Evaluation of biorational pesticides against Bemisia tabaci Gennadius and Amrasca biguttula biguttula Ishida and its impact on natural enemies population in cowpea ecosystem

Abstract

The whitefly (Bemisia tabaci Gennadius) and leafhopper (Amrasca biguttula biguttula Ishida) are two major sucking pests causing considerable damage in cowpea production. Considering the negative impact of chemical pesticides on food safety, environment, and human welfare; an eco-friendly approach is aimed at utilizing naturally derived products for effective management of the aforesaid pests and maintain ecological balance. The present study was performed under field conditions to evaluate the performance of five naturally derived components [water plant extracts viz. chili (Capsicum annum), garlic (Allium sativum L.), and neem (Azadirachta indica A. Juss.) along with cow urine in three different combinations, two formulated entomopathogenic fungi (Metarrhizium anisopliae and Beauveria bassiana) along with one positive (Imidacloprid) and negative (water) control. The study was designed in RCBD with three replications for the years 2019 and 2020, respectively. Combined application of neem, chili, garlic, and cow urine extracts (NCGC) at 10% w/v had the highest population reduction of whitefly (0.09 & 0.10 per three leaves) and leafhopper (0.03 & 0.04 per three leaves) over both standard controls after two round of application in the year 2019 and 2020, respectively. Natural enemies (coccinellids) population was drastically reduced in positive control whereas the population build-up strengthened in all other treatments including negative control. Cowpea treated with NCGC produced a higher economic yield (1.54 Mg ha−1) than those of other treatments. The study suggests that NCGC is an effective biorational based technology for sustainable management of whitefly and leafhopper in cowpea cropping system with ensuring food safety and eco-friendly approach. This novel finding can be integrated with an integrated pest management program for diverse cropping systems.