Cool, tiny moth doing a little tail-chasing dance on a valley oak leaf. Saw one more, also on valley oak, but there was plenty of coast live oak nearby, which is supposed to be the larval host.

Original description by Opler is at http://biodiversitylibrary.org/page/41066596, but the only additional ecological info is that it forms leaf mines in Q. agrifolia and Q. wislezenii. Extensive discussion and pics of larvae can be found at http://bugguide.net/node/view/384085

Timing is kind of weird. According to Powell & Opler and the MPG charts this should be a spring species.