Development and validation of integrated pest management modules against spotted pod borer Maruca vitrata Fabricius on garden bean Lablab purpureus var. typicus (L.)

Abstract

To reduce the detrimental effect of insecticides, an effective Integrated Pest Management (IPM) module is necessary for the eco-friendly management of Maruca vitrata in garden bean ecosystem. Two field trials were carried out to evaluate the efficacy of different insecticides and botanicals against M. vitrata on Lablab purpureus var. typicus. Two seasons field evaluation of insecticides revealed that chlorantraniliprole 18.5 SC  was the most effective treatment to control the pest recorded 0.11 and 0.36 larva/plant in two seasons, respectively after two rounds of spray followed by flubendiamide 20 WG (0.46 and 0.92 larva/ plant) and emamectin benzoate 5 SG (0.50 and 0.95 larva/plant). Among botanicals tested, commercial neem formulation and 5% Ageratina adenophora recorded the least larval count of 1.64 & 1.05 larva/plant and 2.24 & 1.45 larva/plant in two seasons, respectively. IPM modules were developed with three effective insecticides (chlorantraniliprole 18.5 SC, flubendiamide 20 WG and emamectin benzoate 5 SG), two effective botanicals (commercial neem formulation 1500 ppm and 5% A. adenophora) along with the pheromone trap for validation. All the IPM modules were equally effective in managing M. vitrata population on L. purpureus and recorded a significantly (at 5 %) lower larval population than the farmer’s practice. The residues of chlorantraniliprole, flubendiamide and emamectin benzoate reached below the detectable level at the time of harvest. The population reduction of predatory coccinellids and spiders was also lower in IPM modules than in farmer’s practice. An increased benefit cost (1.95 to 1.99) ratio was observed in IPM modules.