A year of mosquito monitoring at Robertson Barracks and the nearby Millner swamp, Northern Territory, Australia

Large numbers of military personnel are based in northern Australia, generating risks to them from endemic tropical mosquito-borne diseases.In addition, posting of the military to Timor- Leste and other overseas locations poses a risk that mosquito-borne disease, notably malaria and dengue fever, will be imported back to Australia, a potential problem both for those personnel and the wider community. Robertson Barracks, near Palmerston in the Northern Territory (NT), lies adjacent to a seasonal freshwater wetland and 1.5 km from the seasonal fresh, brackish and saline habitats of Millner Swamp, and its mosquito incidence is consequently an issue of concern. Here, we report weekly monitoring over 12 months from October 2005 to September 2006 at 2 sites, 1 in the Barracks area, and the other between the Barracks and Millner Swamp. 6 mosquito species of particular concern were common to abundant at both sites; Anopheles farauti s.l. and Anopheles bancroftii as potential vectors of malaria, Aedes vigilax and Culex annulirostris as vectors of prevalent arboviral diseases due to Ross River, Barmah Forest and Murray Valley encephalitis virus infection, and Coquillettidia xanthogaster and Mansonia uniformis as nuisance value. However, there was considerable fewer An. bancroftii and even less An. farauti s.l. and Ma. uniformis at the Barracks compared to Millner Swamp. An.farauti s.l., a key potential vector for malaria,and other disease vector species breed in Millner Swamp. Maintenance of the buffer distance separation between the Barracks and Millner Swamp is an important part of the strategy to prevent local transmission of malaria, and to reduce the pest and vector-borne disease potential to Barracks personnel