Erynnis brizo burgessi

Sleepy Duskywing

Erynnis brizo burgessi is perhaps best known from Arizona and Nevada, but it also reaches eastern California in the eastern Mojave ranges where oak shrubs such as Quercus turbinella grow.

This butterfly was named by Henry Skinner in his 1914 article "Review of the Genus Thanaos," avaliable here (and excerpted below). In the full article, Skinner descibes quite a mess that he was grappling with when it came to the dark spread-winged skippers. His study sought to improve upon the purely genitalic analysis of the group by Scudder and Burgess, whose slides that constituted the types were lost after Burgess's death. In any event, Skinner named Thanaos burgessi, which he considered similar to Thanaos brizo but genitalically distinct from it. His types are from Mt. Graham in Arizona. Obviously, this butterfly is now considered a subspecies of brizo. I believe most of the taxonomic issues were worked out by John M. Burns in his monograph, Evolution in Skipper Butterflies of the Genus Erynnis, University of California Publications in Entomology, Vol. 37, 1964. I don't yet own this and it isn't online, and I'm not quite ready to spend $50 and wait a month for it to arrive from London. So there's that.

Erynnis brizo burgessi - Sleepy duskywing skipper
Erynnis brizo burgessi from the New York Mountains off Caruthers Canyon Road. May 6, 2020. It's the only one I saw that day.
Erynnis brizo burgessi - Sleepy duskywing skipper original description
Excerpt of Skinner's description of Erynnis brizo burgessi.

©Dennis Walker