author(s)
Ravindra Kumar and Pramod Mall

abstract
Thiamethoxam spray at mustard pre-bloom negatively affects the activity of Apis mellifera L. The average bee activity from 6 to 14 DAE was significantly less as compared to control. The data on A. mellifera foraging activity on different days and timing revealed that the activity of A. mellifera during 2018 and 2019 peaked 15.25 and 15.00 bees on 6 DAE at 1200h in thiamethoxam spray at pre-bloom; while in control the activity of A. mellifera was recorded on the peak (23.75 and 25.50 bees) on 8 DAE at 1200 h. The data on the interaction between treatment and time further revealed that average activity of A. mellifera in control was highest at 1200h (21.89 and 23.25 bees) significantly superior over 1000h (15.44 and 17.36 bees) and 1600h (9.81and 10.81 bees), while in thiamethoxam spray at pre-bloom the bee activity was highest at 1200h (5.83 and 7.58 bees) significantly superior over 1000h (4.44 and 6.11 bees) and 1600h (3.95 and 4.56 bees). Foraging activity during 2018 and 2019 irrespective of day and time was statistically higher in control (15.71 and 17.14 bees) in comparison to thiamethoxam spray at pre-bloom (4.74 and 6.08 bees), respectively. Therefore, it is evident from the experiment thiamethoxam 25 WG negatively affects the honey bee population. If the thiamethoxam 25 WG used continuously, the population of both managed as well as the wild honey bee will decline drastically in the near future. As a result of which total food production, particularly fruits and oilseed crops dependent on the honey bee for pollination will be decreased.