Evaluation of a new spraying machine for barrier treatment and penetration of bifenthrin on vegetation against mosquitoes

The effectiveness and penetration of a novel, truck-mounted mist sprayer (3WC-30-4P provided by American LongRay) was evaluated with bifenthrin in a large, park-like setting with historic floodwater and woodland mosquito populations. Efficacy evaluations were determined through adult population collections and excised leaf bioassays. Trapping results showed a mean reduction of 77% in mosquito populations in the treated area for 5 sampling events up to 4 wk posttreatment. Leaf bioassays revealed an average mortality of 80% at 2.7 m and 51% at 5.5 m against laboratory-reared Aedes aegypti for 5 posttreatment samples. Leaves collected from the treated areas caused higher mortality at distances closer to the sprayer, though the distance and coverage of bifenthrin application was effective up to 5 m.