Reproductive behaviour of female Chorthippus biguttulus grasshoppers

Female grasshoppers of acoustically communicating species assume series of reproductive states that are associated with particular behaviours. Studies on laboratory populations of Chorthippus biguttulus (L.) revealed that females of this species lack the period of ‘passive copulatory readiness’, increase their attractiveness to males by sound production and mate multiple times before their first oviposition. In particular, female Ch. biguttulus display a period of ‘primary rejection’ after their imaginal moult during which they reject male mating attempts followed by a period of ‘active copulatory readiness’ in which they produce acoustic signals and may copulate with courting males. Female stridulation generally stimulated male mating activity and stridulating females attracted more male mating attempts than mute females in the same cage, indicating that males preferentially court females that signal ‘active copulatory readiness’. After receipt of a spermatophore, Ch. biguttulus females displayed periods of ‘secondary rejection’ followed by re-establishment of ‘active copulatory readiness’. Acoustic responses of females to male songs, an indicator of reproductive readiness, were significantly reduced until 2 days after mating and remained slightly reduced in comparison to pre-mating levels. Some females mated multiple times before their first oviposition and cycled between ‘secondary rejection’ and ‘active copulatory readiness’.