EFFECTS OF SOME INSECT GROWTH REGULATORS AND BIO-INSECTICIDE (ABAMECTIN) IN REPRODUCTIVE POTENTIAL OF THE COTTON LEAFWORM

Abstract

Studies were conducted to evaluate the biological effects of chitin synthesis inhibitor (Applaud) in the reproductive potential of cotton leafworm when larvae fed on food treated with different concentrations of Applaud a sub sequent effect was obscures adults with females laid an average of 563.60 and 604.30 eggs/female for those early and late stages treated with 0.075 g (ai) /l, respectively. Females in control treatment laid an average 918.70 and 919.30 eggs/female for those early and late stages. The hatchability was also decreased depending on concentrations used and type of mating .The results showed that mating of males and female emerged from treated Larvae during their late stage with concentration of 0.075 g (ai) /l of Applaud, the percentage of hatching reached to 63.30% when treated males mated with untreated females the percentage of hatching were 66.14%, while it was 96.22% in control. Methoxyfenozide negatively affected the fecundity of adults emerged from larvae treated late stages. Results showed that when treated females and males were paired the number of eggs laid was 150 eggs / female at 0.08 g (ai) /l concentration On other hand , when untreated females mated with treated males or treated females mated with untreated males the number of egg/females reduced to reach to 320, 315 eggs / female respectively, at the same mentioned concentration, while it was 920 eggs/female in control. Meanwhile the fertility was reduced to 80% when the treated males and females were mated at 0.08 g (ai) /l. The treatment of late stages larvae by using the concentration 0.045 ml (ai)/l led to a complete prevention of females emerged from lay eggs whether these females mated with treated or untreated males but when untreated females mated with treated males the eggs/females reach to 350, The percentage of egg hatching reached to 24%, while the numbers of eggs laid was 920 eggs/females in control treatment.