Female abdomen position signal sreceptivity during courtship in the Japanese sulfur butterfly , Colias Erate (Pieridae)

Abstract

Females of the Japanese sulfur butterfly, Colias erate, eclose in the grassland vegetation in early morning and copulate immediately after their wings fully expand. Once mated, females lose their interest in mating with males that approach them. Receptive females exposed their abdomens toward courting males, whereas unreceptive females hide their abdomen. Field observation of males' courtship behavior to females was carried out by focusing on the abdomen posture of females. We glued the wings of females together, forced their abdomen to be either exposed from their wings or hidden in their wings, and presented them to males. When males found the females, most males hovered around the female. Males alighted near the females when their abdomens were exposed. However, when their abdomens were hidden, males stopped courting and left the females. Females with exposed abdomens, irrespective of mating experience, copulated with the male courting. Thus, the female posture of hiding her abdomen was a signal of unreceptivity, as well as the rejection of the courting males.