We’ve known for a while that bees are in trouble. Since around 2006, beekeepers have been seeing entire colonies disappear, as if they’d been zapped away by aliens.
This phenomenon, dubbed “colony collapse disorder” (CCD), has been attributed to fungi, stress, and malnutrition, among other causes. A number of factors likely play a role. But a growing body of research seems to show that pesticides are the prime culprit.
The trouble stems from one class of pesticide, in particular: neonicotinoids (neonics for short). When seeds are treated with neonics, the chemicals are taken up into the plant’s vascular system and “expressed” in nectar and pollen. As built-in pesticides, neonics turn an innocent corn plant into an insect-killing machine.
Neonics are used on a huge portion of our crops, including almost all of our corn. According to Pesticide Action Network of North America, at least 140 million acres are planted with neonic-treated seeds.
How do neonics affect bees? Tom Philpott has the answer:
The ubiquitous pesticides appear to affect bees in two ways: in big lethal doses that occur at the time of seed planting, when neonic-infused dust wafts around in growing areas; and in tiny doses that happen when bees bring neonic-infused pollen into hives, which don’t kill them immediately but appears to damage their immune systems and homing abilities.
But that’s not all. Harvard scientists recently found that high-fructose corn syrup, fed to bees by beekeepers, can trigger CCD. Since corn plants are treated with neonics, corn syrup contains traces of the pesticide–not enough to kill bees right away, but enough to slowly destroy colonies.
More new research further clarifies the problem:
- A paper released in the journal Science found that small doses of a neonic hinder bees’ ability to locate their hive “at levels that could put a colony at risk of collapse.”
- Another Science paper showed that (surprise!) neonics harm bumble bees, as well, causing an 85 percent reduction in the number of queens produced. Maybe that’s why bumble bees in the US have declined 96 percent in the last few decades.
- A study in Environmental Science & Technology looked into the effects of neonic-contaminated dust. The result? “Environmental release of particles containing neonicotinoids can produce high exposure levels for bees, with lethal effects compatible with colony losses phenomena observed by beekeepers.” In other words, bees can die immediately after flying over freshly-sown cornfields.
[Image: William Warby]