NEW YORK -- A new bee is buzzing in New York City. The tiny insect, the size of a sesame seed, sips the sweet nectar of the city -- sweat, The Wall Street Journal reports.

"They use humans as a salt lick," according to entomologist John Ascher, who netted the first known specimen of the species in 2010 while strolling in Brooklyn's Prospect Park near his home. "They land on your arm and lap up the sweat."

North America is home to thousands of species of native bees. But they have long been overshadowed by imported honeybees, prized for their honey and beeswax since the time of the Pharaohs and a mainstay of commercial agriculture. Now, native bees are generating serious buzz.

So puzzling was the greenish-blue city bee he netted, though, that it took 41-year-old Ascher -- who oversees a digital catalog of 700,000 bee specimens at the American Museum of Natural History -- months to pinpoint its proper place in the insect kingdom.

In the end, only DNA testing by sweat bee specialist Jason Gibbs at Cornell University could identify its niche. Last November, they announced the discovery of Lasioglossum gotham, in a peer-reviewed journal called Zootaxa. The newbie joined the growing catalog of easily-overlooked wild native bees.

Sweat bees do not have a high profile outside academic circles. Unlike honeybees, which originally were imported from Europe, native bees do not make much honey. To their credit, though, sweat bees rarely sting; their occasional pinprick registers a one on the Schmidt Sting Pain Index, the lowest on the four-point scale.

These bees prefer sweaty people -- over most animals -- because the human diet usually is so salty that their perspiration is saturated with the essential nutrient, experts said. Yet most people never notice when the tiny bees alight on a bare arm or leg.

By the latest count, about 250 species of native bees are known to nest in New York City's sidewalk cracks, traffic median strips, parks and high-rise balcony flower pots -- more perhaps than any other major city in the world, several entomologists said.

"For certain species, the city is as good as or better than a natural area," Ascher said.

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