By Jake Buehler
It’s been roughly 80 years since the Xerces blue butterfly was last spotted flitting about on pastel wings across coastal California sand dunes. But scientists are still learning about the insect.
New research on DNA from a nearly century-old museum specimen shows that the butterfly was a distinct species. What’s more, that finding means that the Xerces blue butterfly (Glaucopsyche xerces) is the first U.S. insect species known to go extinct because of humans, researchers report July 21 in Biology Letters.
The butterfly used to live only on the San Francisco Peninsula. But by the early 1940s, less than a century after its formal scientific description in the 1850s, the gossamer-winged butterfly had vanished. Its rapid disappearance is attributed to the loss of habitat and native plant food as a result of urban development and, possibly, an influx of invasive ants likely spread though the shipment of goods.
But it’s long been unclear if the Xerces blue butterfly was its own species, or simply an isolated population of another, more widespread species of blue butterfly, says Corrie Moreau, an entomologist at Cornell University.