Jeff Pettis on the continuing mystery of honeybees’ decline

Honeybees in the U.S. are still dying at an alarming rate. The story came to light four years ago, and it’s still true, according to Dr. Jeff Pettis, head of the U.S. Department of Agriculture’s Bee Research Laboratory in Maryland. He said figures released in spring 2010 show that, during the winter of 2010, the U.S. lost 34%, or just over a third of its managed honeybee colonies.

Jeff Pettis: What’s unusual is that they’re dying in such high numbers and so rapidly, so it’s just this dramatic depopulation.

At first, scientists thought a new strain of disease might be responsible. Right now, he said, that doesn’t appear to be the case.

Jeff Pettis: These bees have multiple viruses. They have multiple bacterial infections. And it’s the cumulative effect of all these that’s killing them.

Pettis explained that, like humans, bees are more susceptible to illness when they’re stressed.

Jeff Pettis: We ask a lot of them. We move them from crop to crop to pollinate and to feed on things that are not their ideal diet.

He added that low-level pesticide exposure also weakens bees immune systems. Armed with this knowledge, said Pettis, bee experts are increasingly focused on boosting bees’ general health to prevent population crashes. He underscored that this effort is not for the sake of bees, alone.

Jeff Pettis: About a third of our diet comes from things that are pollinated by insects. Often that’s the honeybee, in agriculture. That third is all the fruits nuts and vegetables that really enrich our diet.

Pettis said the trend of honeybees’ decline has been recorded by the USDA and the Apiary Inspectors of America for the past four years.

The USDA released its honeybee statistics in April of 2010. Dr. Pettis and his colleagues are still combing through to figure out more about what’s ailing the bees. He clarified that bees – while dying in large numbers in the winter months – can sometimes make up their population loss in the summer months. But, he told EarthSky, this is not done by entirely natural means. Beekeepers have to split a hive in half, and introduce a new queen. In other words, bees are still very much ailing and human intervention is needed to keep their numbers strong.

Jeff Pettis: The beekeeper may see a real strong colony one week, and then three weeks later they’re asking, “What happened?”

He said the mystery of honeybees’ decline is putting many beekeepers out of business, with consequences for agriculture. He mentioned particular crops like apples and almonds, which require pollination by bees. And he added that honeybees in the U.S. are not the only pollinators at risk.

Jeff Pettis: I and a number of other people around the world are working on pollinator health. It’s not just honeybees that are at risk. It’s what we call the 4 “b”s – birds, bats, bees and butterflies.

He said that people can get information online about what plants are useful in their particular geographical region for attracting bees, or pollinators, in general.

Special thanks to apiarist Dennis van Engelsdorp for his contribution to this article.