Males of a subsocial spider choose among females of different ages and the same reproductive status

Abstract

Most sexual preference studies test female choice between different males or test male choice between females with different reproductive status, but few studies test male preference towards females of different ages within the same reproductive status. In subsocial spiders, males can share the nest with subadult and adult females of different ages. We exposed a male of Anelosimus cf. studiosus to three kinds of females simultaneously: a subadult female, a recently moulted female and a mature adult female (both virgins) comparing male preferences and female interactions. Males courted mature and recently moulted females indiscriminably, but preferentially mated with mature females, while subadult females were not courted. Mature females did not interfere with male courtship towards other females whereas some recently moulted females unsuccessfully attempted to interfere with male courtship towards mature females. In spite of these interferences, no female-female fighting was observed. Taking into account the fact that males court and pseudocopulate with subadult females in uni-female nests, this research using multi-female nests suggests that male preferences show plasticity according to the social context. The preference for copulation with mature females could be due to possible mechanical problems associated to the moult, constraining attempts by males to mate with recently moulted females. This hypothesis and our findings suggest that male may recognize female state and age of adulthood.