EVALUATION OF THREE BATTERY- POWERED BACKPACK SPRAYERS TO APPLY ADULTICIDES AGANIST AEDES AEGYPTI

Backpack mist sprayers have been used for control of adult mosquitoes on limited small scales. A study was conducted to evaluate three battery powered backpack sprayers to assess their suitability to apply adulticides. The three sprayers are the Field King 190515, the Ryobi One+, and the Tornado (model Spray Mate). The Field King operated at 276 kPa, the Ryobi One+ at 414 kPa, and the Tornado at 414kPa (option at 276 or 414 kPa) were used for this study. Due to higher flow rates of these sprayers compared to ULV sprayers, Aqualuer™ 20-20 was used as an adulticide by diluting with water. To achieve application rates of 9, 37, 74, and 148 mL/ha for different sprayers at their flow rates, the formulation was diluted 26 to 1,209 times. All dilutions were replicated three times and one application rate of all sprayers was tested in a day. Adult female Aedes aegypti mosquitoes at 25 /cage were used for the experiment. Caged mosquitoes were placed on the poles before spray and removed after the spray ended. Mortality was recorded at 24 -h after treatment. The Tornado backpack sprayer provided the highest mortality, better than or similar to Ryobi One+ and Field King provided the least mortality. The sprayers were effective up to 3.0 m from the spray line. By increasing application rate from 9 to 74 mL/ha, mortality increased but did not increase as the rate went from 74 to 148 mL/ha. Application with the Tornado at 74 mL/ha was the best option for short distance control.