A five-year survey of parasites and diseases affecting honeybee colonies found the varroa mite, regarded as a major factor in population declines, “is far more abundant than previous estimates indicated and is closely linked to several damaging viruses,” says Feedstuffs. In addition, “the previously rare chronic bee paralysis virus has skyrocketed in prevalence since it was first detected by the survey in 2010.” The lead author of the study, Kirsten Traynor of the University of Maryland, said it was the first systematic survey of disease and, “It highlights some troubling trends and indicates that parasites strongly influence viral prevalence.”
“More than 50 percent of all beekeeping operations sampled had high levels of varroa infestation at the beginning of winter – a crucial time when colonies are producing long-living winter bees that must survive on stored pollen and honey,” said Feedstuffs. The researchers said they plan to conduct a similar baseline assessment of pesticides and bee health. Neonicotinoid pesticides in particular have been cited as a factor in population losses along with parasites, disease and poor nutrition.