Nonlethal exposure has significant impacts, new study shows
The evidence keeps mounting that pesticides are the main driver of honey bee declines. In a new study, scientists with the University of California San Diego showed that a commonly used neonicotinoid pesticide (thiamethoxam) 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.
Experts say more vigilance is paying off, but loss rate still high
U.S. beekeepers said they lost 33 percent of their honey bee colonies during the year spanning April 2016 to April 2017. Rates of both summer and winter losses declined from previous years, with winter losses at the lowest level since the formal survey started in 2007.
FRISCO —The latest in a series of studies linking declines in bee populations with systemic pesticides shows that fipornil and imidacloprid affect basic cell functions. The findings help explain why the pesticides are toxic to bees.
Concentrations in some streams are high enough to kill aquatic organisms
By Summit Voice
FRISCO — Scientists with the U.S. Geological Survey studying streams in the Midwest have found levels of neonicotinoid insecticides at up to 20 times the concentrations deemed toxic to aquatic organisms. The systemic pesticides have raised concerns because they’ve been linked with honey bee declines.
Traces of the chemicals were widespread in streams throughout the region — not surprising in the heart of the country’s agricultural belt. In all, nine rivers and streams, including the Mississippi and Missouri Rivers, were included in the study. The rivers studied drain most of Iowa, and parts of Minnesota, Montana, Nebraska, North Dakota, South Dakota, and Wisconsin. These states have the highest use of neonicotinoid insecticides in the Nation, and the chemicals were found in all nine rivers and streams. Continue reading “Environment: USGS study shows neonicotinoid pesticide pollution common in Midwest streams”→
FRISCO — Honey bee colonies continues to die off at an alarming rate last year, with beekeepers reporting that they lost 23.2 percent of their colonies during the 2013-2014 winter. The preliminary numbers are from a survey conducted by the Bee Informed Partnership and the U.S. Department of Agriculture.
The drop in mortality may be a small ray of hope in an otherwise bleak picture, showing mortality that is not economically sustainable for beekeepers. Of course it’s not just honey that’s at stake. Commercial beekeepers truck thousands of hives around the country to help pollinate many commercial food crops. Continue reading “Environment: Honey bee mortality drops slightly”→
Bees leave their hives and die after exposure to neonicotinoids
By Summit Voice
FRISCO — The closest thing yet to a smoking gun in the ongoing decline of honeybees has emerged. Scientists with the Harvard School of Public Health say their research links systemic neonicotinoid insecticides with colony collapse disorder. The findings contradict suggestions that a parasitic mite is the main cause of the honeybee decline.
After closely tracking the fate of several bee colonies in New England, the researchers said they found that, when bees were exposed to low doses of imidacloprid or clothianidin, they abandoned their hives over the winter and eventually died.
“We demonstrated again in this study that neonicotinoids are highly likely to be responsible for triggering CCD in honey bee hives that were healthy prior to the arrival of winter,” said lead author Chensheng (Alex) Lu, associate professor of environmental exposure biology at HSPH. Continue reading “Environment: Smoking gun in honey bee die-off?”→
More evidence showing that systemic neonicotinoids are having a significant impact
By Summit Voice
FRISCO — Even if systemic neonicotinoid pesticides don’t kill bees directly, they are contributing to the collapse of honey bee colonies, according to new research by scientists from Royal Holloway University.