Mosquitoes associated with an urban estuary and implications for the management of pest and public health risks in Sydney, Australia

Mosquito populations associated with the heavily urbanised Cooks River and Wolli Creek estuaries, Sydney, Australia, were investigated to assist in identifying potential pest and public health threats and assist local authorities in developing management strategies. Adult mosquitoes were sampled using carbon dioxide baited light traps at five locations, including two sites alongside Cooks River (Steel Park and Gough Whitlam Park), two sites alongside Wolli Creek (Jackson Track and Turella Reserve) as well as an additional location, Barton Park (Muddy Creek). These locations represented at least one of three distinct landscape characteristics, dominated either by bushland, parkland, or estuarine wetland habitats. Three trap sites were established at each location and sampling adult host-seeking mosquitoes took place on a weekly basis for 4 weeks. All mosquito specimens were identified to determine differences in relative abundance and community composition. There was a distinct difference in the abundance and community composition of mosquitoes collected between the five locations with the differences due to the presence and abundance of Aedes vigilax, Culex sitiens, Aedes notoscriptus Those locations close to estuarine wetlands were dominated by A. vigilax while other sites were dominated by mosquitoes associated with urban habitats such as stormwater infrastructure or backyard water-holding containers (e.g. A. notoscriptus and Culex quinquefasciatus). Sites adjacent to urban bushland contained a higher species richness, but not necessarily greater abundance, of mosquitoes than other sites. This study provided an insight into mosquito populations within a previously unstudied area of Sydney and highlight that local authorities should carefully consider wetland management and urban planning strategies in the future to assist in identifying potential risks of nuisance-biting, mosquito-borne disease and in determining the need for further public health action.