Morphological and Molecular Phylogenetic Analyses of Gryllotalpidae:

What Came First, the Chirp or the Trill?

Cara Hoffart, Bachelor’s Student, Biology, Peggy Hill

 

The prairie mole cricket (Gryllotalpa major) is a burrowing insect native to the tall grass prairies of the southern United States. The male produces a loud, long-range calling song at sunset in April and May. In addition, he produces courtship songs and aggressive calls. The cricket wing morphology is responsible for sounds and calls. Rubbing the plectrum of one wing along the file of the other wing produces a series of “chirps.” The wing morphology of G. major was compared to five other mole cricket species found in North America: N. hexadactyla, G. gryllotalpa, S. abbreviatus, S. vicinus, and S. borelli. Twelve other species found in Australia and New Zealand were compared to these. Achetus domesticus is the outgroup in this study. The overall wing structures of the crickets in North America were similar, yet calling songs differ in that G. major and N. hexadactyla chirp while the others trill. S. abbreviatus does not have a calling song. The type of calling song may reflect an adaptation that promotes being heard in a particular habitat and may influence the type of mating system of a species. In addition, DNA sequence data will be compared for the same species. A morphological phylogeny for Gryllotalpidae was constructed to determine if the different species express a similar trait because they inherited it from a common ancestor or because they acquired it independently. The phylogenies account for the history of character change and allow for hypotheses to be developed regarding the course of the mole crickets’ evolution and the correlation of this with behavior traits.