Common pesticide damages honey bee’s ability to fly
April 26, 2017, University of California – San Diego
Biologists at the University of California San Diego have demonstrated for the first time that a widely used pesticide can significantly impair the ability of otherwise healthy honey bees to fly, raising concerns about how pesticides affect their capacity to pollinate and the long-term effects on the health of honey bee colonies.
Previous research has shown that foraging honey bees that ingested neonicotinoid pesticides, crop insecticides that are commonly used in agriculture, were less likely to return to their home nest, leading to a decrease in foragers.
A study published April 26 in Scientific Reports by UC San Diego postdoctoral researcher Simone Tosi, Biology Professor James Nieh, along with Associate Professor Giovanni Burgio of the University of Bologna, Italy, describes in detail how the neonicotinoid pesticide thiamethoxam damages honey bees. Thiamethoxam is used in crops such as corn, soybeans and cotton. To test the hypothesis that the pesticide impairs flight ability, the researchers designed and constructed a flight mill (a bee flight-testing instrument) from scratch. This allowed them to fly bees under consistent and controlled conditions.
Months of testing and data acquisition revealed that typical levels of neonicotinoid exposure, which bees could experience when foraging on agricultural crops—but below lethal levels—resulted in substantial damage to the honey bee’s ability to fly.
“Our results provide the first demonstration that field-realistic exposure to this pesticide alone, in otherwise healthy colonies, can alter the ability of bees to fly, specifically impairing flight distance, duration and velocity” said Tosi. “Honey bee survival depends on its ability to fly, because that’s the only way they can collect food. Their flight ability is also crucial to guarantee crop and wild plant pollination.”
Long-term exposure to the pesticide over one to two days reduced the ability of bees to fly. Short-term exposure briefly increased their activity levels. Bees flew farther, but based upon other studies, more erratically.
“Bees that fly more erratically for greater distances may decrease their probability of returning home,” said Nieh, a professor in UC San Diego’s Division of Biological Sciences.
This pesticide does not normally kill bees immediately. It has a more subtle effect, said Nieh.
“The honey bee is a highly social organism, so the behavior of thousands of bees are essential for the survival of the colony,” said Nieh.” We’ve shown that a sub-lethal dose may lead to a lethal effect on the entire colony.”
Then the related article that posits taking too much honey and swapping in High Fructose Corn Syrup is making it worse:
(Phys.org) —A team of entomologists from the University of Illinois has found a possible link between the practice of feeding commercial honeybees high-fructose corn syrup and the collapse of honeybee colonies around the world. The team outlines their research and findings in a paper they’ve had published in the Proceedings of the National Academy of Sciences.
Since approximately 2006, groups that manage commercial honeybee colonies have been reporting what has become known as colony collapse disorder—whole colonies of bees simply died, of no apparent cause. As time has passed, the disorder has been reported at sites all across the world, even as scientists have been racing to find the cause, and a possible cure. To date, most evidence has implicated pesticides used to kill other insects such as mites. In this new effort, the researchers have found evidence to suggest the real culprit might be high-fructose corn syrup, which beekeepers have been feeding bees as their natural staple, honey, has been taken away from them.
Commercial honeybee enterprises began feeding bees high-fructose corn syrup back in the 70’s after research was conducted that indicated that doing so was safe. Since that time, new pesticides have been developed and put into use and over time it appears the bees’ immunity response to such compounds may have become compromised.
The researchers aren’t suggesting that high-fructose corn syrup is itself toxic to bees, instead, they say their findings indicate that by eating the replacement food instead of honey, the bees are not being exposed to other chemicals that help the bees fight off toxins, such as those found in pesticides.
Specifically, they found that when bees are exposed to the enzyme p-coumaric, their immune system appears stronger—it turns on detoxification genes. P-coumaric is found in pollen walls, not nectar, and makes its way into honey inadvertently via sticking to the legs of bees as they visit flowers. Similarly, the team discovered other compounds found in poplar sap that appear to do much the same thing. It all together adds up to a diet that helps bees fight off toxins, the researchers report. Taking away the honey to sell it, and feeding the bees high-fructose corn syrup instead, they claim, compromises their immune systems, making them more vulnerable to the toxins that are meant to kill other bugs.
So since these two interact with each other, laboratory testing showing neo-nics are not harmful enough to be the problem while NOT feeding them the way real working hives are fed will hide the doubled problem. Similarly, testing HFC feeding abasent neo-nics in the diet will have a lesser problem shown.
While real hives in the real world worked with HFC and exposed to neo-nics will have bees with poor immunity who can’t fly back to the hive well at all.
The good news is that it looks like folks are finally getting insight into the multifactor causality.