Phylogenetic status, distribution, and biogeography of Cryptocercus (Dictyoptera : Cryptocercidae)

Recent morphological studies on Blattaria, as well as molecular data on both these insects and their fat body bacterial endosymbionts, do not agree with Grandcolas's phylogenetic placement of Cryptocercus deep within the Polyphaginae [Grandcolas. P. 1999. Systematics, Endosymbiosis, and Biogeography of Cryptocercus clevelandi and C. punctulatus (Blattaria: Polyphagidae) from North America: a Phylogenetic Perspective. Ann. Entomol. Soc. Am. 92: 285-291]. Therefore, we retain the traditional classification and proposed geographic time frame for evolution of this taxon, which is supported by recent estimations of molecular evolution on endosymbionts (70-25 MYBP) and by geological evidence indicating a window of opportunity for transcontinental movement in North America for an insect with the ecological requirements of Cryptocercus (65-34 MYBP). Further refinement and integration of these hypotheses with the biogeography of related taxa awaits the development of a single, phylogenetically based, internationally accepted classification of relevant cockroach genera, and an explicit delineation of the relationships among extant species of Cryptocercus.