Mosquito Control

Worldwide, mosquito-borne viruses and parasites are major causes of human and animal sickness and death. There are almost 100 species of mosquitoes in Western Australia and many of them can be serious pests, interfering with leisure time and outdoor activities. Therefore it is important for people to take personal measures, such as the use of repellents, to reduce the risk of contracting a disease and to reduce breeding.

Mosquito bites cause discomfort and pain, particularly to babies and those with sensitive skin. Only the female mosquito bites. They need protein from blood to be able to develop their eggs.

Mosquitoes can pass on viruses when they bite.  The main viruses transmitted by mosquitoes in WA are:

  • Ross River Virus (RRV) - this is the most common virus transmitted by mosquitoes in WA.  Symptoms or RRV disease include joint pain and swelling, sore muscles, rash, fever and fatigue.  Symptoms may persist for several weeks to months. 
  • Barmah Forrest Virus (BFV) - BFV disease has similar symptoms to RRV disease but is not as common.
  • Murray Valley encephalitis (MVE)  MEV is a rare but potentially fatal disease that occurs mainly in the northern half of WA.  Symptoms include fever, drowsiness, confusion, headaches and stiff neck, nausea, vomiting, muscle tremors and dizziness.  In severe cases brain damage, paralysis or death may result.
  • Kunjin virus - While symptoms of this rare but serious disease can be similar to MVE, generally symptoms tend to be milder and not life-threatening.

There are no specific cures or registered vaccines for any of these diseases.  Avoiding mosquito bites is the only way to protect yourself against them.

Two other mosquito-borne diseases, malaria and dengue, cannot be transmitted in WA.

Viruses and parasites transmitted by mosquitoes can also cause illness and death in animals.  Dog Heartworm is caused by a parasitic worm passed on by mosquitoes which, in large numbers, can clog the dog's heart and seriously affect blood flow.

WHAT ARE STATE AND LOCAL GOVERNMENTS DOING REGARDING MOSQUITO CONTROL?

The Department of Health, in collaboration with local governments, conducts mosquito control programs in areas where mosquitoes are suspected of carrying disease. However, despite these programs Ross River virus and Barmah Forest virus will always be a threat as they occur in natural cycles and it is not possible to eliminate all mosquitoes.

The Shire's Environmental Health Officers survey and treat mosquito breeding areas on a regular basis. The Shire has a proactive mosquito control program which involves pre-treating areas which may become inundated during rainfall events with briquette stations. These briquette stations disperse a target specific pesticide that kills mosquitoes while they are in their larval growth stages.

Additional hand application of other larvicides is undertaken where the briquette stations alone are inadequate; this includes both biological and chemical agents. Where possible, the Shire's Environmental Health Service applies target specific products that have minimal effects on both the aquatic life and other non-target insects.

ELIMINATE BREEDING AREAS

Mosquitoes breed in standing water which can be found in old car tyres, pot plant drip trays, water tanks, roof gutters, domestic ponds, neglected pools etc. Removal and prevention of backyard breeding sites is an effective way to reduce the proliferation of mosquitoes and other insects.

How TO eliminate mosquito breeding sites AROUND THE HOME:

  • Dispose of all containers which hold water.
  • Stock ornamental ponds with mosquito-eating fish e.g. Goldfish. Keep vegetation away from water's edge.
  • Keep swimming pools well chlorinated and filtered, and free from leaves.
  • Level or drain depressions in the ground that hold water.
  • Fit mosquito-proof covers to vent pipes on septic tanks systems.  Seal all gaps around the lid and ensure leach drains are completely covered.
  • Screen rainwater tanks with insect proof mesh, including the inlet, overflow and inspection ports. Ensure guttering is not blocked and does not hold water.
  • Empty pot plant drip trays once per week or fill with sand.  Similarly, empty and clean animal and pet drinking water containers once per week.
  • Some plants (especially bromeliads) hold water in their leaf axils.  These should also be emptied weekly.

SPRAYING OF BACKYARD

Residual pyrethroid sprays (eg bifenthrin, deltamethrin), outdoor foggers or permethrin can be used to further reduce mosquito numbers; however, it should not replace the removal and prevention of backyard breeding areas.

how can I AVOID BEING BITTEN

Cover up and use repellents

  • Mosquitoes are most active at dawn and dusk; however, some mosquitoes will also bite during the day.
  • Cover up with loose fitting and preferably light-coloured clothing.  Mosquitoes can bite through fitted clothing, even denim jeans.
  • Application of mosquito repellents is important for avoiding exposure to diseases transmitted by mosquitoes.  When outdoors, carry an effective mosquito repellent for use if mosquitoes are active.
  • The most effective repellents contain either diethyl toluamide (DEET) or picaridin.
  • Lotion or gel repellents are most effective.  Always read the label.  Apply and re-apply repellents in accordance with the manufacturer's instructions.
  • Natural or organic repellents are generally not as effective as DEET or picaridin and may need to be applied more frequently.
  • The best protection for babies and young children is protective clothing, bed nets or other forms of insect screening.  Only infant-strength repellents should be used on young children.

Houses

  • Insect-proof buildings by screening all doors and windows. 
  • Doors should be self-closing and open outward.
  • In high-risk areas build a fully screened outdoor area to protect yourself when outside.

Travelling and camping

  • If you are traveling, discuss with your GP how to protect yourself against diseases transmitted by mosquitoes.
  • Screen caravans, tents, swags and other sleeping equipment or use a mosquito net.
  • Recognise and avoid areas of mosquito activity such as swamps, salt marshes, billabongs and river floodplains.
Last modified: 05/07/2017 12:28 PM
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