What's That Bug? does not endorse extermination

Location:  Wayne, PA
September 18, 2010 5:32 pm
My daughter found this in a wooded area and gave it to me, and I have no idea what type of caterpillar it is. I’m not sure what to feed it, or where to release it.
The first 2 pictures have a little more detail; the last picture shows the color a little more authentically. It’s kind of a greenish red. It’s big – about 3.5” long and about .75” ’tall’.
For some reason, we’ve been finding big caterpillars. First a tomato hornworm, then a hickory horned devil. Now this one, whatever it is.
Thank you!
Signature:  newstart

Imperial Moth Caterpillar

Dear newstart,
This is the caterpillar of an Imperial Moth and we just finished posting another photograph of this species.  Based on your individual’s coloration, we suspect it is getting ready to pupate.  Imperial Moths pupate underground, so when the caterpillars are ready to metamorphose, they climb down from the trees where they have been feeding and they locate an area where they can dig underground.  You probably don’t need to worry about feeding it because it is probably no longer interested in food.  Release it on the ground in an area where the soil is not hard.  We also just received a naked pupa of a Giant Silkworm Moth that might be an Imperial Moth, and we will post that letter next.

Mr. Marlos,
Thank you so much for the information.  I released it near where it was found.

What's That Bug? does not endorse extermination

6 Responses to Imperial Moth Caterpillar

  1. Katie L. says:

    My daughter found an imperial moth this morning. We were wondering a few things:

    1) Can you keep them until they become a moth and if so how?
    2) Do they bite?
    3) What would you feed it if you keep it?

    Thanks for your reply. God bless.

    • bugman says:

      You can raise an Imperial Moth Caterpillar to an adult by keeping it in a small terrarium with ventilation. You need to feed it until it is ready for pupation. Food depends on the subspecies. Some subspecies feed on leaves of deciduous trees and some feed on the needles of conifers. According to BugGuide: “Larvae feed on leaves of Bald Cypress, basswood, birch, cedar, elm, hickory, Honeylocust, maple, oak, pine, Sassafras (Sassafras albidum), Sweetgum (Liquidambar styraciflua), sycamore, walnut.” If you live in a cold climate, keep it in a sheltered but unheated location during the pupal stage during the winter months.

  2. Mandy Davis says:

    Hello, I just found one of these caterpillars today. I homeschool my children and would really like them to see it change. I have read that it would like to bury itself to change. How would I go about helping it do this process in my home? Right now it is in a mason jar with a branch and leaves. Also, how long does it take to change into a moth? WIll it stay buried all winter? Thank you, Mandy

    • bugman says:

      Hi Mandy,
      You did not provide a location. You should keep the pupa in a place that is protected from the severe elements, but that has a temperature similar to the outdoor temperature. Keeping the pupa indoors might cause the adult to emerge too early, and if it cannot find a mate, it will not be able to perpetuate the species.

  3. Katherine Clark says:

    Our question is CAN YOU HOLD AN IMPRIAL MOTH CATERPILLAR? they are rather intimidating.

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