ENVIRONMENTAL AND SOCIAL INFLUENCES ON CALLING EFFORT IN THE PRAIRIE MOLE CRICKET (GRYLLOTALPA MAJOR)

Sexual advertisement in the form of acoustic display is energetically expensive. Calling effort, or metabolic energy expended specifically f or advertisement, is adjusted in some species in response to competiti on from other males or to changes in climatic conditions. The prairie mole cricket (Gryllotalpa major) is a rare insect of the south-central United States that produces its calling song, or advertisement call, from a specially constructed burrow in tallgrass prairie soil. I found that prairie mole cricket males do not adjust their call amplitude wi th competition or female availability, nor do they vary amplitude with soil temperature or moisture within their established range of callin g conditions. Chirp rate adjustments were made with social interaction s and changes in soil temperature, but group size did not influence ca lling effort. Males produced more complex calls in response to closer calling neighbors, but prairie mole cricket males may selectively resp ond to only the nearest one to two neighbors.