Effect of different stimulation methods on colony survival and development of Bombus haemorrhoidalis Smith in Himachal Pradesh

One of the key steps to facilitate year-round rearing of bumblebees is to break diapause period. In the present investigations, different stimulation methods were evaluated viz., cold temperature and CO₂ narcosis, and their effects on colony parameters were studied. The daughter queens collected during winters were exposed to low temperatures i.e. 4±0.5 ^°C for two months. But this did not show any results as all the queens died after two months. Another method used was exposing the queens with single and double CO₂ narcosis. The present study concluded that bumblebee workers kept along with double narcotized queens was one of the best stimulation methods followed by single narcotized queens kept along with bumblebee workers.