Western Tussock Moth (Orgyia vetusta) caterpillar, Stulsaft Park, Redwood City, San Mateo County, California - 7 May 2014. Beat from a flowering California Buckeye tree onto a beat sheet, photographed and released. Likely parasitized by a tachinid fly - note white eggs on the side of the caterpillar. Thanks to Ross Hill and Bug Guide for the species-level ID and for noticing the eggs: bugguide.net/node/view/918005#1632283