Experts scrambling to understand losses in hives across the country are finally identifying the culprits. And the damage to farmed bees is a sign of trouble for wild bees too
Scientists have been scrambling to discover what happened; now the culprits are emerging. A research paper published by the US Department of Agriculture (USDA), though not yet peer-reviewed, has found nearly all colonies had contracted a bee virus spread by parasitic mites that appear to have developed resistance to the main chemicals used to control them.
Adee says: “We had mites for 20 years, and we never had over 3% losses.” He believes there is a “combination of things” that makes the bees more stressed and the mites more deadly.
He cites the use of neonicotinoid insecticides in the US, which harm bees’ nervous system, paralysing and ultimately killing them. Some researchers have warned of neonicotinoids causing another “silent spring”, referring to Rachel Carson’s 1962 book on the effects of the insecticide DDT on bird populations.
Dave Goulson, professor of biology at the University of Sussex, says the study provided no evidence that the viral load was higher in weaker colonies. “Almost all bee colonies have these viruses, but they only do significant harm when the colony is stressed.”
Varroa mites spreading disease.