The eerie mystery of the vanishing honeybees has not been put to rest.
In the last few weeks, three separate studies explored the effect of insecticides on honeybee and pollinator health. One paper linked neonicotinoids, a new class of systemic insecticides that have come into widespread use in recent years, to impaired honeybee navigation; a second noted the effects of low levels of the pesticides on bumblebee reproduction.
The most talked about study, from a Harvard team, found that the colonies fed neonicotinoid-laced corn syrup collapsed in a manner that appeared to mimic the effects of Colony Collapse Disorder, or CCD—the mysterious phenomenon in which otherwise-healthy bees simply vanish from their hives. Neonicotinoids, declared the Harvard team, were “the likely culprit in sharp worldwide declines in honeybee colonies since 2006.”
“Dramatic headlines soon followed: “Mystery of the Disappearing Bees: Solved!” announced a Reuters headline. Ah, if only that were true. Even if neonicotinoids were banned tomorrow, honeybees would still be in big trouble.
The recent studies add to mounting evidence that low levels of neonicotinoids may have “sub-lethal” outcomes—long-term effects on pollinators that haven’t been measured in chemical-company testing submitted for EPA approval. What those papers don’t prove, unfortunately, is that “neonics,” as they are called, cause CCD—or explain the troubling colony losses we’ve seen in recent years….”