Polyphemus Moth

As I dropped my son off at school this week, I noticed this gorgeous moth beside the sidewalk. The Polyphemus moth or Antheraea polyphemus is a type of silkworm (Saturniidae) that is common in the United States, southern Canada, and northern Mexico. Adults begin to emerge in the spring to mate and lay oval eggs. Caterpillars develop through several molts before spinning a cocoon among dead leaves that usually fall to the ground. These moths have two generations per year. The adult moths have vestigial mouths, meaning their mouth parts have been reduced, and they cannot eat. The adult moths only live for less than a week once they have emerged from their cocoons.

The caterpillars of this moth emerge as small yellow caterpillars and go through five instars before turning into the large, three to four-inch-long, bright green caterpillar with silver spots. These caterpillars are considered generalist feeders and will eat from a number of host species, but prefer elm, birch, and willow leaves. The caterpillars are voracious feeders and can eat up to 86,000 times their weight in a little less than two months. Now that’s a very hungry caterpillar. Due to their low numbers, these moths aren’t considered a pest of any species. It’s also an important reminder that caterpillars can eventually turn into something beautiful, even if they are in your garden.

 

Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.

Phone: (316) 321-9660

Email: callae@ksu.edu