Certain species of mosquitoes breed only in salt marsh waters. These are termed 'saltmarsh mosquitoes'.
Some species of saltmarsh mosquito are predominantly nuisance mosquitoes, while others are responsible for the transmission of Ross River Fever.
In Townsville, tides over 3.48 metres in height cause inundation (flooding) of low lying salt marsh areas. With these high tides and/or heavy rains, areas where mosquito eggs may lay dormant are flooded, causing them to hatch and mature into adult mosquitoes in as little as seven days.
The table details the species of saltmarsh mosquito that can be found in Townsville. Refer to the descriptions below the table for further information on each mosquito.
|Example of saltmarsh
mosquito breeding habitat
|Another example of saltmarsh|
mosquito breeding habitat
Saltmarsh mosquitoes in Townsville
||Most of coastline
||Temporary pools in saltmarshes flooded during higher tides or by rain.
||Major pest species. Vector of Barmah Forest Virus, Ross River Virus and heart worm in dogs.|
||Coastal saline and brackish
||Commonly found in pools formed when high tides flood the upper limits of marine wetlands. Heavy breeding can occur where natural drainage in tidal wetlands is blocked.
||Occasional pest where residential areas are close to breeding sites. Ross River Virus isolated.|
Ae vigilax is the primary vector of Ross River Virus (the cause of epidemic polyarthritis) and Barmah Forest Virus in Queensland. Both viruses are notifiable disease that can have debilitating effects on those infected.
The distribution of Ae vigilax is throughout Australia is wide spread along the coastline of all states. The major breeding sites of the Ae vigilax include temporary brackish pools and marshes filled as a result of tidal inundation and are commonly associated with salt water couch grass (Sporobolus). The habits of the adult mosquito include resting amongst dense foliage for shelter throughout the day where possible. They are a voracious biters and will feed off humans and animals day or night. Within 15km of a breeding site, these mosquitoes can be found in quite heavy numbers. They can travel up to 40km from breeding sites. Peak feeding activity is during dawn and dusk.
Cx sitiens can become a major pest species during summer months. Current research indicates that this species is also a competent vector of Ross River Virus within the laboratory setting with further research continuing to determine transmission efficiency as a possible field vector.
As with Ae vigilax, Cx sitiens is found along most coast lines of Australia and has the ability to travel large distances in order to seek a blood meal. The major breeding sites of the Cx sitiens is the same as Ae vigilax - temporary brackish pools and marshes filled as a result of tidal inundation.
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.
For more information, please phone 1300 878 001 or contact Environmental Health Services.