HONEY BEE DIE-OFF ALARMS BEEKEEPERS, CROP GROWERS AND RESEARCHERS

During 2006, an alarming number of honey bee colonies began to die across the continental United States. Subsequent investigations suggest these outbreaks of unexplained colony collapse were experienced by beekeepers for at least the last two years.  Reports of similar die offs are documented in beekeeping literature, with outbreaks possibly occurring as long ago as 1896.   The current phenomenon, without a recognizable underlying cause, has been tentatively termed “Colony Collapse Disorder” (CCD), and threatens the pollination industry and production of commercial honey in the United States.

To better understand the cause(s) of this disease and with the hope of eventually identifying strategies to prevent further losses, a group of researchers, extension agents, and regulatory officials was formed.  This group represents a diverse number of institutions including Bee Alert Technology, Inc. (a bee technology transfer company affiliated with the University of Montana), The Pennsylvania State University, the USDA/ARS, the Florida Department of Agriculture, and the Pennsylvania Department of Agriculture. 

Broadly this group has identified its mandate as: “Exploring the cause or causes of honey bee colony collapse and finding appropriate strategies to reduce colony loss in the future”. 

Penn State's College of Agricultural Sciences UNIVERSITY PARK, Pa. -- An alarming die-off of honey bees has beekeepers fighting for commercial survival and crop growers wondering whether bees will be available to pollinate their crops this spring and summer.

Researchers are scrambling to find answers to what's causing an affliction recently named Colony Collapse Disorder, which has decimated commercial beekeeping operations in Pennsylvania and across the country.

"During the last three months of 2006, we began to receive reports from commercial beekeepers of an alarming number of honey bee colonies dying in the eastern United States," says Maryann Frazier, apiculture extension associate in Penn State's College of Agricultural Sciences. "Since the beginning of the year, beekeepers from all over the country have been reporting unprecedented losses.

"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," she says. "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 working group of university faculty researchers, state regulatory officials, cooperative extension educators and industry representatives is working to identify the cause or causes of Colony Collapse Disorder and to develop management strategies and recommendations for beekeepers. Participating organizations include Penn State, the U.S. Department of Agriculture, the agriculture departments in Pennsylvania and Florida, and Bee Alert Technology Inc., 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," says 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 one disease being identified as the culprit, vanEngelsdorp explains. Ongoing 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 been quick to respond to the crisis. The National Honey Board has 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.

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

"For instance, the state's $45 million apple crop -- the fourth largest in the country -- is completely dependent on insects for pollination, and 90 percent of that pollination comes from honey bees," Frazier says. "So the value of honey bee pollination to apples is about $40 million."

In total, honey bee pollination contributes about $55 million to the value of crops in the state. Besides apples, crops that depend at least in part on honey bee pollination include peaches, soybeans, pears, pumpkins, cucumbers, cherries, raspberries, blackberries and strawberries.

Frazier says to cope with a potential shortage of pollination services, growers should plan well ahead. "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 advises. "If growers do not have an existing arrangement with a beekeeper but are counting on the availability of honey bees in spring, they should not delay but make contact with a beekeeper and arrange for pollination services now.

"However, beekeepers overwintering in the north many not know the status of their colonies until they are able to make early spring inspections," she adds. "This should occur in late February or early March but is dependent on weather conditions. Regardless, there is little doubt that honey bees are going to be in short supply this spring and possibly into the summer."

A detailed, up-to-date report on Colony Collapse Disorder can be found on the Mid-Atlantic Apiculture Research and Extension Consortium Web site at http://maarec.org.

Pollination Background

Many valuable crops benefit from insect pollination; the transfer of pollen from the male parts of a flower to the female part of a flower. Cross-pollination is the transfer of pollen among different plants or varieties of the same species. This process increases fruit yield and, often, the size of the fruit. Honey bees are important pollinators because they can be managed and easily moved to crop sites. In the United States, the added value to agriculture from honey bee pollination is over $14 billion annually, and many beekeepers earn extra income from renting colonies for pollination. In Georgia, bee hives are rented to pollinate apples, blueberries, cucumbers and watermelons. Professional recommendations vary for the number of hives needed for good pollination, but for these crops 1-2 colonies per acre is commonly used. If the pollen is compatible, fertilization of the ovule and seed formation occur. Generally, more seeds develop when large numbers of pollen grains are transferred. Seeds, in turn, stimulate surrounding ovary tissue to develop so that, for example, an apple with many seeds will be larger than one with fewer seeds. In this way, good pollination improves both fruit yield and size.

Many insects visit flowers to collect pollen and nectar as food. As they forage, these insects spread pollen grains among flowers, accomplishing pollination. Many flowers offer sugary liquid nectar as an added enticement for these pollinating insects. Among insect pollinators, bees are especially efficient because they eat pollen and nectar exclusively, visit many flowers of the same species during a single trip, and have hairy bodies which easily pick up pollen grains.

There are over 3000 species of bees in North America. Most of these are solitary bees, but a well-known minority are social, that is, they live together in colonies and cooperate in colony tasks. Both solitary and social species are important in crop pollination, but the social species - namely honey bees and bumble bees - are more easily managed.

Compared to honey bees, some wild bees pollinate certain crops more efficiently because of unique and desirable behaviors. For example, Southeastern blueberry bees buzz-pollinate blossoms by shaking pollen from the flower with high frequency muscle vibrations; for blueberry, this greatly improves pollination efficiency.

In many parts of the country, fruit and vegetable growers are concerned about declining numbers of wild bees. Human activities destroy bee habitat and forage. Generally, growers are receiving less "free" pollination from wild bees and increasingly they must make up for this by renting managed honey bee hives during bloom periods.