The Burrowers

Cockroaches that burrow in wood or soil exhibit a remarkable convergence in overall body plan related to the ability to loosen, transport, and travel through the substrate, and to maneuver in confined spaces. These insects are often wingless, with a hard, rigid, pitted exoskeleton and a thick, scoop-shaped pronotum. The body is stocky and compact, and the legs are powerful and festooned with stout, articulated spines that provide anchorage within the tunnels and leverage during excavation (Fig. 1.13). The cerci are short, and can be withdrawn into the body in Cryptocercus (thus the name) and Macropanes-thia. Long cerci make backward movement in enclosed spaces inconvenient (Lawrence, 1953).

The similarity in the external morphology of Cryptocercus and wood-feeding Panesthiinae is so striking that they were initially placed in the same family (Wheeler, 1904; Roth, 1977). McKittrick (1964,1965), however, examined their genitalia and internal anatomy and demonstrated that the resemblance was superficial. Her studies resulted in placing the two taxa into distantly related families (Cryptocercidae and Blaberidae). They currently offer an opportunity to scientists interested in sorting the relative influences of phylogeny and ecology in structuring life history and behavior.

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