Runnelling to control saltmarsh mosquitoes: long-term efficacy and environmental impacts.

Aedes vigilax is a problem mosquito species prevalent in subtropical Australian coastal wetlands. We evaluate the long-term impacts of runnelling, an environmentally benign habitat modification method, on mosquitoes and the wetland environment. Runnelling uses shallow channels to enhance flushing of the marsh. The method successfully reduced larval numbers to below nuisance levels for the 6.5 year study period. We did not detect any significant difference in the wetland environment between runnelled and unmodified parts of the study area. However, the spatial extent of the effects may have extended beyond the modified area.