Male advertisement signals and female preference are directly affected by ambient temperatures in many exothermic species. Previous studies indicate that male Metrioptera roeselii increase their buzz duration and vary other call parameters with increasing temperature. This study examines female M. roeselii responses to the playback of male calls to determine if they show variation in preference for calls produced at different temperatures. Comparing the strength of female response to male calls produced at higher temperatures with calls produced at lower temperatures may provide insight into the factors that affect the perceived quality of a male signal. To examine this, I placed virgin adult M. roeselii females individually into an arena and and played recordings from one of three male katydids taken at 20°C, 30°C, and 40°C or a silent control signal to each individual. The response of each female was measured on a continuous scale from 0 – 5, with zero being no response, and 5 representing a female climbing the arena wall to reach the speaker. Females showed significantly stronger responses to male calls that were recorded at higher temperatures. The results suggest that the increase of acoustic energy generated by males calling at higher temperatures may be perceived as signals from higher quality males than calls produced at lower temperatures. Moreover, the increased duration of calls at higher temperatures could also make it easier for a female to recognize a conspecific male as compared to the intermittent short buzzes that are produced at lower temperatures. Therefore, increasing female responsiveness may relate to an unambiguous signal from males producing longer buzzes at higher temperatures
