Bees getting hooked on pesticides
PARIS—Like nicotine for humans, certain pesticides seem to hold an addictive attraction for bees, which seek out tainted food even if it may be bad for them, research showed on Wednesday.
Not only did bees show no signs of avoiding neonicotinoid-laced food in lab tests, they seemed to prefer it, said a study in the science journal Nature.
“We now have evidence that bees prefer to eat pesticide-contaminated foods,” said study author Geraldine Wright of Newcastle University.
This suggests, she said, “that like nicotine, neonicotinoids may act like a drug to make foods containing these substances more rewarding.” Neonicotinoids are lab-synthesized pesticides based on the chemical structure of nicotine.
They are widely used to treat crop seeds designed to be absorbed by the growing plant and attack the nervous system of insect pests.
Previous research, however, has linked them to scrambling memory and navigation function in bees, affecting the little pollinators’ ability to forage.
Colony collapse disorder
Bees have been hit in Europe, North America and elsewhere by a phenomenon called “colony collapse disorder,” which has alternatively been blamed on mites, a virus or fungus, pesticides, or a combination of factors.
Bees account for 80 percent of plant pollination by insects, a function estimated to be worth at least $153 billion (142 billion euros) a year globally.
Pending clarity on the safety of neonicotinoids, a topic that is fiercely debated among scientists, environmentalists and agrochemical producers, the European Commission has restricted their use in bee-attracting plants for two years since Dec. 1, 2013.
A second study carried out by Nature on Wednesday found further evidence of risk for some bee species from neonicotinoids, which come in three types: clothianidin, imidacloprid and thiamethoxam.
“Foraging-age bees of both species did not avoid any of the concentrations of any of the three neonicotinoids,” Wright said.