Toxicity of insecticides to Halyomorpha halys (Hemiptera: Pentatomidae) using glass-vial bioassays

A scintillation glass-vial bioassay was used to test technical grade insecticides against the non-native stink bug Halyomorpha halys (Stål). Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is emerging as an important pest in the Mid-Atlantic States, especially in tree fruits and as a homeowner nuisance during the winter. Pyrethroid insecticides, especially bifenthrin, caused mortality against H. halys at low doses, with LC50 values of 0.03-0.49 (microg [AI]/cm2) (mg body mass(-1)). Three nicotinoids were tested against adults with LC50 values ranging between 0.05 and 2.64 (microg [AI]/cm2) (mg body mass(-1)). Phosmet had LC50 values that were up to 3.6-fold higher than other classes of insecticides tested. Fifth instars of H. halys were evaluated against selected chemicals, and they were generally susceptible at lower rates than the adults. Due to significant differences in weight, males and females were individually weighed, tested, and analyzed separately. Sex-related differences in susceptibility were found in the responses to thiomethoxam with males being less susceptible despite having a smaller body mass.