Coping with the cold: temperature and mating activity of male sagebrush cricketsCyphoderris strepitans(Orthoptera: Haglidae)

Abstract

Abstract. The effect of temperature on male sexual displays is well documented but its role in mediating the differential mating success of males is less well established. Male sagebrush crickets Cyphoderris strepitans Morris and Gwynne occur in high-elevation sagebrush meadows in mountainous areas of the western U.S.A., and often are observed singing at temperatures as low −8 to −4 °C to attract sexually receptive females. Males exhibit differential mating success based on their previous mating experience: virgin males have a higher probability of obtaining a mating than do non-virgin males of securing an additional mating. This differential mating success is mediated in part by an unusual form of nuptial feeding behaviour. Females feed on males’ hind wings at mating and the costs imposed on males as a consequence of this behaviour constrain male mating success. In the present study, to determine whether sagebrush crickets are capable of some degree of thermoregulation, and also to investigate whether this ability is influenced by male mating experience, thoracic temperatures of males of varying mating status were measured in relation to ambient temperature throughout the breeding season. A full factorial model examining the effect of site of capture, mating status, body mass and ambient temperature reveals that only ambient temperature has a significant effect on thoracic temperature after controlling for all other factors. It is concluded that differences in the calling times of virgin and non-virgin males and their ability to secure mates does not result from differences in their ability to cope physiologically with low temperatures.