URBANA — As the nation’s primary pollinator, the European honeybee is responsible for adding around $15 billion to crop values in the U.S. But nationally, the bees are facing the highest death rate ever recorded, alarming beekeepers and researchers.
“Honeybees are unique because their colony kind of cycles throughout the year,” said Sreelaksmhi Suresh, a horticulture educator for Illinois Extension who has spent the last 10 years studying bees. “They have their largest population in the summer and the smallest population in the winter. So some degree of loss is expected, but a lot of times we want to see that really under 30%.”
While survey results from the U.S. Department of Agriculture aren’t officially released until August, Suresh said January is usually when conversations about bee losses start.
“The alarming news for me and many other researchers was that we were seeing preliminary responses showing up to 75%, 80% winter losses, which is crazy,” they said. “What was especially kind of surprising… was that a lot of these losses were being reported by who we call commercial beekeepers,”defined as beekeepers who have more than 500 colonies.
What’s causing this startling spike in bee deaths?
Every year, the USDA National Agricultural Statistics Service sends surveys to beekeepers who have registered more than five managed colonies.
Rena Wilson-Jones is co-president of the Eastern Illinois Beekeepers Association. She manages approximately 60 colonies between Champaign, Vermillion and Piatt counties. She counts herself lucky: Despite the country seeing an all-time high in bee deaths, she only lost 6% of her colonies this winter.
“The commercial beekeepers this year have really taken quite a hit. These are experts. It’s their livelihood… to manage bees,” Wilson-Jones said.
Historically, the highest colony losses come from hobbyists, who care for fewer than 50 hives. They have the least experience supporting their bees through the winter, when low temperatures and a lack of forage make the bees most vulnerable.
But that may be changing. Between June 2024 and March 2025, the surveys show commercial beekeepers had a death rate of 62% — up from 38% the year prior.
“The fact that [commercial beekeepers] are losing so many of our bees, more than our hobbyists… that is weird, to put it lightly. And concerning, honestly,” Suresh said.
Research on the cause of this major loss rate is ongoing, but researchers and beekeepers alike have a few common enemies in mind. The usual threats are known as the four P’s: parasites, pathogens, poor foraging and pests, Suresh said.
Follow-up surveys on colony loss overwhelmingly show beekeepers attributing the latest loss on the varroa mite parasite.
Varroa mites are tiny parasites that target honeybees and can kill a colony in just one season. They attack bees in multiple ways. The first step is laying eggs inside cells of honeycomb where the bees themselves grow from eggs to adults. Once the mites have matured, they attach themselves to bees growing in the cell, creating open wounds that leave the bees vulnerable to infections and viruses.
“If you’ve got a lot of them in the colony in the winter, I wish I could say this wasn’t the case, but your colony is probably done for,” Suresh said. “And the thing is, just one female mite can lay hundreds of eggs.”
Changing weather patterns appear to be affecting bees as well
While beekeepers can treat for varroa mites, Wilson-Jones, of the Eastern Illinois Beekeepers Association, said the bees are also suffering from climate change.
Droughts, floods and other severe weather conditions can wipe out food supplies for the bees and weaken colonies — and lessen the availability of other necessary resources like pollen and plant resins.
Changing weather patterns, including warmer winters and hotter summers, also impact the life cycle of flowering plants that bees rely on to produce food.
“And that’s true of not just honeybees, but for butterflies and other insects,” Wilson-Jones said. “I mean, there’s hundreds of thousands of insects and across other species… their behaviors are hardwired into them and can get out of sync with what Mother Nature is really doing at that time. So it can cause a weakening of that particular species for various reasons.”
Illinois isn’t a major player in commercial beekeeping, and the state’s primary crops of corn and soybeans are self-pollinating. But climate change remains a growing concern for the nearly 37,000 bee colonies kept by thousands of beekeepers across the state.
Right now, it is too early to determine one particular factor that’s causing the historic death rate of honeybees. But Suresh said the USDA agricultural research facility is carrying out research on the matter.
“There’s researchers in New York, in Florida, in Mississippi, all across the country, really trying to figure out what is going on. And so I’m hopeful that we’ll get some answers,” Suresh said. “And once we have some answers, or at least an idea of what might be going on, that’s when we can figure out how to help or mitigate the problem.”
EDITOR’S NOTE: This story has been updated to include additional information and context regarding honeybees, including their reduced activity during winter months.