Metabólito secundário eugenol no controle do gorgulho do milho Sitophilus zeamais Motschulsky 1885 (coleoptera: curculionidae)

Abstract

Brazil is one of the largest grain producers in the world, making storage an essential activity. Corn culture stands out for its importance due to its high consumption and versatility in human and animal nutrition. However, during storage, attacks by some pests may occur, causing losses such as reduced weight, quality, germination power and, consequently, reduced commercial value. The corn weevil, Sitophilus zeamais Motschulsky 1885 (Coleoptera: Curculionidae), is one of these pests classified as primary, internal, of great economic importance that causes significant losses in grain quality. The quality is depreciated due to the damage caused to the grain mass by the presence of eggs, larvae, pupae, adults and excrement, also causing losses during processing. Basically, its control is carried out by synthetic chemical insecticides, which has led to the occurrence of contamination in the environment, as well as selecting resistant populations. Studies with natural products have been an alternative, with essential oils having great potential with proven biological action against stored grain pests. Therefore, the objective of this work was to prove the contact lethal effect of the secondary metabolite eugenol against corn weevils. Contact tests were carried out in glass arenas containing 20g of corn grains containing different concentrations of eugenol, to estimate lethal concentrations. As a result, eugenol proved to be very promising, presenting a lethal effect with LC50 and LC95 of 7.33 and 12.74 μL/40g of grains, respectively. The secondary metabolite eugenol, with 99.68% purity, is promising for controlling S. zeamais, with lethal effect on contact.