Monday, December 14, 2009

Polyphemus Moth

This large gorgeous moth is the Polyphemus (Antheraea polyphemus). They have a wingspan of almost 6 inches. Their coloring is spectacular, with various shades of tan, brown, gray and beautiful pink. Those large eyespots on their hindwings are used for protection from predation. Many birds and other creatures might think twice before trying to dine on this insect if they assume it is something other than what it is, which is where those "eyes" come in. The one pictured here is a female. Three simple ways to tell male from female are

1.) The males have large feathery antennae, these are used to detect the pheromone the female emits. He can
      smell her from great distances.
2.) The females are typically much larger than the males.
3.) The females also have very large abdomens, this is for egg production.

The Eastern portion of the United States is home to many large moths in the family Saturniidae, which are the silk moths. These include the Polyphemus, Luna, Promethea, Rosy Maple, Io, Cecropia, and the Imperial to name but a few. Each of these reside in Missouri. The Polyphemus is one of my favorites, second only to the Luna.

 The overly large caterpillars of these moths are nearly as beautiful as the adults. These caterpillars are eating machines, they eat huge amounts of leaves gaining so much weight that by comparison if a human baby ate as much as a caterpillar, in a single weekend your baby would weigh as much as a hippo. They need to pack on this excessive weight to keep them alive as adults long enough to mate and lay eggs. Once they reach adult size they do not eat, their only goal is to find a mate, breed and lay eggs. The extra weight that they put on as caterpillars is what keeps them alive for the 5 to 7 days of their adult life.

They can be found in or near hardwood forests, as well as urban, suburban areas and orchards and wetlands. The caterpillars feed on maple, elm, oak, willow, and birch as their host plants. The caterpillars rarely become a serious agricultural pest as the female's egg laying habits are very random. If they were to use a very young tree as a host there is the potential the tree could damaged. Occasionally these moths are attracted to lights at night. I've found several of them at a mercury vapor light and a white sheet that I put up.


  1. Lovely photos and great post! I'd read about the Polyphemus moth in Annie Dillard's Pilgrim at Tinker Creek. (Have you ever read that? I think you would like it.) But I'd never seen one before, and it's true, the eyes are quite striking. I did not realize they stop eating once they reach adulthood -- or that it was so very brief for these lovely things.

  2. Oh, and by the way, I couldn't find an e-mail address to ask my question, so I'll ask it here. I posted about a bug this summer on my garden blog, and the photo is found here:

    I'd be curious to find out what it's called, and anything about it, if you know. It was such an unusual thing, to my eye.

  3. I've heard of the Pilgram at Tinker's Creek and did not know what it was about. I will have to try and find it for a winter's read. Thank you for your kind comments. I'm so glad you are enjoying the posts. My email is feel free to email me anytime.

    I looked at your photo and your mystery bug is a Golden Tortoise Beetle. They feed on plants in the morning glory family. They are truly unique and wonderful little insects. I've seen Argus Tortoise Beetles and Mottled Tortoise Beetles feeding on some wild morning glory that grows in my backyard. It always twines itself around my peppermint, and I pull it to no avail, it just keeps coming back. So I gave up and let the tortoise beetles have at it. If you visit and enter in Golden Tortoise beetle in the search bar I'm sure there will be more info available for you.

  4. A beautiful moth. I especially like their clear eye spots. I usually see several during the course of the spring and summer, but saw none in 2009. I have no idea why, except that maybe our ice storm took its toll on their pupal cases.

  5. They truly are beautiful. I love the eyespots too. Mother nature is absolutely amazing.I didn't see in the past season either. The ones photographed here were photographed in 2008. I found several that year. I agree that the ice storm probably took it's toll on them. We were hit hard as well. I have a pupa at home on my front porch of one of the giant silk moths, but I suspect it is a Cecropia. Which are equally as gorgeous as this species. Hopefully once spring arrives the mystery will be solved and I will get to see what is hiding in that papery cocoon.

  6. Thank you so much for the prompt and correct answer to my question! You are a treasure trove :)

  7. Meredith, you do make me smile. I've been called a lot of things but never it! Have a blessed Christmas Season.

  8. My mom and I found one of these at the store. It's very sad they live such a short life but that's life. Thank you so much, you helped out alot.

  9. I always thought it was sad too that they live such a short time. Doesn't seem near long enough to enjoy something so pretty. I'm glad you found the post helpful

  10. We just found one these huge caterpillars this afternoon. After that huge rain we had a few days ago, water pooled in different areas on our land. Under an oak tree, in a puddle, we found it. We thought it was dead, but we wanted to look to see what kind it was, brought it in the house, layed it on the computer desk and went to eat supper before searching online. After supper, and much to our delight, we discovered it moving across the desk. Our research brought us to your post, thank you. Being homeschoolers...this hands on learning is invaluable and your posts will be something we continue to study from. Thank you!

  11. I'm so happy that your little caterpillar was still alive. One of my co-workers brought me polyphemus caterpillar that he found the other day at a local park. I placed it in a container with some leaves and it has already made a cocoon. I was so excited. I just love these fat caterpillars, they are so pretty.

    Knowing that you will be using my blog as an educational tool with your children is the kindest compliment anyone could give me, thank you for letting me know and for visiting.

    I work as a naturalist and one of my favorite groups to plan programs for is the homeschool group.

    I look forward to hearing from you again.