The rare and imperiled North American grasshopper Shotwellia isleta (Gurney) and the phylogeny of the Chortophaga genus group of band-winged grasshoppers (Orthoptera: Acrididiae: Oedipodinae)

Phylogenetic relationships among the Chortophaga genus group of North American band-winged grasshoppers (Orthoptera: Acrididae: Oedipodinae) were analyzed with particular reference to Shotwellia isleta (Gurney), a rare species in a monotypic genus known only from a few isolated locations in Mexico and New Mexico. Shotwellia isleta occurs in threatened wetland environments in the Chihuahuan Desert, and is considered to be imperiled. However, little is known about its biology, and its current classification is uncertain. Earlier analyses used morphological and behavioral characters to classify the Chortophaga genus group, and Shotwellia isleta is currently placed within this group based on adeagii similar to the genera Chortophaga (Saussare) and Encoptolophus (Scudder). However, this classification remains untested within a modern cladistic context. Six genes (16S rDNA, 12S rDNA, wingless, histone III, cytochrome c oxidase I and II) were sequenced for 24 taxa representing all four genera, and 7 species within the Chortophaga group, all genera and 12 species in the Arphia genus group, four genera and 4 species from the Hippiscus genus group, and one species from the Sphingonotus genus group (used to root the tree). Our analysis provides insight into the phylogenetic placement of Shotwellia isleta and the classification of the genera and species within the Chortophaga genus group.