The Dark Phalaenostola Moth has a wingspan of about 1 inch 25 mm). The forewing is brown, crossed by dark brown antemedial, post medial and subterminal lines. There is a dark, broad band in the median area. The wavy subterminal line is accented with 2 black bulges before merging with a black apical dash. The labial palps are upturned. The hindwing is paler than the forewing and is crossed by 2 dark bands. The caterpillar is brown with pinkish abdominal banding and a dark brown dorsal stripe that narrows anteriorly. This species was identified by expert volunteers at the BugGuide Website.