Individual study: Laboratory-reared colonies of Western bumblebee Bombus occidentalis allowed to forage freely produce as many workers as captive colonies on agricultural land at Pitt Meadows, British Columbia, Canada
Whittington R. & Winston M.L. (2004) Comparison and examination of Bombus occidentalis and Bombus impatiens (Hymenoptera: Apidae) in tomato greenhouses. Journal of Economic Entomology, 97, 1384-1389
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Reintroduce laboratory-reared bumblebee colonies to the wild
Whittington & Winston (2004) placed seven laboratory-reared colonies of the rapidly declining Western bumblebee B. occidentalis in agricultural land and woodland in British Columbia, Canada, and compared the numbers of bees and brood with seven similar colonies prevented from foraging but supplied with water and pollen. Both groups were supplied with sugar syrup. Outside colonies produced as many workers (40-80 workers per colony on average) and more brood than enclosed colonies, but after five weeks, their syrup supply was robbed by honey bees Apis mellifera, resulting in high bumblebee mortality.