Use of Chemical and Microbial Insecticides Against Pests of Common Beans

Abstract

Effects of chemical insecticides and a microbial insecticide on insect pests in relation to yield of common beans, Phaseolus vulgaris L., were investigated. Two preflowering applications of lindane or carbaryl, two postflowering applications of Bacillus thuringiensis Berliner ( Bt ), and a spray of lindane or carbaryl effectively controlled bean pests. Lindane or carbaryl applications controlled preflowering pests and flowerthrips, Taeniothrips sjostedti Trybom. Two applications of Bt during the postflowering growth stage of bean plants controlled the larvae of pod borers, Maruca testulalis (Geyer) and Heliothis armigera (Hubner) as effectively as two applications of lindane or carbaryl over the same period. Two applications of lindane during the prellowering and the late pod stages combined with two applications of Bt gave high seed yields of 1,308 and 1,307 kg/ha for 1982 and 1983 trials, respectively. Thus, Bt is as effective as chemical insecticides in controlling pod borers. Integrated use of chemical and biological insecticides could be used for controlling bean pests.