Orthosia transparens 
 
 
  
I have found the caterpillar of this moth on Salal Gaultheria 
  shallon. It has also been recorded on Arbutus and on Manzanita, all of 
  which are in the same botanical family Ericaceae. Winter is spent as a pupa, 
  and the adult moth is to be found in the early spring.