The role of chemical communication in sexual selection: hair-pencil displays in the diamondback moth, Plutella xylostella

Abstract

Theory suggests that if secondary sexual characteristics (or signals) are costly and females choose between mating partners, males should display more vigorously in the presence of competition. We investigated the use of chemical signals during courtship in the diamondback moth, Plutella xylostella. Males of P. xylostella have a hair-pencil gland on the tip of their abdomen, which allows for the release of chemical signals during courtship. Males detected potential competitors using chemical signals, but male investment in sexual signalling did not increase linearly in the presence of increasing numbers of competitors. The patterns of male display and mating behaviour among the parental popu..