Summer Bee Loss Concerning, Remains Unknown

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summer bee loss
Researchers started tracking annual bee loss five years ago, instead of just winter mortality. Summer bee loss totals over the last three years are surprising the industry.

When honey bees started to decline, a lot of research went into why bees were dying off rapidly in the winter. “When we first started monitoring colony losses 10 years ago, we only did winter months, and by winter we mean between October and April,” University of Maryland Assistant Professor Dennis vanEngelsdorp said. “We did this because we knew that colonies traditionally die in the winter. It’s cold, there’s less food, and just like us, bees are more likely to be sick in the winter.”

At this year’s Almond Conference, vanEngelsdorp presented bee research he’s been working on. He said researchers started tracking another number five years ago. They tallied the annual total bee loss, which gave the summer bee loss numbers when the winter numbers were subtracted.

The researchers weren’t surprised by the findings from the first couple of years, but summer bee loss numbers from the last few years have surprised everyone. “The first two years it did exactly what we expected. It was only a fraction of what the loss was over the winter,” vanEngelsdorp said. “However, during the last three years, colony loss has been more or the the same as our winter loss, which is a huge surprise.”

The continued loss is concerning. According to vanEngelsdorp, this means bee keepers are sustaining a consistent loss of their colonies all year round. “This really costs the bottom line. Not only do you lose that colony for productivity, but also to replace those loses, what bee keepers need to do is take a live colony, split it in half, buy a queen, insert it into the other colony, and you’ve made two splits,” he said. “That replaced colony costs a lot of money in terms of labor, and you have to put a lot of inputs in both of those colonies to get them back up to strength.”

Current research looking at colony loss has been focused toward the winter months so much that vanEngelsdorp said the research community needs to rethink its approach to address summer loss.