A new genetics study of wild honeybees offers clues to how a population has adapted to a mite that has devastated bee colonies worldwide. The findings may aid beekeepers and bee breeders to prevent future honeybee declines.
The researchers genetically analyzed museum samples collected from wild honeybee colonies in 1977 and 2010; the bees came from Cornell University's Arnot Forest. In comparing genomes from the two time periods, the results – published Aug. 6 in Nature Communications – show clear evidence that the wild honeybee colonies experienced a genetic bottleneck - a loss of genetic diversity - when the Varroa destructor mites killed most of the bee colonies. But some colonies survived, allowing the population to rebound.
"The study is a unique and powerful contribution to understanding how honeybees have been impacted by the introduction of Varroa destructor, and how, if left alone, they can evolve resistance to this deadly parasite," said Thomas Seeley, the Horace White Professor in Biology at Cornell and the paper's senior author. Sasha Mikheyev '00 [sic], an assistant professor of ecology and evolution at Okinawa Institute of Science and Technology (OIST) in Japan, is the paper's first author.
More after the break.
"The paper is also a clear demonstration of the importance of museum collections, in this case the Cornell University Insect Collection, and the importance of wild places, such as Cornell's Arnot Forest," Seeley added.
In the 1970s, Seeley surveyed the population of wild colonies of honeybees (Apis mellifera) in Arnot Forest, and found 2.5 colonies per square mile. By the early 1990s, V. destructor mites had spread across the U.S. to New York state and were devastating bee colonies. The mites infest nursery cells in honeybee nests and feed on developing bees while also transferring virulent viruses.
A 2002 survey of Arnot Forest by Seeley revealed the same abundance of bee colonies as in the late 1970s, suggesting that either new colonies from beekeepers' hives had repopulated the area, or that the existing population had undergone strong natural selection and came out with good resistance.
By 2010, advances in DNA technology, used previously to stitch together fragmented DNA from Neanderthal samples, gave Mikheyev, Seeley and colleagues the tools for whole-genome sequencing and comparing museum and modern specimens.
The results revealed a huge loss in diversity of mitochondrial genes, which are passed from one generation to the next only through the female lineage. This shows that the wild population of honeybees experienced a genetic bottleneck. Such bottlenecks arise when few individuals reproduce, reducing the gene pool. "Maybe only four or five queens survived and repopulated the forest," Seeley said.
(Score: 4, Informative) by Runaway1956 on Tuesday August 11 2015, @02:31PM
I don't place the likelihood extremely high. Next to bees, the best pollinators are butterflies. Flies have never been noted as reliable pollinators. A couple of wasp species frequent some of the plants, primarily because they expect to find prey there. Wasps are kinda hairy, so they manage to do a little pollinating, but again, not reliable.
But, back to butterflies. They're more sensitive to pesticides and garden chemicals than bees. People routinely dust their gardens with deadly butterfly poison.
Speaking of which - there's a pretty thistle bush outside the window, which I can see from the computer desk. That thing bloomed - I dunno - two, three weeks ago. Now it's just a bunch of down drooping from the tops of the leaves. I sat here, and watched hummingbirds, butterflies, bees, wasps, and assorted unidentifiable gnats, midges, and whatever visit that flowering thistle.
The wife hated the idea that a thistle was growing near the house, but I enjoyed watching the visitors come and go. Her moonflowers (also visible from my desk) didn't get that kind of traffic!
Plant those wild flowers, and you'll see lots of butterflies, as well as the bees!
If you don't have an assault rifle, sell your cloak and buy one. - Jesus
(Score: 2) by gnuman on Tuesday August 11 2015, @04:19PM
The wife hated the idea that a thistle was growing near the house,
And here's the real problem. People destroy everything. Dow Chemical truly won in their quest to sell more crap.