Efficacy of biopesticides against the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on parthenocarpic cucumber grown under protected environment in India

Background: The whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is one of the most damaging pests of crops grown in open field and under protected conditions. Owing to the indiscriminate use of insecticides, whitefly has developed resistance against various insecticides belonging to different chemical groups. Use of microbial biopesticides (entomopathogenic fungi) can be an effective alternate to chemical insecticides. Results: This study was planned for the evaluation of entomopathogenic fungi (EPF) formulations, namely, Beauveria bassiana Balsamo (Vuillemin), Lecanicillium lecanii (Zimmerman) Viegas and Metarhizium anisopliae (Metschnikoff) Sorokin and botanical pesticide, Neem Baan, for the management of different life stages of B. tabaci on parthenocarpic cucumber grown under protected conditions. The liquid formulations of Neem Baan at 10 and 15 ml/l were the most effective (90.7 to 93.3% in eggs, 93.3 to 97.1% in nymphs, and 92.4 to 94.2% reduction in whitefly adults after 3rd spray, respectively) as compared to EPF. Among the EPF, L. lecanii and B. bassiana at 10 and 15 ml/l (80.6 to 86.5% in eggs, 85.7 to 91.5% in nymphs, and 58.5 to 69.2% in whitefly adults after 3rd spray, respectively) were found to be more effective than M. anisopliae at 10 and 15 ml/l (78.4 to 82.8% in eggs, 82.5 to 85.9% in nymphs, and 57.7 to 62.8% in whitefly adults after third spray, respectively) in reducing different life stages of B. tabaci on cucumber. Significantly high yield of cucumber fruits was obtained from the plot where Neem Baan at 10 and 15 ml/l (2337.5 to 2420.8 g/plant) was used. Minimum fruit yield were recorded in untreated control plots. Conclusions: The integration of these biopesticides in the management schedule of the whitefly under protected conditions will enhance the quality and market value of parthenocarpic cucumbers.