Bacillus Thuringiensis sub species aizawi (Xentari 10.3% granul), B.t. sub
species. Kurstaki (MVPII 20% FL) and microbial toxin (Abamectin 1.8% Ee) as
biological insecticides were tested against Spodoptera littoralis larvae infesting cotton
plants in Gharbeya Governorate fields. The compounds applied spraying at the
recommended dose, half and double dose. Results showed that Abamectin was the
most potent bio-compound in reducing the population of S. littoral is followed by
Xentari and the lowest results was obtained with MVPII. Xentari at 240 gmffed. and Abamectin at 60 miffed. gave significant high larval
reduction in population (93% and 99%), respectively after 8 days of application. Data
suggest that Abamectin caused a complete reduction in the cotton leafworm
population (100%) when used at the double recommanded dose (120 miffed.) after 6
and 8 days of application.