SAN FRANCISCO—For the past several years, scientists have been puzzled by Colony Collapse Disorder (CCD), or declining honey bee populations. Pesticides, parasites and various stressors are believed to have some role in the decline, but a conclusive, underlying cause is still unknown. Researchers at San Francisco State University (SFSU) recently found a new parasite that appears to be body-snatching the honey bees.
According to the researchers, the fly parasite, Apocephalus borealis, deposits its eggs into a bee’s abdomen, after which the bees abandon their hives and congregate near lights, often walking around in circles and exhibiting disoriented, “zombie-like" behavior. About seven days after the bee dies, fly larvae emerge from between the bee’s head and thorax.
So far, the fly parasite has only been found in honey bee hives in California and South Dakota, said SFSU Professor of Biology John Hafernik. But the possibility that it is an emerging parasite “underlines the danger that could threaten honey bee colonies throughout North America, especially given the number of states that commercial hives cross and are deployed in," he says.
Bees that left the hives at night were more likely to bear the parasite than those who foraged during the day, the researchers found. The next step, they say, is to find out exactly how the parasite is affecting the bees’ behavior, and whether the infected bees are leaving the hive of their own accord, or if perhaps they give off some sort of chemical signal that provokes their hive mates into throwing them out.
“We don’t know the best way to stop parasitization, because one of the big things we’re missing is where the flies are parasitizing the bees," Hafernik noted. “We assume it’s while the bees are out foraging, because we don’t see the flies hanging around the bee hives. But it’s still a bit of a black hole in terms of where it’s actually happening."