Honey bees at OIST’s observation hive
(August 19, 2015) An
international research team has some good news for the struggling honeybee, and
the millions of people who depend on them to pollinate crops and other plants.
These valuable pollinators have faced widespread colony
losses over the past decade, largely due to the spread of a predatory mite called
Varroa destructor. But the bees might not be in as dire a state as it seems,
according to research recently published in Nature Communications.
Researchers found a population of wild bees from around
Ithaca, New York, which is as strong today as ever, despite the mites invading
the region in the mid-1990s.
Researchers
collected wild bees from the same forest in Ithaca, NY
in 1977 and 2010,
which allowed them to observe genome-wide changes over this time.
The red arrow
points to the bee nest in the tree.
“They took a hit, but they recovered,” said Alexander
Mikheyev, a professor at the Okinawa Institute of Science and Technology
Graduate University (OIST) in Japan and lead paper author. “The population
appears to have developed genetic resistance.”
Mikheyev and his collaborators at OIST and Cornell
University studied the population genetics of the wild colony by comparing the
DNA of specimens collected in 1977 with bees collected from the same forest in
2010. To conduct the study, they developed a new DNA analysis tool that works
especially well for degraded DNA stored in museum samples.
Museum bees (blue
bars) are more closely related to modern bees from the same
population (red
bars), which is represented by the grey lines connecting the groups.
A U.S. domestic
population (black bars) is more closely related to modern bees
than museum
specimens, which is represented by the orange lines connecting the
three groups. This
pattern confirms that modern bees experience gene flow from
the wild bees in
past, and from other domestic populations.
Such a study is extremely rare, especially with bees. Few
people collect them, and even fewer collect in a way that is good enough for a
population level study. Luckily, Cornell Professor Tom Seeley worked in this
area during his Ph.D., and deposited his samples in the Cornell University
Insect Collection. This is the first time scientists have been able to observe
genome-wide changes after a specific event like the mite invasion.