The number of honey bee colonies in the United States experienced an 8 percent decline in 2015, according to a recently released study from the U.S. Department of Agriculture.

The Honey Bee Colony Loss survey, which was given to more than 20,000 honey beekeepers, gathered statistics on the  number of colonies, colonies lost, colonies added, and colonies affected by certain stressors, like Varrao mites. The survey was developed as part of the "National Strategy to Promote the Health of Honey Bees and Other Pollinators," which has a goal of reducing honey bee colony losses during winter months to no more than 15 percent within 10 years. The survey is also a tool that will help the USDA identify a strong baseline of information about honey bee losses and will help guide honey bee management decisions in the United States.  

"Pollinators are essential to the production of food, and in the United States, honey bees pollinate an estimated $15 billion of crops each year, ranging from almonds to zucchinis," said Dr. Ann Bartuska, the USDA deputy under secretary for research, education and economics. "This new data will add to USDA's robust scientific body of knowledge on the inventory, movement and death loss of honeybees in the United States."

The National Agriculture Statistics Service surveyed 3,300 beekeeping operations with five or more colonies on a quarterly basis, following their operations throughout the year. In addition, NASS surveyed a sample of 20,000 beekeepers who have less than five colonies annually.

According to the survey, there were 2.59 million or 8 percent fewer honey bee colonies on Jan. 1, 2016 than the 2.82 million present a year earlier on Jan. 1, 2015 for operations with five or more colonies. The new quarterly data shows researchers the quarters that experience higher levels of colony loss and quarters that were more successful in renovating colonies. For example, colony loss was at its highest level country wide during the January to March quarter, when it hit 18 percent, and at the lowest level in the April to June quarter when it fell to 12 percent. The April to June quarter also had the highest number of renovated colonies across the country with 692,850 colonies renovated for 24 percent. Renovated colonies are those that were requeened or received new honey bees.

Honey beekeepers with five or more colonies reported Varroa mites as the leading stressor affecting colonies. They also reported more colonies with symptoms of Colony Collapse Disorder lost in the first quarter of 2016 with 113,930 than the 92,250 lost in the same quarter in 2015.

California has the largest population of honey bee colonies in the country, with the total number of colonies ranging quarter to quarter, from 730,000 at the lowest to 1.4 million at the highest. The majority of colonies lost in California last year were caused by Varroa mites, according to the survey.

“Varroa mites are native to Asia and the honey bees we use here are native to Europe, so the bees don’t know how to handle them on their own and need our help,” said Carlen Jupe, the secretary/treasurer for the California State Beekeepers Association.

The Varroa mites leave honey bees exposed and weak to diseases that normally they would be able to withstand, Jupe explained. It is one of the primary concerns expressed by the association’s members when it comes to health of the honey bees.

The survey correlates to other information the USDA and its partners have been collecting for years. For example, in March NASS released its annual report on honey production and prices for 2015. This report, which is used by the USDA, producers, economists, agribusiness and others, found that U.S. honey production in 2015 from producers with five or more colonies totaled 157 million pounds, down 12 percent from 2014. There were 2.66 million colonies from which honey was harvested in 2015, down 3 percent from 2014. Honey prices were 209.0 cents per pound, down 4 percent from a record high of 217.3 cents per pound in 2014.

The USDA's Research, Education and Economics mission also is undertaking several research projects to help the overall health of honey bees, including:

- The National Institute of Food and Agriculture is currently seeking applications for a total of $16.8 million in grant funding for research projects with an emphasis on pollinator health;

- The Agricultural Research Service (ARS) is organizing a national bee genebank as part of the agency's response to ongoing problems facing the country's beekeepers. The genebank, which will be located in Fort Collins, Colorado, will help preserve the genetic diversity of honey bees, especially for traits such as resistance to pests or diseases and pollination efficiency;

- ARS has launched a research project aimed at determining the effects of seasonal pollens on brood rearing, on bees' immune response to pathogen stress, and on whether geographic location influences such effects;

- ARS has launched a study to determine whether hyperspectral imaging can be used as a non-invasive method of monitoring bee colony health; and

- ARS has launched a project to determine colony survival, population size, cost and the return on investment of two overwintering strategies for controlling Varroa mites.