With shades ranging from azure to cyan depending on which way the light hits it, the Xerces blue (Glaucopsyche xerces) is a beautiful butterfly. The tips of its wings, covered in soft down, are outlined in black with an intricate pattern of spots on their undersides. And the core of its body — the whole thing about as wide as a AA battery — has longer white hair flecked with grey.
It was first described in 1852, but the last time anyone saw one alive was in the early 1940s. “It’s a wrong place, wrong time kind of species,” says entomologist Jaret Daniels, a curator at the Florida Museum of Natural History. “Human expansion really was the deathblow to this species.”
