Susceptibility of Bagrada hilaris (Hemiptera: Pentatomidae) to Insecticides in Laboratory and Greenhouse Bioassays

Field-collected nymphs and adults of Bagrada hilaris (Burmeister) (Hemiptera: Penatatomidae) from three locations were evaluated for susceptibility to insecticides representing 10 classes of insecticide chemistry. Although relative susceptibilities differed between leaf-spray and leaf-dip Petri dish bioassays, consistently low LC50 values were determined for chlorpyrifos, bifenthrin, and lambda-cyhalothrin. Fenpropathrin and methomyl had intermediate values. Susceptibility to dinotefuran varied depending on the bioassay, possibly owing to leaf substrates used in the two bioassays. In soil systemic bioassays, the LC50 value of dinotefuran was significantly greater than that of two other neonicotinoids, imidacloprid and thiamethoxam, and the anthranilic diamide, cyantraniliprole. Mortality and feeding damage of B. hilaris and plant growth on insecticide-treated plants in greenhouse trials were consistent with the laboratory bioassays; the best results were seen with bifenthrin, methomyl, and chlorpyrifos. Mortality to the neonicotinoids was not evident; however, feeding damage and plant growth responses on dinotefuran-treated plants damage were similar to the noninfested control. This highlights the apparent antifeedant properties of dinotefuran that may have prevented adults from injuring broccoli plants after exposure to foliar spray residues. Data presented serve as baseline susceptibilities that can be used to monitor for resistance development in field populations of B. hilaris.