BIOACTIVITY OF Eucalyptus cv. “Urocam” ESSENTIAL OIL ON Sitophilus zeamais

Abstract

Sitophilus zeamais is one of the more important and severe pests of stored grains. Its control is carried out predominantly by synthetic insecticides, a practice that must be rethought assuming the increasing demands for pesticide-free foods. This work aimed at evaluating the bioactivity of Eucalyptus cv. “Urocam” essential oil on 10- to 30-day-old S. zeamais. Essential oil from the leaves of Eucalyptus cv. “Urocam” was sprayed on corn kernels, infected by S. zeamais, at the rate dosage of 0.0; 1.0; 2.0; 3.0 and 5.0 L t-1. A completely randomized experimental design with five replicates was used to conduct the experiment. All data were analyzed by the F test and whenever a significant interaction was found, analysis of variance and regression tests were performed (Assistat 7.7 Beta software). The terpene with the highest concentration in the Eucalyptus cv. “Urocam” essential oil was Eucalyptol (74%). Based on our results, it can be inferred that Eucalyptus cv. “Urocam” essential oil presents a good potential of use in the dosages of 3.0 and 5.0 L t-1 of corn kernels due to the high mortality of S. zeamais within the first hours after application, reaching 100% by the end of the first 24 hours.