Factors influencing mating duration and male choice in the red milkweed beetle, Tetraopes tetrophthalmus (Forster) (Coleoptera Cerambycidae)

Abstract

Mating behavior of Tetraopes tetrophthalmus was investigated in the laboratory and in a field population. Mating duration varies considerably in this species and factors influencing mating duration (defined as the total time a male is mounted on a female) were elucidated. Males, rather than females, were more likely to terminate matings by disengaging, but a significant number of matings were ended by interference from other males, especially under high densities. Males mate longer with larger females but male size was not related to mating duration. Additionally, duration was negatively related to time–of–day, but not because of physical factors such as temperature. Males initiated copulations sooner with larger females with greater reproductive value, but male size was not related to time–to–copulation. Because both males and females often mate many times a day in this species sperm competition may also have a large effect on male mating behavior, especially mating duration.