Atividade inseticida do óleo essencial de Lavandula dentata L. sobre Anticarsia gemmatalis (Hübner 1818)

Abstract

Anticarsia gemmatalis, known as soybean caterpillar, consumes crop leaves, causing economic losses to producers. One of the forms of control of this pest is through the use of agrochemicals, however, its indiscriminate use has increased the resistance of these pests. Thus, it is necessary to search for different control alternatives. The objective of this work was to evaluate the chemical composition of Lavandula dentata L. essential oil and the bioactivity of oil on A. gemmatalis. Bioassays were performed with caterpillars at the 3rd instar, with three replicates per treatment. Oil rates (0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9; 1,0% v/v) diluted in Tween-80® (0,5% v/v, were incorporated into the artificial diet given to caterpillars. The controls were: water, Tween-80® (0.5% v/v) and Rimon Supra® (0.075% v/v). For tests without choice, soybean leaf discs were used (Glycine max) increased or not of treatments and offered to caterpillars. The majority compounds of essential oil were 1.8-cineol (31.52% m/m), camphor (16.63% m/m) and fenchona (15.93% m/m). In the bioassay, mortality of 100% was observed from the concentration 0.6% v/v of the essential oil of L. dentata in 24 h. In the test without chance of choice, it was observed deterrence of caterpillars to treatments when compared to control. It was observed that L. dentata essential oil can be used in the control of A. gemmatalis.(sic)