WILBERFORCE, Ohio –They’re called OB1 bees. They may become a bee of the future in Ohio, Indiana and elsewhere, able to reduce mite infestations in hives and enhance long-term bee sustainability.

Among the bee research underway at Central State University (CSU) in Ohio and Purdue University is an area that addresses hive health through bee genetics. Each year, beekeepers in these two states lose nearly 60-70 percent of their bees over winter.

“There are many causes for hive colony loss, but the main cause is a parasitic mite called the Varroa,” said Michelle Wallace, CSU’s agriculture and natural resource extension educator for Northwest Ohio. “The tiny mites cause colony losses by feeding on the bee pupae and creating defects in bee development. The mites also transmit viruses into the colonies that are detrimental to the health of the colony.”

 According to Wallace, one solution being worked on at CSU by Associate Professor Hongmei Li-Byarlay, is breeding OB1, or “Ohio Mite Biters No. 1.” The goal behind the breeding program is to produce worker bees that are better groomers or do a better job of keeping pests out of the hive, which is essential to hive health.

“Bee hygienics isn’t learned, it’s inherited,” Wallace said. “Worker bees with slightly smaller mandibles are better groomers. Currently, about 10 percent possess the fully hygienic trait. The smaller mandibles give the bees a better ability to bite off parts of the mites, impacting their ability to attach to the brood or adult bees.”

Li-Byarlay’s research, in conjunction with Purdue University, is working to breed the biting trait into a larger percentage of a hive’s bees. They are collecting mites to determine hives that have a large percentage of mite-biter bees. They hope to collect drones from those hives and use the males to artificially inseminate the queen as a way to introduce new strains of bees into the hive. In nature, Wallace says, it takes 15 to 20 drones to inseminate a queen. Fifty to 60 drones and a tiny syringe are needed for the artificial insemination process.

Purdue Apicultural Specialist Krispn Given received the prestigious “Behind the Research” award in 2021 for his work in breeding the Purdue “Mite-biter” honey bee strain, in addition to his other contributions to honey bee research. Purdue’s mite-biters are genetically bred to literally do direct combat with the mites, removing them from their bodies and biting them, causing mortality.

Given arrived at Purdue as an apiary research assistant in 2003, tending to 100-plus hives at the university. By 2007, he had the tedious job of mite-counting. He noticed that some of the mites had legs that had been bitten off. That same year, Given and his staff made a sharp turn in the breeding program, and to breed specifically for bees that bit a high proportion of the mites that fell onto the sticky board below the hives.

Purdue’s work proved that (like that of CSU’s) mite grooming and biting are heritable, and also that colonies that have a high proportion of chewed mites have smaller mite populations.

“We wondered, what the mechanism was that the bees were responding to that initiated mite biting,” Given said. “Perhaps the bees are responding to the movement of mites in the darkness of the hive, but there is much we still don’t know. Factors other than genetics can influence the number of bitten mites in the hive, and the beekeeper must take into consideration the history of the colony. Mite biting is also influenced by environmental factors, like the time of year. In the fall there can suddenly be an uptick.”

Purdue has been selecting its best mite-biting hives and crossing those bees to increase expression of the trait. After 16 years as a honey bee breeder and researcher, Given is finding much higher levels of mite biting, as well as lower number of mites overall, than were found in Purdue’s hives in 2007 when the trait was first noticed.

“We had 5 percent mite-biters in the beginning, and have achieved upward of 50 percent overall,” Given said. “Bee breeding is a process, not a goal. We can never say, because we’ve achieved 50 percent mite-biters, for example, that we’ve ‘arrived.’ Because queens naturally mate with multiple drones in the drone stream, many of which would have no mite-biter genetics, it’s a constant battle to keep breeding for the desired traits so they’re not diluted and lost. You also have to be alert for, and breed out, undesirable deleterious alleles that can pop up in trait selection, like chalkbrood or aggressiveness. It’s like walking a tightrope. Some traits are easier to select for than others. Mite biting is a very complex trait. The mites are also adapting to behavioral shifts in the nest.”

Wallace encourages beekeepers in her state to get involved in the research to help solve the problem by improving mite-resistant, high-grooming and mite-biting genetics.

“They can help by sending the hive’s bottom boards before the hives are treated with pesticides,” Wallace said. “The bottom boards should be wrapped in plastic wrap, or mites can be collected in small plastic cups with lids, like those used in condiments at restaurants. Researchers will count the number of mites which have been bitten to determine if the hive has a high number of mite-biters.”

Samples can be sent to: Dr. Hongmei Li-Byarlay, Central State University, 1400 Brush Row Road, Wilberforce, OH 45384.