It turns out the phenomenon is nothing new. In 1905, the A.I. Root Company, beekeeping suppliers still operating today, kept 28 hives on the roof of a building on Vesey Street in Manhattan, near two big candy factories. The bees flew into the boiling room of one factory through windows kept open "on account of the great heat within," The New York Times wrote. They sucked up what sugary liquids they could find, stinging workers who stood in the way and a Board of Health inspector conducting too assiduous an investigation.

There have always been bees, said Dell's Maraschino Cherries owner Arthur Mondella, gravel-voiced and dough-faced with a widow's peak. His office is filled with a sweet scent, and jars of cherries adorn every desk: Some are an alarming shade of jade, others PlaySkool hues of blue and orange, but most are that shrieking, tropical-sunset red that tops Manhattans and old-fashioned cherry Cokes. In the past, Mondella said, small numbers of bees would show up looking for cherry juice in the fall, when few flowers bloom with nectar. But he would throw shrink wrap over the bins of cherries, and the bees would disappear.

This year, the bees came in the middle of the summer, and didn't go away. They'd crawl onto the wrap, and go for tiny drops of cherry syrup on the plastic. Mondella got stung. "I was outside, and we were getting swarms, hundreds of bees," Mondella said. "Well, it's not like Alfred Hitchcock's 'The Birds.' But you'd see a bee. And then there'd be two. And then there'd be three. And then a dozen." Soon he learned that the city had legalized beekeeping this spring, and several new beekeepers had set up nearby hives—though some insects were coming from as far away as Governors Island.

"When a beekeeper opens a bee factory next door, what can you do?" Mondella asked. With the danger of bees contaminating his cherries, and threatening his 62-year-old family business, he had to find out. He contacted the Health Department, the Brooklyn Borough President's Office, a local business development group. He hired Andrew Coté, the head of the New York City Beekeepers' Association, to come up with a solution.

Robin Shulman

Like Mondella, the owner of the candy factory overrun by bees in 1905 was concerned. He "has lost a lot of sleep lately figuring up how much sugar he has been robbed of to keep a colony of 3,000,000 bees," the Times said (perhaps overestimating the numbers). Later, in 1911, bees at City College produced honey as green as pistachio ice cream (which might even then have itself been dyed). "Who outside of a nature-faker's book ever heard of green honey?" asked the president of the college, John Huston Finley. For a time, he suspected the bees of stealing chemicals from a biology laboratory, but then he identified their more likely source, a candy kitchen on Amsterdam Avenue.