ارزیابی عصاره زیتون تلخ (Melia azedarach L.) علیه مینوز گوجه فرنگی، Tuta absoluta (Merick) (Lepidoptera: Gelechiidae) در شرایط آزمایشگاه و گلخانه

Tomato leafminer, Tuta absoluta (Merick) (Lep.: Gelechiidae) is one of the most important tomato pests that can be considered as a serious threat to Iranian tomato production. One of the main means of managing this pest is the use of chemical insecticides, but excessive reliance on the use of chemical insecticides quickly leads to the emergence of pest resistance to pesticides. Using essential oils and plant extracts in pest control is a suitable way to reduce the side effects of chemical insecticides in the environment. In this research, the contact toxicity of Chinaberry ((Melia azedarach L. (Meliaceae)) extract on egg, second instar larvae and pupa stages was investigated. The plant extract was extracted using hexane solvent. All experiments were performed at 27 ± 2oC degrees, 65 ± 5% RH and a photoperiod of 16L: 8 D hours. The plant compounds of the above extract were identified using GC/MS. In M. azadarach extract, methyl linoleate, methyl oleate and methyl palmitate compounds were the main chemical compounds with 69.375, 17.231 and 7.361%, respectively. The results showed that with the increase in the concentration of the extract, the mortality of pest eggs, larvae and pupae also increased. Probit analysis of the data showed that LC50 for M. azadarach extract was 948.93, 346.72 and 1.75 µl/ml in egg, second instar larva and pupa stage, respectively. The repellency rate of second instar larvae in LC10 concentration was estimated to be 76.67% higher than this rate in LC25 concentration with 38.33%. The repellency rate decreased after 1, 12, 24 and 48 hours. The sublethal concentrations of LC10 and LC25 of this extract left an anti-nutritional effect within 24 hours. The sublethal LC10 and LC25 concentrations of this extract stimulated insect oviposition compared to the control. In greenhouse experiments, the effect of spinosad toxin on larval lethality and the effect of LC50 lethal concentration of M. azadarach extract on egg lethality were observed. The results showed that this extract has a high potential to control the tomato leafminer in open and closed environments and it is recommended to protect the environment and the health of users.