EFFECTS OF NEEMAZAL-T/S CHITIN SYNTHESIS INHIBITOR (CSI) ACTIVITY AGAINST GALLERIA MELLONELLA (L.) (LEPIDOPTERA: PYRALIDAE)

Effects of NeemAzal-T/S on the chitin synthesis inhibitor (CSI) of sixth instar larval integument of Galleria mellonella L. have been investigated. With probit analysis method oral LC95 value of NeemAzal-T/S was determined as 4200 ppm for G. mellonella larvae. Decreasing concentrations of the substance such as, 4200 ppm, 2100 ppm, 1050 ppm and 525 ppm were used. Morphologically, in all exposed the larvae slowing of the movements, growth inhibition, loss of tissue fluid, blackout and bleeding were observed in a dose/response manner. Nevertheless, the changes were not at the same level in all group. The moulting was unsuccessful at four different concentrations. NeemAzal-T/S was found to be effective on cuticle thickness. Histologically, cuticle secretion of epidermal cells was blocked at a dose/response manner and the blockage was more definite at higher concentrations and endocuticular lamellae formation was blocked. Cuticle secretion of the larvae decreased 27% in 525 ppm, 29% in 1050 ppm, 33% in 2100 ppm and 37% in 4200 ppm NeemAzal-T/S containing diet. The action mode of NeemAzal-T/S was found to be similar to that of the classical CSIs (chitin synthesis inhibitors).