Toxicities of Neonicotinoid Insecticides for Systemic Control of Brown Marmorated Stink Bug (Hemiptera: Pentatomidae) in Fruiting Vegetables1

Abstract

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is an invasive pest of various crops, including fruiting vegetables, throughout the mid-Atlantic U.S.A. Current control strategies for this pest rely almost exclusively on foliar applications of broad-spectrum insecticides, which disrupt IPM programs and cause secondary pest outbreaks. Systemic neonicotinoids applied to the root-zone via soil drench or chemigation may be a more IPM friendly tactic for insect control in vegetables. Laboratory bioassays that utilized a plant uptake method showed that the neonicotinoid insecticides clothianidin, dinotefuran, imidacloprid, and thiamethoxam were all toxic to H. halys nymphs, with estimated LC50 values of 0.077, 0.013, 0.068, and 0.018 ppm, respectively. Field efficacy experiments in Virginia showed that two soil applications of each of the aforementioned neonicotinoid insecticides significantly reduced stink bug damage to pepper and tomato. Field experiments conducted on tomatoes in North Carolina in 2012 and 2014 revealed a similar reduction in stink bug damage with a single-drip chemigation application of either dinotefuran or imidacloprid. In those trials, clothianidin was not efficacious and thiamethoxam was only effective in 2012. Our studies demonstrate the potential for soil applications of neonicotinoids to reduce stink bug damage to fruiting vegetables.