New Delhi, May 16 -- On an unusually mild May morning, Sunder Nursery in Delhi's Nizamuddin Basti area is all abuzz. Quite literally. Behind the stone wall marking the end of the territory accessible to visitors, some winged creatures are fluttering around over a few private acres of wilderness. At a glance, they look about the size of a housefly or gnat. But these busy creatures are, in fact, stingless bees, one of the several species of bees in this 16th-century Mughal garden.

"There must be 100 stingless bees around Sunder Nursery," says Rakesh Gupta, a beekeeper for over 20 years and chief adviser to the Lucknow-based Golden Hive Foundation, founded in 2015. "These are extremely versatile pollinators. Some varieties of this species o...