Xerces blue

plural Xerces blues

1. A recently extinct species of gossamer-winged butterfly (Lycaenidae), Glaucopsyche xerces.

   Last seen at the Presidio, the Xerces blue finally passed from existence in 1943.

   2010, Robert Michael Pyle, Mariposa Road

   2 more examples

   In fact, the xerces blue survived that first wave of habita destruction, only to succumb in the 1940s to continuing development especially of sand dune habitats.

   2012, Peggy L Fiedler, Conservation Biology, page 180

   The Brown Satyr butterfly, endemic to San Francisco, where I live, became extinct sometime in the 19th century, and the Xerxes Blue vanished during World War Two when its Golden Gate habitat was overtaken by military expansion.

   2015, Rebecca Solnit, “Middle-Aged and Dishevelled”, in London Review of Books, volume 28, number 6