Factors influencing the choice of female mate rejection strategies in the seaweed fly Coelopa nebularum (Diptera : Coelopidae)

Female Coelopa nebularum attempt to avoid mating with males by adopting lip to three behavioral responses. Kicking and shaking are designed to dislodg e mounted males, whereas downward abdominal curling prevents engagement of genitalia. We find that some females are more willing to mate than others, but their choice of rejection strategy is inconsistent. Mating does not aff ect behavior in immediately subsequent encounters. Male size influences the choice of rejection strategy and is positively associated with mating succ ess. Different strategies have similar success rates. The response to a mou nt is not influenced by the size of a male encountered immediately beforeha nd We propose that these results are in consistent with adaptive mate choic e or mate assessment and suggest that females are simply attempting to avoi d the costs of mating with all males.