Cercyonis sthenele silvestris

Common Name
Cercyonis sthenele silvestris

The currently-favored common name is misleading insofar as this species occurs widely in California west of the Great Basin. Like the other species of Cercyonis it is single-brooded, and the adults rather long-lived. On the transect it is abundant in grassland, shrub-steppe and alfalfa fields at Sierra Valley and occurs at lower density in brushy, rocky areas at Washington and Lang Crossing on the West slope. Adults fly low, near the ground, moving jerkily through the vegetation. They often sit on rocks or in paths but this is not territorial perching. They infrequently visit flowers, with Composites and Eriogonum nudum the most frequent choices. At all sites where it occurs, it flies primarily in June and July, with a few stragglers into autumn. There is a single record at Gates Canyon and one at Suisun, undoubtedly strays (from where?). On the West slope, there are subtle phenotypic differences between populations from the Yuba River drainage north and those from the American River south.