Control Of Floodwater Mosquitoes In Wetlands
  Key Words  
  Mosquito control in wetlands, Bacillus thuringiensis israelensis.
  Peter Lüthy
  Flood water mosquitoes have been successfully controlled in Switzerland for 25 years with products based on Bacillus thuringiensis israelensis (Bti). These mosquitoes have a flying range of up to 10 km in search of a blood meal. Before the interventions the quality of life of residents in villages near the mosquito breeding areas was greatly reduced, and tourism suffered financial losses. The logistic to block the mass development of the flood water mosquitoes, dominated by Aedes vexans and Ochlerotatus sticticus is demanding. Accurate forecast of precipitation in the breeding areas is an important for the planning stage. Flooded breeding sites require monitoring for the presence of mosquito larvae. Only a few days are available for Bti-interventions. Time slots for aerial treatments by helicopter have to be obtained. Ground application equipment has to be ready. Mosquito larvae have to be eliminated in their third instar, once in the fourth instar the efficacy of Bti drops. Post-treatment monitoring has to show 95% to 99% elimination of mosquito larvae. It is the goal to limit the Bti-treatments to one or two interventions per year. Bti-treatments to control flood water mosquitoes requires governmental approval.