Toxicity of abamectin, azdirachtin, spinosad and thiamethoxam to the vegetable serpentine leafminer Liriomyza trifolii (Diptera: Agromyzidae)

Liriomyza trifolii is a major pest of numerous vegetable and ornamental crops worldwide. In this studysoil application of abamectin, azdirachtin, spinosad and thiamethoxam on immature stages of L. trifolii oncucumber and tomato plants were investigated. The plants infested with L. trifolii eggs were treated with fiveconcentrations of each insecticide. Soil drenching and leaf spray were used for treatment. Larval density,larval mortality and pupal mortality were evaluated. Abamectin was effective against immature stage of theleafminer when it was applied to soil, but not in leaf spray method. When abamectin was sprayed on leafsurface, it was about 10 times more toxic for eggs and larvae. Azdirachtin was highly toxic to leafminer insoil drenching and caused high larval and pupal mortality. Azdirachtin was not effective on eggs and larvae.Spinosad caused significant larval and pupal mortality in both application methods. Leaf spray ofthaimethoxam had no considerable effect on larval mortality in comparison with other compounds tested, butwas more effective when applied to soil. Species of the plant affected systemic activity of the insecticides.Soil application of insecticides can improve selectivity of them for beneficial arthropod.

کلیدواژه ها:

Liriomyza trifolii ، abamectin ، azdirachtin ، spinosad ، thiamethoxam