A comprehensive study was conducted during kharif-rabi, 2024-25 at Biological Control Research Farm, ICAR Unit-9, Anand Agricultural University, Anand to monitor the population dynamics of key insect-pests and their natural enemies on cotton and the influence of weather parameters. Aphid population started appearing in late July, attained peak during 51st SMW, with populations negatively correlated with minimum temperature, humidity, rainfall and wind speed, but positively associated with bright sunshine hours. Jassids activity was recorded from July to November, showing a significant positive correlation with maximum temperature. However, thrips incidence remained below economic threshold levels with showing no significant correlation with weather parameters. While, whitefly population attained peak in 42nd SMW, exhibited a strong positive correlation with maximum temperature. Pink bollworm infestation was maximum in 51st SMW, exhibiting a significant negative correlation with temperature and rainfall. Among natural enemies, green lacewing, both eggs and larvae were observed from September to January, eggs and larvae negatively correlated with humidity, and minimum temperature and larvae positively influenced by sunshine hours. Coccinellid beetles showed negative correlations with humidity and positive trends with temperature and sunshine hours. Spiders were active during the same period, negatively affected by humidity, wind and rainfall, but positively influenced by sunshine hours. The study clearly showed that weather play a crucial role in shaping the population of pests and their natural enemies in cotton fields. Understanding these relationships helps farmers to anticipate pest outbreaks and implement better, more timely strategies that are tailored to seasonal changes, ultimately leading to healthier crops and more effective pest control.
Patel et al. (Wed,) studied this question.