Apiculture and the environmental impact of bees

PHOTO BY SCOTT BAUER.
The deadly parasitic varroa mite on the back of this honey bee is one of many insect pests that sugar esters may be useful in controlling. Sucrose octanoate, a sugar ester, can kill the mite without harming the bee.

Bees pollinate one-third of the world’s plants, thus enabling sexual reproduction of many flowering plants. Without bees, most ecosystems would be drastically different.

Apis mellifera, the European honeybee, serves an essential function within agriculture and ecosystem maintenance. The current decline in the honeybee population poses a threat to the future of fruit, nut and vegetable production throughout the country.

While honeybees get the most publicity, there are almost 4,000 other bee species native to North America. Each ecosystem within the United States has its own native species. In Maine, there are over 70 species of native bees associated with lowbush blueberry alone; in Wisconsin, 500 native species exist. Bees feed on nectar and pollen, which comes exclusively from flowers. Different types of bees require different types of nesting sites. The three basic types are underground, inside wood cavities and in hives.

Because of their social nature, bumblebees and honeybees live in colonies, which they can build in various locations, such as compost piles or abandoned rodent nests. They will also nest in man-made hives.

Basics, benefits and challenges

Honeybee beekeepers operate at three basic levels: hobbyist/family farmer, sideliner and commercial. One of the biggest challenges for beekeepers of all sizes is to keep their colonies healthy. Proper nutrition; disease and pest prevention; and maintaining a low-stress environment for their bees are issues that all beekeepers face.

Sideliner and commercial beekeepers who rent bees to farms in need of pollinators also must consider the safest way to transport their bees. Concerns differ for the sideliner, who is most likely traveling less than 50 or 100 miles, and the commercial beekeeper, who may log thousands of miles each year bringing bees on multiple cross-country trips. Commercial keepers regularly lose 10 percent of their queens in transit, and often find their bees stressed from traveling 1,000 miles or more in conditions such as desert heat.

Another challenge to bees and beekeepers is climate change. For example, New England’s extremely rainy summer of 2009 affected apiaries badly in numerous ways. Frequent downpours made serving growers in need of pollination services difficult for apiaries. Dan Conlon, of Warm Colors Apiary in South Deerfield, Mass., recalls, “In some cases, farmers’ fields were flooded so badly, I couldn’t get my truck onto the property to deliver hives.”

The unrelenting wet weather also watered down the pollen, necessitating that bees work harder, making several trips to get the same amount of pollen they would in a drier year. Such conditions not only reduce honey yields, they also take a toll on the bees, bringing them to the brink of physical exhaustion and starvation.

In Conlon’s opinion, these issues contribute to the risky nature of beekeeping. In addition to keeping hives for honey production, Conlon also serves the farming community in Massachusetts’ Connecticut River Valley by teaching new beekeepers the tried and true ways of running a successful apiary, and as a sideliner, by renting his bees out as pollinators. A current focus of the apiary industry is on reducing the risk factors in the business, and Conlon says beekeeping has grown more challenging in the last 30 years. “I’ve been doing this long enough to remember what it was like before everything went wrong,” he says.

Mites, diseases and CCD

What went wrong was the introduction of two mites, varroa and tracheal mite (Acarapis woodi), into the European honeybee colonies of the United States. U.S. government quarantine imposed on bees in the 1920s left only two means for bees to enter from other countries: smuggling or natural migration. Varroa, an Asian mite that is visible on the back of the honey bee, attacks bees in the pupal stage and creates deformities and ultimately kills immature bees. Scientists also believe varroa mite infestation compromises the bee’s immune defense system against several viruses.

Although no one is quite sure how varroa entered the United States, some people suspect that the mite entered on an Asian variety of queen bee that was smuggled into the country in the 1980s.

The tracheal mite’s entry into the United States is also mysterious, but many believe it was accidentally introduced from Europe in the same year that varroa entered the U.S. Tracheal mites infest a bee’s breathing tubes until the bee suffocates. While a varroa infestation is clearly visible on a bee, a tracheal mite infestation can only be diagnosed post-mortem in a forensic investigation.

Today, several bacterial, fungal and viral pathogens have joined these two parasitic mites in stressing honeybee colonies across the country. Significant exposure to multiple insecticides may also be weakening colonies. Weak colonies are more at risk for colony collapse disorder (CCD), the most notable challenge in the beekeeping industry to date. Although theories abound as to the cause, there is still no conclusive evidence as to the origin of the problem. However, over the past several years, changes in Maine’s honey-bee colonies have reflected the increasing parasitism rates of the varroa mite and the microsporidian fungus, Nosema ceranae, and an increase in the death rate of colonies.

PHOTO COURTESY OF UNIVERSITY OF MAINE.
Frank Drummond, professor of insect ecology at the University of Maine, working with bees during research.

One hot topic of conversation is the potential relationship between the decline in the honeybee population and other insects. Frank Drummond, professor of insect ecology at the University of Maine, says there is no solid evidence to link the declines in native butterflies, beetles and bees to the problems witnessed with honeybees. “Many are hypothesizing that climate change, habitat fragmentation, ubiquitous insecticide exposure and spread of pathogens jumping between host species are creating community declines which in some areas of the globe are becoming very noticeable,” he explains.

