A heap of dead bees was supposed to become food for a newly captured praying mantis. Instead, the pile ended up revealing a previously unrecognized suspect in colony collapse disorder a mysterious condition that for several years has been causing declines in U.S. honeybee populations, which are needed to pollinate many important crops. This new potential culprit is a bizarre and potentially devastating parasitic fly that has been taking over the bodies of honeybees (Apis mellifera) in Northern California.
John Hafernik, a biology professor at San Francisco State University, had collected some belly-up bees from the ground underneath lights around the University’s biology building. “But being an absent-minded professor,” he noted in a prepared statement, “I left them in a vial on my desk and forgot about them.” He soon got a shock. “The next time I looked at the vial, there were all these fly pupae surrounding the bees,” he said. A fly (Apocephalus borealis) had inserted its eggs into the bees, using their bodies as a home for its developing larvae. And the invaders had somehow led the bees from their hives to their deaths. A detailed description of the newly documented relationship was published online Tuesday in PLoS ONE.
The parasitic fly lays eggs in a bee’s abdomen. Several days later, the parasitized bee bumbles out of the hives often at night on a solo mission to nowhere. These bees often fly toward light and wind up unable to control their own bodies. After a bee dies, as many as 13 fly larvae crawl out from the bee’s neck. The bees’ behavior seems similar to that of ants that are parasitized and then decapitated from within by other fly larvae from the Apocephalus genus.
“When we observed the bees for some time the ones that were alive we found that they walked in circles, often with no sense of direction,” Andrew Core, a graduate student who works with Hafernik and a co-author on the new paper, said in a prepared statement, describing them as behaving “something like a zombie.”
Sir David Attenborough and the Planet Earth team discover the weird world of the Cordyceps; killer fungi that invades the body of an insect to grow and diminish the insect population. Fascinating animal and wildlife video from the BBC epic natural world masterpiece 'Planet Earth'.