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Minnesota researcher helps fight an invasion of mites

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Honeybees
A hive of honeybees at the University of Minnesota's St. Paul campus. University researchers are raising a strain of bees that can defend themselves from a pest called the varroa mite.
MPR Photo/Tim Post

A row of pastel-colored wooden boxes sits in atree-lined corner of the University of Minnesota's St. Paul campus.  It's on the edge of a farm field, far away from buildings and students.  That's because each of these boxes, and there are dozens of them, holds tens of thousands of honeybees. 

University of Minnesota entomology professor Marla Spivak is the beekeeper for this colony.  But Spivak is not interested in collecting honey. She's breeding a special strain of queen bees, and this is essentially her outdoor laboratory.    

Spivak has raised hundreds of queen bees over the summer, something she's done for the past several years. She's breeding  bees to help beekeepers deal with a particularly dangerous threat to their livelihood, the varroa mite.  

Varroa mite
The tiny varroa mite is responsible for killing millions of bee colonies in the U.S. in the past decade. The parasite attaches itself to bees and their larvae, sucks their blood, weakening or killing the insects.
MPR Photo/Tim Post

The tiny mite makes its way into a hive, attaches itself to a bee and sucks its blood, making them more susceptible to cold weather and disease.  And the parasites can even feast on bee larvae, decimating a hive. 

Spivak isn't sure how many bees have died because of the mite, but it's been a devastating invasion for beekeepers.

"It's really hard to get an accurate estimate of how many bee colonies have been lost.  But certainly since the introduction of the parasitic mites in the late 80s, millions of bee colonies have been lost in the United States," Spivak said.

Spivak's specialty bee is helping out with the problem.  The queens she's raising are called Minnesota Hygienic Bees.  The queens lay eggs and then all the offspring in the hive have the same hygienic behavior.  

"I'm not breeding a bee that can resist the mite, it's not that they don't ever get diseases or they don't ever get the mites, they do have these problems but they can defend themselves. And they do this through a behavior where they'll actually detect young bees that are sick or have mites on them and they throw them out of the nest," Spivak said.

Spivak raises the queens with this behavior and then gives them to a beekeeper in Texas who breeds more queens, which are then sold to beekeepers across the country.  One of them is Mark Sundberg.  

Marla Spivak and her bees
University of Minnesota researcher Marla Spivak is checking a bee hive at the University of Minnesota's St. Paul campus. She's raising a special strain called the Minnesota Hygenic Bee.
MPR Photo/Tim Post

"I still believe that Varroa mite is our number one problem, that's at the very top," Sundberg said.

Sundberg is a beekeeper in west central Minnesota.  He has about 6,000 bee colonies spread across three counties.  He usually has 7,000, but many of his bees died last winter because of the varroa mite. 

Regardless, Sundberg has a positive outlook.  He's replacing more and more of his queen bees every year with the Minnesota Hygienic line, and he's seeing results.  Sundberg says because the hygienic bees can better take care of themselves, he doesn't need to use as many chemicals to control mites. 

"That saves us time, saves us money and it just keeps things out of the bee hives that shouldn't be in it.  It's just a better natural control for the bees," Sundberg said.

Marla Spivak's research is driven by her desire to help both beekepers and the bees they watch over. 

"They're both suffering, the beekeepers economically and the bees healthwise.  So if I can help at all my helping the bees then that will help the beekeepers," Spivak said. 

And if you think Spivak's research only benefits beekeepers, she reminds everyone that a healthy population of bees is needed to pollinate the world's crops.  She tells people to remember that the next time they sit down to a plate of fruit and vegetables.