Flitting from blossom to blossom, bees represent an ecological lifeline from one generation of plants to the next – paid in nectar and pollen to keep the reproductive ball rolling on farms, in woods, and in backyard gardens.
But since 2006, concerns have grown over a decline in bee colonies worldwide. One of several potential suspects researchers have identified: a class of pesticides known as neonicotinoids. Formulated to be less harmful to mammals than its predecessors, neonicotinoids spread throughout a plant to boost its resistance to insects.
But the pesticide also finds its way into nectar and pollen, and therein lies the rub. A growing body of research has identified several ways neonicotinoids can harm wild and domesticated varieties of bees. But the results sometimes have encountered criticism, especially from pesticide makers, for whom neonicotinoids, by some estimates, represent more than 20 percent of their market.
Taken together, the two studies point to a compound that, with repeated exposure, can be detrimental to bees who can't stop themselves from going back for more.
With each visit, "they're getting their little buzz, as it were," said Geraldine Wright, a researcher at Newcastle University's Institute of Neuroscience in Britain who led a team performing one of the two studies.
(Peter Spottes. Can bees become addicted to pesticides? Christian Science Monitor. April 23, 2015.)