Control of <em>Spodoptera frugiperda</em> in different larval ínstars in soybean crops

Abstract

Spodoptera caterpillars are emerging as significant defoliators in the soybean crop, causing significant yield losses. Among the species, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) stands out among the species due to its strong ability for polyphagy and migratory habits. This study sought to assess the efficacy of chemical insecticides in the control of S. frugiperda in soybean crops. The experiment was conducted in a laboratory setting with a completely randomized design using seven treatments. The applications were carried out in the field, using the soybean cultivar BMX Icon. After the natural drying of the insecticides, leaves were collected from the upper part of the plants, and these were supplied to the caterpillars in the laboratory. For lab infestations, three larval instars were used to determine mortality and leaf consumption (cm²). The results indicated that insecticides chlorfenapyr, spinetoram, chlorantraniliprole, indoxacarb + novaluron and thiamethoxam + lambda-cyhalothrin are efficient for the control of 1st instar caterpillars. Moreover, the insecticides chlorfenapyr, spinetoram, chlorantraniliprole and indoxacarb + novaluron are efficient for the control of 3rd and 5th instar caterpillars. There was no residual effect at 14 days after insecticide application.