North Dakota researchers examine alfalfa bee disparity in US

Matt Mikus
Minnesota Public Radio News
Elisabeth Wilson pulls an alfalfa leafcutter bee nest out from the NDSU's Insect Cryobiology and Ecophysiology lab's bee hotel in Fargo, N.D., on Thursday, Aug. 16, 2018. The lab is a partnership between the university and the U.S. Department of Agriculture.

FARGO, N.D. (AP) - Elisabeth Wilson drives to a small field every day to check her nests set out along a research field at North Dakota State University. They're home to the alfalfa leafcutter bee.

This species is nothing like a honey bee. It lives a more solitary lifestyle. They're smaller and they don't live in hives. Instead, they create nests in tiny, deep holes.

Every year farmers spend thousands of dollars to purchase larvae from bee brokers in Canada. The bees are sold by the gallon and shipped into the United States. In 2016, more than 70,000 gallons of leafcutter bees were exported from Canada.

But these bees struggle to reproduce. Most of their offspring die in the U.S. — it averages out to a half a bee surviving per female leafcutter imported. However, each mother bee in Canada can produce about two and a half larvae.

Now, scientists like Wilson are trying to find out why there's a disparity, Minnesota Public Radio News reported.

"That is the whole purpose of this lab and our central question because it really doesn't make sense to us," Wilson said. "So all the research in this lab looking at all the little intricacies of this bee that's why we're trying to figure out why is this bee not doing well."

Alfalfa leafcutter bees fly around a container near Fargo, N.D., on Thursday, Aug. 16, 2018. The insect isn't native to North America. But farmers and researchers noticed that when they kept leafcutter bees nearby, the production of alfalfa seeds tripled.

Alfalfa is the fourth largest crop in the country, and it's grown to feed livestock like dairy cows, sheep and horses.

The alfalfa leafcutter isn't native to North America. But farmers and researchers noticed that when they kept leafcutter bees nearby, the production of alfalfa seeds tripled.

Mark Wagoner is an alfalfa seed farmer based in Washington state, and he relies on two bee species to help pollinate and produce the seeds for the crop. He buys leafcutter bees by the gallon to help pollinate more than 1,300 acres of alfalfa.

"Honey bees won't pollinate alfalfa, they will just get the nectar, the alfalfa plant has to be physically tripped to get the pollen," Wagner said.

When the alfalfa plant is tripped, the plant can smack a larger honey bee right in the face. But a leafcutter bee is small enough that it's not bothered by the plant being triggered as it's pollinated.

The students and researchers keep their bees in a "bee hotel". This small structure has thousands of holes that are a little smaller than the width of a pencil. In each hole they place a small paper straw. That lets the researchers pull out the nests so they can study them back in the lab. When you walk up to the lab's bee hotel, you don't even need a protective suit.

Wilson's nests were created in a lab with a 3D printer, and designed so she can monitor the temperature inside the nest at any given time. They look like nine large purple stacking blocks, with four holes for nests on each block, facing four different directions.

Even as she's studying the effects of temperature, she's making observations that might help farmers in the future.

"Currently farmers place their boxes facing southeast. And the reason behind that is that on the southeast side that's the sun hits it first thing in the morning it kind of wakes the pollinators up and gets them out into the field earlier," Wilson said. "However we don't even know if the bees prefer that side."

Wilson's preliminary data show the bees don't like to nest on the southeast side. Given a choice, many of the bees went to the northeast and northwest sides of the box, she said.

This is the kind of detail that the students and researchers are studying at this lab. It's a partnership between North Dakota State University and the U.S. Department of Agriculture.

Alfalfa farmer Mark Wagoner said he appreciates the research the USDA has done with local universities, but he doesn't expect a solution anytime soon.

"Well it would save me a lot of money because in 2017, we spent like $350,000 at least on leafcutter bees, which is a lot of money," Wagoner said. "If they could figure this out, that'd be great. But we've been trying to figure this out since the '70s."