Beekeepers seek resistant wild honey bees

When beekeeper Dwight Wells focuses on mites under a microscope, he likes to see missing body parts.

Varroa parasitic mites are a serious threat to honey bees in Ohio, but some populations of wild honey bees defend themselves by chewing the mites’ legs and eating in their abdomen, he explained.

Improvement project

This chewing behavior is one of the adaptations he’s researching as part of the Ohio Queen Bee Improvement Project. Earlier this year, Wells and fellow beekeeper Zale Maxwell started the Ohio Queen Bee Breeding Project to selectively breed bees well adapted to Ohio conditions.

For several years, they have both worked with other beekeepers in the state to capture swarms of wild bees that thrive without human assistance. Now, they hope to use the superior genetics of these wild populations to develop more resilient captive bee colonies.

“We want to make beekeeping fun again,” Wells said.

Wells, who lives near Troy, Ohio, is retired from a career as an engineer. Maxwell lives near Carroll and is also a retired engineer. They both started beekeeping long before Varroa mite infestations became a problem in the mid-1980s.

Wells made his debut in 1954 for a 4-H project, and Maxwell started in 1964 to earn a Boy Scouts Beekeeping Merit badge. Beekeeping was simpler then, Wells recalls.

Varroa mites and the diseases they carry have made it much more difficult to maintain colonies. “Beekeeping hasn’t been the same since,” he says.

Discourage losses

Barbara Bloetscher, state beekeeper at the Ohio Department of Agriculture, said Ohio beekeepers lose 30 to 40 percent of their colonies each winter. Varroa mites are a major cause of these losses. Colony losses and management challenges are becoming too great for some beekeepers, Bloetscher added. She sees many new beekeepers give up after about three years.

Mites weaken bee colonies by feeding on adult bees and bee larvae. For a bee, a mite is a big pest, explained Bloetscher. “Comparatively, it’s the size of a rat on us. “

The mite also spreads disease, she said. “While it weakens bees, it also injects viruses.”

Controlling mites with acaricides is expensive, Bloetscher added. It’s also tricky because mites and bees are so closely related.

Identifying wild populations that defend themselves against mites is a promising alternative, she said.

Wild Benefits

Honey bees were first introduced to North America in 1622 as a managed species. When bees escape human management and form new colonies, they are considered wild. These colonies must either adapt to local conditions or disappear, Maxwell explained.

Honey bees have a short reproductive cycle and a high rate of genetic recombination, so swarms of wild bees are likely to come from well-adapted wild colonies that have grown too large, Maxwell said.

“These wild bees have already survived a winter in Ohio where the swarm would not have occurred.”

To survive, wild bees develop a variety of traits that are also valuable in managed colonies, Maxwell added. One such trait is the chewing behavior of mites.

Some wild populations also tend to work earlier in the morning and later in the evening than the commercial stock, which is an advantage for honey production.

Maxwell and Wells have also identified wild bees that defend their colonies against small hive beetles, another pest that kills bee larvae. They don’t yet know if bees can kill beetles, but, said Maxwell, “they pester the bejesus out of them. “

Swarm trappers

Wells and Maxwell draw on wild bee research conducted by Greg Hunt at Purdue University, Tom Seeley at Cornell, and other researchers around the world.

After learning about their efforts, Wells began trapping swarms in 2012. He and Maxwell enlisted a network of swarm trappers statewide.

“We’re now at the point where we have a science-based approach to trapping swarms,” he said.

Some of the most promising genetic lines come from wooded areas along the Ohio River and its tributaries. They also trapped well-adapted populations in Champaign County and downtown Dayton.

Wild bee colonies can be found in all parts of the state, but those in remote locations, isolated from managed bee colonies, are more likely to be well adapted to Ohio conditions, a explained Wells. This is because they are less likely to have crossed paths with managed colonies imported from other parts of the country.

In addition to bringing better genetics to captive bee colonies, trapping swarms is a more economical way to get into beekeeping, Wells pointed out. It is still necessary to buy beehives and protective gear, but the bees themselves are free.

He works with a 14-year-old 4-H member who built his own honey business by capturing 26 bee colonies. As part of their bee breeding project, Maxwell and Wells run beekeeping and queen rearing classes at Maxwell’s farm. They are particularly interested in helping young beekeepers get started, Maxwell added.

Research objectives

After capturing wild swarms, Wells and Maxwell assess them for mite chewing and other helpful traits. To help them with their research, they enlisted Greg Stahl, a beekeeper from Champaign County.

Stahl is a retired Harvard professor with experience in cardiovascular research. He became interested in wild bees after starting beekeeping as a retirement hobby. He saw an example of the resilience of wild bees when pesticides were sprayed on a nearby farm, he said.

Many forager bees from its commercial colonies have died, but its colonies of captive wild swarms have suffered few losses. The question, he said, is why the wild bees fared better.

More research is needed to determine if wild colonies have a better immune system, if they have a way of knowing how to avoid spray fields, or if there is some other reason for this advantage.

Stahl is using his research experience to design studies to examine the physical and behavioral differences between commercial and wild bees, he explained. “Where are the differences and why are the differences important? “

For example, he is investigating whether the chewing behavior of mites is related to the size of bees’ mandibles. Stahl is also studying test methods for bee diseases. Rapid tests would help beekeepers identify and manage diseases without having to wait for lab results, he explained. “Ideally, I want something like a pregnancy test. “

Pedigrees of bees

Another goal of the project is to develop a way to track bee genetics for predictable results, Wells said. German beekeepers have already implemented a certification program for queen bees, similar to cattle pedigrees. He would like something similar here to help beekeepers select queens with the characteristics they want.

With more data, beekeepers can make better management decisions for their bee colonies, Wells said. “We have to become beekeepers. Everything in agriculture today is done by data.