Asynchronous maturation of the sexes may limit close inbreeding in a subsocial spider

We studied the temporal patterns of maturation and sexual receptivity of a subsocial spider, Anelosimus cf. jucundus, in southern Arizona. In subsocial spiders, sibling males and females share a common nest for a large portion of their life cycle, often only dispersing short distances close to the mating season. We found that, on average, male A. cf. jucundus matured 9 days earlier than females and that females did not become sexually receptive until 10 days following their final molt to maturity. The periods of sexual receptivity of sibling males and females, therefore, would be separated in time by a significant fraction of an adult male's life cycle. We also found significant asynchrony in maturation dates across nests and nest clusters at the two collection localities. We suggest that these temporal patterns may limit the opportunities for sibling males and females to mate with each other, thus explaining the apparent absence of mechanisms to discriminate against kin as mates in this species.