Breeding information and Habitats

Council officer inspecting a pot plant base, a perfect breeding site for the dengue mosquito

Freshwater mosquitoes may breed in any low-lying area or drain (artificial or natural) containing water. The water may be clear and fresh or highly polluted. Certain species favour artificial water-filled containers (eg Dengue mosquito) while others prefer clean water or polluted water.

These freshwater mosquitoes can cause problems following heavy rains, often in drains where dormant eggs lie which do not carry water all year round. Water bodies that are more permanent in nature often support a number of fish capable of effectively controlling mosquito larvae, without the need for chemical treatments.

Diseases

Similar to the saltmarsh mosquitoes, some freshwater mosquitoes are capable of transmitting diseases such as Ross River Virus, whereas others only cause nuisance. It is only the Dengue mosquito (Aedes aegypti) which breeds in artificial water-filled containers that transmits Dengue Fever.

The table below provides details of the freshwater mosquitoes found in Townsville.

Aedes aegypti

Aedes aegypti is of great importance as it is the major carrier of Dengue Fever and Dengue Haemorrhagic Fever in Queensland (and throughout the world). This mosquito is commonly associated with human habitation.

The Ae aegypti can be found in natural breeding places such as tree holes, fallen palm fronds and plants such as bromeliads. It has however adapted very successfully to human habitation breeding in any available artificial container such as pot plant bases, buckets, tyres, rainwater tanks, roof gutters etc. This mosquito has a limited flight range of around 250m in search of a blood meal. This mosquito is very allusive tending to bite persons around feet, ankles, and under tables. The Ae aegypti is an indoor day time biter.

Aedes notoscriptus

As with Ae aegypti, Ae notoscriptus is primarily considered a domestic species taking advantage of a range of artificial containers. Its importance relates to the similarity with Ae aegypti and the common breeding areas shared. Laboratory studies have shown this mosquito capable of carrying a number of arboviruses and believed to be suitable vector for Barmah Forest, Ross River Virus and heart worm in dogs.

Culex annulirostris

Culex annulirostris is an efficient vector of a range of arboviruses including Ross River Virus, Barmah Forest Virus, Japanese Encephalitis and Kunjin as well as being a vector for myxomatosis and an effective carrier of dog heartworm.

Cx annulirostris is wide spread throughout Queensland and Australia. Preferred breeding areas include freshwater wetlands and low lying grassy areas that are commonly inundated following rain as well as irrigation areas having a heavy organic effluent component.

Peak feeding activity is predominantly at dusk (up to 2 hours following), and to a lesser degree at dawn. They feed off both animals and humans and have the capacity to travel 5 10 km from breeding sites.

Verrallina funerea

Verrallina funerea may be a major pest in communities such as Rowes Bay, Pallarenda and Cungulla where residential housing is in very close proximity to breeding sites. Ve funerea has the ability to breed in both fresh and slightly brackish water.

Ve funerea is considered a very aggressive and painful biter. This species does not travel far from its breeding ground and can be a major pest for communities adjacent to or in close proximity to their coastal breeding areas.

There is currently no evidence to suggest that Ve funerea is capable of transmitting disease to humans however it has been shown to carry a number of arboviruses in the laboratory.

Aedes vittiger

Aedes vittiger often becomes a pest species in the Townsville region following summer rains.

Current research indicates there is no evidence of field transmission of human disease however it has been shown to carry Murray Valley Encephalitis in the laboratory.

Ae vittiger breads in large numbers following rains with the preferred habitat being depressions filled by summer rain. Ae vittiger is an aggressive biter readily feeding off humans during the day at regular peak feeding times. This species may continue to be a pest from one to three weeks after breeding areas are inundated.

Aedes alternans

Aedes alternans can reach reasonably high pest levels following extended periods of rain. They have the ability to breed both in temporary brackish pools and marshes on the coast along with Ae vigilax and further inland in freshwater areas with Ae vittiger.

Ae alternans are very aggressive biters and will attack throughout the day and night and have the ability to travel 5-8 km from breeding sites in search of a blood meal. As with Ae vittiger this species may continue to be a pest from one to three weeks after breeding areas are inundated. Ross River Virus has been isolated from Ae alternans (in the laboratory), however this is yet to be proven in the field.

Mansonia uniformis

Mansonia uniformis can prove a major pest problem in Townsville due to the abundance of fresh water lagoon type habitat (including Ross River, Town Common, Louisa Creek/Blakeys Crossing). It has the unique larval structure of a piercing siphon which allows it to attach to a wide range of aquatic grasses, sedges and aquatic plants such as water hyacinth.

Mn uniformis are more aggressive during the night but will feed during the day in protected/shaded areas. The flight range of Mn uniformis is limited to about 3 - 6 km making this species more of nuisance to those living near fresh water areas or those involved in recreational activities in close proximity to such areas.

The University of Queensland has developed a website that provides information on the mosquitoes of Queensland. This may be of benefit in any mosquito research you are conducting.

For more information, please phone 1300 878 001 or contact Environmental Health Services.