The Xerces blue butterfly has the dubious distinction of being the first insect species in the United States to have been driven off the existential cliff of extinction by humans—the last one having been collected at San Francisco’s Lobos Creek in 1941 less than 100 years after the species was first described by biologists.
There is no question that human activities, specifically decades of livestock grazing and urban development that denuded and bulldozed the dunes, caused the Xerces blue to vanish, but in the years after its disappearance a debate emerged concerning whether this doomed butterfly was a distinct species or just an isolated population of the wide-ranging silvery blue butterfly.
This Butterfly Is the First U.S. Insect to Be Wiped Out by Humans | Smart News | Smithsonian Magazine
There is no question that human activities, specifically decades of livestock grazing and urban development that denuded and bulldozed the dunes, caused the Xerces blue to vanish, but in the years after its disappearance a debate emerged concerning whether this doomed butterfly was a distinct species or just an isolated population of the wide-ranging silvery blue butterfly.
This Butterfly Is the First U.S. Insect to Be Wiped Out by Humans | Smart News | Smithsonian Magazine