Spring Field Crickets (Gryllus veletis) Use Two Different Pulse Types When Signaling to Attract Mates

Abstract

Male field crickets acoustically signal to attract females by raising their forewings and rubbing them together to produce “regular” (lemon-shaped) pulse sound waveforms. In contrast, we have observed that spring field crickets, Gryllus veletis, often produce an irregularly shaped pulse that exhibits a complete drop in amplitude near the center of the pulse, termed “gap pulses.” We tracked the occurrence of regular and gap pulses temporally. Males change how they signal through time, producing increasingly more gap pulses later in the night and in the morning than through the afternoon and evening. Wing wear did not explain variation in gap pulse production. However, variation in gap pulse production is attributable to variation in body size, with larger males that signal with longer chirps and at lower carrier frequencies producing relatively more gap pulses than smaller males. We hypothesize possible proximate and ultimate causes for the production of gap pulses.