Effect of a Macrocyclic Lactone Insecticide, Emamectin Benzoate, On Some Biological Aspects of the Cotton Leafworm, Spodoptera Littoralis (Boisd.)

Abstract: The macrocyclic lactone insecticides represent a non-conventional class of pesticides with a novel mode of action. Emamectin benzoate is commercially used in pesticide market under many trade names. This chemical is recommended to control cotton leafworm and other lepidopterous pests. In the present study, the effect of this chemical on the development and the reproductive capacity of cotton leafworm was undertaken to answer the question "what could happen if cotton leafworm larvae exposed to sublethal concentration of this insecticide?. In general the chemical is highly toxic as a stomac poison and less toxic via contact. In addition larval stage was the most sensitive stage as compared to adult and egg stages. Also, the obtained data revealed that treated larvae with sublethal concentration of emamectin benzoate negatively affect food consumption. Larvae consumed less food, gained less weight. In addition, durations of larvae and pupae elongated and emerged adult females significantly laid less eggs compared to the untreated check. Moreover, most of deposited eggs did not hatch.