The taxonomy of fire ants has been plagued by difficulties in recognizing species on the basis of morphological characters. We surveyed allozyme markers and sequences of the mtDNA COI gene in several closely related nominal species from two areas of sympatry in the native ranges to learn whether the morphology‐based delimitation of these species is supported by genetic data. We found that Solenopsis invicta and Solenopsis rich...

One possible mechanism for interspecific transfer of Wolbachia is through the intimate contact between parasites and their hosts. We surveyed 10 species of fly parasitoids ( Pseudacteon spp.) and one inquiline social parasite, Solenopsis daguerrei , for the presence and sequence identity ( wsp gene) of Wolbachia . Two Wolbachia variants infecting S. daguerrei were identical to known variants infecting the two common ant host s...

Wolbachia are endosymbiotic bacteria that infect arthropods. As they are maternally transmitted, the spread of Wolbachia variants within host populations may affect host mtDNA evolution. We sequenced a portion of the mitochondrial cytochrome oxidase I gene from numerous individuals of two Wolbachia ‐infected fire ant species, Solenopsis invicta and S. richteri , to determine how these bacteria influence patterns of mtDNA varia...

Little is known about what determines patterns of host association of horizontally transmitted parasites over evolutionary timescales. We examine the evolution of associations between mushroom‐feeding Drosophila flies (Diptera: Drosophilidae), particularly in the quinaria and testacea species groups, and their horizontally transmitted Howardula nematode parasites (Tylenchida: Allantonematidae). Howardula species were identifie...