SHADLEY, J.R.*; HILL, P.S.M.: Talking back: sending soil vibration signals to lekking prairie mole cricket males.

The prairie mole cricket, Gryllotalpa major, native of the tallgrass prairie of the south central U.S., is the largest North American cricket. A male constructs a specialized acoustic burrow in the spring in the prairie soil from which he generates an airborne calling song that attracts flying females for mating. At the same time, vibrations with the same temporal scale and pattern as the airborne signal are produced in the substrate through an unknown mechanism. These ground vibrations can be distinguished from background vibrations in the soil with a geophone (transducer) buried in the soil at distances up to 3 m, depending on soil conditions and conditions that control the background vibration environment (e.g. wind, highway traffic). We hypothesize that males use the vibration component of the call as information for spacing as they form display arenas, or leks. We used modified field recordings of soil vibrations from singing males with an electromechanical vibration exciter to simulate the vibration component of a singing male in playback experiments. Airborne sounds of males were monitored for two minutes before and two minutes after the introduction of the ground vibration signal with a tape recorder microphone placed 20 cm from the burrow opening. Males did respond to the manipulation experiment; although, we observed individual variation in the level of response.