Diel oviposition periodicity of Anopheline mosquitoes (Diptera: Culicidae) from the Americas: Anopheles albimanus Wieldemann and Anopheles freeborni Aitken

The diel oviposition patterns of Anopheles albimanus and An. freeborni derived from Panama and California, U.S.A., respectively, were studied in the laboratory by recording the egg-laying of individuals and colonies at 2-h intervals. Anopheles freeborni oviposition patterns were almost exclusively nocturnal, with 80% of eggs being laid during the scotophase. A large, well-defined peak of oviposition, comprising about 70% of eggs laid, occurred 4-6 h before sunrise. Anopheles albimanus oviposition patterns were bimodal with crepuscular and nocturnal components, 68% of eggs being laid shortly before lights went 'off' or 'on' and 32% during the scotophase. A small, well-defined peak of oviposition, comprising about 42% of eggs laid, occurred immediately following lights off (i.e. 18.00-20.00 hours). Nulliparous females allowed to engorge on human blood matured, on average, 104 follicles (range 80-142) for An. albimanus and 114 follicles (range 31-201) for An. freeborni.