Natural Enemies in Different Bt Cotton Hybrids under Protected and Unprotected Conditions

Abstract

A field experiment was conducted to analyse the population dynamics of natural enemies including Chrysoperla, coccinellids, and spiders, in Bt cotton under both protected and unprotected conditions. The results indicated that the population of natural enemies was significantly higher under unprotected conditions compared to protected fields, where insecticides were applied. Among the tested hybrids, G. Cot. Hy.10 BG Ⅱ recorded the highest predator activity, showing a greater population of Chrysoperla, coccinellids, and spiders in unprotected conditions. In contrast, the lowest predator activity was observed in RCH 2 BG Ⅱ, while Ajeet 155 BG Ⅱ and ATM BG Ⅱ had minimal natural enemy presence. These findings highlight the importance of unprotected conditions in preserving natural enemies and suggest that certain Bt hybrids, such as G. Cot. Hy.10 BG Ⅱ, may better support predator populations. This research is crucial for understanding how insecticide use affects natural enemy populations and identifying hybrids that promote predator activity. Incorporating natural enemies into pest management strategies can enhance the sustainability of cotton production. Predators of pests, coccinellids and Chrysoperla, were observed from the 33rd to 52nd, whereas spider populations were observed from the 31st to 52nd SW under unprotected conditions.