Atividade inseticida do extrato bruto hidroetanólico de Ipomoea setifera Poir. (Convolvulaceae) sobre Helicoverpa spp. (Lepidoptera: Noctuidae)

Abstract

Some species of the genus Ipomoea L. (Convolvulaceae) have insecticidal effect on insects and mammals, however, little is known about the toxic effect of Ipomoea setifera. This study aimed to evaluate the insecticidal effect of the crude hydroethanolic extract of Ipomoea setifera on Helicoverpa spp. Caterpillars. The collection of caterpillars occurred in a soybean plantation in the municipality of Sinop, Mato Grosso, Brazil. The plant material was collected in the Lagoa da Cerâmica, on the banks of the Teles Pires River in four quarterly collections (September - dry; December - 2016 flood; March - full; June - ebb 2017) to verify the toxicity of the plant species. different times of collection. The experiments were developed during the first semester of 2018 at the Federal University of Mato Grosso / Sinop Campus. 24 well tissue culture plates, 1.5 ml artificial diet in each well and 3rd instar caterpillars were used for the bioassays. 3,672 caterpillars were used to compose 11 treatments with 6 repetitions each. A completely randomized design was used in a 4x2 factorial scheme (time of collection x mode of action). The results obtained were evaluated using the Scott-Knott test (5% significance) using the Sisvar program. The results when compared between the treatment averages (negative - water control and positive - insecticide control) and factorial (collection time and mode of action) had a significant effect on the use of the extract. According to the obtained results, it is concluded that the contact bioassay presented better results when compared to the other bioassays, being a potential insecticide for Helicoverpa spp. under laboratory conditions.