Genes from European dark honeybees surprisingly found in Arkansas

by George Jared ([email protected]) 3,345 views 

Honeybees are not indigenous to the Western Hemisphere. The first documented shipment of honeybees to the New World was recorded in 1622, according to the U.S. Department of Agriculture. Many of the first bees brought to North America were European dark honeybees.

Those first bees are now extinct in many states, but the genetics from those first honeybees still exist in parts of the Natural State.

Allen Szalanski, professor and insect geneticist for the Arkansas Agricultural Experiment Station, said research to identify the distribution of pathogens in managed honeybee colonies in Arkansas uncovered this hidden genetic history. Arkansas has more than 3,800 registered beekeepers managing more than 61,000 honeybee colonies, according to the Arkansas Department of Agriculture. Most of the managed honeybee colonies in Arkansas are local backyard hives, Szalanski said. Arkansas has about 100 species of bees.

Bees are big business in the agriculture industry.

The insects pollinate about one-third of the world’s food supply, according to Sustain, a nonprofit agriculture policy organization. Bees pollinate all manner of fruits, vegetables, crops, and even some of the wild grasses used to feed cattle and other livestock. Their impact on the U.S. economy is valued at about $15 billion per year, according to Scientific American. During the winter of 2018-19, beekeepers across the country lost an estimated 38% of their honeybee colonies mostly due to an Asian parasitic mite that is resistant to some pesticides that kill mites.

Honeybees were first imported from Europe in the 1600s by immigrants who treasured their honey and agricultural value. Those early honeybees, often called European dark honeybees or “German” honeybees, were darker in color than the more familiar, yellow-striped bees that are common today.

Entomologists call the ancestry of European dark honeybees the “M” lineage, Szalanski said. They were the most common managed pollinators in the United States until the 19th century. In 1852, a Philadelphia-born clergyman and beekeeper named Lorenzo Lorraine Langstroth invented a modular beehive with moveable frames in which the bees build honeycombs. This construction, called a Langstroth hive, is still the most popular honeybee hive in use today by professional and amateur beekeepers.

Langstroth, descended from Italian immigrants, preferred southern European honeybees, sometimes called Italian honeybees. He said this type of bee was “gentler” and easier to manage than the German honeybees that were still common at that time.

While serving Congregationalist churches around Massachusetts, Langstroth studied the behavior of his bees and designed a moveable frame hive based on a principle he termed the “bee space.” He published the results of his research in a book, “The Hive and the Honey-Bee,” which is still highly regarded by beekeepers.

Langstroth came to be known as the father of American beekeeping and through his influence, Szalanski said, the Italian honeybee — part of what entomologists call the “C” lineage — became the standard subspecies for beekeepers.

As the European dark honeybees became less desirable, Szalanski said, some of their colonies became feral, taking up residence in the wild. Szalanski said many beekeepers believed that, because they were no longer protected by managed beekeeping practices, those feral German honeybees would probably die out.

“Today, the queen breeders for managed colonies nearly all belong to the “C” lineage, familiar to observers as the yellow striped honeybees,” Szalanski said.

Szalanski, while conducting a genetic survey of honeybees with former graduate student Dylan Cleary, found the genetic strain “M” lineage of those earlier European dark honeybees among numerous samples of “C” lineage honeybees. Cleary, who graduated last year with a doctorate in entomology, sent collection kits to registered Arkansas beekeepers. She and Szalanski conducted genetic tests on the samples that were sent back.

“We received samples from 110 beekeepers around the state,” Szalanski said. “The samples represented 540 colonies from 47 counties.”

Their goal was to identify pathogens and parasites that infected managed honeybees in the state. But they also tested mitochondrial DNA from the bees to identify the maternal lineages, or matrilineal DNA. Mitochondrial DNA is handed down through the mother and is often used to track ancestry in animals and humans. Szalanski said they identified four lineages in the Arkansas honeybees. The vast majority were the “C” lineage that includes the Italian honeybees.

They also found smaller numbers of “A” lineage, designating Africanized honeybees, and “O” lineage, known as oriental honeybees. But the surprise was the discovery that some Arkansas bees had mitochondrial DNA from those earlier European dark honeybees that were the standard domesticated pollinators for 200 years.

Szalanski said this research will be published in the Journal of Apicultural Research later this year. He believes the European dark honeybee lineage became part of managed honeybee colonies when beekeepers gathered a swarm — a bee mating behavior — from a feral colony into a hive.

“It can be difficult for a beekeeper to determine the source of a honeybee swarm,” Szalanski said. “It can be from their own or a neighbor’s managed colony, or from one that has been feral for a long time. We really don’t know how many feral colonies exist. This research provides evidence that descendants of these ‘M’ lineage honeybees still exist in Arkansas.”

Why European dark honeybee descendants still exist in Arkansas is a mystery.

“Do they survive better in Arkansas’ climate?” Szalanski asked.

It’s not uncommon for some managed honeybee swarms to become established as feral colonies in hollow tree cavities or other favorable environments. But Szalanski said entomologists expected that feral European dark honeybees would be long gone, likely wiped out by Varroa mites, the most important parasite of domesticated bees.

“Descendants of these ‘M’ lineage honeybees are rare or nonexistent in northern states, but not in Arkansas,” Szalanski said. “They may have become adapted to the environment in Arkansas. We need more study to understand why they exist here.”