Abstract

DE ASSIS CARDOSO ALMEIDA, Francisco et al. Efficiency of vegetal extracts as insecticide on Sitophilus zeamais in stored maize grains. Rev Cie Téc Agr [online]. 2014, vol.23, n.2, pp. 57-62. ISSN 2071-0054.

The Sitophiluszeamais is considered the most important pest of maize (Zea mays L), stored in tropical and subtropical regions. To minimize the undesirable effects of synthetic chemical insecticides, the control of this pest with vegetal extracts has been turning into a promising safe and inexpensive alternative for applicators and consumers. Repellency, attractiveness and mortality of Sitophiluszeamais in maize grains treated with powders and hydroalcoholic extracts of Piper nigrum L. and Annonasquamosa L were laboratory tests. To study the dust of the plant extracts mentioned earlier about the attractiveness and repellency of adult insects, we used an arena with five boxes arranged diagonally, with the central interconnected to the others. Corn samples treated with the extract powder were placed in two containers, in the other two untreated corn containers were placed, and 30 unsexed insects were placed in the central arena container. The hydro alcoholic extracts were obtained from the seed powder of these species, in percolator, with ethyl alcohol (70% v/v), and these extracts were taken to the insects in vapor form. The experimental design was completely randomized with treatments arranged in a factorial design, in which the quantitative factors were analyzed by regression analysis of variance. The repellency percentage was 86.75% with the extract powder of Annonasquamosa and 79.25% with the Pipernigrum. 100% mortality was obtained with the extract of Annonasquamosa (5 mL dose) and 98% with Pipernigrum extract at a dose of 14 mL, indicating the influence of the dose and the extract on the mortality of adult Sitophiluszeamais.

Keywords : insecticide effect; mortality; maize weevils; repellency.

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