I have never found any males, but there seems to be lots of females under bushes. I'm wondering if maybe males hang out in the bush instead of under it. I'll have to take a better look next week. I did get a reply from someone at the California Academy of Sciences:
"The cockroach that you are seeing was first noticed in Marin County a few years ago. Specimens were sent to the California Department of Food and Agriculture, and they in turn sent the specimens to a specialist in Germany. So far, we have not heard back from them. There are no specimens of this species in the CAS collection. It appears to be from a species group found in SE Asia. By the way, only females are wingless – males have wings."
Norman D. Penny, Ph.D.
Sr. Collections Manager
Entomology Department
California Academy of Sci.