Entomology (Study of Bugs)/what is this?


mystery caterpillar.
mystery caterpillar.  
I found this caterpillar on the side walk on my way home. it was huge! probably the length of my middle finger at least. i took a picture with my phone. i think its a luna moth caterpillar but i want to check.  if i'm right? is it rare? or invasive?

Hi, Lydia:

The insect in the image is the caterpillar (larva) of the Polyphemus Moth.  It is likely looking for a place to spin a cocoon and will emerge next year in all likelihood as an adult moth.  Here's more information:


This is assuming you found it somewhere east of the Rocky Mountains or in the Pacific Northwest.  There is a different species in Arizona and the southwest.


Entomology (Study of Bugs)

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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

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One of the top 50 experts in all categories for AllExperts.com, 2009.

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Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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