Culex molestus Forskal (Diptera: Culicidae) in Australia: Colonisation, stenogamy, autogeny, oviposition and larval development

Abstract

The Culex pipiens subgroup of mosquitoes contains some of the most important vector species internationally. In Australia, there are four species currently present that belong to that subgroup, with Culex molestus one species that is closely associated with urban environments, and concern has been raised as to the potential role this species may play in the transmission of exotic and endemic Flaviviruses. An understanding of the biology and ecology of this species is crucial for the establishment of laboratory colonies and further experimentation. Using field-collected adult mosquitoes, a laboratory colony of Cx. molestus was established and sustained for 10 generations. The species was strongly stenogamous and, across all generations, over 95% of females laid autogenous egg rafts with a mean egg raft size of 54.2±17.7 eggs. The females did not display a preference for highly organic oviposition water and readily laid eggs in clean water. While colony maintenance could be sustained on autogenous egg rafts alone, the species readily fed on rodents and post-blood feeding egg rafts were significantly larger than autogenous egg rafts. Larval development was the shortest, 12.9±0.4days, at a mean temperature of 24.6±0.6°C and the longest was 29.4±0.7days at 12.1±3.2°C. Adults emerging from larvae raised at 12.1±3.2°C maintained the ability to lay autogenous egg rafts. Results indicate that Cx. molestus can be readily colonised and large numbers of mosquitoes can be reared for biological, ecological and vector competence experiments. © 2011 The Authors. Journal compilation © 2011 Australian Entomological Society.