Passalid Mating Behavior

Passalid beetles are monogamous. It is believed that one beetle (male or female) begins a gallery and is later joined by a mate, who usually stays for the duration of the breeding season (Schuster and Schuster 1985). In Louisiana, reproduction begins in May and continues through August (personal observation), with offspring from up to three successive clutches living together in the gallery (Gray 1946, Schuster and Schuster 1985). Eggs are generally laid in fresh galleries (Gray 1946), indicating that passalids are continually seeking fresh space in a log for reproduction during the breeding season. Passalid pairs vigorously defend their galleries from other passalid intruders (Schuster 1975b), though this territoriality may relax as the summer moves on (Gray 1946).

Second instar passalid larvae