Danos e controle do percevejo marrom (Euschistus heros) em soja e do percevejo barriga-verde (Dichelops melacanthus) em milho

Abstract

The stink bug complex that occurs in soybean and corn affects the quality and productivity of these impotent crops, with emphasis on Euschistus heros (Fabricius, 1794) and Dichelops melacanthus (Dallas, 1851), that attack soybean and corn, respectively. With the objective of evaluating the damage and the control strategies of these pests, a present study aims to evaluate the damage of E. heros in different stages of development and its management in soybean with different chemical insecticides when applied on sobean crop. In corn, the damage caused by different stages of development of D. melacanthus and damages of adults in four stages of development of the plant were evaluated. It was also evaluated the residual effect of four insecticides used in seed treatment for the control of D. melacanthus under greenhouse conditions. As result, it was found that E. heros adults, when present at the end of the vegetative stage (V8) or at the beginning of the reproductive stage (R2), do not affect soybean yield regardless of the population density of this Pest. However, the stages R4 and R5 were susceptible to stink bug attacks. All the chemical insecticides applied in the soybean crop were efficient in controlling the insect, especially when the salt was mixed with the insecticide. In maize, it was observed that the small nymphs of D. melacanthus do not damage or affect the dry weight of the aerial part of the plant in the vegetative phase (V1), but the medium nymphs, large nymphs and adult insects cause damage to the plants. The stages of maize V1 and V3 were the most susceptible to the attack of D. melacanthus, while the V7 stage the stink bug did not affect the yield of the grains and the dry mass of the plant. With regard to the seed treatment of corn with insecticides, the chemical treatments clotianidina (60 g ai / ha) and tiametoxam (42 g ai / ha) showed the greatest residual effects, ensuring control of D. melacanthus effective control of D. melacanthus up to 28 days after plant emergence.