SUBLETHAL EFFECT OF NEONICOTINOIDS AND LAMBDA-CYHALOTHRIN ON THE FEEDING BEHAVIOR OF Euschistus heros FABRICIUS (HEMIPTERA: PENTATOMIDAE)

Soybean plants (Glycine max) L. Merrill are often attacked by various pests from planting to harvest. Damage can affect the root system, the main stem, leaves, flowers, and pods. Among the pests associated with soybeans, the stink bug group is noteworthy because it includes one of the most economically damaging pests, the Neotropical brown stinkbug, (Euschistus heros) Fabricius (Hemiptera: Pentatomidae). The present study aimed to evaluate the mortality and possible sublethal effects of dinotefuran, thiamethoxam, and lambda-cyhalothrin on E. heros in soybean pods under laboratory conditions. The first bioassay aimed to assess the sublethal effects on the neotropical brown stink bug estimating the LC10 and LC25 values. The estimated LC10 and LC25 for dinotefuran were 1.31 and 5.41 g of active ingredient (a.i.) ha-1; thiamethoxam were 0.37 and 2.74 g a.i. ha-1, and lambda-cyhalothrin were 10.65 and 76.58 g a.i. ha-1. The feeding behavior studies were conducted in Petri dishes consisting of two pods and five adults of E. heros. The treatments were applied to the pronotum of each insect using the LC10 and LC25. Evaluations were performed by noting the number of insects from each Petri dish present on the pods at 10, 30, 45, 60, 120, and 180 minutes after application. The consumption of the pods of the different treatments was assessed for 180 minutes, evaluating the number of insect punctures, the total feeding time per insect, the feeding time per puncture, and mortality. The low concentrations of dinotefuran and lambda-cyhalothrin (LC10 and LC25) reduced the time adults of E. heros spent on the pods and their feeding times.