Key to honeybee loss? Mite's stink, MSU expert suggests

A Michigan State University researcher may have found the key to the infiltration and destruction of the nation's honeybee colonies.

It has to do with the invader's stink. Specifically, the now-infamous Varroa mite uses a chemical camouflage to match its body odor — or something close to it — to its honeybee host. It even fine-tunes the formula to mimic the subtle differences of smell among bees in individual colonies.

"Honeybees rely a lot of on chemical communications," said Zachary Huang, an MSU entomologist and lead author on a paper in the academic journal, Biology Letters, explaining the mite's ability to deceive.

Huang has been studying honeybees for about 30 years. They live in surprisingly complex, sophisticated colonies, he said.

Consider a honeybee that has been gathering nectar. Trying to enter the wrong hive can be deadly as she tries to get by the guard bees who will sniff out intruders.

"They can be bribed with a large load of nectar," Huang added. "If she comes with nothing, she probably will die."

And the Varroa mite?

About the size of a pinhead, the mite is believed to be a main reason for the collapse of the nation's honeybee population in recent years. But just how it infiltrated such socially complex, organized colonies was unclear. It was first known to use the Asian honeybee as host.

At Michigan State, researchers analyzed the chemical cloak of the mites, finding them surprisingly similar to bees.

In other words, the mite "tries to make itself smell like a bee," Huang said.

And moving from one colony to another means simply waiting for the opportunity. When bee colonies are dying — sometimes because of the mites — intruder bees steal the honey.

The stealthy mite hitches a ride on the intruder bee, entering a new colony undetected and settling into a hexagonal cell of a larvae. It then feeds on hemolymph, or bee blood, much like a tick attaches itself to a human or other mammal.

Just as devastating for the hive, the mites brings with it viruses, said Mike Risk, a long-time beekeeper and owner of Risk's Apiary and Honey House northeast of East Lansing.

"We're not only dealing with the blood-sucking mite, it's the viruses that it introduces," said Risk, whose bees produce more than 6,000 pounds of honey each year.

Huang's research could be part of a strategy of fighting the mite without harming the bee, said Risk, who also raises queen bees, which he hopes one day may be more resistant to the mites.

"The more we know, the better we're all going to be," he said.

Contact Robin Erb : 313-222-2708 or rerb@freepress.com . Follow her on Twitter @Freephealth.