Wisconsin’s tiniest livestock — honeybees — are threatened by mites, pesticides and lack of food

Honeybees are having a rough year. Threats like mites, diseases, hunger and pesticides could wipe out up to 70 percent of honeybee colonies across the country.

But unlike natural pollinators that face similar threats, honeybees have people helping them out. 

“Honeybees are like livestock,” Hannah Gaines Day, a University of Wisconsin-Madison researcher who studies how pollinators interact with the environment and agricultural operations, told WPR’s “Wisconsin Today.” “They’re like little, tiny livestock that the beekeeper is taking care of, and so they have someone looking out for them and feeding them and giving them medicine if they need it if they’re sick. But the wild pollinators don’t have that.”

Gaines Day said that hive losses in Wisconsin vary widely among commercial and hobby beekeepers. The insects are facing four main threats, she said, or the “four P’s”: pests, pathogens, poor nutrition and pesticides.

“We have the Varroa mite, which was introduced to the United States in the 1990s, and that’s the main pest of honeybees. They transmit many viruses,” she said. “Poor nutrition has to do with what flowers they’re able to get on the landscape. So, modern agricultural landscapes look a lot different from historical landscapes, and today we have a lot fewer flowers out there for the bees to visit and collect upon.”

“And then finally, a lot of bees are encountering pesticides in the landscapes, and that can have lots of detrimental effects for the bees, both death and also just sublethal effects, how they can learn or navigate,” she added. 

Many honeybees in Wisconsin are part of agricultural operations that are shipped around the country to pollinate crops as needed. But other colonies are kept by hobby beekeepers and remain year-round in Wisconsin. 

Joe Bessetti, president of the Dane County Beekeepers Association, told “Wisconsin Today” that he’s also noticed the effects of mites, diseases and poor nutrition on the hives that he’s kept. Poor nutrition is particularly noticeable during dry summers. 

“When we have a nice, wet summer and the fall flowering plants do well, I always see an uptick in survivorship and strength in my colonies during winter,” Bessetti said. “But when we have a four-to-six week period of really dry weather in the middle of summer, like we sometimes get July through August, it really makes it hard for the bees to get good nutrition because those fall blooming plants just didn’t get what they needed. So, it’s a domino effect.”

Varroa mites can do a lot of damage to honeybees, Bessetti said. A few mites aren’t a problem, but they can rapidly reproduce to overwhelm a colony. 

“(The bees) don’t forage as well, if at all. They die young and early,” he said. “They don’t do the jobs they need to do inside the hive as well. So there’s just a lot of collateral damage with that infestation, and then the viruses on top of that can really run rampant, even at relatively low mite numbers, and so beekeepers that want to keep their hives healthy have to really stay on top of things.”

There are different options for trying to control Varroa mites, including miticides and natural agents. Bessetti said he has avoided treating his hives, but he looks for bees that have a natural resistance. That approach means he loses a lot of colonies, but the ones that survive tend to be resilient. He’s used bees from Trevor Bawden of Lloyd Street Bees in Milwaukee, which have a resistance to mites.

“(The bees) actually detect reproducing mites inside the cells. They open up those cells and disrupt the mites’ reproductive cycle, and so they can maintain a very low mite number,” he said. “So we’ve been trying to get more of our club members interested in getting these bees, whether you use mite treatments in your hives or not, bees that can do at least part of that job for you are beneficial for everybody.”

Despite the many threats facing honeybees and natural pollinators, both Gaines Day and Bessetti are hopeful that pollinators — with some love and attention — can thrive. 

“Beekeepers are going to continue troubleshooting and finding different ways to treat the mites,” Gaines Day said. “We have a lot of wild bees here, and we have a diverse landscape in Wisconsin that supports these wild pollinators. It’s sort of redundancy in the system, and the wild bees are sort of a backup plan. And so if we can continue to increase floral resources on the landscape and just be mindful that our actions impact pollinators, I think that we’re going to be OK.”