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.

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The whitefly, Bemisia tabaci (Gennadius) is a polyphagous pest, widely distributed in diverse agroecosystems across the globe. Several bioagents including predators and parasitoids from diverse groups have been recorded against whitefly worldwide. A field survey was conducted during 2016 and 2017 in different cotton growing districts of Punjab to record the natural enemies associated with whitefly. Sixteen species of natural enemies were recorded, including 7 species of insect predators; 2 species of parasitoids and 7 species of spiders. Coccinella septempunctata Linneaus, Cheilomenes sexmaculata (Fabricius) and Brumoides suturalis (Fabricius), Serangium parcesetosum Sicard, Chrysoperla zastrowi sillemi (Esben-Peterson), Zanchius breviceps (Wagner), Geocoris sp. and spiders were most commonly recorded predators. Out of these, Chrysoperla was the predominant species. Encarsia lutea (Masi) and Encarsia sophia (Girault & Dodd) were the two parasitoids that emerged from whitefly pupae. The mean parasitization of whitefly by Encarsia spp. in different cotton growing areas of Punjab was 5.20 per cent (range = 1.5 to 9.1 %).

On farm impact of Trichogrammatids was studied against lepidopteran pests, i.e., yellow stem borer, Scirpophaga incertulas (Walker) and leaf folder, Cnaphalocrocis medinalis (Guenee) in organic basmati rice (var. Pusa 1121) over an area of 20 and 60 hectares during 2014 and 2015, respectively. Six augmentative releases of Trichogramma chilonis and T. japonicum each @ 1,00,000 parasitoids/ha were made starting from 30 days after transplanting (DAT) and was compared with untreated control. Based on the overall mean, the biocontrol treatment (1.74% DH) was significantly effective in reducing the dead heart incidence as compared to untreated control (4.52% DH). The reduction in dead hearts was 61.50 per cent in biocontrol over untreated control. The mean incidence of white ears was also significantly lower in biocontrol field (2.05%) as against untreated control (4.89%) resulting in a reduction of 58.08 per cent. Similarly, leaf folder damage in biocontrol (2.04% LFDL) resulted in 62.50 per cent reduction over untreated control (5.44% LFDL). Grain yield in biocontrol fields (29.81 q/ha) was 18.76 per cent more than the untreated control (25.10 q/ha). The increase in yield due to control of stem borers and leaf folder in biocontrol fields resulted in an additional benefit of INR 16332/-and INR 9818/-during 2014 and 2015, respectively. Conclusively, 6 releases of T. chilonis and T. japonicum each @ 1,00,000/ha resulted in lower incidence of rice insect pests and higher grain yield in organic basmati rice with an additional benefit over untreated control.