Introduction: The tomato leaf miner moth, Tuta absoluta (Povolny) (Lep.: Gelechiidae), is one of the most significant pests of tomato, posing a serious threat to tomato production in Iran. One of the main tools for managing this pest is the use of chemical insecticides; however, excessive reliance on chemical insecticides quickly leads to the development of resistance in the pest. The use of essential oils and plant extracts in pest control is a suitable method for reducing the environmental side effects of chemical insecticides.
Materials and Methods: The contact toxicity of bitter olive oil extract was evaluated on the egg, second instar larva, and pupa stages. The plant extract was obtained using hexane as a solvent. All experiments were conducted at a temperature of 27 ± 2°C, relative humidity of 65 ± 5%, and a photoperiod of 16 hours light and 8 hours dark. The chemical compounds of the extract were identified using a GC/MS device.
Results and Discussion: In the chinaberry extract, the major chemical constituents were methyl linoleate (69.375%), methyl oleate (17.231%), and methyl palmitate (7.361%). The results showed that increasing the concentration of the extract led to higher mortality rates in the egg, second instar larva, and pupa stages of the pest. Probit analysis of the data revealed that the LC₅₀ values of the bitter olive extract for the egg, second instar larva, and pupa stages were 948.93, 346.72, and 1.75 µL/mL, respectively.
Conclusion: The results indicated that this extract has high potential for controlling the tomato leaf miner moth (Tuta absoluta) in both open-field and greenhouse environments, and is recommended for protecting the environment and user health.