Efficacy of some natural oils on the residual toxicity of emamectin benzoate, spinosad and spinetoram against egyptian cotton leafworm

Abstract EN

During the 2006 and 2007 growing seasons, two semi-field trials were carried out to determine the efficacy of two plant oils (neem and jojoba) and two light mineral oils (Star and K-meson) on the persistence and residual toxicity of emamectin benzoate, spin sad and spinet ram as determined by cotton leaf worm, Spodoptera littorals, 2nd in star larvae bioassay.

The aim of this study was to extend the residual life (increasing persistence) and to increase the residual toxicity of these insecticides.

The tested insecticides were applied at the recommended rates, while oil concentrations were selected for field testing based on their performance in a laboratory study.

Results showed that, jojoba oil (at 200 ppm) increased the residual toxicity of spin sad, spinet ram and emamectin benzoate against the 2nd in star larvae of S.

littorals during the two seasons.

Also, neem oil (at 200 ppm) extended the residual toxicity of spin sad, spinet ram and emamectin benzoate, but to a lesser extent than jojoba oil.

Although, K-meson and Star mineral oils (at 1500 ppm) increased the toxicity of spin sad, spinet ram and emamectin benzoate in the laboratory, these oils had no effects on the residual toxicity of the tested insecticides in the field.