Start of the salt marsh mosquito season

The Top End Health Service is urging people to protect themselves from salt marsh mosquitoes, as numbers are expected to increase in NT coastal areas due to the high tides last week. Elevated numbers are expected from 8 October, lasting 7 to 10 days.

Director of Medical Entomology, Nina Kurucz, said the increase of salt marsh mosquito numbers will occur despite mosquito control carried out by the Medical Entomology unit in Darwin, which included spraying of 170 hectares of salt marsh mosquito breeding area in swamps adjacent to Darwin’s northern suburbs.

The Medical Entomology unit conducts surveys via helicopter around swamps, on foot in urban areas and in liaison with the NT Parks and Wildlife Commission in Casuarina Coastal Reserve, Charles Darwin National Park and the Botanic Gardens to determine areas where spraying is required.

“This is the time of the year when high tides and rainfall trigger extensive salt marsh mosquito breeding until monsoonal rains flood all the breeding areas,” Ms Kurucz said.

She explained that there is only a narrow window of about three days to effectively spray the larvae (juvenile mosquitoes) in the breeding areas. Darwin is surrounded by swamps and with a flight range of 50km, these mosquitoes will make their way into Darwin, Palmerston and rural areas from outside the control area.

Salt marsh mosquitoes can carry the Ross River virus. Although the high risk period for RRV starts in December, the virus can be contracted all year around. “This means people need to start taking precautions to avoid being bitten,” Ms Kurucz said.

To avoid being bitten Top Enders are advised to:

  • avoid locations near coastal swamps and mangrove areas
  • use mosquito-proof accommodation and camping facilities at night
  • wear light-coloured clothing with long sleeves, long trousers and socks, especially between dusk and dawn in areas where mosquito bites are likely
  • use a protective repellent containing 20 per cent DEET or Picaridin as a supplement to protective clothing, with creams providing best protection
  • use mosquito coils, mosquito lanterns, and barrier sprays in patio and outdoor areas near houses
  • ensure children and animals are adequately protected against mosquito bites.

A salt marsh mosquito pest calendar is available on the Medical Entomology website:

https://nt.gov.au/wellbeing/emergencies-injuries-and-accidents/bites-and-stings/insects-of-medical-importance.