Calibrated funnel trap for quantifying mosquito (Diptera : Culicidae) abundance in wells

Our article addresses the problems of sampling and quantifying the abundanc e of immature Aedes aegypti (L.) and other mosquitoes that use subterranean habitats such as wells and service manholes. Two versions of the funnel tr ap, Austrap and Vietrap were extremely sensitive for detecting the presence of Ae. aegypti larvae in wells, and the modified version, the Vietrap, sam pled on average 20.5% of 3rd and 4th instars when set overnight for 12h. Fo r both models, regression analyses between trap catch and absolute abundanc e indicated high coefficients of determination (R-2 = 0.932 and 0.992) enab ling accurate direct calibration. The effects of immature age, mosquito spe cies, well diameter, and trap size on catch size were investigated. Because of its simplicity, efficacy, and inexpensiveness, the Vietrap will facilit ate the comprehensive assessment of key larval habitats for Ae. aegypti, da ta critical for the development of effective control programs.