Tuesday, April 13, 2010

Looking for Answers for Bees

Bees got through the winter reasonably well. In a normal year, you would expect about one in seven bee colonies to die during the winter. This year, the rate of bee colony deaths has been about twice that, but that’s no worse than the last five years. The weather across most of the northern states was unusually harsh during the late winter, so it may have been a contributing factor in the death of some bee colonies.

Bees across the United States have been having unusual problems in recent years, and scientists still have not figured out the cause. The consensus now is that bees are suffering from pesticides, fungi, parasites, and viruses, but the reason bees are so susceptible to these stresses remains a mystery. It could just be a matter of cumulative stress, or there could be a primary cause, a specific pesticide chemical or virus, that has not yet been identified.

Whatever the problem is, it seems to be spreading. Three years ago, commercial beekeepers were mystified when they found many of the bee colonies vacant for no apparent reason. Now it is clear that wild bees are also in decline, though there isn’t enough data on wild bees to say for sure that they are being killed by the same causes.

Most food crops depend on bees for pollination, all the more so now that pesticides have reduced the populations of other pollinating insects, such as butterflies. The fear is that if we run out of bees, yields of crops from tomatoes to walnuts could be significantly reduced, leading to shortages and higher prices. Beekeepers are trying to increase their bee populations by feeding the bees more and reducing their exposure to pesticides, with some success, but a more targeted solution might be found if the specific cause of the bees’ problems could be discovered.