Adult sphinx moths have protruding heads, large eyes, a large “furry” thorax, and a conical abdomen that extends well beyond the hindwings when the moth flies. This species, the white-lined sphinx, has the top of the long forewing dark olive brown with a narrow tan band running from the base of the wing to the tip and with light tan streaks along the veins.
Larvae vary; they range from bright yellow-green to bluish-black with rows of whitish to yellow spots or dots and veinlike tracings. The caudal horn, which looks something like a tail, is yellowish green or black.
Similar species: More than 50 species of sphinx moths live in Missouri, all with the distinctive body shape, but none with the same pattern of lines on the wings as in this species.