The Gin Trap as a Device Facilitating Coercive Mating in Sagebrush Crickets

Female sagebrush crickets (Cyphoderris strepitans) feed on males’ fleshy 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 functional significance remains unknown. The objective of the present study was to determine the adaptive significance of the gin trap by independently manipulating the ability of males to provision and secure females during 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 been disabled. We conclude that the gin trap functions as a device by which males with insufficient hind-wing material are able to force copulations upon females unwilling to accept their spermatophores.