The global spread of a virus that leads to stubby wings and early mortality for honey bees has been linked to beekeeping practices, suggests a recent study by campus scientists in tandem with other institutions.
Mike Boots of UC Berkeley, in collaboration with scientists at the University of Exeter, led the team in analyzing the genomes of various viruses in order to trace the origins of Deformed Wing Virus to human-managed honey bee colonies in Europe. Their study, published in Science magazine on Feb. 5, adds to growing concerns about the health of global honey bee populations.
According to Lena Bayer-Wilfert of the University of Exeter, the study’s lead author, beekeepers often trade queen bees among different colonies to maximize honey production or to breed other desirable traits. This practice, while producing better-quality honey, can lead to the spread of infectious viruses such as DWV.
According to Robbin Thorp, a UC Davis professor emeritus and member of UC Davis’ Honey Bee Research Facility, large agricultural operations such as almond farms rely on imported honey bee colonies to make production of pollinated fruits and vegetables possible. Although honey bees are not the most efficient pollinators, they are ideal for transportation, Thorp added.
Thorp noted that the disease can spread easily in such operations because hives from different parts of the country may be housed in close proximity on the same orchard.
The disease, originally found in Asian honey bees, has spread to European honey bees and across the globe over the last 80 years. Thorp described rules governing colony movement as a “real problem” for beekeepers trying to stop the spread of the virus.
According to the study, the disease is transmitted through parasitic varroa mites that feed on bees’ blood. The combination of mites and disease hurts honey bee colonies’ ability to survive cold winters and adds to existing difficulties faced by honey bee colonies, such as disorientation from pesticide use and colony collapse disorder, in which the majority of worker bees abandon a hive.
The study urged for tighter controls on the movement of bee colonies. Bayer-Wilfert added in an email that beekeepers need to follow existing legislations regarding transportation of colonies, which include screenings for disease.
Healthy bees and other wild pollinators are vital for human food security and are just as important for maintaining biodiverse communities and resilience in ecosystems, according to Bayer-Wilfert.
“They provide much of the fruit and vegetables that make our food tasty and healthy,” Bayer-Wilfert said in an email. She added that the preservation of honey bees is especially important to solving the problem of long-term food supply.
“Any damage that might be done has been done,” Thorp said. “We’re just beginning to realize that some of these things are going on.”
Contact Alexander Barreira and Jason Kim at [email protected].