Protogygia milleri (Grote, 1876)
Protogygia milleri is a distinctive powdery gray medium size (FW length 15–18 mm) moth with black lines and spots found at mid to high elevations in central and south-western Oregon. The median area is slightly darker than the rest of the wing. The transverse lines and spots are black and somewhat indistinct. The antemedial line is slightly uneven and is oriented nearly perpendicular to the wing axis. The post medial line is scalloped and smoothly excurved. The subterminal line is black and jagged. The three spots are black and are filled with lighter gray. The orbicular spot is oval and the reniform spot is moderately indented laterally. The fringe is checkered with dark gray. The hindwing is gray, darkest at the base of the fringe. The fringe itself is nearly white. The head and thorax are powdery gray, with black on the collar and edges of the tegulae. The abdomen is similar gray to the hindwing. The male antenna is bipectinate.
Pacific Northwest populations of this species differ from those further south in being gray and black without warmer colors. Those from California have pink suffusion distal to the cell and in the basal and mid fold on the forewing.
This species can be told from other gray species with similar features by the powdery appearance, indistinct black lines, and elongate wing shape.
Larva is smooth, pale gray-white with thin white dorsal and subdorsal lines. It is illustrated by Lafontaine and Fauske (2004).
This species is narrowly endemic to drier forest habitats along the east slope of the Cascades and Sierra Nevada. In the Pacific Northwest, it is common to abundant in juniper woodlands at middle elevations east of the Cascades, and in lodgepole pine forests on volcanic ash soils at higher elevations along the east slope of the Cascades. It is rare in spruce-fir forests at high elevations along the summit of the Cascades, and in dry, open sagebrush steppe at low elevations east of the Cascades. This species may require loose soils of volcanic ash. It is also thought to be management sensitive, and benefits from thinning and burning that maintains an open pine forest and juniper woodland community.
Protogygia milleri is found along the east slope of the Cascade Mountains and in the adjacent Ochoco and Klamath Mountains in central and southern Oregon. The most northerly record is from Santiam Pass in Jefferson County, Oregon.
The range of this species extends south along the Sierra Nevada to southern California. It is also found in the Transverse Ranges north of the Los Angeles Basin.
No information is presently available regarding larval foodplants of this species, but it may be a burrowing cutworm the burrows through loose soils of volcanic ash and feeds on herbaceous vegetation.
Adults are single brooded and are on the wing from late May until early August in our region. They are nocturnal and come to lights.
Lafontaine & Fauske (2004)
Miller & Hammond (2007)