Effect of imidacloprid on foraging behaviour of wild bee species on coriander

The experiment was carried out at Beekeeping Unit, TCA, Dholi (Muzaffarpur) during ‘rabi 2021-22’ on c.v. of coriander ‘Rajendra Dhania-2’. Foraging behaviour of rock bee and little bee such as duration of foraging, foraging speed and rate was studied under two conditions i.e. with and without insecticide application. In untreated area duration of foraging was maximum in Apis dorsata (7.16 second) and minimum in Apis florae (3.51 second). Foraging rate was highest in A. florea (11.66 flowers) followed by A. dorsata (6.64 flowers).Application of insecticide imidacloprid @ 25 gm a.i/ha completely ceased the activity of honey bee species on flowers of coriander for three days. Effect of insecticide on foraging behaviour was observed for a period of 4 to 5 days in wild bee species. Insecticide application caused 20 to 25 % reduction in foraging activity of both wild species during complete flowering period.