The field cricket Gryllus assimilis and two new sister species (Orthoptera: Gryllidae)
In preparation for revisionary studies of western U.S. Gryllus field crickets, some eastern U.S. names for species with supposed transcontinental distributions must be resolved. One such species, Gryllus assimilis (F.), as currently characterized, occurs in the West Indies, Brazil, Central America, and Mexico, and in five of the southernmost U.S. states. Our studies of calling songs and morphology indicate that at least three species exist among these populations. The type locality of G. assimilis is Jamaica, but the type specimen is lost and two similar species of Gryllus occur there. One of these species occurs widely outside of Jamaica, and we assign it to G. assimilis and designate a neotype. The other occurs only in Jamaica and is assigned to Gryllus jamaicensis T. J. Walker n. sp. Nearly all populations formerly known as G. assimilis from southern California, southern Arizona, southern Nevada, and Mexico west of the continental divide are assigned to Gryllus multipulsator Weissman n. sp. Populations located elsewhere (with one exception) are deemed conspecific with Jamaican G. assimilis, although G. assimilis from islands east and south of Hispaniola have calling songs with dominant frequencies higher than is characteristic of the species elsewhere. Studies of mitochondrial DNA of assimilis-type Gryllus from widespread localities are compatible with the above species classification. Hybridization trials between G. assimilis and G. multipulsator demonstrated high interfertility. Gryllus contingens F. Walker and Gryllus mundus F. Walker are removed from synonymy with G. assimilis.