HILL, P.S.M.; Univ. of Tulsa, Oklahoma USA: Surface opening variations, dominant frequency and amplitude of song in the prairie mole cricket

Mole crickets in the Orthopteran family Gryllotalpidae are known for their digging forelimbs and their singing from specialized burrows they have constructed in the soil. Few descriptions of singing, or acoustic, burrows are available in the literature, but conventional wisdom is that burrows vary enough for them to be useful taxonomic characters at the species level. Surface openings of these burrows are known to vary among species from none to six openings from a single acoustic horn. However, within species variation is rarely reported. The prairie mole cricket, Gryllotalpa major, is a rare grasslands native of the south-central United States. The well-developed acoustic horn constructed by an individual male has a single surface opening, but I have documented six distinct shapes that opening might take. Since the surface opening acts as the sound ‘radiator’, I am interested in how these variations in the radiating surface are related to variations in the calling song (sexual advertisement call) produced by males singing from them. This paper reports on an analysis of the relationship between surface opening shape and the dominant frequency and maximum amplitude of calling songs produced by prairie mole cricket males over an eight year period on White Oak Prairie in Oklahoma, USA.