The Riddle of the Bee Deaths: Solved at Last?

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Bees have had it hard for the past few years. Ever since 2006, entomologists and other scientists in the U.S., Europe and Asia have been trying to figure out what’s causing wholesale deaths of of once-healthy hives—an epidemic that’s wiped out from 20% to 60% of colonies in the affected areas. Now, according to a paper published in the online journal PLoS One, scientists at the University of Montana, Missoula and the U.S. Army Edgewood Chemical Biological Center in Maryland appear to have cracked the problem. Surprisingly, it’s the Department of Homeland Security (DHS) that may have provided the final piece to the puzzle.

The bee deaths—known as colony collapse disorder (CCD)—follow a very particular pattern. Hives that had been active and productive one week are suddenly all-but empty the next— devoid of life except for the abandoned queen and a few loyal workers. The rest of the community is nowhere to be seen and nor—inexplicably—are many of their bodies.

The few bee remains that have been found have allowed some entomological autopsies to be conducted and investigators elsewhere had already identified a fungus, known as Nosema apis, in the guts of the dead insects. That would seem to be the smoking gun, but the problem is, the fungus isn’t lethal—and indeed seems entirely harmless to bees.

Recently, Jerry Bromenshenk, of the University of Minnesota, who had been working for years with bees, teamed up with microbiologist Charles Wick and other scientists at Edgewood, in part because the investigators there had some post-9/11 equipment that seemed perfectly suited to the job. In order to protect both civilians and battlefield soldiers from the danger of biological weapons, the government developed new protein-sniffing software that can identify biological agents more effectively, even when what they are is a complete mystery. That’s no small thing since it’s always easier to detect a pathogen if you at least know if it’s a spore or a bacterium or a virus. If all you know is that it’s something biological and deadly you need a lot more computing muscle.

When the Army software, owned by DHS, was turned on the bee remains, it detected not only the fungus, but also a virus known as the invertebrate iridescent virus (IIV). Like the Nosema fungus, the IIV by itself does not seem to do bees any harm. It’s only when the two come together, the scientists now believe, that they somehow prove deadly.

It’s that “somehow” of course that the scientists must pin down next. The fact that the bees seem to fly off in all directions before they die has led Bromenshenk to theorize that their complex navigation system—the one that allows them to forage over hundreds of square acres, then return to the hive and lead other colony members back to a food source—may somehow be damaged. Bromenshenk also told the New York Times that some kind of pathogen-triggered bee “insanity” may be at work.

The good news for the bees—and the world’s farmers and consumers who rely on bee pollination to grow food crops—is that fixing the problem could be relatively easy. Since it takes the interaction of the fungus and the virus to trigger the dying, you have to knock only one of them out to stop it. Anti-fungal agents, which already exist, might be up to the job. Let’s hope they are. Bees may spoil the odd picnic, but without them to produce the food in the first place, there wouldn’t be a whole lot to eat.