Blinded Sphinx Moth Not Really Blind At All

Updated: Jun 28

The hawk moth family, or family Sphingidae, includes many of the largest moth species around. Moths from this family that you may know are the cecropia moth, which can have a wingspan of up to 6 inches; the hummingbird moth; and the large green hornworm caterpillars that eat your tomato plants year after year. One of the most common members of the hawk moth family is the blinded sphinx moth. They are found throughout the United States.

A blinded sphinx moth. (Photo by Angela Rafac)

Adult blinded sphinx moths are shades of gray and brown with very dark patches near the center of each wing. The forewing is scalloped, with many indented semi-circles along the margin. They have thick, stocky bodies, and their wingspan is between 1½ inches and 2 inches.


Blinded sphinx moths are not blind at all. They have eyes and can see as well as other moths. But like many other moth and butterfly species, they have “eye spots” on their wings. Eye spots are meant to intimidate potential predators. The blinded sphinx moth has blue eye spots on the upper side of its hind wings. They are only revealed when the wings are open all the way. The eye spots are just to the inside of a little pink patch also located on the upper side of the hind wing. It is because the eye spots lack a fake pupil that these moths are called blind.

 

Words to know

Margin: The edge or border of something.

Proboscis: An elongated sucking mouthpart on many insects that is typically tubular and flexible.

Scalloped: To be edged in half circles.

 

While many sphinx moths are known for their extra-long tongues, or proboscises, the blind sphinx moth does not have mouth parts at all. These adults do not eat. Instead, they put all their energy into finding a suitable mate and reproducing.


After mating, the female will lay eggs on the leaves of host plants for the caterpillar. Host plants in our area include many trees like oak, poplar, cherry, hawthorn, basswood, willow and birch. Eggs hatch seven to eight days after they are laid. The caterpillars are green, hoping to remain hidden in the leaves from potential predators like birds and parasitic wasps.


These green caterpillars are covered in tiny white bumps. They have three pairs of true legs near their head. (True legs have knees!) Additionally, they have four pairs of prolegs (no knees) to help them move around. They also have a pointy horn at the tip of their butt. This spike is harmless to us, but because of it, caterpillars in this family are commonly called “hornworms”


In the fall, the fully grown caterpillars will form a brown cocoon that is camouflaged among the dead leaves on or underground. They will transform in their cocoon, or pupate overwinter and emerge as adults the in the spring. In Will County, the moths are mostly seen in June and July, so keep your eyes out for this spectacular creature of the night.

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