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Achemon Sphinx Moth Caterpillars

Updated March 06, 2019
Professional headshot of Amanda Bachmann

Amanda Bachmann

SDSU Extension Urban Entomology Field Specialist

It seems that this is the week for caterpillar questions. A live sample and a few emails have come in of Achemon sphinx moth caterpillars (Eumorpha achemon). At this point in the year, the caterpillars are quite large (3 inches long) and wandering in search of a place to pupate. Both their size and their behavior are getting them noticed.

Profile

a long, worm-like caterpillar with small black spots and white markings
Figure 1. Achemon sphinx moth caterpillar. Photo: Amanda Bachmann

Appearance

These caterpillars are similar in shape to the commonly encountered tomato hornworm. Achemon sphinxes have white markings on their sides and a distinctive eyespot on the top of their hind end (Figure 1). The later instars are a pinkish brown color, but there are individuals that may be green.

Behavior

Achemon sphinxes feed on wild grape (Vitis), Virginia creeper, and related vines. In a backyard or garden environment, they are not considered to be an economically important pest species. The caterpillars pupate in the soil and will emerge as an adult moth in the spring. The moths are also large (3-4 inch wingspan) and feed on nectar.