Apr 7, 2007

New Disease – Colony Collapse Disorder – Strikes Honeybees

Researchers are scrambling to find answers to what’s causing “colony collapse disorder,” a recently named disease that has struck commercial beekeeping operations across the country.

The alarming die-off of honeybees has beekeepers fighting for commercial survival and fruit and vegetable producers wondering whether bees will be available to pollinate their crops. The poor state of so many hives made the news as beekeepers began readying for their trips West to pollinate the almond crop in California in February and March, before heading back to the fields and orchards of the East and upper Midwest.

“During the last three months of 2006, we began to receive reports from commercial beekeepers of an alarming number of honeybee colonies dying in the eastern United States,” said Maryann Frazier, apiculture Extension associate at Penn State University. “Since the beginning of the year, beekeepers from all over the country have been reporting unprecedented losses.”

Penn State published the news Jan. 30, and took people by surprise.

“This has become a highly significant yet poorly understood problem that threatens the pollination industry and the production of commercial honey in the United States,” Frazier said in the Penn State news release. “Because the number of managed honey bee colonies is less than half of what it was 25 years ago, states such as Pennsylvania can ill afford these heavy losses.”

A group of university faculty researchers, state regulatory officials, Extension educators and industry representatives is working to identify the cause or causes of colony collapse disorder (CCD) and to develop management strategies and recommendations for beekeepers. Participants include Penn State, USDA, the agriculture departments in Pennsylvania and Florida, and Bee Alert Technology, a technology transfer company affiliated with the University of Montana.

“Preliminary work has identified several likely factors that could be causing or contributing to CCD,” said Dennis vanEngelsdorp, acting state apiarist with the Pennsylvania Department of Agriculture. “Among them are mites and associated diseases, some unknown pathogenic disease and pesticide contamination or poisoning.”

Initial studies of dying colonies revealed a large number of disease organisms present, with no single disease identified as the culprit, vanEngelsdorp said. Case studies and surveys of beekeepers experiencing CCD have found a few common management factors, but no common environmental agents or chemicals have been identified.

The beekeeping industry has responded to the crisis. The National Honey Board pledged $13,000 of emergency funding to the CCD working group. Other organizations, such as the Florida State Beekeepers Association, are working with their membership to commit additional funds.

The loss of colonies could seriously affect the production of several important crops that rely on pollination services provided by commercial beekeepers.

Frazier said growers should plan ahead to cope with a potential shortage of pollination services.

“If growers have an existing contract or relationship with a beekeeper, they should contact that beekeeper as soon as possible to ascertain if the colonies they are counting on will be available,” she said.

“However, beekeepers overwintering in the north may not know the status of their colonies until they are able to make early spring inspections,” she said. “This should occur in late February or early March, but is dependent on weather conditions.”

Detailed, up-to-date reports on CCD can be found on the Mid-Atlantic Apiculture Research and Extension Consortium Web site, http://maarec.org. There, beekeepers can also find a confidential survey.

Jerry Bromenshank of the University of Montana and Bee Alert Technology said it is vital that beekeepers send information to scientists, regardless of how well or poorly their bee colonies are faring.

David Hackenberg, a beekeeper from Lewisburg, Pa., who keeps his bees near Dade City, Fla., during the winter, said he has less than 1,000 living colonies left out of 2,900.

“The bees just disappeared,” he said. “They just left.”

In one location where he had 400 hives, he found 46 contained bees. The rest were empty boxes. He said some beekeepers have reported losses of more than 85 percent of their hives, but others have had no problem whatsoever.

Oren Best, a beekeeper from Sunfield, Mich., who overwinters his 1,500 hives of bees in Florida and Georgia, said his bees look very nice.

The warm weather in the Southeast allowed the bees to work right through the winter collecting pollen, he said. His normal procedure is to make splits in his Southern bee yards in winter, putting new queens in all the boxes and increasing his number of hives from about 1,500 to 2,500.

In some years, he said, bees will overwinter well and there may be a dozen frames of bees in each hive when he makes the splits. In weak years, he may have to merge hives to have eight frames per hive.

This year, he said, hives were strong – strong enough that he feared hives might swarm.

In the north, the warm weather as the new year started encouraged queens to lay eggs and expand the brood. Cold weather followed. Worker bees would have to work hard to keep their brood warm, which means using up honey stores, he said. He expects beekeepers who keep bees in the north during winter will have to “feed, feed, feed” this spring.

Best said that “disappearing bees” is a common enough problem when hives are under stress. Stressed bees will desert the hive and either seek refuge in other hives or go off by themselves and die. They do not die in the hives.

Hackenburg said the deserted hives contained honey stores and had not been robbed or attacked by other insects.

Aaron Fisher at Fisher Bee Farm in Lewistown, Pa., who also keeps his bees near Dade City, Fla., for the winter, said he had a good winter. The good pollen flow kept hives growing and they were “strong – maybe too strong.” Hives that might average eight frames of bees had 12 to 15, presenting a clear threat of swarming.

With nearly 7,500 hives, the family business hires about 10 workers to move bees to California in February and then to the fields of vine crops in Michigan and Ohio and the wild blueberry fields of Maine in early summer. Best moved his bees into south Florida for citrus pollination late this winter, taking fewer bees than usual on the long trip to California. He focuses on Michigan apples and blueberries later in the spring.

Until this new syndrome, varroa mites had been the chief culprit behind winter hive losses, Fisher said.

While neither Best nor Fisher were struck by colony collapse disorder, they’re concerned about having one more thing to worry about in an industry where disease and mites have already made beekeeping more difficult than it used to be.