Silent spring? Bee disease spreads


As beekeeper for Penn’s Morris Arboretum in Chestnut Hill, Jim Bobb plays a key role in keeping the arboretum’s spectacular gardens blooming strong.
Not as key as his bees, though.

So as a mysterious disease spreads through America’s honeybee population—by some estimates, the illness has already killed up to 40 percent of the 200,000 commercial beehives in Florida—Bobb is joining his fellow beekeepers in wondering, and worrying, what might happen to their hives when spring arrives.

“The problem right now is occurring with migratory beekeepers—the large keepers that move their hives down to Florida [for pollination] then move back up here for apple season, then over for blueberries in New Jersey, then back to Florida for winter,” says Bobb, an Arboretum volunteer who also serves as president of the Pennsylvania State Beekeepers Association. “What they noticed was that though their colonies were strong [in the fall], when they went back to check on them, some of the hives were just empty and others had collapsed down to just a queen and a few worker bees.”

Similar incidents have now been reported in 22 different states, with some beekeepers reporting half of their hives killed off due to the illness, which has been named Colony Collapse Disorder. Even more strange, affected beekeepers report that the bees in the infected hives seem to have completely disappeared.

“It’s an unusual situation,” explains Bobb, who says he won’t know whether the Arboretum’s hives are affected until later this spring, when the bees become more active. “With many bee diseases, you would see dead bees in the hives. But with this, there are no dead bees in the hives, and there are no dead bees around the hive.”

Bobb maintains 22 hives for the Arboretum, 20 of which are located across Northwestern Avenue from the Arboretum’s main gate and are used primarily to pollinate the Arboretum’s fruit trees. Two more hives are located in the main garden area to help keep holly bushes in bloom.
The Arboretum’s reliance on bees as pollinators is just a small example of how important honeybees are to agriculture.

Apple crops, for example, are completely reliant on bees, and local pumpkin, blueberry and cherry crops also rely heavily on honeybee pollination. Nationwide, bees help bolster citrus crops in Florida and almond crops in California, and some experts say a massive collapse of U.S. bee populations could cost American farmers billions in lost revenue.
But even though the first reports of CCD trickled in this winter, scientists don’t yet know what the disease is, where it originated or if it’s contagious.
“That’s what the beekeepers are worried about,” Bobb said. “The non-migratory beekeepers are worried that if this turns out to be something contagious, [what happens] when all of these bees are brought back to Pennsylvania to do apple blossom pollination? We’re hoping to find out more about this disorder to see if our hives will be exposed to the problem.”

Originally published on March 15, 2007