So glad I finally scrolled down and found this forum. I don't have an insect field guide for the US. Should probably get one as I travel there often, but I've been relying on on-line guides and so far have been able to identify most of the butterflies, moths, and dragonflies I encounter there. This one, however, has me stumped. It was clinging to some grass in the meadow on the bluff over the shoreline at Sea Ranch (northern California), Aug 22 this year. Very striking moth, so I'm assuming it's a known species. Thanks in advance for your help with the ID.