Parnassius clodius

Common to abundant from Lang Crossing up to Castle Peak; not at Sierra Valley. Common at Washington, near the lower elevational limit of its range. Higher-altitude specimens are consistently smaller than at Washington and Lang. The male of this species generates a large waxy vaginal plug (the sphragis) that prevents the female from mating again (though other males do try). It does not, of course, interfere with egg-laying! Both sexes visit Yerba Santa, Coyotemint, and a wide variety of other flowers.

Parnassius phoebus behrii

A characteristic alpine species of the central and southern Sierra Nevada, seemingly becoming rarer in recent years. Our transect lies entirely north of its breeding range, but it has been picked up a couple of times as an apparent stray. One brood, July-August; males hilltop. Host plant Sedum, which is common enough on the granodiorite balds at the east end of Donner Pass, but the butterfly does not breed there.