Since the latest rounds of honeybee disappearances was noted in 2006, study into its causes has been frenetic. That was when the cases of the condition called colony collapse disorder (CCD) began to ramp up dramatically. Theories abound on why it is happening. Some include cell phones, sun spots, viruses, and diseases. Scientists seem to agree there may be a range of factors causing bees to disappear.
Two Suspects Eyed
Case Not Closed
Why should the public care about honeybees?
Bee pollination is responsible for $15 billion in added crop value, particularly for specialty crops such as almonds and other nuts, berries, fruits, and vegetables. About one mouthful in three in the diet directly or indirectly benefits from honeybee pollination. While there are native pollinators (honeybees came from the Old World with European colonists), honeybees are more prolific and the easiest to manage for the large-scale pollination that U.S. agriculture requires. In California, the almond crop alone uses 1.3 million colonies of bees, approximately one half of all honeybees in the U.S., and this need was projected to grow to 1.5 million colonies in 2010.
The number of managed honeybee colonies has dropped from 5 million in the 1940s to only 2.5 million today. At the same time, the call for hives to supply pollination service has continued to climb. This means honeybee colonies are trucked farther and more often than ever before.
Honeybee colony health also has been declining since the 1980s with the advent of new pathogens and pests. The spread into the U.S. of varroa and tracheal mites, in particular, created major new stresses on honeybees.
Has CCD ever happened before?
The scientific literature has several mentions of honeybee disappearances — in the 1880s, the 1920s, and the 1960s. While the descriptions sound similar to CCD, there is no way to know for sure if the problems were caused by the same agents as today’s CCD.
There also have been unusual colony losses before. In 1903, in the Cache Valley in Utah, 2,000 colonies were lost to an unknown “disappearing disease” after a “hard winter and a cold spring.” More recently (1995-1996), Pennsylvania beekeepers lost 53% of their colonies without a specific identifiable cause.
Varroa mites are a major threat to honeybee health and are becoming resistant to two compounds (coumaphos and fluvalinate) used to control them. Beekeepers now have a simple assay to determine whether mites are resistant and thus ensure use of appropriate control measures.