Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis


Agriculture, Food and Environment



First Advisor

Dr. Charles W. Fox


Sexual conflict over mating duration drives the evolution of male and female adaptations that facilitate the manipulation of mating interactions in their favor. This conflict drives the evolution of traits that improve the fitness of the focal sex despite inflicting costs on mates. However, males can express multiple traits that increase and decrease female fitness simultaneously. When the effects of male traits on female fitness increase or decrease with duration of exposure, females traits that influence mating duration are selected upon. Females of Callosobruchus maculatus, a bruchid bean beetle, kick mates to forcefully end copulation. Although both negative effects of male genital spines and positive of effects ejaculatory materials on female fitness have been documented, it is not yet clear how these male traits interact to influence the timing of female kicking. In this study, we observed the effect of male genital spine size, ejaculate size and mating history, and manipulated mating duration to disentangle the effects of male traits on the timing of female kicking behavior. We found that male mating history and mate body size dimorphism predicted the timing and duration of female kicking, but that male ejaculate size and spine length did not predict female kicking timing.

Digital Object Identifier (DOI)