In this book two chapters were discussed, the climatic factors determine seasonal activity and infestation of different insect pests of cotton. The results of present study would be helpful in developing efficient pest management strategies against insect pests of Bt-cotton and Non Bt-cotton crops for increased yields, profit, besides safety to the environment. As on today the information available on the Bt-cotton and Non Bt-cotton reaction to insect pest complex and their natural enemies is very much limited. The performance of the Bt-cotton and Non Bt-cotton varieties varies from region to region with change in agro climatic conditions, the pest and their predators abundance is quite different. Another way to overcome the fluctuations in predator populations as results of sprays of pesticides and weather factors predators could be highly mobile and migrate from further afield. Humidity and free standing water could be an important for distribution of predators with in the cotton fields. These are many factors influence the abundance of predator population in cotton ecosystems. One of the major findings of this book was to identity some factors contributing to variation in predator populations, the flections in predators indicated that rainfall and Relative humidity have a positive impact on predator population. Hence, there is need to develop the Integrated Pest Management (IPM) and Bio-Intensive Pest Management (BIPM) module on Bt-cotton and Non Bt-cotton. The results of this study might be helpful to pest management agencies for effective control measures in coming future.