She appeared outside of our window in Sebastopol last night (20 April 2012) — the Vestal Tiger Moth (Spilosoma vestalis). Beautiful, shimmering white wings, with tiny black spots.
Close-up of the hindwings.
Black stripes on the abdomen. Relatively thin antennae indicating that this is a female. Long white hairs on the head and thorax.
And startling bright red forelegs.
Vesta is the Roman goddess of hearth and home. In ancient Rome, the Vestal Virgins guarded a sacred, undying fire in the Temple of Vesta. It appears as though the color of the forelegs of Spilosoma vestalis reminded Packard (who described the species) of this sacred fire.
According to the Moths of Western North America (Powell and Opler 2009), the Vestal Tiger Moth ranges along the West Coast from Washington south to Baja. The main flight period is listed as late May (rarely April) through June. Perhaps the warm air temperatures during the past week caused an early emergence?