Ultra structural studies of the ovaries of susceptible and insecticide-resistant Plutella xylostella (linnaeus)

The present study was aimed to compare the ultra-structural changes in ovaries of susceptible and insecticide-resistant P. xylostella. Ovaries of the adults of P. xylostella from the susceptible and insecticide-resistant populations were dissected, prepared chemically and were observed under scanning electron microscope. The length and breadth of the ovarian follicles were measured and their size was calculated. Considerable variations in shape, size and appearance of ovarioles in susceptible and resistant moths were recorded. Ultra structural studies revealed reduction in dimensions i.e. length, breadth and consequent size of the ovarian follicle in resistant moths as compared to the susceptible one. The variations in the dimensions of ovarian follicles in resistant and susceptible moths are indicators of influence of insecticides there upon.