“Zombie” Parasite Turns Bees into Buzzing Dead

Researchers have reportedly identified a new threat to North American honeybees after discovering evidence of a parasitic “zombie” fly infestation in some bee populations. Andrew Core, et al., “A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis,” PLOS One, January 2012. According to the study, scientists detected a known paper-wasp and bumblebee parasite, the phorid fly Apocephalus borealis, in 77 percent of honeybee hives sampled in the San Francisco area, as well as in commercial hives located in South Dakota and California’s Central Valley.

Known to manipulate behavior in other arthropods such as fire ants, phorid
flies apparently cause their honeybee hosts to abandon the hive and die, at
which point “up to 13 phorid larvae emerge from each dead bee and pupate
away from the bee.” The parasite could thus be one of the multiple factors
contributing to colony collapse disorder (CCD), suggested the researchers,
who also noted that the flies may themselves spread two other CCD pathogens,
deformed wing virus and Nosema ceranae, often found among phorid
carriers.

In particular, the report authors expressed concern that as phorid flies adapt
to exploit honeybees, they could devastate mobilized commercial bee
operations. “Bumblebees live in relatively small colonies that last only a single
season with only queens overwintering,” the scientists warned. “Honeybees,
on the other hand, live in much larger colonies with tens of thousands of
individuals living in hives that are warm even in winter. If these flies have or
can gain the ability to reproduce within hives they could greatly increase their
population size and levels of virulence.”