February 4, 2019 by Misti Crane, The Ohio State
University
It's about time for the annual mass migration of honeybees to
California, and new research is helping lower the chances the pollinators and
their offspring will die while they're visiting the West Coast.
Each winter, professional beekeepers from around the nation stack
hive upon hive on trucks destined for the Golden State, where February coaxes
forward the sweet-smelling, pink and white blossoms of the Central
Valley's almond trees.
Almond growers rent upwards of 1.5 million colonies of honeybees a
year, at a cost of around $300 million. Without the bees, there would be no
almonds, and there are nowhere near enough native bees to take up the task of
pollinating the trees responsible for more than 80 percent of the world's
almonds. The trouble was, bees and larvae were dying while in California, and
nobody was sure exactly why. The problem started in adults only, and beekeepers
were most worried about loss of queens.
Then in 2014, about 80,000 colonies—about 5 percent of bees
brought in for pollination—experienced adult bee deaths or a dead and deformed
brood. Some entire colonies died.
With support from the Almond Board of California, an industry
service agency, bee expert Reed Johnson of The Ohio State University took up
the task of figuring out what was happening. Results from his earlier research
had shown that some insecticides thought safe for bees were impacting larvae.
Building on that, Johnson undertook a new study, newly published in the
journal Insects, that details how combinations of insecticides and
fungicides typically deemed individually "safe" for honeybees turn
into lethal cocktails when mixed.
Johnson, an associate professor of entomology, and his study
co-authors were able to identify the chemicals commonly used in the almond
groves during bloom because of California's robust and detailed system for
tracking pesticide applications. Then, in a laboratory in Ohio, they tested
combinations of these chemicals on honeybees and larvae.
Posts
