Mosquito Management during the Summer Storm Season
Mosquito numbers are likely to increase due to the heavy rainfall from the storms that the region has experienced
Things you can do to protect yourself
- Use repellent containing DEET if you are outside
- Wear long sleeve shirts and trousers, light colours are best
- Check around the home for any containers holding water and empty
- Check items such as BBQ covers which maybe holding water
Small amounts of water can breed large numbers of mosquitoes under the right conditions
Around the house
- Spray screens with residual products
- Increase light and air movement around dark and damp areas
- Outdoor areas can be treated with products containing BiFenthrin for control over longer periods.
- Limit time outside around dawn and dusk
What Council is doing
- Conducting aerial treatments across the region
- Ground treating areas holding water around parks, gardens and roadsides
- Conducting barrier treatments and fogging in ‘hot spot’ areas
Council’s regionally based mosquito management program involves both aerial and ground treatments. The aerial program uses helicopters to spray biological control products and is focused on saltmarsh areas.
Breeding of mosquitoes in these areas is triggered by tides over 2.45 metres and rainfall events. After such events there is a small window of opportunity lasting three to four days when mosquito treatments need to be carried out.
The mosquito season occurs from September to May.
Council uses two main biological control products to manage mosquitoes:
- Bti (Bacillus thuringiensis israelensis) - which is used in the majority of treatments, is a bacterium that specifically targets the gut lining of mosquito larvae. It is only effective when consumed by the mosquito larvae and therefore has little or no impact on the ecology of the area.
- Methoprene - an insect growth regulator that specifically targets the larvae’s development and stops them becoming adults. As such, it has little impact on the environment. Both of these products are only effective against mosquitoes in the larval stage which is the best time to treat mosquitoes, because populations are contained in specific areas.
Treatments targeting adult populations are carried out when mosquito numbers are excessively high. Misting, fogging and barrier treatments are then carried out, but these treatments are only effective in small areas.
Common mosquito areas
Aedes vigilax mosquito breeds in the region’s saltmarsh/mangrove areas. This mosquito is the major target of the mosquito management program, as it is a prolific breeder and is very aggressive.
Breeding is triggered when the tide is greater than 2.45m or if a rainfall event occurs, because this provides enough water to flood the low lying tidal flat areas. These mosquitoes can easily travel up to 50 kilometres from their breeding sites. The adult female is a medium size, dark mosquito with white banding on its legs and is most active at sunrise and sunset.
Salt Marsh Treatment Areas
Culex annulirostris - the freshwater mosquito - is mostly noticeable after periods of heavy rain. It breeds in temporary and semi-permanent freshwater pools, especially those with grassy linings such as roadside gutters and freshwater ponds. It can travel five to 10 kilometres from its breeding sites and will feed at sunset and sunrise. The adult is brownish, medium sized and has banding on its legs.
Fresh Water Treatment Area
Containers such as plant saucers, tyres, blocked guttering or buckets provide ideal sites for Aedes notoscripts to breed. These mosquitoes are active day and night and are very common in the shaded areas around houses.
This species can also be active during the winter months. The female is small with white markings on its head, body and legs. The adults can emerge in as little as five days.
Containers around the house that breed mosquitos
Reducing mosquitoes in your backyard
Residents can do a lot to reduce mosquito numbers around their houses including:
- Throwing out containers in the yard that hold water (eg. tyres, tins, jars, etc)
- Changing water in bird baths and pet bowls frequently
- Cleaning roof gutters on a regular basis
- Emptying pot plant saucers every week or filling them with sand
- Keeping swimming pools clean and chlorinated
- Keeping ornamental ponds and fountains stocked with fish.
- Creating a frog-friendly garden
Mosquitoes & rainwater tanks
Rainwater tanks can provide ideal conditions for mosquitoes and midges to breed. A hole the size of a matchstick end is enough to allow mosquitoes into the tank and for thousands of larvae to develop. Tanks must be checked on a regular basis.
Checks should include the screens on every opening, such as the overflow. Other containers used to hold rainwater, such as drums or movable tanks, will also provide ideal mosquito breeding locations. Any holes must be fitted with mosquito-proof screens.
If you have any concerns about mosquitoes and their breeding areas, please contact council.