Evaluation of non-conventional insecticides for the control of Aphis gossypii Glover (Hemiptera: Aphididae) in beans

Abstract

The lethal concentration (CL) is used to estimate the toxicity of pesticides in arthropods; however, CL is an incomplete measure of the effects of these products on populations, since it only examines toxicity as a function of mortality. It is known that individuals which survive the exposure to pesticides may suffer sublethal effects. This work studied, under laboratory conditions the lethal and sublethal effects of lime sulphur, Azadirachta indica (Bioneem®) and Allium sativum- Capsicum chinense (Alisin®) on the population growth of A. gossypii and the phytotoxic effect of these insecticides on bean plants. Lethal effects were estimated through tests of acute toxicity to obtain dosage-response curves and their respective lethal concentrations and sublethal effects by estimating the instantaneous population growth rate (ri). The lethal and sublethal concentrations of lime sulfur against were 1.22 and 0.25% of the product, respectively, for the Bioneem® were 1.22 and 0.71% of the product, respectively, and the Alisin® 2.18 and 0,94% of the product, indicating that it could be used to control this phytophagous insect. There were no severe symptoms of phytotoxicity detected on sprayed plants. The management of A. gossypii in beans can be made with lime sulphur, Bioneem® and Alisin®.