Journal of Global Agriculture and Ecology

An experiment was conducted to evaluate the toxicity of alpha terpinene on protein content and lipid peroxidation of rice weevil Sitophilus oryzae (L.) (Coleoptera: Curculionidae). The dried un-infested local rice used was obtained from a rice farm at Ilesa, Osun state, Nigeria. Bioassay was used to evaluate the effects of Alpha- terpinene on survival of Sitophilus oryzae. The efficacy of alpha- terpinene used on the antioxidant enzymes used on the S. oryzae, some of the biocidal efficacy of the compound on the activities of CAT, SOD, GPx, AChE, and GST was reported. Dosages of the treatment recorded above 40% mortality of the insect, except 10µl dosage of the compound that recorded 36.67% mortality of the insect. Only 50 µl dosage of the compound was able to record 100% mortality of the insect with 48 hrs treatment application and was significantly (p<0.05) different from other treatments. The negative coefficient of the compound indicated that the higher the dosage of the compound, the higher the mortality rate of the insect. Only 40 and 50 µl dosage of the compound effected 100% inhibition of the adult insect. The compound is significantly (p<0.05) different from the control. The research showed that the compound slowed the reactions in the insect which reduced. the activities and caused increase in mortality of the insect.