Salt marsh mosquito larval control in Leanyer coastal wetland, Northern Territory

Abstract

A coastal wetland with important larval habitats for Aedes vigilax (Skuse), the northern salt marsh mosquito is located adjacent to the northern suburbs of Darwin. This species is a vector for Ross River virus and Barmah Forest virus, as well as an appreciable human pest. To improve aerial larval control, we identified the most important vegetation categories and climatic/seasonal aspects associated with aerial control operations in this wetland after inundation with tide, rain and tide and rain combined. The analyses showed that the Schoenoplectus/mangrove areas require most of the control after inundation by tide only (30.1%), and also extensive control when tides and rain are coinciding (18.2%). Tide-affected reticulate vegetation requires extensive control after inundation by rain only (44.7%), and when tide and rain inundation coincide (38.0%). The analyses further showed that most of the control needs to be carried out between September and January, with a control peak in November and December. To maximise the efficiency of aerial salt marsh mosquito control operations in northern Australia, aerial control efforts should concentrate on Schoenoplectus/mangrove and tide-affected reticulate areas, especially between September and January.