Tiny Fly May Help Explain Honeybee Die-Off

Northern California scientists say they have found a possible explanation for a honeybee die-off that has decimated hives around the world: A parasitic fly that hijacks the bees' bodies and causes them to abandon hives. Scientists say the fly deposits its eggs into the bee's abdomen, causing the infected bee to exhibit zombie-like behavior by walking around in circles with no apparent sense of direction. The bee leaves the hive at night and dies shortly thereafter. The phorid fly, or apocephalus borealis, was found in bees from three-quarters of the 31 hives surveyed in the San Francisco Bay area.

The symptoms mirror colony collapse disorder, in which all the adult honey bees in a colony suddenly disappear. The disease is of great concern, because bees pollinate about a third of the US food supply. Its presence is especially alarming in California, the nation's top producer of fruits and vegetables, where bees play an essential role in the $2 billion almond industry and other crops. The latest study is published in the science journal PLoS ONE. (More disappearing bees stories.)