggest that WHM and decreased male aggression in male N. giraulti evolved as a response to the spread of the host generalist N. vitripennis.