Mosquitoes

At a public forum around mosquito issues about fifty residents came to express their concerns about being bitten and about environmental protection. We heard strongly- worded views about the need for personal safety, about concern for native species and about how Council responds to these concerns.

Resident after resident told their story about cycles of mosquitoes in the evenings. Very many people demanded that the City fog the Canning River wetlands regularly. Many felt that the City was not responding to their needs.

After an hour of clearly- expressed views of residents the City’s Manager, Environmental Health outlined the very extensive work carried out over five years. Sebastian’s team, all with Environmental Science qualifications, had trapped, mapped and measured mosquito issues in the area. Sebastian presented a summary of work done and conclusions reached. He also presented a background of control measures already taken and plans for the future.

The second speaker, Department of Health medical entomologist Sue Harrington, provided some scientific background on the 210 species of mosquito in Australia and their breeding, biting and bothering habits. She pointed out that fogging over marine wetlands was illegal and likely to cause widespread fish deaths. Fogging also kills all types of insects- bees, spiders, moths and mosquitoes.

Ms Harrington compared local mosquito levels with those in Capel and the Kimberley, where truly massive concentrations occur. She also suggested that residents live near the river because they value the environment, with its trees, fish and other fauna. In order to sustain these things we value she suggested that we treat the mosquito issue with respect for the whole environment.

One particular control measure Ms Harrington suggested was a naturally- occurring bacteria, widely used throughout WA. Capel has been hugely successful with this measure. They spread this biological agent twice a year, never fog and hardly see a mosquito. Their mosquito management strategy is on their web site. A good thing about this method is that the biological agent does not affect other species.

A third speaker, from Swan River Trust, provided information on wider issues of environmental management. An outcome of the meeting was to set up a residents’ committee to meet with the City and  communicate more about management of mosquitoes.

How Can You Assist? (Quoted from Capel)

Mosquitoes breed in STANDING WATER. Standing water can be found in old tyres and other water holding containers, pot plant drip trays, septic and water tanks, roof gutters, domestic ponds, etc. By eliminating these breeding sites you can help to reduce mosquito numbers in your backyard.

You can help eliminate breeding in your backyard:

• Dispose of all containers which hold water.

• Keep ornamental ponds stocked with mosquito-eating fish, e.g. goldfish.

• Empty self- watering pot plant trays once a week or fill them with sand.

• Empty and clean animal and pet drinking water once a week.

• Keep swimming pools well chlorinated and filtered and free of dead leaves.

• Fill or drain depressions in the ground that hold water.

• Prevent leaking taps which can maintain semi-permanent pools.

• Avoid over watering lawns. This can lead to high water tables or run off to storm water drains and create permanent pools.

• Vent pipes on septic tank systems must be fitted with mosquito- proof cowls. Seal all gaps in the lid, and ensure leach drains are completely covered.

• Screen rainwater tanks and/or add paraffin oil to cover surface.

• Ensure roof guttering does not hold water.

• Some plants (especially bromeliads) hold water in their leaf axils. These should be emptied of water once a week.

I look forward to hearing that a collaborative approach has this matter under control to everyone’s satisfaction.