Male mate choice and female receptivity lead to reproductive interference

Abstract

Mating between species is common, but seldom adaptive. Mate preferences and receptivity to mating attempts may both contribute to such matings, also called reproductive interference. Here, we tested the hypothesis that both male mate preference for female body size and female receptivity contribute to reproductive interference between two secondarily sympatric insect species. In north-central Florida, the squash bug Anasa tristis co-occurs with a recently introduced, smaller congener, Anasa andresii. Male A. andresii are frequently found copulating with larger female A. tristis in the field. We found that male A. andresii prefer larger heterospecific females over conspecific females, that female A. tristis accept some mating attempts by heterospecific males, and that female A. tristis are more promiscuous with conspecifics than are female A. andresii. Our findings suggest that both male mate choice and female receptivity contribute to mating between these species.