Mating and Pupal Attendance in Deinocerites cancer and Comparisons with Opifex fuscus (Diptera: Culicidae)

Abstract

Males of the crab-hole mosquito, Deinocerites cancer Theobald, spend much time on the water in the crabholes where the aquatic stages are found. They seek pupae, sieze them, and describe circles about the pupal horns with the tips of their antennae. In doing this and in seeking the pupae, the antennal tips are held slightly above the water film and are vibrated rapidly. This behavior may be related to the extreme development of sensilla campaniforma in the antennal tips. A male which is attached to a pupa at emergence time copulates with the new female before the latter is entirely out of the pupal skin, and may remain in copula up to 2 hours; an emerging male is not recognized as such until genitalial contact has been made. Females emerging unattended are contacted by searching males, which copulate with them at once. As do the males of D. cancer, those of the New Zealand rock-pool mosquito, Opifex fuscus Hutton, search for pupae and neonate females, attend pupae, copulate with females as they emerge or soon thereafter, and fight among themselves over pupae, neonate females, and pupal skins. The initial search is guided by vision in Opifex, and by olfaction and some unknown aerodynamic or hydrodynamic mechanism in D. cancer. Consummatory copulation is similar in both genera. Pupal attendance is probably a derivative and recent development from early copulation; early copulation is probably the result of close association of generations on the breeding water; and this in turn is probably the result of limited dispersal because of an unfavorable environment for copulation and survival at any distance from the breeding site.