Abstract
The whitefly, Bemisia tabaci (Genn.) (Homoptera; Aleyrodidae) is one of the utmost destructive pests of field crops. The insect has developed resistance against synthetic pesticides due to repeated and undiscerning usage of pesticides having same mode of action. Solicitation of green synthesized silver nanoparticles (NPs) from Azadirachta indica extract is an emerging biological nanotechnology. It could prove to be a better substitute to synthetic pesticides for the proficient management of B. tabaci. The current study was premeditated for assessment of entomocidal impact of green synthesized silver NPs for the effective control of various life stages of B. tabaci under controlled conditions. Synthesis of the NPs was being done through standard protocols and surface morphology was confirmed by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Results revealed that silver nano formulation at 1200 ppm proved the most effective (41.11, 71.11, 80 and 82.22%) reduction in whitefly 3(rd) instar nymphs after 24, 48, 72 and 96 h of the post-treatment, respectively as compared to other concentrations of silver NPs used. The same concentration of silver NPs was also the most effective against adult population of whitefly, resulted in 37.77, 67.78, 76.66 and 77.77% suppression afterward 24, 48, 72 and 96 h application respectively. Rest of the concentrations gave the lower results. The LC50 data indicated that LC50 = 411.054 ppm concentration were required to kill the 50% of test population of 3(rd) instar nymphs of whitefly while LC50 = 465.331 ppm were required to kill the 50% of adult population of whitefly after 96 h exposure time. The assimilation of nanoparticles impregnated with biopesticides can be a best option to make the Integrated Pest Management (IPM) of whitefly successful leading to boost up the worth and value of cotton crop in the market.