Surface Activity of the Xylophagous CockroachCryptocercus punctulatus(Dictyoptera: Cryptocercidae) Based on Collections from Pitfall Traps

Little information is available on the extra-log movement patterns of Cryptocercus punctulatus Scudder (Dictyoptera: Cryptocercidae), despite its key taxonomic position as a member of the xylophagous cockroach family that is sister group to termites. We conducted a field study in which individuals of C. punctulatus were collected from pitfall traps checked daily for 7 mo on the grounds of Mountain Lake Biological Station, VA. In total, 50 large nymphs, subadults, and adults of both sexes were captured, with adult activity strongest from midsummer through autumn. Surface activity seems unrelated to rainfall. The female-to-male sex ratio of trapped cockroaches was 2:1 overall and 1.5:1 in adults. Nymphs do not begin exploring outside of natal logs until they are at least half grown and significantly pigmented and sclerotized. Dissections of adult females indicated that more than half captured outside of logs (56%) had sperm in the spermatheca, and one female was carrying a spermatophore. These results suggest that sexual exclusivity cannot be assumed between paired individuals of this species.