Pyronyl Crop Spray Effective in Controlling Larvae of the Asian Tiger Mosquito (Aedes albopictus [Skuse] [Diptera: Culicidae]) in Non-Circulating Hydroponic Nutrient Solution

Abstract

One to two ppm of Pyronyl Crop Spray (Pyronyl) effectively controlled larvae of the Asian tiger mosquito Aedes albopictus (Skuse). The mean LT99 was 35.8 hrs for 1.0 ppm and 2.3 hrs for 2.0 ppm Pyronyl. Pyronyl concentrations of 0, 0.062, 0.125 and 0.25 ppm resulted in similar time to the LT99 (greater than 200 hrs). Pyronyl mixed in the nutrient solution at 1.25, 2.5 and 5.0 ppm did not reduce the mean head weight of lettuce grown in the nutrient solution for 5 weeks. Pyronyl at these concentrations did not affect root weight at 1.25 and 2.5 ppm, but a slight reduction in root weight was observed at 5.0 ppm. Based on these results, Pyronyl is an effective compound for commercial non-circulating hydroponic lettuce growers to use against A. albopictus. Growers typically add approximately 4.0 L of nutrient solution per plant, utilizing this approximation, 1.0 ml of Pyronyl solution per 125 plants would provide A. albopicuts control.