Utilização de óleos essenciais e fixos no controle de Callosobruchus maculatus (Fabr., 1775) (Coleoptera:Bruchidae) em caupi, Vigna unguiculata (L.) Walp. armazenado

Abstract

The weevil Callosobruchus maculatus is considered the most important pest of cowpea stored in tropical and subtropical regions. Focusing minimize the undesired effects of synthetic chemical insecticides, vegetal origin oils is a promissory alternative to control it because its low cost and safety to the applicator and consumers. Essential oils (Cymbopogon martini Roxb., Piper aduncum L., P. hispidinervum C.DC., Melaleuca sp. and Lippia gracillis Shau) and fixed oils (Helianthus annus L., Sesamum indicum L., Gossypium hirsutum L., Glycine max L. and Caryocar brasiliense Camb.) were tested in cowpea grains (cv. Ever Green). These oils were used in the concentrations of 10, 20, 30, 40 and 50μL/20g, corresponding to 0.5, 1.0, 1.5, 2.0 and 2.5 L/t and impregnated to the grains into the plastic recipients using an automatic pipette and handly agitated for two minutes. Plots of 20g from cowpea were infested with eight females of C. maculatus from 0 to 48 hours old. Each oil was tested separately in a randomly arrangement with six replicates. The essential oils of C. martini, P. aduncum and L. gracillis provoked 100% of mortality in all concentrations, P. hispedinervum from 1.5 L/t and Melaleuca sp. in the concentrations of 2.0 and 2.5 L/t. The reduction of the viable eggs and emerged insects was about 100%. By the other hand, the fixed oils, in spite of its low mortality in all tested concentrations, reduced at almost 100% the number of the viable eggs and emerged insects.