Sound Production in Mole Crickets (Orthoptera: Gryllotalpidae: Scapteriscus)1,2,3

Abstract

Males of the southern mole cricket, Scapteriscus acletus Rehn and Hebard, and the changa, S. victims Scudder produce calling songs after sunset for 1.0-1.5 h in specially constructed subsurface chambers. Calling songs of 70 acletus and 62 vicinus were tape recorded in the field at temperatures (soil and air) ranging from 18-32°C. The mean carrier frequency, pulse rate, and intensity (Sound Pressure Level; SPL) of acletus calling songs were 2.6 kHz, 55 pulses/sec (p/s), and 69 dB (at 15 cm, Reference SPL; 2×10−5 N m−2) and of vicinus were 3.2 kHz, 136 p/s, and 65 dB respectively. Regression analysis of the weather factors (viz., soil and air temperatures, relative humidity and rain) on the different parameters of calling songs revealed that the pulse rates of acletus and vicinus are functions of soil temperature. Males of acletus and vicinus produce aggressive and courtship songs similar to calling songs with respect to carrier frequency and pulse rate. Sound production by females of Scapteriscus species had never been reported, but ♀ vicinus made sounds with energy at frequencies varying from 2-6 kHz. Courtship of vicinus included producing long and short intermittent trills and tapping the soil with the forelegs.