Efficacy of Some Essential Oil against The Immature Stages of

The toxicity of neem oil; jojoba oil; peppermint oil; garlic oil and ginger oil essential oil were evaluated against the immature stages of the cotton leafworm, Spodoptera littoralis, field strain in comparison with conventional insecticide cyhalothrin. The results showed that cyhalothrin was the most potent compound followed by neem oil, and jojoba oil and the least three materials were peppermint oil; garlic oil, and ginger oil. Tested compounds, cyhalothrin at 15.0 ppm achieved 31.9 % mortality of treated egg masses, while neem oil; jojoba oil; peppermint oil; garlic oil and ginger oil at the same concentration caused 89.0; 75.9; 59.6; 53.5, and 51.0 % mortality, respectively. The toxicity of tested compounds were evaluated against newly hatched larvae at 24, and 48 hrs, post treatment. The results showed that cyhalothrin; neem oil and jojoba oil were the more potent than peppermint oil; garlic oil and ginger oil. Cyhalothrin and tested essential oils gave not exhibited any toxic action against pupae of S. littoralis. The interactions of cyhalothrin with tested essential oils in vivo on the inhibition of Na+,K+-ATPase was investigated. Results proved that pretreated of neem oil, and jojoba oil with cyhalothrin increased the percentage inhibition for Na+,K+-ATPase to 91.4, and 88.3 % respectively. Results proved that the five essential oils mixed with pyrethroid insecticide, (cyhalothrin), caused more toxic effect than single treatment, the present results proved that the five essential oils are potent for control of cotton leafworm, the neem oil, and jojoba oil, resulted in more effect than peppermint oil; garlic oil, and ginger oil. Generally, essential oils enhance the toxicity of som