Mosquito Management


While Murray is fortunate to border a large area of the Peel Harvey Estuary, its salt marshes provide an ideal breeding ground for mosquitoes. This creates significant risk for residents, especially those living in residential areas in close proximity to the estuary.

Besides being a nuisance, mosquitoes found in Murray can transmit:

  • Ross River Virus
  • Barmah Forest Virus

Current Conditions, Treatment and Results

Current Conditions

Ross River Virus is currently active in the region.

Considering recent rainfall, increased tidal activity and rising temperatures, mosquito numbers are likely to remain high with the virus active in the environment.

It is important that residents and visitors take precautions to protect themselves and their loved ones.

Treatments and Results


Size of Treatment Area 


Barragup, Furnissdale, Stake Hill, Yunderup 278 hectares 6 October 2023
Barragup, Furnissdale, Stake Hill, Yunderup, Birchmont 423 hectares 21 September 2023
Barragup, Furnissdale, Stakehill, Yunderup 259 hectares 8 September 2023
Barragup, Furnissdale, Stake Hill, Yunderup 157 hectares 31 August 2023
Barragup, Furnissdale, Stake Hill, Yunderup 80 hectares 11 August 2023
Barragup, Furnissdale, Stake Hill, South Yunderup 145 hectares 22 July 2023
Barragup, Furnissdale, Stake Hill, Yunderup 122 hectares 6 April 2023
Barragup, Furnissdale, Stake Hill, Yunderup, Birchmont 407.2 hectares 28-29 March 2023
Barragup, Furnissdale, Stake Hill, Yunderup 232 hectares 21 March 2023
Barragup, Furnissdale, Stake Hill, Yunderup 383.5 hectares 3 March 2023
Barragup, Furnissdale, Stake Hill, Yunderup 192 hectares 26 February 2023
Barragup, Furnissdale, Stake Hill, Yunderup 278 hectares 18 February 2023
Barragup, Furnissdale, Stake Hill, Yunderup, Birchmont 414 hectares 9 February 2023
Barragup, Furnissdale, Stake Hill, Yunderup 320 hectares 25 January 2023
Barragup, Furnissdale, Stake Hill, Yunderup 200 hectares 11 January 2023


How is the mosquito treatment schedule determined?

Tides that flood saltmarshes lead to mosquito eggs hatching.

Tides in the Peel Harvey Estuary can rise unexpectedly due to low pressure systems, northerly winds and local climatic events.

As a guide when tides in the Peel Region reach 0.76m, hatching of mosquito eggs is likely to be initiated on most breeding sites.

Our mosquito control officer monitors breeding sites to assess the extent and location of mosquito breeding and determine when to conduct treatments.

The mosquito growth cycle is an important consideration because treatments are only effective in the larval stage and not the pupal or adult stage. There may be multiple cohorts of larvae activated by separate trigger tides and an ideal application would treat these before any mosquitoes emerge as adults.

Weather conditions are also taken into account because:

  • Wind affects helicopter safety and the even distribution of larvicide
  • Rain reduces visibility and clumps granular treatments, affecting its application
  • Strong incoming tides can dilute larvicide and strong outgoing tides can wash larvicide out to sea

We time our treatments so that they have the greatest impact on the mosquito numbers.

How do you treat mosquito breeding areas and is it safe?

Larviciding is the main method of mosquito reduction in the Peel Region. This technique targets the mosquito larvae before they emerge as adults and is the most effective control method to reduce adult populations.

As large areas (up to 600hectares of saltmarsh) need to be treated the larvicides must be applied by helicopter.

The two main products used are sand based S - methoprene and a liquid product called Bti (Bacillus thuringiensis israelensis).

These are the most environmentally appropriate products available and pose very low toxicity to non-target organisms and public health.

A treatment has just been completed. Why are there still mosquitoes?

Whilst the vast majority of larvicide treatments are effective in reducing mosquito populations, the limitations of the larvicides and environmental conditions do not permit total eradication. This is why even after successful treatments there will always be residual mosquito activity.

Larviciding treatments are not always effective due to environmental conditions and it is important that you take personal protective measures.

Protect Yourself

There is no cure or vaccine to protect against mosquito-borne diseases acquired in Australia. The only way to prevent infection is to avoid being bitten.

The worst months for Murray (and the wider South West region) are spring and summer, September to March.

Mosquitoes breed all year round however, so it is important that we stay vigilant.

Protect yourself from being bitten

Cover Up

  • Wear long, loose-fitting, light coloured clothing, covering as much of the body as you can


  • When outdoors, apply insect repellent containing DEET (diethyltoluamide) or picaridin evenly to exposed skin


  • Try and stay indoors during increased mosquito activity, such as at dawn and dusk

Reduce mosquito breeding around your home and property

Clean Up

  • Remove, empty or cover water-holding containers
  • For horse troughs, poultry drinking vessels of other receptacles, frequently change the water and ensure it remains free from vegetable matter and slime


  • Ensure insect screens are intact

Peel Mosquito Management Group

The largest mosquito management partnership of its type in Western Australia, aimed at reducing human cases of mosquito borne disease and minimising the nuisance caused by mosquitoes. 

Members Include:

  • Department of Health
  • City of Mandurah
  • Shire of Murray
  • City of Rockingham
  • Shire of Waroona
  • With assistance provided by The University of Western Australia

Mosquitoes are a part of life in the Peel Region.Without the programs operation, mosquito borne disease and mosquito populations in our region would be significantly higher.

Given that mosquitoes don’t recognise local government boundaries, we are working to cooperatively achieve effective and sustainable mosquito management.