Erynnis propertius (Propertius Duskywing)

There is a spot near Catherine Creek in the Columbia River Gorge where I go to find early season butterflies, and Propertius Duskywings are almost always there. It is a muddy seep on an old road and there are often dozens of these butterflies puddling there, along with Anise Swallowtails, California Tortoishells, various blues, and even the odd Julia Orangetip, although they don’t settle for long.

A puddle party with Erynnis prpertius, Papilio zelicaon, and an unidentified Blue.

This visit is a rite of spring for me, a sort of touchstone of the vernal resurrection, my symbolic canary in a coal mine. As long as the seep is still running, the lomatiums and balsamroots are blooming, and the Propertius Duskywings are puddling, I can convince myself that, at least in this small sector, the system is still functioning, and the natural world is withstanding the advance of so called civilization.

There is an odd gap in the range of these members of the skipper family (Hesperides), not having been found in Clark, Cowlitz, or Lewis Counties in Washington, or in Columbia County, Oregon. There are plenty of Garry Oaks in this area, but it seems to utterly lack any Propertius Duskywings. Bob Pyle has been puzzling over this for years, but despite extensive research and exploration he has yet to find an answer or an Erynnis propertius.

I have to admit that, because my first identification of this species was through the combination of binoculars, cell phone photos, and habitat, I had never noticed before that the forewing spots are hyaline (transparent). But then I kept reading that term in my research for this post, so I examined my photos and realized that those spots that I thought of as white were actually yellowish when it was perched on balsamroot. So, while I don’t think they are absolutely clear, they are certainly transparent.

Description– Medium sized (ws 30-38 mm) grey and dark brown butterfly with light and dark markings; dorsal forewing mostly grey with dark rimmed hyaline spots forming the transverse lines; those in the postmedial line are triangular; spots are larger on females; dorsal hindwing dark brown with darker smudges; males have a slight costal bulge holding pheromone producing scales.

Similar species-Duskywings are difficult to differentiate from each other because they are very similar in appearance, and variable in maculation; very clear and detailed photographs are a necessity in lieu of genitalic dissection; E. icelus has larger bulges in the forewing along the costa, and usually lacks hyaline spots on the dorsal forewing; other duskywings are smaller and less contrasted between fore- and hindwings.

Habitat– Wherever there are native oaks.

Range-Western North America; primarily west of the Cascades in our region, as well as east in the Columbia River Gorge and north along the east slope of the Cascades following the range of Garry Oak.

Eats-Larval hosts are Quercus spp., almost exclusively Quercus garryana in our region, although they are also known from golden chinquapin and may utilize other oaks in s Oregon.

Reproduction-Univoltine; larvae overwinter by hibernating in an oak leaf nest, and pupate in the spring.

Adults active– March to July; avid puddlers and hilltoppers.

Etymology of names–Erynnis is the name of the underworld deities from Greek mythology that we know as the Furies. It alludes to the irregular and erratic flight of these butterflies, as though they were attempting to escape the avenging goddesses. The specific epithet propertius honors a noted ancient Roman poet of that name.