The Cryptocercus punctulatus species complex (Dictyoptera: Cryptocercidae) in the eastern United States: Comparison of cuticular hydrocarbons, chromosome number, and DNA sequences

The goal of the current study was to determine if cuticular hydrocarbons could be used to empirically delimit taxa within the Cryptocercus punctulatus species complex in the eastern United States. Cockroaches were collected from rotting logs in 22 locations across four states. Hydrocarbon phenotypes and two mitochondrial (16S and COII) genes and one nuclear (ITS2) gene were independently analyzed to determine their relationship with chromosome number. Five distinct hydrocarbon phenotypes were found, but these were only partly congruent with chromosome number and thus with purported species descriptions. Molecular and cuticular hydrocarbon data each indicate that Cryptocercus with a male karyotype of 2n = 43 belong to at least two distinct, distantly related lineages. One 2n = 43 lineage is sister group to the 2n = 37 and 2n = 39 clade, and has a unique hydrocarbon profile. The other 2n = 43 lineage is sister group to the 2n = 45 samples, and its cuticular hydrocarbons group with four samples of the 2n = 45 lineage. The cuticular hydrocarbons of two additional 2n = 45 samples diverge from this assemblage. Results indicate cuticular hydrocarbons and chromosome number have some degree of evolutionary independence; neither is completely reliable in delineating historical lineages. Our data provide support for the parallel model of chromosome evolution in the species complex.