Mosquito, integrated management guidelines
The South Australian Integrated Mosquito Management Strategy (SAIMMS) process was initiated due to the need to promote and integrate mosquito management practices throughout SA to ensure that these programs are as effective, economical and environmentally sensitive as possible.
The key concept here is integration. Significant gains can be achieved from making integrated mosquito management practices a priority and from collaboration across agencies in ecologically sustainable development and activities that give due regard to the human - environment interface.
For detailed information on integrated mosquito management, refer to:
Integrated mosquito management is aimed at reducing the number of mosquitoes in a specific area in an environmentally appropriate manner in order to decrease the risk of disease transmission to humans. It is neither feasible nor desirable to eliminate mosquitoes entirely from any ecosystem.
Why mosquitoes need to be managed
Immediate health risks associated with mosquitoes in South Australia include Ross River virus (RRV), Barmah Forest virus (BFV), nuisance impacts, and to a lesser extent Murray Valley encephalitis virus (MVEV).
While some threats, for instance new vectors and diseases such as dengue and malaria, the risks need to be identified and managed in light of the serious consequences posed by their introduction and establishment in South Australia.
Main players in mosquito management
Everyone has a responsibility to help manage the risks posed by mosquitoes, however the key players include:
- the community
- landowners and managers
- local government
- state government
- commonwealth government
- others such as research institutions, tourism interests
The local, state and Federal Government agencies have key identifiable legislative, regulatory and community responsibilities which may impact on, or be impacted upon by mosquito management practices, quite often both.
Mosquito surveillance plays an integral role in mosquito management and is undertaken to monitor mosquito populations in a given area. Surveillance allows pest and vector mosquito species to be identified and also provides a means to monitor abundance and fluctuations in populations over time.
Surveillance process includes:
- mosquito trapping - traps are baited and set to catch mosquitoes for further analysis
- larval sampling - enables aquatic breeding grounds to be identified and seasonal fluctuations in breeding determined
- identification - microscopic examination of morphological characteristics referred to in a mosquito key to identify the different species
- data recording - used to determine the need for a control program, to plan and guide the control program and to later evaluate the effectiveness of the program
Determining the need for mosquito control
The decision to undertake mosquito control should only be made following careful consideration of all the factors involved. To assist in your decision, refer to Section 11 of the South Australian Integrated Mosquito Management Resource Pack 2006 (PDF 991KB).
Mosquito control methods
While the control options referred to below are known to be effective in the eradication of mosquitoes, application is only suitable in certain circumstances and due regard must be given for the receiving environment at all times.
For full details refer to Section 13 of the South Australian Integrated Mosquito Management Resource Pack 2006 (PDF 991KB).
Chemical control involves the use of larvicides and adulticides to reduce mosquito populations. The type of chemical applied for larval control varies with factors such as habitat type, the number of larvae present, growth stage of the larvae and environmental significance of the site. Two chemical applications used in South Australia are s-methoprene, and to a far lesser extent temephos.
As all chemicals have the potential to create adverse human and environmental effects, it is important to recognise the need for careful consideration of the anticipated benefits versus the negative impacts as shown in the model in Section 11 of the South Australian Integrated Mosquito Management Resource Pack 2006 (PDF 991KB). If chemical control is deemed necessary, chemicals must be used in accordance with the Agricultural and Veterinary Products (Control of Use) Act 2002 and the Agricultural and Veterinary Products (Control of Use) Regulations 2004.
Microbial larvicides are generally bacteria that have been registered as pesticides due to their toxicity to the larvae of certain insects. At present, the most common strain of Bacillus thuringiensis used for mosquito control in Australia is israeliensis.
Physical control - land modification and/or engineering-type solutions
Physical control of mosquitoes is achieved through environmental modification to decrease or eliminate the habitat of mosquito larvae. Several methods of physical mosquito control are available including:
- environmental modification – an alteration of habitat characteristics such as pH or vegetation load to render it unsuitable for mosquito breeding,
- water management - making water bodies unsuitable for mosquito habitation through methods such as runnelling, ditching or adjustment of depth,
- filling - larval habitats are filled in or covered with sand, earth or other material to eliminate the topographical depression that once filled with water, can act as a breeding ground for mosquitoes
- draining - drainage of the habitat so it no longer supports mosquito larvae including open ditching, gravity drainage and installation of tidal gates