The Mosquito Management Program
The City of Greater Geelong's Health Services Unit coordinates the Mosquito Management Program, which is responsible for the ongoing monitoring and treatment of mosquito breeding sites around the City of Greater Geelong. The Program normally operates from August to late March each year. Generally mosquito numbers are very low during the winter months and monitoring and treatment are not needed during this period. The exact start and finish dates for the program vary from year to year and program activities normally start with the onset of warmer weather and higher rainfall levels, which is when mosquito activity increases.

Mosquito Species
Several species of mosquitoes are found in this region and most can survive a broad range of weather conditions. Mosquitoes breed in standing water, including the many wetlands in the area and some freshwater areas, especially after heavy rain or king high tides.  The main species of mosquitoes found in the Geelong area include:  

•  Aedes camptorhynchus which breeds in salt or brackish water
•  Aedes notoscriptus which breeds in freshwater and containers like buckets, tins, etc
•  Coquillettidia linealis which breeds in vegetated freshwater
  

Mosquito Life Cycle

• Egg stage- Eggs are laid on or near the surface of water or on damp soil that will be flooded by water. Some mosquitoes lay their eggs separately while others lay eggs in rafts of 200 or more. Most eggs hatch into larvae within 48 hours.
• Larval stage- Mosquito larvae, also known as ‘wrigglers,' live many different types of water (freshwater, saltwater, and containers holding water). Most larvae have siphon tubes for breathing and hang from the water surface. Larvae go through four growing stages, called instars, and after the fourth instar stage, larvae develop into pupae.
• Pupal stage- The pupal stage is a resting, non-feeding but mobile stage where the juvenile mosquito turns into an adult. Pupae look like little balls in the water.  It takes about two days before the adult is fully developed. When development is complete, the pupal skin splits and an adult mosquito emerges.
• Adult stage- The newly emerged adult rests on the surface of the water for a short time to allow itself to dry and its body parts to harden. The wings have to spread out and dry before it can fly. It takes about 7-14 days for a mosquito to develop from an egg to an adult.

Mosquito Monitoring and Treatment

• Monitoring- Mosquito breeding sites across the Bellarine Peninsula and areas around Lara are monitored by Council contractors on a 5 to 7 day basis to check for mosquito larvae. Depending on how many larvae are present, a decision is made at each site as to what type of treatment will be most effective. 
• Ground Treatment- If breeding sites are easily accessible by land, ground crews can treat the areas manually. The ground based crew use two All Terrain Vehicles (ATV Argo's) and a four-wheel motor bike to access wetlands or heavily vegetated areas for manual treatments. 
• Aerial Treatment- Aerial helicopter treatment of mosquito breeding sites is very effective in wetland areas that are difficult to access by land.  The City has a permit that allows aerial treatment of mosquito breeding sites in RAMSAR protected wetlands in accordance with the Environment Protection and Biodiversity Conservation Act 1999 (Geelong Mosquito Control EPBC 2005/2132). This Permit outlines a range of operational conditions that the City must comply with and enables prompt treatment at critical times.

Mosquito Control Products
In accordance with Australian best practice, the City does not use broad base pesticides in its program for larval mosquito treatment.  Instead it uses two biological products called Bacillus thuringiensis israelensis (Bti), which is found naturally existing in soil, and methoprene. Both of these products target specific aspects of the mosquito biology and do not adversely affect humans, other species or the general environment.

• Bacillus thuringiensis israelensis (Bti)
  Bti produces proteints that react with cells of the gut lining of the mosquito. These proteins paralyse the digestive system, and the infected mosquito stops feeding within hours. Bti affected mosquito larvae generally die from starvation.  Bti is only toxic to cells of the gut lining of mosquito larvae and not to humans, animals or other insects. It has no residual properties and does not magnify in the food chain.
• Methoprene
  Methoprene is an insect hormone analogue, which when applied to larvae, prevents the larvae from completing development to an adult mosquito. Methoprene products mimic the juvenile hormones of larvae, resulting in the pupation of an immature insect that is not able to emerge as an adult mosquito.

Aerial view of Edwards Point, St Leonards