Amphizoa is a genus of beetles, placed in its own family, Amphizoidae. The vernacular name "trout-stream beetle" comes from the original finding of A. insolens and A. lecontei in high mountain streams, although other species occur at lower elevation. They are notable as a possible intermediate stage between terrestrial and aquatic beetles; while living in the water, they are not good swimmers and physically resemble ground beetles more than other types of water beetle.
There are a few records of Amphizoidae in BugGuide for California, but none in SoCal.
One species is known from area per The California Beetle Database .
Amphizoa insolens