Sequential application of ultra-low-volume ground aerosols of fenitrothion for sustained control of Aedes aegypti.

A trial was carried out of the efficacy of fenitrothion ultra-low-volume aerosol applied by vehicle-mounted cold aerosol generator for the control of Aedes aegypti. Five applications of fenitrothion at intervals of 11-49 days at dosages of 511-1 095 ml/ha gave sustained control for 4-5 months in an area of some 14 ha containing 1 300 houses. Immediate killing of adult mosquitos and some larvicidal effect interrupted oviposition and retarded the recovery of the mosquito population. Sequential treatments applied in advance can evidently suppress the population throughout the rainy season, when epidemics of dengue haemorrhagic fever occur, and have operational advantages over larvicidal treatment. The Culex pipiens fatigans population was suppressed for only a few days after each treatment.