Massachusetts honeybees are disappearing without a trace. Hives are left barren of bees, save for a small cluster of larvae, nurse bees, and an abandoned queen.
The question is: Why?
Tuesday on Beacon Hill, scientists and lawmakers convened to explore the phenomenon of colony collapse disorder and to seek ways to protect decimated bee populations.
“We saw a 40 percent loss in bees this year in Worcester County,” Kenneth Warchol, program director of the Worcester County Beekeepers Association, said in an interview. “Bees are like canaries in a coal mine — they’re sending us a message that something’s wrong here.”
Three pieces of legislation to address the bee crisis are pending before the Legislature. Two bills would create committees charged with investigating colony collapse and protecting honeybees.
The third proposal would limit use of neonicotinoids, a pesticide that, at low doses, affects bees’ neural behavior, according to some scientists.
“At high levels, the insect would be paralyzed to death,” said Chensheng Lu, an associate professor at the T.H. Chan Harvard School of Public Health. “At low levels, the bee can’t find its beeline, and doesn’t find its way home to the hive.”
In a study conducted by Lu, Warchol, and Dick Callahan of the Worcester beekeepers association, four hives were treated with different levels of neonicotinoid, while one hive was left untreated. That study was presented to the Joint Committee on Environment, Natural Resources, and Agriculture.
The majority of bees from the untreated hive survived the winter, while most of the neonicotinoid-tainted bees died, Lu said. According to Callahan, the untreated hives retained more bees, both dead and alive, while the treated hives saw a disappearance in bee bodies consistent with colony collapse disorder.
“When you affect the behavior of insects, they can’t navigate well after being exposed to small amounts of neonicotinoids,” Callahan said. “It’s like the . . . effects with DDT. That’s what’s happening here.”
A University of Massachusetts Amherst professor disagreed. To John Burand, a microbiology professor at UMass, neonicotinoids should not be the committee’s main priority.
“The problem with the bees is multifactorial,” he said. “Certainly, pesticides are involved in some ways, but there are other factors that contribute to failing bee health that are equally important or more so.”
Burand said Varroa mites are the number one cause of colony collapse disorder. The mites, a virus-transmitting parasite that attacks honeybees, have frequently been found in hives hit by colony collapse, according to the US Department of Agriculture website.
“The most important factor in [colony collapse] is clearly Varroa mites,” said Ed Bemis, owner of Bemis Farms Nursery. “I’m no fan of chemicals — I only use them when there’s no alternative. But if neonicotinoid use is restricted, what would fill the gap?”
Rosa Nguyen can be reached at firstname.lastname@example.org.