Dead larva found inside an acorn, probably from Q. chrysolepis. Acorn was buried under ~1/2 inch of duff, and found this when I cracked it open. It's long dead and pretty dried out, unfortunately.
Found on eucalyptus at the SLO arboretum
Found on bottle from river
Pulsating movement 1.3-1.9 cm diameter
Freshwater on San Joaquin River (still water)