The White-lined Sphinx has a wingspan of 2.5 to 3.5 inches. The long forewing is dark brown with a broad, tan stripe extending from the base to the apex. Thin, white streaks cross it. The short hindwing is black with a pink median band. The thorax is dark brown with white vertical lines. The abdomen is brown with a white vertical line down the middle and black and white crossbands. The mature caterpillar grows to 2.75 inches. It is either yellow and black or bright green with a highly variable pattern. The head, thoracic shield and anal plate are all one color, either green or orange and covered with small pale dots. The horn at the end of the abdomen is yellow to orange and straight.
This is a common moth in Fontenelle Forest and Neale Woods. It flies often during the day and also at night. It can be seen nectaring at flowers and also comes to artificial lights.
The caterpillars eat the leaves of Evening Primrose and apple trees, but also many other herbs and woody species. This large Sphinx moth is sometimes mistaken for a hummingbird as it hovers over flowers while using it’s long proboscis to extract nectar. Large numbers of the adult moths have been seen to migrate at night along highways in the western U.S.