Insects and Pest Management

S-Methoprene and Bti, (Bacillus thuringiensis israelensis) and are the most environmentally appropriate products available for mosquito control and are utilised across the world. Both of these larvicides have been approved for use by the Australian Pesticides and Veterinary Medicines Authority, approved by the Department of Health and are certified for the management of mosquitoes in natural and urban environments. Both are exempt from poisons scheduling. Extensive studies have been undertaken showing that the use of S-Methoprene and Bti has no negative impact on birds, other wildlife and aquatic invertebrates. The chemical is used during the aerial treatment in the Peel Region. The chemical is not considered hazardous to humans based on appropriate application in accordance with the manufacturer’s and Department of Health instructions.

The aerial treatment may be aborted if there are significantly large number of birds present showing no intention to fly away from the treatment areas.

Mosquito breeding at The Spectacles is primarily determined by environmental and meteorological factors such as rainfall and temperature. The City requires access permissions and authorisations from the landowners and management bodies including the Water Corporation and the DBCA.

The City has set up multiple monitoring sites and is working with the Department of Health to establish when an aerial and/or hand treatment is required. Treatment by hand application is restricted to accessible sites.

Aerial treatment is the best option for controlling high numbers of mosquitoes as access to the Spectacles is very difficult due to dense canopies, vegetation with multiple stems and organic substrates. The Spectacles is a conservation wetland and a Bush Forever site.

The City is also working with the Water Corporation to ensure that the Peel Main Drain that runs through the North and South Wetland is cleared from overgrown vegetation.

Currently, there are 16 traps and 12 larval sampling sites around Kwinana and these sites are continuing to grow. Some of these traps are not fixed and are continuously relocated to ensure new areas are investigated. Monitoring of adult mosquito populations are carried out on a fortnightly basis between September and April, and once per month for the remainder of the year (May to August). Regular surveys will assist to indicate the current mosquito populations and provide information on changes in habitats which may give rise to mosquito population fluctuations. Larvicidal treatment may be undertaken in areas where results demonstrate that disease thresholds are exceeded. The City also requires private landowners and developers to manage mosquito breeding.

The City is unable to treat all breeding areas and it is crucial that residents also take measures in their own properties and undertake personal protection.

Fogging is not recommended as it only kills adult mosquitoes and not controlling larvae breeding. Fogging may potentially be harmful to non-target species and only provides short term control with no residual effect.