Understanding the biology and ecology of an exotic mosquito Culex molestus Forskal (Diptera: Culicidae) to assess public health risks in urban areas of Australia

Culex molestus is thought to have been introduced into Australia in the 1940s. The initial introduction possibly via US military movement through the South Pacific, but there may also have been multiple introductions over the past 70 years. Molecular analysis revealed there is genetic similarity of this mosquito between locations within Australia and also overseas. It is now found in most urban areas of the country with the exception of Queensland and Northern Territory. Laboratory studies have shown that the species is uniquely adapted to subterranean habitats and the current trend towards increased water storage in urban areas has raised concerns of increased nuisance-biting and public health risks in the future. Concern has been raised as to the potential role this species may play in the transmission of exotic arboviruses such as West Nile virus and locally important arboviruses such as Murray Valley encephalitis virus. However, notwithstanding the vectorial capacity of this species, there may be ecological barriers that diminish the public health risks associated this species. The mosquito is active throughout the year but, as it delays taking its first blood meal until after it lays its first autogenous egg batch, it may be less likely to play an important role in the transmission of urban mosquito-borne pathogens. This paper will present the findings of biological, ecological and mosquito genetic studies of Culex molestus with implications for the assessment of mosquito-borne disease risk.