May 1 (UPI) -- The virus responsible for chronic bee paralysis is spreading rapidly among honey bee colonies in Britain, according to a new study.
Between 2007 and 2017, scientists visited 24,000 beekeepers to survey the health of commercial bee colonies in England and Wales. In 2007, the disease was found only in Lincolnshire, a county in eastern England. Just ten years later, the virus had spread to 39 of 47 English and six of eight Welsh counties.
Though the virus was isolated among just a handful of colonies to start, it quickly made itself apparent. Researchers detailed the disease's spread in a new paper, published this week in the journal Nature Communications.
"The symptoms of the disease are quite easy to spot once you have seen them a few times," said lead study author Giles Budge, professor of environmental sciences at Newcastle University. "Symptoms of chronic bee paralysis can include shaking, black hairless bees with nibbled wings or shaking, greasy looking bees with dislocated wings. Bees can also simply shake too. Colony level symptoms include piles of dead bees right outside the front entrance."
Researchers used lab tests to confirm the presence of chronic bee paralysis virus at colonies where signs of infection were observed.
Bees infected by the virus usually die within weeks. Once infected, the disease can spread quickly among colony members. Roughly 40 percent of infected colonies are lost entirely, according to figures collected by Budge and his colleagues.
After surveying reports of the virus' spread, scientists confirmed that colonies managed by professional beekeepers, particularly those with imported queens, were more susceptible to the disease -- which were twice as quick to be infected by the virus.
"Emerging diseases are tricky to study because the number of cases start low and then can build up rapidly," Budge said. "As such, we look for clues that highlight risk, and then we can try to explain why these heightened risks occur -- hence our observations on apiaries owned by professional beekeepers and those that contain imported queens."
A variety of management practices distinguish professional from amateur beekeeping, but scientists aren't yet sure why professionally managed bee colonies are more susceptible to the virus.
Though the disease can decimate entire colonies, the virus is distinct from the phenomenon known as colony collapse disorder, which was first reported in the United States. As well, pesticide exposure, while allowing the virus to replicate more quickly, doesn't appear to increase the risk that a colony will succumb to the virus.
Still, researchers suggest the quickly spreading virus is a significant threat to bees and other insects.
"Honey bees are susceptible to many different viruses, and when considered in isolation, I'd argue that CBPV is one of the most important," Budge said. "This disease gets added as a pressure facing honey bees, although it is also worth noting that the virus can also infect other bees and ants, and so should be seen as an insect virus rather than a honey bee virus."
So far, scientists are ready to do little more than warn beekeepers of the threat of chronic bee paralysis virus, but Budge and his colleagues hope to identify effective mitigation strategies sooner rather than later.
"We are part way through a four year program of research, and have a lot to do before we can advise on evidence based management strategies for chronic bee paralysis," he said. "We are working closely with the Bee Farmers Association, their members, and the national Bee Unit to achieve mitigation as our end goal."