الفهرس 
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Abstract
The aim of the present study was to evaluate the toxic and biological effects of some locally available essential oils in comparison with an organophosphorus insecticide, malathion, against Callosobruchus maculatus. Contact and residual methods were used to evaluate the toxic effects of the tested oils and malathion. Results showed that basil (Ocimum basilicum L.) and cassia (Cinnamomum cassia L.) were the most effective oils after malathion against C. maculatus in both contact and residual toxicity studies. On the other hand, caraway (Carum carvi L.) and spearmint (Mentha spicata L.) were the weakest oils in the efficacy, while fennel (Foeniculum vulgare) exhibited middle effect. The biological effects of the tested oils and malathion were investigated through exposing adults of C. maculatus to the median lethal concentration of each oil or insecticide individually for 24 hr., in petri-dishes experiments or continuously exposed to in seed-treatments. Cassia and caraway showed the highest effective oils on all studied biological parameters comparing to other oils, malathion or control in petri-dish experiments. In the treated seeds experiment, all the tested oils as well as malathion showed the same effect on the studied parameters which was significantly different compared to control. Total protein levels showed non-significant decrease in all treatmentes of cowpea insects with oils or malathion compared with control after exposure for 24 hr., Acetylcholinesterase (AChE) activity was significantly inhibited due to C. maculatus exposure to malathion for 24 hr., Non of the tested oils except cassia, showed reduction in the activity of AChE. Glutathione S-Transferase (GST) activity was significantly inhibited due to C. maculatus exposure to fennel and spearmint for 24 hr., non of the other tested materials showed reduction in the activity of GST. Malondialdehyde (MDA) concentration significantly (p˂0.05) increased in the treated adults basil, cassia, fennel and spearmint compared with control adults. Germination of cowpea seeds after exposure to LC50 and LC90 values of the tested oils or insecticide for 1, 2 and 3 months showed non-significant differences compared with control. Effect of C. maculatus infestation on the quality of cowpea seeds was investigated through determining fat, protein , moisture content , ash, fibers, carbohydrate, energy and some minerals (i.e. calcium, iron, magnesium, potassium and zinc) in uninfested and infested cowpea seeds. Results showed significant loss in the quality of cowpea seeds due to the attack of C. maculatus. The current data show the importance of the tested essential oils in C. maculatus control.