Two batches found 7-12-08. One was first instar and one an egg ring when found. Eggs hatched 2-15-08. One batch now appears 3rd instar the other mostly 2nd (some still 1st). Found on and feeding primarily on Salix exigua (have also nibbled on Salix babylonica, S. irrorata, and Prunus serotina).

Sorry the quality isn't better.

Presumed to be Saturniidae? Perhaps Automeris or Hemileuca? I find images of Automeris larvae this young, and they do appear similar. Could be A. io or A. zephyria. The most likely Hemileuca for the region on Salix is H. nevadensis, but larvae seem to be the wrong color and to have hatched too late (?). They are lt. orange with pale longitudinal stripes and spines on first two instars grayish to blackish, or on a few creamy yellow. On third instar they are white and black or gray. Am I way off here?