Geographic and interspecific variation in susceptibility of Euschistus heros and Diceraeus furcatus (Hemiptera: Pentatomidae) to selected insecticides in southern Brazil

Abstract

The Neotropical brown stink bug, Euschistus heros (F.), and the green belly stink bug, Diceraeus furcatus (F.) (Hemiptera: Pentatomidae), are key sucking pests of soybean and maize in Brazil and other South American countries. The management of both species is usually carried out through chemical control. Thus, a 2-year study was carried out to assess the geographic and interspecific variation in susceptibility to insecticides in populations of E. heros and D. furcatus in southern Brazil. Adult stink bugs collected throughout the 2021/2022 and 2022/2023 soybean seasons were exposed to the field label doses of selected insecticides commonly applied for their control in dip-test bioassays using fresh green bean pods. Populations of both species exhibited high mortality and relatively low geographic and interspecific variation in susceptibility to the field label doses of acephate, ethiprole, bifenthrin, acetamiprid + bifenthrin and imidacloprid + bifenthrin. Diceraeus furcatus was also susceptible to dinotefuran + lambda-cyhalothrin. In contrast, populations of both species had relatively low mortality and a wide geographic variation in susceptibility to the field label doses of lambda-cyhalothrin, acetamiprid, thiamethoxam + lambda-cyhalothrin and sulfoxaflor + lambda-cyhalothrin. In summary, the results presented here will contribute to more effective control and resistance management of stink bugs in soybean and maize in southern Brazil and neighboring countries.