Looks Like Confirmation: UCSD Links Neonics To Bees' Flight Failures, Colony Collapse
A key to the epidemic of honey bee colony collapse may be an agricultural pesticide that impairs bees’ ability to fly, according to a paper published Wednesday (April 26) in the journal Scientific Reports.
Biologists at the University of California San Diego attached harnesses to the backs of honey bees and flew them in circles in a specially designed contraption resembling an amusement park swing ride, except for bees. A sensor attached to the swing could detect slight changes in speed as the bees flew, at their own pace and for as long as they could, both before and after being exposed to doses of the neonicotinoid thiamethoxam at amounts akin to what they might encounter in a crop field.
The differences were stark: Within an hour of exposure, the bees entered what the researchers called an “excited” state, suddenly able to fly dramatically longer distances and for longer periods of time. This might help explain the phenomena documented in other studies of honeybees leaving their hives to forage and then not returning, said James Nieh, a professor at UC San Diego and an on the paper. “Bees that fly more erratically for greater distances may decrease their probability of returning home.” (Other scientists have suggested that the pesticides actually alter bees’ ability to retrieve navigation memories.)
But after being exposed for one or two days, the bees’ ability to fly dropped. Their speed reduced, as did their endurance; they flew for a 54% shorter length of time, and traveled a 56% shorter distance. And bees that can’t fly well can’t feed themselves, “because that’s the only way they can collect food,” said Simone Tosi, a UC San Diego biology researcher and another author on the paper. “Their flight ability is also crucial to guarantee crop and wild plant pollination.”
Thiamethoxam, one of the most commonly-used chemicals in the neonicotinoid class of pesticides, is sold under the product names Helix Xtra and Cruiser, made by agrochemical firm Syngenta. The European Union is contemplating a total ban of neonicotinoids, as is Canada.
EDIT
https://qz.com/969630/the-flight-of-the-honey-bee-is-considerably-messed-up-thanks-to-a-common-pesticide/
