HILL, Peggy S M; HOFFART, Cara; BUCHHEIM, Mark; Univ. of Tulsa: Tracing relationships in the Gryllotalpidae

Male prairie mole crickets (Gryllotalpa major) aggregate their acoustic burrows in a lek arena where they display for females. Individuals produce a loud advertisement call of chirps just at sunset on spring evenings in the south-central prairies of the U.S. The airborne component of the calling song is directed towards flying females, but the call is also transmitted as substrate-borne vibrations that we think provide information used by males in spacing. This reproductive behavior is remarkable in that it is not the rule for members of the mole cricket family, nor even Orthopteran insects in general. In fact, the prairie mole cricket is the only member of the Orthoptera known to mate in a lek. These males are also one of only four of a probable 66 mole cricket species world wide that chirp their calling song. The trilling species do not demonstrate pronounced substrate sensitivity that would suggest the use of vibration as a communication channel. Morphological features of the file mechanism of the forewings do not account for differences in the types of calls produced, and so a phylogenetic analysis of the family was initiated to generate testable hypotheses about evolutionary relationships in this group. Examination of specimens of the five species currently living in the United States and a metadata analysis of the literature yielded a set of 34 species from four genera for which significant morphological data were available. All analyses were rooted by the outgroup method using data from Gryllus texensis, a local representative of the Gryllidae. Analyses with PAUP and MacClade resulted in a tree containing 14 species in four genera roughly organized into clades by call type. This presentation reports on that work.