EFFECTS OF THREE PESTICIDES ON SOME BIOLOGICAL ASPECTS OF COTTON LEAF WORM (Spodoptera littoralis, BOISD) LARVAE UNDER LABORATORY CONDITIONS

The effects of bromoxynil (Brominal W 24 % EC, herbicide) and mancozeb (Acrobate mancozeb72% WP, fungicide) on some biological aspects of Egyptian cotton leafworm, Spodoptera littoralis (Boisd.) larvae compered to profenofos (Silicron 72 % EC, insecticide), as a refrence compound were investigated. 4th instar larvae were fed on castor-bean leaves treated with profenofos at 40, 45, 50, 60, 75 and 90 ppm, bromoxynil and mancozeb, both at 500, 750, 1000, 1250, 1500, 2000 and 2500 ppm. The obtained results showed that larval and pupal weights, growth rate,consumption index (C.I.), fecundity level , % of hatchability , % of deformed pupa , %of emergency and % of sterility decreased by the tested pesticides compared with that in control. Profenofos, caused significant increases in larval and pupal duration,but not observed with bromoxynil and mancozeb concentrations. Profenofos markedly affect all the tested parameters of 4th instar larvae of cotton leaf worm, S. littoralis.