Wednesday, February 11, 2015

Young Bees Under Stress

wild hive; Mark Chappell
Scientists have been working to find a definitive explanation for the syndrome known as Sudden Colony Collapse. North America has lost a third of its honeybees since this phenomenon began being reported by beekeepers. {26.08.08, For Want of a Bee} A team of British researchers at Queen Mary College, University of London say stressed young bees are forced out of their colonies to forage as older workers die off. But like young pilots at war, younger bees are less likely to successfully complete a sortie. Younger workers foraging is likely to be an adaptive behavior to a reduction in the number of adult bees. If the colony is not strong or the increased death rate continues too long the division of labor in the colony could be upset with catastrophic consequences. Loss of the adult population leaves only brood, food, and a few adults insufficient in number to keep the hive functioning. The scientists used data from a bee tracking model and studied the impact on bee colonies in a computer simulation. Increasing stress, such as exposure to toxic pesticides or parasite infestations causes older workers to die off. These food gatherers have to be replaced with younger bees that ordinarily would remain in the hive to develop more fully. Younger foragers turn in less food which leads to a rapid increase in colony mortality consistent with actual observations of colony collapse around the world. The study findings are published in the journal of the Proceedings of the National Academy of Sciences.