CONTROL OF Sitophilus zeamais MOTSCHULSKY WITH THIRTEEN OILS OF VEGETABLE AND MINERAL SOURCE

Abstract

The maize weevil (Sitophilus zeamais Motschulsky) is a major pest of stored grains. Synthetic insecticides are commonly used to control this pest but problems such as residues in foods and resistance development have required new control alternatives. Thirteen oils in concentrations of 0.5, 1 and 2% (v/w) (volume/weight) were evaluated under laboratory conditions. The evaluated variables in adult were mortality and adult insect emergence and weight loss and seed germination, and in the immature stage adult insect emergence (F1 ) and grain weight loss were evaluated. The experiment was conducted in a completely randomized design with five replicates per treatment. The highest adult insect mortality was obtained by almond (Prunus amygdalus L.), sun ower (Helianthus annuus L.), nut (Juglans regia L.) and soybean ( and soybean (Glycine max L.) oil at 1 and 2% (v/w) with 100% of dead insects. The lowest adult insect emergence was observed in the treatments with grape seed (Vitis vinifera L.), sesame (Sesamum indicum L.) and sun flower oil at 1 and 2%(v/w) with 0% of dead insects. At the immature stage, the lowest F1 was recorded with the mineral oil at 2% (v/w) with 14% of adult insect emergence. Hazelnut (Corylus avellana L.), pumpkin ( ), pumpkin (Cucurbita pepo L.), corn (Zea mays L.), groundnut (Arachis hypogaea L.), sun ower, grape seed, castor Ricinus communis L.), sesame, soybean and mineral oils did not effect maize germination significantly. It was concluded that vegetable and mineral oils have potential for controlling S. zeamais.