Susceptibility of Euschistus heros and Dichelops furcatus (Hemiptera: Pentatomidae) to insecticides determined from topical bioassays and diagnostic doses for resistance monitoring of E. heros in Brazil

The Neotropical brown stink bug, Euschistus heros (F.), and the green belly stink bug, Dichelops furcatus (F.) (Hemiptera: Pentatomidae), are the main sucking pests of soybean and maize in Brazil. Here, we characterized the susceptibility of populations of E. heros and D. furcatus to insecticides and define doses for resistance monitoring of E. heros. Stink bug populations collected in the seasons from 2018 to 2020 were exposed to technical grade insecticides in topical bioassays. Populations of E. heros presented low variation in the susceptibility to acephate (LD50 = 0.22–0.69 μg a.i./stink bug), thiamethoxam (LD50 = 0.0039–0.032 μg a.i./stink bug) and bifenthrin (LD50 = 0.021–0.10 μg a.i./stink bug), with resistance ratios