Aceites esenciales para el control de Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) y efecto sobre la calidad del grano de maíz Zea mays Linnaeus (Poales: Poaceae)

Abstract

In order to find natural alternatives for the control of the weevil Sitophilus zeamais Motschulsky, the effect of niaouli (Melaleuca quinquenervia), eucalyptus (Eucalyptus globulus) and oregano (Origanum vulgare) essential oils were studied on mortality, emergence and epellency of S. zeamais, as well as their effect on the grain quality of corn during storage (germination, amount of phenols, flavonoids and antioxidant capacity). The technique used for the bioassays was saturation of atmospheres, in volumes of 100, 200 and 300 µL, having national white corn as substrate. The three oils showed 100% insecticidal activity at 72 hrs. The emergence of adult insects (F) was null in all treatments. Repellency was observed in all treatments at 24, 48 and 72 hrs. Germination was not affected in volumes of 100 µL. The content of total phenols and flavonoids were higher both in the oregano oil (94.68 mg GAE/g and 0.27 mg QE/g respectively) and in the corn treatment with oregano (16.09 mg GAE/g and 0.18 mg QE/g respectively). Similar behavior was observed in the antioxidant capacity in both DPPH and ABTS, presenting ranges from 76.31 to 93.73% inhibition. It is concluded that the three essential oils have potential for the control of S. zeamais, improving the quality of the corn grain.