University of Florida

Colony Collapse Disorder

Why Are Honey Bees Disappearing?

Through the years, U.S. beekeepers have faced obstacles to healthy bee management. Now a new problem—colony collapse disorder (CCD)—threatens honey bees.

What Is Colony Collapse Disorder?

Beekeepers have reported higher than normal colony losses since 2006. These high losses have been called colony collapse disorder.

Bee colonies affected by CCD can appear healthy, but then the adult bees disappear from the colonies.

The Mid-Atlantic Apiculture Research and Extension Consortium (MAAREC) is the current clearing house for CCD-based information produced by the CCD Working Group, which has defined the symptoms of CCD colonies as follows:

Collapsed Colonies

  • Contain no adult bees, with few to no dead bees around the colony
  • Contain capped brood
  • Contain food stores that are not robbed by neighboring bees or colony pests

Collapsing Colonies

  • Do not have enough bees to maintain colony brood
  • Have a workforce workforce that consists of younger adult bees
  • Contain a queen
  • Are reluctant to eat food provided by the beekeeper

What Causes CCD?

CCD may not be a new disorder. In past decades, colonies have died in connection with symptoms similar to those of CCD. These historic occurrences may not share a common cause with modern-day CCD, but they do share its symptoms.

The cause of CCD has not been determined and every realistic cause remains a possibility. The following list of causes does not place them in a particular order and is not comprehensive. This list may change based on new research.

For more detailed information about each possible cause, see the original publication, Colony Collapse Disorder (CCD) in Honey Bees.

  • Traditional bee pests and diseases.
    These are most likely not responsible for CCD because do not produce the symptoms, but they may intensify the problem.
  • Bee management.
    Management of hives varies among beekeepers, but poor management can make any colony problem worse.
  • Queen source.
    Queens affect genetic diversity and bee lineage. In the US, only a few breeder queens are used to produce queen bees (and therefore all US honey bees), which leads to poor genetic diversity.
  • Chemical use in bee colonies.
    Chemicals used to treat bee diseases and pests have been found to have sub-lethal effects even when used according to the label and management recommendations.
  • Chemical toxins in the environment.
    Bees can be exposed to toxins while foraging, drinking contaminated water, or by inhaling them directly.
  • Genetically modified crops.
    Many GMO seeds are dipped in systemic insecticides that later may appear in the plants' nectar and pollen.
  • Varroa mites and associated pathogens.
    Varroa mites remain the world's most destructive honey bee killer. The mites, the viruses they transmit, and the chemical treatment they require are considered possible causes of CCD.
  • Nutrition.
    Malnutrition causes stress to bees, possibly weakening their immune systems.
  • Undiscovered or new pests and diseases. Unidentified or recently introduced pests and pathogens are considered possible causes of CCD.

Many scientists believe that CCD is caused by a combination of the above factors. This combination effect makes CCD more difficult to study.

What Does CCD Mean for Us?

Most people recognize the importance of honey bees and associate them with honey production. However, honey production is of minor importance compared to bees' role in pollination.

Effects on Industry & Consumers

Beekeepers who keep bees for pollination load their colonies on trucks and move them around the country to pollinate crops.

Growers pay beekeepers to bring honey bees to their fields to ensure adequate pollination of their crops. In return, the growers benefit through higher crop production per acre, larger size and better product shape, and even enhanced product taste.

US agriculture depends on honey bee pollination. No one expects bees to disappear altogether, but if bees continue to die at the current rates, we may experience increased food prices and decreased food availability.

Signs of Environmental Problems

Honey bees are biological indicators, meaning that honey bee health reflects the general health of the environment. Bee losses are possibly a symptom of a much greater environmental problem.

Searching for Solutions

Beekeepers, governmental officials, and scientists from universities, industries, and the USDA have initiated a number of investigations into the possible causes of CCD.

It is safe to assume that most potential causes of CCD are being investigated. Many granting agencies have realized the importance of honey bees and have distributed research funds in an effort to find the cause and a cure.

What Can Beekeepers Do?

Although the causes of colony collapse disorder are not yet known, the following recommendations may provide beekeepers with some options:

  • Do not combine collapsing colonies with healthy ones.
  • If you find abandoned hive equipment, and the cause of bee death is suspicious, store the equipment so other bees cannot live in it. Do not reuse this equipment.
  • Use an integrated pest management (IPM) approach for varroa control in honey bee colonies. This will minimize bee exposure to potentially toxic chemicals.
  • Keep colonies strong by practicing best management practices.

For more detailed discussion of these tips, see the original publication, Colony Collapse Disorder (CCD) in Honey Bees. Contact your local Extension agent for more information about CCD, honey bees, or beekeeping in general.

Adapted and excerpted from:

J. Ellis, Colony Collapse Disorder (CCD) in Honey Bees (ENY-150), UF/IFAS Entomology and Nematology Department (rev. 07/2010).

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