The disappearance of large numbers of honey bees, known as colony collapse disorder (CCD), has been linked to any number of potential factors, including the widespread use of pesticides.
Now there is a study suggesting that supposedly benign pesticides that are intended to make bees healthier might actually be harming them.
The study, led by a scientist at Virginia Tech, says the pesticide affects bacteria in bees that can reduce their ability to process sugars and peptides. Without that ability, their health can suffer.
“Although helpful for ridding hives of parasites and pathogens, the chemicals in beekeeper-applied pesticides can be harmful to the bees,” said Mark Williams, an associate professor of horticulture at Virginia Tech. “Our research suggests that pesticides could specifically impact the microbes that are crucial to honey bee nutrition and health.”
The research project studied genomic data from bees from hives treated with pesticides and those that were not. The results were pretty clear cut – bees from hives treated with the pesticides showed the greatest change in gut microbiome.
There could be other reasons
Could this affect honey bee survival? The researchers say it might. They've called for additional study to more definitively answer the question.
The U.S. Department of Agriculture (USDA) defines CCD as a dead colony with no adult bees, no dead bee bodies, a live queen, and usually honey and immature bees still present. As yet, scientists don't know what causes it.
However, bees have other threats. The USDA says the threat from CCD has actually begun to decline, eclipsed by the threats of poor nutrition and parasites.
In Virginia, the study says annual hive loss is around 30%, with no end in sight. That, researchers predict, will likely drive up the cost for important crops that pollinating bees make possible, such as fruit and vegetables.