FAQ

  • There are a number of suburbs that are in very close proximity to large mosquito breeding sites. After the adult mosquitoes have emerged they leave the breeding sites to seek out food and resting places such as backyard gardens, reserves and natural remaining bushland. Once mating has occurred, the female will seek blood meals and then return to the breeding grounds to lay her eggs. Once her eggs have been deposited she will return back to feed and rest in these types of areas over her entire lifetime. Males will feed on nectar and plant juices but do not seek blood.

    Areas that have particularly thick foliage and shade may attract higher numbers of mosquitoes. These types of areas that are close to breeding sites will inevitably attract higher numbers of adult mosquitoes.

  • The average life span for an adult mosquito can be between two to four weeks although it can be longer in certain conditions and cooler months. Males usually die before the females.

  • The majority of treatments that are undertaken are targeted on the larval stage of the mosquitoes lifecycle not the adult stage. These treatments are carried out once hatching or larval activity has been detected via breeding site surveys. The aerial treatments are not scheduled as such but are undertaken and timed to result in the highest possible reduction of potential mosquito numbers. Once adults have emerged they disperse over a large distance and make adult mosquito management very difficult.

  • Generally local government does not utilise adulticiding (fogging) as a main method for mosquito reduction. Adulticiding has not proven to be very effective in our area and the most effective treatment method is larviciding. Occassionally we will utilise adulticiding at times of very high disease risk or when mosquitoes are in extreme numbers. The areas that are targeted with adulticides will usually be those adjacent to breeding sites or particular areas that harbour large numbers of adult mosquitoes.

    Adulticiding is non-specific (ie. it kills other beneficial organisms and is also heavily dependent on wind conditions and requires winds of less than four knots). The chemicals are lethal to aquatic life (especially fish), can be toxic to birds and may cause eye and respiratory irritation to humans. For these reasons the City uses adulticiding (fogging) sparingly and as a last resort.

  • Some species travel only short distances from their breeding sites, whilst others like the Aedes vigilax that breeds in the South West during the summer months has been known to travel more that 20km from its breeding sites. This is why some people who do not live close to breeding sites are still at risk of being bitten by mosquitoes that carry disease and also find them in nuisance levels. Within 3km of a breeding site, mosquitoes of most species in the Leschenault and Geographe Regions will move freely and be likely to cause nuisance at certain times.

  • Yes there are a number of species of both fresh and saltwater breeding mosquitoes that are known carriers and transmitters of Ross River virus and Barmah Forest virus. If you think you have become unwell after being bitten by a mosquito you should visit your GP to seek medical advice.

  • The local government authorities’ mosquito management program is largely successful in reducing and maintaining acceptable numbers of mosquitoes. Due to extensive breeding areas and larval densities, total eradication is not possible and the program aims for the best kill rates possible. Weather conditions can also impact on the effectiveness of treatments particularly if storm surges are received immediately after larvicides are applied. It is important for residents and visitors to remember that personal protective measures are required in the Geographe Bay Region and greater south west.

  • Some species of mosquitoes will bite during the day, the Aedes vigilax, which is present in the South West during the warmer summer months is a day time biter. This particular mosquito is very aggressive in its biting manner. If you are going to participate in outdoor activities when this mosquito is present protective clothing, mosquito repellent and a head net should be worn to reduce being bitten. Other times to avoid mosquito activity are early morning and early evening especially when the sun is going down. Calm or humid weather conditions can also lead to higher mosquito activity. These times are when resting adults will be on the move and actively biting.

  • In the South West we use a highly targeted pesticides in its helicopter treatment program and for ground based larviciding operations, which selectively target the development of juvenile mosquitos, and have no impact on other parts of the ecosystem.  The products that are used are very environmentally sound and are extremely specific to mosquitoes. S-methoprene and Bacillus thuringiensis israelensis (Bti) are the two main larvicides currently used by the program and by many mosquito management authorities throughout Australia and the world. Both products have been certified to be used in Australia by the Australian Pesticides and Veterinary Medicines Authority.

  • Mosquitoes require a source of water to complete their lifecycle, so if you have water containing receptacles like bird baths, buckets, unused fish ponds, or any other containers that can hold water and are not cleaned or emptied on a regular basis, mosquitoes may be breeding in those areas. Mosquitoes do not breed in vegetation like long grass and trees, but they harbour in these areas. Due to the large and numerous breeding sites in the South West it is most likely that these mosquitoes are coming from these breeding grounds.

    Generally we do not carry out mosquito treatments on private property. However if you have a legitimate concern about a potential mosquito breeding source (a stagnant body of water) on your property or a neighbouring property, you can contact your local government agency and a site inspection may be requested.

  • Personal repellents that contain DEET (diethyl toluamide) or picaridin have shown to be most effective against mosquitoes. These come in sprays, lotion and gels. Lotions have been recognised as the most effective. There are also a variety of natural based repellents that may suit those that prefer not to use product containing DEET or picaridin. The efficiency of the natural based repellents has not been adequately researched so this option is not recommended.

    Visit Choice Link to for its consumer test of some insect repellants.

  • Yes there are many different predators of mosquito larvae and adult mosquitoes, however the numbers of mosquitoes are so immense that virtually no effect on the population is seen from predation. One small breeding site can support millions of mosquito larvae and produce consecutive generations over a short timeframe. Introducing predators, such as native larvae eating fish, can be effective in some domestic situations but in sensitive environments the use of this mechanism of control is limited.