To Boost Bee Immune Systems, Researchers Strap In Honeybees For Live Test Flights

To Boost Bee Immune Systems, Researchers Strap In Honeybees For Live Test Flights



Viruses spread through honeybee hives like the flu virus in a crowded waiting room.

Looking to boost bee immune systems and better understand viral infections, researchers at Montana State University (MSU) are testing supplements and harnessing honeybees into a little contraption before forcing them to fly in circles.

Researchers call these unique machines flight mills, which leash in bees and measure flight distance and speed as the bees buzz around and around.

One MSU study is examining the impact of viruses on honeybee flight performance — distance and speed — in a laboratory setting.

A second MSU study is looking at nutritional supplements as a way to boost honeybee immune systems and reduce virus infection levels.

“Beekeeping is important in Western states like Montana, Wyoming, and the Dakotas,” Michelle Flenniken, a researcher and professor at the MSU Department of Plant Sciences and Plant Pathology, told Cowboy State Daily.

“Montana has like almost 300,000 honeybee colonies here in the summer and the bees from the western U.S. are transported to the Central Valley of California for the almond pollination, which is the world's largest pollination event for honeybees,” said Flenniken.

In addition to organized gangs of bee rustlers stealing bees during big pollination events in California, the honeybees also face the possibility of encountering new viruses brought in by other colonies.

Just as humans load up on supplements like bee pollen and echinacea at the start of cold and flu season, Flenniken sees potential benefits in adding health supplements to the honeybee’s diet.
Just A Tad Could Do

As part of the team at MSU’s Pollinator Health Center, Flenniken is like the person at the smoothie shop who asks if you’d like an extra shot of supplements—only she’s serving honeybees, because they really need a boost.

“Colony losses have averaged roughly 38% in the U.S. in the past 15 years. Despite these losses, beekeepers in the U.S. have maintained the number of bee colonies at roughly 2.5 million by dividing one colony to make two—a process called ‘splitting,’” according to a recent MSU press release.

Splitting might help offset some of the colony die-offs caused by mite infestation, chemical exposure and pathogens — including viruses.

Just as preschool teachers and health clinic receptionists face an onslaught of viruses and other communicable diseases, such is life inside a honeybee hive.

That’s why Flenniken wants to know if tiny supplement doses of thyme oil and thymol might provide a boost to honeybee immunity.

“We’re trying to boost the bees' immune system by stimulating it with a really, really low dose of thymo or thyme oil,” said Flenniken.

“A honeybee, they weigh about 100 mg,” added Flenniken. “And it would be like the equivalent of putting approximately half the weight of a bee into 260,000 gallons of sucrose syrup, for a dose of 0.06 parts per billion.”
Tracking Invisible Viruses

Some viruses bring on obvious symptoms in honeybees. Viruses even get their names from the symptoms, like deformed wing virus.

However, many virus-infected bees don’t exhibit symptoms, and Flenniken wonders if these overlooked infections may be significantly detrimental to honeybee health.

To measure the impact of invisible viral infections with no outward symptoms, Flenniken relies on a flight mill.

“That little string that hangs down and has a really powerful magnet. It's very tiny on the end,” said Flenniken, explaining how to coax test honeybees into flying. “You bounce the arm down once they'll feel a little bit like they're falling or they'll be encouraged to fly.”

Around the honeybees go, and each time the rotating arm blocks the optical sensor it records another rotation. Then MSU researchers calculate the flight distance and relate it to the recorded flight time. That allows MSU researchers to compare the results obtained from healthy honeybees to results from virus-infected bees.

According to an MSU press release, this research “found that bees infected with some viruses don’t fly as far or as fast as healthy bees. The reduced flight distance in infected bees may reduce the ability of forager bees to obtain nectar and pollen to feed their colony, extending the impacts of infection to a community of roughly 30,000 bees.”

Flight mills and flight enclosures are a powerful tools for researchers. But sometimes, according to a University of Wyoming researcher, the honeybees appear to get bored.

Michelle Flenniken, with the MSU Department of Plant Sciences and Plant Pathology. Montana and Wyoming are home to more than 300,000 colonies of honeybees. (Montana State University)

Imagine a hot walk — the circular pen where a harnessed horse walks in circles. This flight mill built to harness honeybees at Montana State University is a tiny version of that, but it measures distance and speed. (Montana State University)

Honeybee pollinating. (Montana State University)

The western honeybee, Apis mellifera. The genus name Apis is Latin for “bee”, and mellifera is Latin for “honey-bearing” or “honey-carrying.” (U.S. Geological Survey)Arrow leftArrow right





Bee Boredom

One side-effect of test flying honeybees, researcher Jordan Glass told Cowboy State Daily, might be the monotony of it all.

“It's tricky because sometimes they can get bored. They just don't cooperate,” said Glass, a post-doctoral researcher at UW’s Department of Zoology and Physiology.

Glass is excited by MSU’s recent honeybee research.

“What's neat about their study is that they found really clear differences between their different treatments,” said Glass, noting honeybees are not endangered, but hive loss remains a significant problem.

Glass and colleagues took a different approach than the MSU researchers to assess honeybee health. They wanted to know how eating fungicide-contaminated pollen impacts a honeybee’s ability to build flight muscles and fly.

When honeybees are reared eating contaminated pollen they “end up as adults with smaller flight muscles, which can impact foraging and pollination,” said Glass.

“In other words, they can't fly as long, as far, as fast, or carry as much pollen or nectar. This means they likely visit fewer flowers before having to turn around and head home, which means they are less efficient at pollinating crops,” said Glass.

The MSU group attached their bees to a circular flight mill, like a mechanical hot walker built for one horse. Glass and his team instead let the bees fly on their own inside a container filled with a helium-oxygen mixture and measured their metabolism.

“Instead of having nitrogen in the air, we swap it out for helium,” which is less dense, said Glass, explaining how it gives the flying honeybee no choice but to flap harder.

When their wing motion slows and they seem distracted, Glass speculates this is a sign that the research honeybees are bored out of their little bee skulls.

“You don't know,” said Glass. “But you can kind of tell because they just give up and they just stop. They don't want to fly anymore.”