Sphinx moths are notable for their fast flight and rapid wingbeat. These attributes account for one of their common names — “hawk” moth. Most species of sphinx moths are capable of hovering in front of the flower from which they are drinking nectar, and some species are referred to as “hummingbird” moths.
In their larval form, sphinx moths are notable for the horn which extends upward near the end of their abdomen. Tomato growers are familiar with the Tobacco Hornworm (Tobacco Hawk Moth/Carolina Sphinx Moth) and Tomato Hornworm (Five-spotted Hawk Moth).
Less frequently encountered is the larva of the Great Ash Moth (Sphinx chersis). Named for a host plant of the adult moth, this greenish or pinkish caterpillar has seven long diagonal lines along its body, which are sometimes edged with pink. Its black spiracles (external openings that allow gas exchange) are elongate and ringed with white. Its horn is blue or pink. As an adult moth, it is gray with black markings and has a wingspan of up to five inches. You’re most likely to see this moth at dusk, feeding at deep-throated flowers. (Thanks to Heidi Marcotte and Tom Wetmore for photo op.)
The larvae of sphinx moths, commonly called hawk or hummingbird moths, are easily recognized by the horn, eye spot or hardened button that is near the tip of their abdomen. Most readers are probably familiar with the larval stage of tobacco and tomato hornworms (Carolina Sphinx Moth and Five-spotted Hawk Moth, respectively) which are found on tomato plants. A less observed sphinx moth, Abbott’s Sphinx Moth (Sphecodina abbottii), can be found on grape and Virginia creeper vines. As a larva it molts several times and assumes three different appearances by the time it pupates.
Abbott Sphinx Moth larvae start out green, with a horn near the tip of their abdomen, like most other sphinx moths. However, when they are about half-grown, they turn blue-green and the horn develops into an orange knob (see inset). In the last stages before they pupate, the larvae molt and the knob turns into an “eye,” complete with a black pupil and encircling iris. The finishing touch is a white reflection spot that makes the eye appear moist and shiny. At this point, the larvae may be either brown with a “wood-grain” pattern (resembling grape vines, a host plant) or brown with ten pale green saddles along the back (thought to resemble grapes). Pictured are the second and third stages of a brown “wood-grain” Abbot’s Sphinx Moth larva.
Moths in the family Sphingidae are commonly called “hummingbird” (for their habit of hovering as they feed on nectar from flowers), “sphinx” (the larva holds its legs off the surface and tucks its head underneath, resembling the Egyptian Sphinx) or “hawk” (they fly with great speed and precision) moths. Most are fairly large, with some species having a wingspread of up to 5” or more.
One group of sphinx moths is referred to as the “Eyed Sphinx Moths,” two of which are the Blinded Sphinx Moth (Paonias excaecata) and the One-eyed Sphinx Moth (Smerinthus cerisyi). The derivation of their respective common names can be easily ascertained by examining the upper surface of their hind wings. The Blinded Sphinx Moth has a single blue eyespot on each hindwing, whereas the One-eyed Sphinx Moth has a round or diamond-shaped black spot (“pupil”) in the center of each blue eyespot. The Blinded Sphinx Moth is light brown, whereas the One-eyed is a violet-gray. Both moths have scalloped wings that are held elevated and slightly away from the body. They are nocturnal, and regularly visit lights in small numbers. Their life is short, and adults of both species do not feed.