In Washington State we have ten species of butterflies which are loosely grouped as “checkerspots” owing to the cancellate or squarish patterning of intersecting lines on the wings. Our checkerspots are scientifically grouped into three separate genera, Euphydryas, the “true checkerspots” to many lepidopterists, Phyciodes, also known as the “crescents”, and Chlosyne, the remaining checkerspots which include our species. The genus Euphydryas can be distinguished by the very straight leading edge of its forewings, and Phyciodes can be distinguished by the presence of a distinct light-colored crescent-shaped mark near the outer margin of the ventral hindwing. Chlosyne has strongly curved forewings and lacks the crescent-shaped mark.

Chlosyne hoffmanni is found in a narrow band extending along the Cascade, Sierra and Siskiyou Mountains from southern British Columbia to central California, thus is a strictly western North American species. In Washington State the species is found primarily east of the Cascade crest in the north, but along both slopes further south.

The Hoffmann’s Checkerspot flies from early May to mid August, depending on elevation and the annual climate, and is strictly single-brooded in Washington. After mating the female lays a large mass of eggs on the host plant, usually in

July and typically on Cascade Aster (Eucephalus ledophyllus) or Showy Aster (Eurybia conspicua). The eggs hatch ‘en masse’ and the young larvae live communally in loose silk nests beneath which they skeletonize the aster leaves. The larvae diapause in the 2nd or 3rd instar, overwintering in this state. When the aster host plants begin growing fresh in the spring the surviving larvae disperse, usually only one or a few per plant. If disturbed the larvae coil into a ball and tumble to the ground as a predator escape response. The larvae pupate and the fresh adults eclose a couple of weeks later to repeat the cycle. The other nine species of Washington’s checkerspots generally have a similar life cycle, although one is multi-brooded and food plants are not restricted to asters in all of the other species.

The three species of Chlosyne can be a challenge to separate in the field, although dissection of male genetalia is diagnostic. The Hoffmann’s Checkerspot is blacker at the base of the dorsal forewing than the other species, and sexes are alike. The Sagebrush Checkerspot, Chlosyne acastus, a shrub-steppe species which flies earlier in the season, can be distinguished by its all black females. The Northern Checkerspot, Chlosyne palla, is more challenging, but can usually be distinguished by its less solidly black base of dorsal forewing; also it flies later in the season, and only in northern Klickitat County does its range barely overlap with C. hoffmanni.

Hoffmann’s Checkerspot is a montane species, typically found in relatively moist areas near streams or seeps in forest openings where asters are common. The reported elevation range is 1000 – 6000 ft, but most seem to occur in the 2000- 3000 ft. elevation range. Adult males can be found mudding along unpaved roads, often in the company of Euphydryas checkerspots. Chlosyne hoffmanni can be rather numerous at times and in some places; one good locality is Derby Canyon near Peshastin, Chelan County.

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