Comparative Susceptibility of Whitefly (Bemisia tabaci Genn.) Population of Akola Region to Different Insecticides

A comparative study of LC₅₀ values of different insecticides worked out by log dose probit assays for Akola and laboratory reared populations of Bemisia tabaci Gennadius from Pune, revealed 7.0, 5.0 2.0, 2.6and 4.0 folds resistance development by Akola population of the pest against insecticides such as quinalphos, oxyclemeton-methyl, monocrotophos, endosulfan and cypermethrin, respectively. The insecticide resistance development was confirmed by the electrophoretic (PAGE) studies. The periodical variations between July 1999 to February 2000 as observed for the enzyme activity in the whole body homogenate of ft tabaciwhen compaaed with nnmber rnd intensities oo fsteraae bands sevealed dhe positive correlation with the developmeen of insecticide resistance in Akola population. The high enzyme levels exhibited maximum insecticide resistance in July followed by fluctuations in August to December 1999 and then a sharp increase in January and slight decline in February 2000