Four bumblebee species once common across North America have suffered precipitous—and so far mysterious—declines, a new study shows. Within the past 20 years abundances of the bee species Bombus occidentalis, B. affinis, B. pensylvanicus, and B. terricola have plummeted by up to 96 percent. The finding is based on a new analysis of more than 73,000 museum collections of bumblebees, which showed where bees had been found over the last century, as well as collections of wild bees across the USA. (source: news.nationalgeographic.com)
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