Toxicity of nectar of tea (Camellia thea L.) to honeybees
O. P. Sharma, Desh Raj And Rajesh Garg
Honeybee (Apis mellifera) colonies at Darang, India, have suffered brood mortality in October, when tea bushes are in flower, in each year since 1977. Three colonies (4- 5 combs each) were established on empty combs in October 1983, and given one comb of healthy brood and combs containing fresh nectar taken from Darang colonies. It was established by pollen analysis of nectar taken from foragers that the nectar was tea nectar. Symptoms of poisoning appeared in all colonies within 2-3 days; larvae turned yellow and died, emitting a rancid odour. Larvae which were fed on tea nectar in the laboratory showed similar symptoms, whereas larvae fed with diluted nectar taken from healthy colonies developed normally. There were no apparent harmful effects on adults. It is concluded that the presence of poorly managed small tea estates in the foot-hills of the Dhauladhar range of the Himalayas renders the area unsuitable for A. mellifera colonies in autumn.