US Honeybees Suffer, Numbers Drop More Than 40 Percent
US honeybee populations continue to suffer - the reason for which still eludes scientists - as new research has revealed that their numbers have dropped more than 40 percent during the year spanning April 2014 to April 2015.
That's surprising, considering that the decline of our world pollinators - also including butterflies - has been all anyone in the animal world can talk about - even recruiting the White House and garden retailers like Lowe's to help.
While winter loss rates improved slightly compared to last year, summer losses - and consequently, total annual losses - were more severe. Commercial beekeepers were hit particularly hard by the high rate of summer losses, which outstripped winter losses for the first time in five years, fueling concerns over the long-term trend of poor health in honeybee colonies.
In past talks, the focus has been on Colony Collapse Disorder (CCD) - a mysterious behavior that leads to the mass death of entire honeybee colonies during winter months. However, it seems that survival through the summer months can no longer be ignored.
"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," Dennis vanEngelsdorp, an assistant professor of entomology at the University of Maryland, and project director for the Bee Informed Partnership, said in a press release. "But we now know that summer loss rates are significant too. This is especially so for commercial beekeepers, who are now losing more colonies in the summertime compared to the winter. Years ago, this was unheard of."
The Bee Informed Partnership, together with the Apiary Inspectors of America, each year conducts a survey asking both commercial and small-scale beekeepers to track the health and survival rates of their honeybee colonies. During the 2014-15 year, beekeepers who responded to the survey lost a total of 42.1 percent of their colonies during that time. Winter loss rates decreased from 23.7 percent last year to 23.1 percent this year, while summer loss rates increased from 19.8 percent to 27.4 percent. (Scroll to read on...)
For backyard beekeepers, the culprit was clear: the varroa mite, a lethal parasite that can easily spread between colonies. However, among commercial beekeepers, the causes of the majority of losses are not as clear.
"Backyard beekeepers were more prone to heavy mite infestations, but we believe that is because a majority of them are not taking appropriate steps to control mites," vanEngelsdorp explained. "Commercial keepers were particularly prone to summer losses. But they typically take more aggressive action against varroa mites, so there must be other factors at play."
As part of a larger research effort to understand why honeybee colonies are in such poor health, everything from pathogens, pesticides, climate change, and even diet have been blamed. But scientists have yet to hit the nail on the head, and so US honeybee populations continue to suffer.
What's more, colony losses aren't just bad for the bees, but for the beekeepers that depend on them as well. This massive decline in honeybees can lead to shortages among the many crops that depend them as pollinators. Some crops, such as almonds, depend entirely on honeybees for pollination. According to estimates, the total economic value of honeybee pollination services range from between $10 billion and $15 billion annually.
"The winter loss numbers are more hopeful especially combined with the fact that we have not seen much sign of Colony Collapse Disorder (CCD) for several years, but such high colony losses in the summer and year-round remain very troubling," said Jeffery Pettis, a senior entomologist at the US Department of Agriculture, and a co-coordinator of the survey. "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."
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