On a mandarinquat tree. Was filled with white powdery stuff when I pulled it off the plant. Not entirely certain on ID. Looks like the fourth photo here:
Stuck to my thumb with surprising tenacity. Rolled up into a ball later.
A pair hopping around and stabbing gleefully at where I'd just turned up the soil.
Observed on Canyon Oak Way, Cupertino, CA while driving at night near County Park.