More and more urban dwellers are starting to keep honeybees as a hobby, but a new study finds it might not be so good for the bees.
Researchers at North Carolina State University in Raleigh studied two dozen honeybee colonies managed by beekeepers in the city and outlying areas. They compared the health of those bees with the health of honeybees in 15 wild colonies found in trees or buildings.
Investigators studied the immune systems of worker honeybees and the “pathogen pressure,” or exposure to disease-causing bugs, that they face.
Steve Frank, an entomologist at N.C. State and co-author of a study published in the journal PLoS ONE, said it appeared that the honeybees kept by urban beekeepers faced exposure to a greater number of bacteria and viruses than their wild cousins.
“We’re not sure of the mechanism, but one possible mechanism is that in urban areas, [because] there are fewer flower patches to feed on, that more bees are visiting the same patches," he said. "And that could increase the rate of pathogen transmission from one bee to another.”
The mortality rate among honeybees collected in the urban environments was three times higher than that of the bees collected in rural environments.
However, investigators found the immune response of managed bees was not affected by urbanization.
Differences in temperatures and more pollution could be taking a toll on managed bees in the city. But Frank said that was no reason not to raise them.
“I don’t think beekeeping in the city should be discouraged at this point," he said. "But it does suggest that urban beekeepers might need to be more vigilant when it comes to monitoring their hives for pathogens or monitoring the health of their colonies.”
Frank said further research was needed to find out why there are greater health threats to honeybee colonies so beekeepers can keep their charges safe.