Male preference and female cues: males assess female sexual maturity and mating status in a web-building spider

Abstract

Reproductive success relies on communication signals used by females to exert mate attraction and assessment of female reproductive value by males. During mate search males of the spider, Stegodyphus lineatus experience high mortality and low female encounter rate. Females vary in sexual maturity and mating status (virgin and mated) and hence in reproductive value for males, which should influence male mating effort. Due to high costs of remating, only virgin females are expected to signal mate attraction. Males would benefit from mating preferentially with virgins due to the costs of overcoming mated females' resistance, although they gain paternity share. Males should avoid immature females, unless guarding precopulatory to access females on maturation. Low encounter rates predict males to invest also in females of inferior reproductive value. We investigated male ability to discriminate immature, virgin, and mated females by assessing: the number of females males visit in the field; male mating effort and male discrimination of females based on silk cues in laboratory trials. In the field, males were found most frequently with virgin females. Male mating effort, copulation success, and preference based on silk cues were higher with mature compared with immature females. Our data suggest that females signal sexual receptivity and that males are able to discriminate both sexual maturity and mating status, however, males do not exert strong preference for virgins. The combination of high costs of mate search and low encounter rate likely exerts selection on males to mate indiscriminately and overcome female resistance to remating.