author(s)
Shifa, FA Zaki, Malik Mukhtar, Ashaq Pandit, Imtiyaz Murtaza, Nagina Nazir and Khurshid A Hakeem

abstract
Bioefficacy of nano-formulation of deltamethrin (average particle size of 90 nm) and its conventional commercial analogue were evaluated under in vitro conditions during the year 2016-2018 against Greenhouse whitefly, Trialeurodes vaporariorum through contact or residual bioassay. Both the insecticide treatments were tested at a range of dose concentrations starting from the recommended concentration of the commercial formulation (0.01%). At this dose conc. (0.01%), mean mortality of 82.95% was obtained in case of nano-formulation which was very high as compared to the mean mortality of 38.77% caused by its commercial analogue. This clearly indicated superior insecticidal activity of nano-formulation and therefore, lower doses for nano-formulation were tested to establish those dose concentrations which invoked equivalent mortality response against T. vaporariorum as the commercial formulation. Nine lower dose concentrations were tested (0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002 and 0.001) which caused 77.32%, 72.00%, 64.01%, 58.32%, 55.68%, 49.36%, 44.21%, 39.87% and 37.20% mean mortality respectively. It was thus established that the mortality percentage of 38.77% caused by the commercial formulation of deltamethrin at the recommended dose (0.01%) was equated by the equivalent mortality response range of 37.20% to 39.87% in case of nano-deltamethrin, caused at very low concentrations of 0.001% to 0.002%. Therefore, decreasing the recommended concentration (0.01%) of commercial formulation by a factor of 5 and even up to 10 yielded the concentration of nano-deltamethrin (0.001% to 0.002%) which induced equivalent quantitative mortality.