Paternal investment of urates in cockroaches

Abstract

During copulation, the male German cockroach [Blattella germanica (L.)] deposits a spermatophore in the female's genital pouch and voids stored urates from his accessory glands (uricose glands) on to the spermatophore¹. About 24 h after mating, the female expels the empty spermatophore with adhering urates. Although uricose glands have been reported in the Blattaria^2,3, and are proposed to act in excretion^4,5, then role in reproduction is unclear. Roth² has suggested that urates may serve to protect the spermatophore from premature consumption by the female or other insects. However, we have noted the disappearance of spermatophoresurates from cages containing mated pah's of cockroaches and have investigated the possibility that these materials have nutritional value. We observed that spermatophores and urates disappeared between 7 and 18 d after females were mated while on a dog food diet; spermatophores were consumed within 4 d by females starved for 3 d after eclosion. Furthermore, we now report that labelled uric acid assimilated by males before, and voided at, mating can be recovered in mated females and their ootheca.