Nearly 500 bee species are thriving in a small patch of US desert

By Jake Buehler

There are about 20,000 known species of bee on the planet, and nowhere else is this diversity more concentrated than in southern Arizona along the US-Mexico border. Hundreds of bee species can be found in a patch of desert there about the size of Heathrow airport, meaning it has the world’s densest aggregation of bee species yet measured.

Unlike plants and many other organisms that see the highest diversity in the tropics, bees seem be most diverse in warm, dry regions …