Cotton leafworm, Spodoptera littoralis (Boisd.) is a serious lepidopterous pest affecting several economic plant families leading to lowering in crop yields as well as crop quality through its larval stages  Efficacy of Dipel 2x^®as bio-insecticide and Hamer^® and Jasper^® as biorational insecticides were investigated against S. littoralis larvae under field conditions in Egypt throughout two seasons August 2018 and 2019 onSugar Beet. Results showed that the population of S. littoralis larvae during both seasons reduced after insecticide application. The highest reduction in infestation percentages was recorded with Jasper^® followed by Hamer^® then Dipel 2x^®. It recorded 96.30%, 90.06%, 80.32%, 78.70% and 68.52%, 67.31% with Jasper, Hamer and Dipel 2x^® during 2018 and 2019, respectively. The overall reduction in infestation percentages was 87.78%, 86.46%, and 64.76%, 60.71 % and 53.67%,49/.10% for Jasper, Hamer, and Dipel 2x^® during 2018 and 2019 Sugar Beet growing seasons, respectively. The activity of acetylcholinesterase (AChE) and Glutathione S- transferase (GST) enzymes play an important role in insect immune response compared to control against susceptibility of field strain 3^rd instar larvae of S. littoralis was determined. Our results revealed that Dipel 2x^® was the most potent bioinsecticide in both crop yields and quality due to its larval activity followed by Hamer^® then Jasper^® among the selected insecticides. The present work discusses the role of biorational and biological insecticides application in integrated pest management and biochemical studies were carried out on 3^rd instar larvae of S. littoralis (Field strain) to determine AChE and GST enzyme activity.