By Izzy Wagner/VtDigger
Honey bee colonies worldwide suffered massive losses last year, but University of Vermont researchers and international partners developed a new testing method that may lead to more disease-resistant colonies in the future, including in Vermont.
“It’s incredibly promising. We are all really excited with the results,” said Andrew Munkres, a beekeeper at Lemon Fair Honeyworks in Cornwall.
Beekeepers in the U.S. lost 70-100% of managed honey bee colonies in 2024, according to the nonprofit group Project Apis m. In order to keep honey bee populations stable, beekeepers must breed replacements — but this can be a time-consuming and costly process.
“It’s definitely more desirable for a beekeeper to have bees that are better adapted at taking care of their diseases themselves,” Samantha Alger, a research assistant professor in UVM’s College of Agriculture and Life Sciences and head of the Vermont Bee Lab, said in a University of Vermont press release.
Alger said the trick to breeding resilient colonies starts with the ability to identify hygienic colonies that can identify and remove diseased brood, which are the hive’s youngest members and include eggs, larvae and pupae.
In a honey bee colony, the queen bee lays one egg inside each cell. As the eggs hatch, nurse bees feed the larvae and eventually cap over the developing cells with a protective wax layer. When nurse bees are stimulated by pheromones to detect sick or dead developing bees, they will uncap the cell and remove the damaged pupa. This is known as hygienic behavior.
That’s where the UBeeO testing method comes in. This screening tool developed at the University of North Carolina at Greensboro tests for hygienic behavior by mimicking the pheromones emitted by diseased bees and measuring the nurse bees’ response.
UBeeO differs from previous hygienic testing methods. Rather than testing the bees’ ability to identify dead brood, it measures the bees’ ability to identify diseased brood, which makes it more “realistic to what bees experience,” Alger said in the release.
The UBeeO method provides a quantitative value of how hygienic the colony is because researchers can count the number of cells that have been manipulated by nurse bees.
“If 60% or more of the cells were manipulated, the colony is considered hygienic, and those are the genetics you want to breed for,” Alger said in an interview.
The Vermont Bee Lab discovered that the UBeeO method detects more pathogen loads than previously thought. This could drastically improve breeding programs, Munkres, a commercial beekeeper, said.
However, the trouble lies in passing on the hygienic behavior to offspring from the disease-resistant colonies.
“Without (hygienic behavior) being more heritable, it’s less useful to test for,” Munkres said.
Alger and other researchers are now investigating the heritability of hygienic behavior and other underlying causes that led to 2024’s massive colony losses.
“People like simple answers, and so they always ask, ‘What’s the reason the bees are dying?’” Munkres said. “What I have to tell them is that it’s like one of those multiple choice tests in school.”
Periodic mites, pathogens, temperature disruptions due to climate change and pesticides all contribute to colony losses, he said.
“Even if we were able to populate the state of Vermont with all of these UBeeO tested hygienic bees, we would still have to deal with controlling the pesticides and creating a healthy environment for the pollinators to live,” Munkres said. “If we can get the pesticide use under control, then this type of technology will be huge in terms of helping to boost healthy populations of bees.”
Vermont lawmakers passed a bill last June to restrict the use of some of the most toxic pesticides, called neonicotinoids — some so lethal that using a teaspoon of them could kill every single bee in the state, Munkres said.
Regulators are currently working on a plan to implement Act 182, which bans farmers from using cereal grain seeds treated with neonicotinoids by Jan. 1, 2029.
About 35% of the world’s food crops — one out of every three bites of food consumed — depend on animal pollinators, according to the United States Department of Agriculture. Therefore, it is crucial to pollinator survival, and to global food security, to ensure the neonicotinoid ban is properly enacted, Munkres said.
