International Journal of Environment and Climate Change

A field investigation studied the seasonal abundance and activity of spider populations in cotton fields across treatment plots in Surat and Bharuch, Gujarat. In Surat, spider activity in unprotected plots of the Bt cotton hybrid RCH 2 BG II was noted from the 29^th to the 1^st Standard Meteorological Week (SMW), peaking (>0.80 spiders/plant) between the 46^th (second week of November) and 51^st SMW (third week of December). In protected plots of the same hybrid, spiders were active from the 31^st to the 1^st SMW, with peak densities observed from the 46^th to 1^st SMW (first week of January). Similarly, in non-transgenic Suraj variety, unprotected plots showed spider activity from the 29^th to the 1st SMW, peaking from the 41^st to 51^st SMW. In Bharuch, spider activity spanned from the 32^nd to the 52^nd SMW in all plots. In unprotected plots of RCH 2 BG II, peak spider activity (>0.80 spiders/plant) occurred from the 44^th (fourth week of October) to the 52^nd SMW. Protected plots of the same hybrid peaked from the 47^th to the 52^nd SMW. In Suraj, unprotected plots peaked from the 44^th (fifth week of October) to the 52^nd SMW, while protected plots peaked from the 46^th to the 52^nd SMW. Positive correlations were found between spider populations and pest species like aphids, jassids, whiteflies, and mealybugs, as well as abiotic factors such as maximum temperature and sunshine hours in Surat. In contrast, significant negative correlations were noted with morning and evening relative humidity, rainfall, and rainy days. At Bharuch, spider populations positively correlated with aphids, whiteflies, mealybugs, and sunshine hours, while negatively correlating with minimum temperature, relative humidity, and rainy days.