State of the Planet

News from the Columbia Climate School

Mysterious Honeybee Deaths Remain Unsolved

According to a comprehensive federal report published by members of the National Honey Bee Health Stakeholder Conference Steering Committee, including The U.S. Department of Agriculture (USDA) and the U.S. Environmental Protection Agency (EPA), the collapse of American honeybee colonies stems from a complex slew of factors, including pathogens, pesticides, nutritional deficiencies, lack of genetic diversity, and bee hive management practice, rather than from one single cause. The bee crisis is far beyond an ecological niche concern; at stake, is more than $15 billion in U.S. crop production each year and global food security.

Since 2006, millions of bees have been dying in a phenomenon known as colony collapse disorder. There are now 2.5 million honeybee colonies in the United States, down from 6 million several decades ago. Photo Credit: Steve Evans
Since 2006, millions of bees have been dying in a phenomenon known as colony collapse disorder. There are now 2.5 million honeybee colonies in the United States, down from 6 million several decades ago. Photo Credit: Steve Evans

Key findings include:

Parasites and Disease Present Risks to Honey Bees:

The parasitic Varroa mite is recognized as the major factor underlying colony loss in the U.S. and other countries. There is widespread resistance to the chemicals beekeepers use to control mites within the hive. New virus species have been found in the U.S. and several of these have been associated with Colony Collapse Disorder (CCD).

Increased Genetic Diversity is Needed:

U.S. honeybee colonies need increased genetic diversity. Genetic variation improves bees thermoregulation (the ability to keep body temperature steady even if the surrounding environment is different), disease resistance and worker productivity. Honey bee breeding should emphasize traits such as hygienic behavior that confer improved resistance to Varroa mites and diseases (such as American foulbrood).

Poor Nutrition Among Honey Bee Colonies:

Nutrition has a major impact on individual bee and colony longevity. A nutrition-poor diet can make bees more susceptible to harm from disease and parasites. Bees need better forage and a variety of plants to support colony health. Federal and state partners should consider actions affecting land management to maximize available nutritional forage to promote and enhance good bee health and to protect bees by keeping them away from pesticide-treated fields.

There is a Need for Improved Collaboration and Information Sharing:

Best Management Practices associated with bees and pesticide use, exist, but are not widely or systematically followed by members of the crop-producing industry. There is a need for informed and coordinated communication between growers and beekeepers and effective collaboration between stakeholders on practices to protect bees from pesticides. Beekeepers emphasized the need for accurate and timely bee kill incident reporting, monitoring, and enforcement.

Additional Research is Needed to Determine Risks Presented by Pesticides:

The most pressing pesticide research questions relate to determining actual pesticide exposures and effects of pesticides to bees in the field and the potential for impacts on bee health and productivity of whole honey bee colonies.

The federal study emerges the same week that European officials decided to restrict the use of a class of pesticides known as that neonicotinoids, derived from nicotine, which have been linked to the massive decline in bee populations.

Still, officials involved in the U.S. analysis said that there was insufficient evidence to advocate for a ban on one specific group of pesticides because the costs of such a decision might outweigh the gains.


Given how important honeybees are to the food that we eat, it is alarming that we neither know why they are dying nor how to respond to the decline.

How important?

According to the U.S. Department of Agriculture, these mighty workers pollinate 80 percent of our flowering crops which constitute 1/3 of everything we eat. Losing them could affect not only the production of broccoli, apples, melons, squash, nuts, asparagus, strawberries, beans, blueberries, cucumbers and countless other dietary staples, but may also pose threats to the beef and dairy industries if alfalfa is not available for cows to feed on. Other ecosystem services that bees provide, such as medicinal therapy, might also be jeopardized if we are unable to save our buzzing friends.

Tell us your thoughts – what do you think about the decline in bees? How might we mitigate the problem?

Interested in learning more? Join EICES in class or online to examine contemporary domestic and international issues that require environmental policy and planning solutions, such as the decline in bee populations. Introduction to Environmental Policy is part of the Earth Institute’s Executive Education Certificate in Conservation and Environmental Sustainability. It is taught by Caleb McClennen, PhD, Director, Marine Conservation, Wildlife Conservation Society, on Tuesdays, May 14, 21, 28, June 4 (4 sessions, 6:10-8:40PM). Contact Desmond Beirne, Manager of Education Programs, at or 212-854-0149 for more information.

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Recent record-breaking heat waves have affected communities across the world. The Extreme Heat Workshop will bring together researchers and practitioners to advance the state of knowledge, identify community needs, and develop a framework for evaluating risks with a focus on climate justice. Register by June 15

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