The Two-banded Checkered Skipper is included in the family Hesperiidae, the large worldwide family of butterflies known as skippers. All North American skippers have recurved antennal clubs. Most skippers fit into two subfamilies, the Pyrgine or “spreadwing” skippers, and the Hesperine or “monocot” skippers. In Washington there are 30 species of skippers, 12 of which are Pyrgine (spreadwing) skippers. The spreadwings include the genus Pyrgus, in which there are three species in Washington.

Skippers in the genus Pyrgus are small. Dorsally they are brown to gray-brown, checkered with contrasting squarish white spots, and the pattern of these spots is useful in identifying the species. Ventrally the pattern is reversed, being white to gray in background coloration with darker squarish brown spots. Our three species of Pyrgus generally occupy very different habitats, P. ruralis in moist, forested areas on both sides of the Cascades, P. communis strictly east of the Cascades in Washington, mostly in lower foothills and the dry Columbia Basin, and P. centaureae in high alpine habitats of the far North Cascades. Two- banded Checkered Skippers can often be found along the shoulders of unsurfaced roads in forested areas, or in such places as gravel pits or along powerline rights- of-way. P. ruralis is the darkest of our three checkered skippers, both dorsally and ventrally.

The Two-banded Checkered Skipper is a strictly western species, occurring from southern British Columbia, south along the coast through more than half of California, and east to the eastern flanks of the Rocky Mountains, exclusive of arid regions within this range. In Washington State Pyrgus ruralis is found on both sides of the Cascade Mountains (although it is much  more  common  on  the  west  side),  and throughout the forested areas around the perimeter of the Columbia Basin.

Pyrgus ruralis is single-brooded in Washington, attributing its long flight period to elevational differences rather than multiple broods. This species overwinters in the chrysalis, allowing it to eclose very early in the spring, one of our earliest butterflies. The reported flight period in Washington is late March through mid July. This skipper uses Strawberry (Fragaria), Cinquefoils (Potentilla) and Mallows (Sidalcea), probably Avens (Geum) and possibly Horkelia (Horkelia) as its larval food plants. Females lay eggs singly on the undersides of leaves of the food plant. The first two larval instars construct silken mats on the leaf surface and live under the mats where they feed by surface grazing. By third instar they become strong enough to tie the leaves, sometimes several, together with silk strands to make protective nests, living on the ventral leaf surfaces and skeletonizing the leaves in the nest, feeding mostly at night. By “poop-shooting” they propel their frass away from the nest. Like many skippers the larvae rest with their heads curved back parallel to the body in a candycane shape.

An adult collected near Nooksack Falls on May 27 produced viable eggs, and a natural egg was found on wild strawberry on Amabalis Mountain near Easton on June 13. At higher elevations the cycle is surely later in the season. Development in captivity took 52 days from egg hatch (June 4) to pupation (July 26).

In Washington Pyrgus ruralis is best separated from the two other species of Pyrgus by its darker coloration, woodland habitat, and by the crude “X” formed by white spots against a dark brown ground color on the dorsal forewing. Additionally P. ruralis is the only checkered skipper found west of the Cascade Mountains.

Photos by Dave Nunnallee

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