Honeybees, pesticides, and colony collapse

“Aren’t honeybees in some sort of trouble?” This is the most common question I get from people when they hear I’ve been attempting to keep bees.

The answer is yes, and defining what is causing so many colonies to fail is one of science’s big mysteries right now. Since its discovery in 2006, Colony Collapse Disorder has been linked to a number of causes, from cell phone tower interference to some mysterious yet-unnamed bacteria.

Last year, an experienced commercial beekeeper told me he was sure of the culprit- a class of pesticides called neonicotinoids. Crop seeds are treated with these chemicals, which are drawn up into all parts of the plant tissue. The neonicotinoid-embedded plants kill leaf-chewing insects that feed on them, but it was thought that the trace amounts of chemicals that made it into the plant’s nectar were far too low to harm pollinating insects.

But the beekeeper I spoke with said that he had lost ninety percent of the hives he had located in an agricultural part of Berks County, where neonicotinoids are used on virtually every field crop. This was in contrast to the 90% survival rate of the hives he was keeping in Philadelphia, where presumably these chemicals are used much less often.

And now it seems that science is backing up his theory. Two European studies link these chemicals to impairment of bees’ memory and ability to learn. Last month, the magazine Science published an article on the results.

The real culprit for Colony Collapse is still a matter of controversy, and it’s not surprising that Bayer, the company that produces the chemical, vigorously disagrees with the findings of the bee studies. No matter what, this situation speaks to the unintended consequences that have regularly occurred because of the human desire to manipulate nature (although there have been some great things that result from this impulse as well.)

And it also speaks to the mysterious quality of honeybees. They are the most studied insects, and for as much as we know about them there is so much more that we still don’t understand. The last time I wrote about bees, I was sadly contemplating the fact that my punky-looking hive didn’t seem like it would make it through the winter.

But I was wrong. Now the hive looks great. Did the bees know more than I did- that we would have a mild winter, and that it wasn’t necessary to support a large population in order to make it through to an early spring?

That mystery, one of many here, remains.