THE GIN TRAP AS A DEVICE FACILITATING COERCIVE MATING IN SAGEBRUSH CRICKETS

Female sagebrush crickets (Cyphoderris strepitans) feed on males' fles hy hind wings during copulation and ingest haemolymph from the wounds they inflict. At the same time, males physically secure females using a specialized, abdominal pinching organ known as a gin trap. Although the gin trap clearly serves a reproductive role, its precise functiona l significance remains unknown. The objective of the present study was to determine the adaptive significance of the gin trap by independent ly manipulating the ability of males to provision and secure females d uring copulation. When the hind wings of males were left intact, there was no difference in the mating success of males with functional and experimentally disabled gin traps, respectively. However, when males' hind wings were removed, males with functional gin traps experienced a significantly higher mating success than those whose gin traps had be en disabled. We conclude that the gin trap functions as a device by wh ich males with insufficient hind-wing material are able to force copul ations upon females unwilling to accept their spermatophores.