Thuja plicata
The larvae feed on "Juniperus scopulorum", "Thuja plicata" and "Chamaecyparis nootkatensis". The larvae are twig mimics. They are mottled yellowish green with a brown head. Full-grown larvae reach a length of about 20 mm. Larvae can be found from April to May and pupation occurs in June. The species overwinters as a mid-instar larva.