Field Evaluation of Some Selected Chemical and Bio Insecticides against the Cotton Leafworm Spodoptera Littoralis (Boisduval) (Lepidoptera: Noctuidae) Which Infesting Soybean

Egyptian cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera. Noctuidae), is a key pest of cotton and many other crops in Egypt. A field experiment was conducted during two successive seasons (2020 and 2021) at Plant Protection Research Institute Farm at Qaha district, Qalubia governorate. The efficiency of two chemical insecticides, Indoxacarb (Doxab) and Methomyl (Copter) and two biocides, Bacillus thuringensis kurstaki (Protecto 9.4% WP) and the entomopathogenic fungus, Beauveria bassiana (Biossiana at 1 x 108 CFUs/g) was evaluated against S. littoralis on the soybean 'Giza111' cultivar. The tested insecticides and biocides were applied at doses recommended by the Agricultural Pesticides Committee. The results showed that Copter and Doxab significantly reduced the number of S. littoralis larvae compared to the untreated area. The reduction percentage of S. littoralis larvae after 10 days was 76.87 and 83.90% during the 1st season and 79.53 and 84.63% during the 2nd season for Copter and Doxab, respectively. Both Biossiana and Protecto® resulted in a significant reduction in insect infestations up to ten days after treatment, recording 58.36 and 69.08% in the first season and 59.47 and 67.32% in the second season, respectively. Farmers can effectively use Protecto, Biossiana, Copter, and Doxab as components of integrated cotton leafworm management in Egypt.