NSW is experiencing heavy rain and significant flooding, resulting in water lying around. This water, combined with warmer temperatures provides ideal conditions for mosquito breeding.

Mosquitoes will lay their eggs on or in still and stagnant water. They lay more than 300 eggs at once – that's a lot of extra mosquitoes. This means there is in an increased risk for people to be infected with mosquito-borne diseases, like Japanese encephalitis.

Reduce the number of mosquitoes around your home or business by taking the following steps at least once a week – Screen up, Clean up!

Frequently asked questions

  • NSW Health undertakes mosquito surveillance across NSW from October/November to April/May each year. Local councils may also undertake mosquito control measures such as fogging and spraying of adulticides and insecticides in outdoor areas, which can assist in reducing local mosquito abundance.

    A national working group of communicable disease, vaccine and arbovirus experts has also been established to support Australia's response to JEV. This includes:

    • mosquito surveillance and control measures
    • identification of those at direct risk, and the rollout of vaccines.

  • ​If you live on a farm, take the following additional steps to reduce the chance of mosquitoes breeding around your farm or property:

    • keep dams and ground pools free of vegetation (e.g. introduce a local species of fish or use of mosquito controlling agents)
    • check dam walls and irrigation bays for leaks
    • be careful not to over-irrigate to avoid water collecting in low-lying areas for long time periods
    • don't allow irrigation water to flow into and lie undisturbed in roadside table drains


  • The best way to reduce the number of mosquitoes around your home is to:

    • use insecticide sprays and vapour dispensing units  
    • install fly screens on windows, doors, vents and chimneys 
    • use mosquito coils outside in well ventilated areas  
    • if camping, ensure tents are well protected with flyscreens, or sleep under mosquito nets

  • Backyard water-holding containers make perfect mosquito breeding habitats because mosquitoes need still and stagnant water to lay their eggs. Take the following steps, at least once per week, to get reduce the risk of mosquitoes breeding around the home:

    • clean up your backyard and remove all water-holding containers, including buckets, tyres, toys etc, and store them in a dry place
    • mow your lawn regularly
    • empty and wipe out bird baths, pet water bowls and water features
    • fill pot plant bases with sand to avoid standing water
    • store anything that can hold water undercover or in a dry place, and keep bins covered
    • remove leaves in water-holding plants
    • clear drains and roof gutters so water runs freely
    • cover or securely screen the openings of septic tanks and rainwater tanks.

  • NSW is experiencing heavy rain and significant flooding, resulting in water lying around. This water, combined with warmer temperatures provides ideal conditions for mosquito breeding.

    Mosquitoes need still and stagnate water to breed, and some mosquitoes can breed in very small amounts of water, such as in the water that collects in a discarded drink can. Mosquito eggs need access to standing water for about a week to complete their development, so emptying a water-filled container once a week can stop the immature mosquitoes from completing their development and emerging as adults.

Current as at: Wednesday 7 December 2022
Contact page owner: Communicable Diseases