Mosquito control during floods and public events

Mosquito control during floods

NSW can experience heavy rains and significant flooding, resulting in water lying around. Stagnant water provides ideal conditions for mosquito breeding.

With more mosquito breeding there is an increased risk of exposure to mosquito-borne viruses such as Ross River virus (RRV) or Barmah Forest virus (BFV), Japanese encephalitis virus (JEV), Murray Valley encephalitis virus (MVE), or Kunjin virus.

The following measures can be considered depending on the abundance of mosquitoes or nuisance biting, local detection of mosquito-borne diseases, the environmental impact of insecticide use, and local environmental condition. To reduce the number of mosquitoes surrounding your property or in public areas, consider the following steps:

• Cleaning up around your home after a flood. Empty and remove all water-holding containers. Common mosquito breeding sites include buckets, pot plants and their bases, plastic containers, boats, trailers, and tarpaulins.
• Remove pools of water around your home. This can involve increasing water movement in drains and creeks by removing debris.
• Spraying your home with over-the-counter insecticides. A range of insecticides are currently registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA) for use against mosquitoes.
• Local Councils can spray insecticides in public areas. Local Councils may need to notify the NSW Environment Protection Authority (EPA) of pesticide use. There are other obligations that councils need to abide by when spraying outdoor public places. For more information, please contact NSW EPA at 131 555 or visit the NSW EPA website.

Mosquito control during public events

Events held in warmer months with substantial outdoor components should consider implementing measures to reduce the risk of mosquito-borne disease.

The following measures can be considered depending on the risk associated with the event. For advice on determining the level of risk, event organisers can contact their local public health unit on 1300 066 055.

Risk reduction measures include:

• Having mosquito repellent available for patrons.
• Displaying posters and signs with information on how to avoid mosquito bites. Mosquito-borne disease resources are available. 
• Providing advice to patrons prior to attending the event on personal protection measures (e.g. information about using appropriate mosquito repellents containing DEET, picaridin or oil of lemon eucalyptus; wearing loose-fitting, light-coloured clothing and covered footwear; covering prams and tents with mosquito netting, limiting outdoor activities at dawn and dusk when mosquitoes are most active).
• Engaging a pest controller to apply adult mosquito control (e.g. residual treatments or fogging) prior to the event for short-term control of mosquitoes. These products can be applied to indoor and outdoor areas where adult mosquitoes take refuge and can assist in reducing local mosquito abundance in proximity to treated areas.
• Undertaking larval control 2-3 weeks before a public event in areas where there is potential for ongoing mosquito breeding (e.g. areas of stagnant water) can effectively control mosquitoes. The application of mosquito control agents targeting immature larval stages can interrupt mosquito breeding and reduce the abundance of mosquitoes.

Expert advice should be sought when selecting an appropriate chemical product for local conditions as the timing of the application of these products is critical to achieving successful mosquito control.

​