Changes in male sexual responses from silk cues of females at different reproductive states in the wolf spider Schizocosa malitiosa

Abstract

Male wolf spiders are capable of recognising sexual signals associated with female silk threads. In the wolf spider Schizocosa malitiosa variations in female receptivity have been studied, but changes in female silk attractiveness remain unknown. We analysed the sexual responses of adult males (leg shaking, papal drumming and searching) exposed to silk cues from subadult, virgin and mated females of different ages, and females that were or were not carrying an egg-sac. Penultimate and recently moulted adult females elicited low levels of male sexual behaviour, while those of virgin females (21–40 days old) were the most attractive. Silk threads slowly became less attractive after mating. Cues from females carrying an egg-sac as well as females in the inter egg-sac period were fairly attractive. The low attractiveness of recently moulted females disagrees with their high sexual receptivity. In contrast, females continued to elicit strong male responses during a 10-day period after mating, despite the fact that they immediately become sexually reluctant, suggesting strong selection for male searching ability. Low attractiveness during the egg-carrying period could reflect the fact that females do not require any further sperm. Concordances and discordances between attractiveness and sexual receptivity suggest that they respond to different physiological mechanisms.