Atividade inseticida de óleo essencial de Ocimum basilicum L. sobre Sitophilus zeamais Mots. 1855 (Coleoptera: Curculionidae)

Abstract

In view of the great losses in quantity and quality of stored corn grains, this work seeks an alternative control to synthetic products for the main corn grain storage pest, Sitophilus zeamais. For the work, different concentrations of essential oil of Ocimum basilicum L. (0; 0.31; 0.62; 1.25; 2.5; 5; 10%) were evaluated in different application methods (immersion, spraying and volatilization). Seven plastic containers (repetition) were prepared per treatment and 15 insects, not sexed, of up to 60 days were packed in each plate. Evaluations were performed at intervals of 1; 6; 12; 24; 48; 72; 96 hours, quantifying dead insects. Essential oil of O. basilicum is effective under the control of individuals of S. zeamais, with doses of 10% showing greater efficiency. The longer the period of exposure to essential oil, the greater the mortality of S. zeamais. The spray method presents better results when compared to the other application methods, showing great efficiency with only one hour after the application of the essential oil. The immersion method presents average results of control of individuals of S. zeamais, increasing considerably only after 96 hours of application of the essential oil. The volatilization method is not efficient for the application of the essential oil of O. basilicum for the control of individuals of S. zeamais, within the tested periods.