I’m a big fan of blueberries, so on our summer vacation in Maine, it was a treat to drive by the blue berry barrens, many of which are now converted to large farms for commercial harvest.
I was less pleased to see widespread signs to keep out—not apparently based on the idea that I might pick a few berries, but stating that the fields had been sprayed with imidacloprid—one of the neonicotinoid pesticides used to protect crops.
Neonicotinoids are systemic pesticides, meaning that when they are applied to crops, they travel through all the plant tissues, offering protection against insects. They are often applied even before there is an insect outbreak—a prophylactic use that affects non-target species.
And, of course, that means they end up in the cash crop as well—in this case blueberries, which we eat. Vertebrates are much less susceptible than insects to neonicotinoids, but the long-term effects are poorly studied.
It is clear that neonicotinoids can persist and accumulate in soils, and leach into nearby streams and rivers, where they are found at concentrations that kill beneficial insects and other invertebrates. Neonicotinoids in nectar and pollen are sufficient to impact colony reproduction in bees.
Currently under a 2-year moratorium in Europe, neonicotinoids are still widely used in the U.S., where the decline in bee populations should concern us all.
Neonicotinoids are certainly less toxic than some of the pesticides they replaced, but it is clear that a scientific judgment on neonicotinoids is not yet in hand. Meanwhile, enjoy your blueberries.
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Photo, taken on July 18, 2005, courtesy of Nadia Prigoda-Lee via Flickr.
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