Current research

Research has been ongoing across the country, and many creative alliances have formed across professional boundaries. Penn State has become the center for evaluating the presence of toxins in bees and effect of toxins on bees. Labs from other schools have joined in their work, including the University of Illinois and Stanford Medical School, which offered use of the diagnostic tools generally reserved for human health assessments on bees. The U.S. Military joined the team to share its extensive information on viruses.

Drummond has kept honeybees for 40 years and has studied native bees in blueberry for 15 years and honeybees in blueberry for the past five years. The professor conducts his research on bees throughout the blueberry fields and wetlands of Maine, in Acadia National Park and in Australia. For the past two years, Drummond has researched colony collapse disorder as part of a national research team representing scientists from Georgia, Tennessee, Minnesota, Michigan, Massachusetts, Connecticut, Pennsylvania, California, Washington, Florida, Texas, Indiana and New York. Drummond is also part of a seven-state research project to identify the causes of CCD.

At 30 stationary hives in each of the research project’s seven states, scientists measure hive strength, insecticide exposure and honeybee diseases throughout the year. This information, combined with an examination of the impact of insecticides on the health of honey- bees and native bees, enables Drummond and his colleagues to search for solutions to colony collapse disorder of honeybees. Utilizing modern molecular and computer modeling methods, Drummond and his graduate students study and assess disease levels in bees. They also examine and assess the efficacy of other species of bees (in particular, bumblebees and leaf cutting bees) as pollinators.

The importance of such research for growers and farmers cannot be overstated. Much of the effort at the University of Maine is in examining the exposure and impact of insecticides (currently used for insect pest management) on honeybees. One of Drummond’s research programs, run by research assistant Judith Collins, aims at finding insecticides that are less toxic to bees, as well as wildlife and people.

“Currently, we have natural products and/or organically approved controls for all but one insect. We are tireless in our pursuit,” says the professor.

“Without bees there is no pollination and thus no fruit,” he emphasizes. “I have been looking at not just honeybee health, but also the health of other commercial bees such as the Impatient Bumblebee and also the health of the native bee fauna … it is hoped that by researching multiple solutions, the relevance of the research will be broad.”

PHOTO BY STEPHEN AUSMUS.
Scientists in the ARS Beneficial Insects Research Unit at Weslaco, Texas, have found that a strain of the fungus Metarhizium anisopliae is deadly to varroa mites, such as this one on an adult worker honeybee’s thorax.

Research in pollination of lowbush blueberry and potential causes of colony collapse disorder (CCD) supports all production systems, including organic, low-input, and capital-intensive high-input systems. The fact is, no matter what the philosophical or economic model, bees are absolutely necessary for blueberry production.

Maintaining North America’s honeybee industry for pollination of crops and native plants is paramount to the health of the agro-economy. “We are facing a crossroad,” says Drummond. “If we have a collapse of both managed and native bees … we will not have affordable access to most fruits, nuts and vegetables.”

Drummond hopes to enhance the abundance and diversity of native pollinator species in Maine and to develop viable economic alternatives to the honeybee, such as the commercial bumblebee. Alternatives will enable farmers of different scales and type of operations to tailor their own pollination strategy.

Do you want to keep bees?

Without question, someone must help bees proliferate throughout the United States. Is it you? David Tarpy, associate professor and extension apiculturist at North Carolina State University, says in light of the threat of CCD, not all farmers can or should keep their own bees.

“It depends on the crop and size of the farm,” he explains. “Keeping a large number of colonies healthy and productive is a full-time job in itself, so often it is better to contract pollination services with beekeepers.”

Tarpy says smaller or part-time farmers with bee-dependent crops can help improve their yields by keeping their own bees, and he encourages anyone interested in part-time apiculture to find a local beekeeping association or experienced beekeeper to serve as a mentor. “It can be difficult to become a beekeeper in a vacuum, so working with others greatly facilitates things.”

Keeping Bees Healthy
Beekeepers can reduce colony stress by controlling mites and bacterial infections using products labeled for such purposes. Researchers warn that using homemade mixtures can have adverse effects. Keeping colonies well fed with a protein supplement during times of stress is also essential in preventing disease.
 

Pollination Strategies
Depending on capital inputs and productivity goals, options include the following:
• Native bee conservation
• Combining commercial honeybees with bumblebees and native bees
Drummond hopes that above all else, a farmer’s pollination strategy will focus on creating and/or maintaining an ecologically sustainable, functioning agro-ecosystem.

 

Interested in Beekeeping?

The MAAREC offers information from basic bee biology to more advanced information about viruses, IPM and other essentials, including the following PDF:

http://www.sripmc.org/IPMelements/MidAtlanticHoneybeeElements.pdf

Farmers interested in increasing native bee pollination on their lands can learn more by downloading this PDF:

http://maarec.cas.psu.edu/pdfs/Will iamsWinfree_NativeBees2009%201.pdf

While this publication is targeted to farmers in New Jersey and Pennsylvania, much of the information applies to farmers throughout the country.

Additional information about bees is available at www.xerces.org.

The author is a freelance writer based in Massachusetts and a monthly contributor to Growing.