Nearly four of every 10 colonies of honey bees die annually, a markedly high rate, according to surveys of beekeepers designed to gauge the welfare of a prominent species for plant pollination. Losses have averaged 37 percent over the past five years.
The rate hit 42 percent in 2014-15, the second time in three years that losses exceeded 40 percent. And it was the first time that summer losses were larger than losses in winter, presumed to be the hardest season for survival, said the USDA, which joined with Apiary Inspectors of America and Bee Informed Partnership in the surveys.
Researchers have focused on honey bee health for nearly a decade, since the emergence of mysterious Colony Collapse Disorder in which adult bees abruptly desert a hive. Many flowering plants depend on pollinators such as bees, making them a key link in food production. Beekeepers collected an estimated $650 million for pollination services in 2012.
The chairman of a House Agriculture subcommittee criticized “activist groups” who want to limit the use of neonicotinoids, a class of insecticides that may be a factor in colony losses. Rep. Rodney Davis of Illinois said the critics leapfrogged other suspects to go after a useful tool for agriculture. “It is frustrating that efforts to innovate … are constantly under attack,” he said in a statement that also criticized EPA research into “neonics” and an Interior Department ban on use of the pesticides in U.S. wildlife refuges.
Scientists say colony losses are likely the result of interacting factors that include pests, such as the Varroa mite; pathogens; poor nutrition; exposure to pesticides; and bee genetics.
For years, beekeepers have reported winter losses that were well above economically affordable levels. USDA chief economist Robert Johansson said “annual losses of colonies remains high, making it difficult to meet rising demand for pollination services.”
There were 2.7 million colonies in 2014, producing an average of 65 pound of honey each.
Beekeepers reported losses of 27.4 percent of colonies during last April-October, the summer period, compared to winter losses of 23.1 percent between October 2014 and April 1, 2015. “Importantly, commercial beekeepers appear to consistently lose greater numbers of colonies over the summer months than over the winter months, whereas the opposite seems true for smaller-scale beekeepers,” said Bee Informed Partnership.
“We traditionally thought of winter losses as a more important indicator of health, because surviving the cold winter months is a crucial test for any bee colony,” said Dennis vanEngelsdorp of the University of Maryland and project director of the Partnership. “But we now know that summer loss rates are significant, too.” USDA scientist Jeff Pettis said, “If beekeepers are going to meet the growing demand for pollination services, researchers need to find better answers to the host of stresses that lead to both winter and summer colony losses.”
Data from Bee Informed Partnership said colony losses were 36 percent in 2010-11, 29 percent in 2011-12, 45 percent in 2012-13, 34 percent in 2013-14 and 42 percent in the past year.
A month ago, EPA announced a moratorium on approval of new outdoor uses for neonics until it completed a review of their impact on bee health. “We plan to announce in the near future … a further acceleration of this re-evaluation,” said assistant EPA administrator James Jones during a hearing by Davis’ subcommittee. Jones said EPA is reviewing more than 40,000 comments on a study that concluded there was little or no increase in soybean yields when growers plant seeds coated with neonics.
The European Academies Science Advisory Council said on April 8 that “there is more and more evidence that widespread use of neonicotinoids has severe effects on a range of organisms that provide ecosystem services like pollination and natural pest control, as well as on biodiversity.” In a report, it said neonics made pest problems worse in some cases by eliminating natural predators of the crop pests. The European Union is to review this year a moratorium set in 2013 on use of neonics on crops that attract bees.
Neonic-coated seeds were used in at least one-third of U.S. soybean area and four-fifths of corn area, says a recent study by Penn State U.