Entomology (Study of Bugs)/HELP


QUESTION: I have a caterpillar that eating the foliage off my tree at a very rapid rate. I should specify that there a million of them. they are large and black with a yellow stripe the length of the body. they appeared almost over night. I have a picture but don't know how to attach it.. or if I even can.... but I would like to know what kind they are


Yes, an image would definitely help, and there should be a way to attach one given that I usually receive images with questions these days....

At bare minimum I must know what kind of tree is being defoliated.  Most insects are very "host-specific," meaning they feed only on the foliage of one kind of plant, or group of related plants.

If you cannot attach a picture, then I need to know if the caterpillars are hairy, spiny, smooth, bumpy....whether there is any kind of silk webbing involved, etc.  How large is "large" in terms of inches or millimeters?  Do the caterpillars behave synchronously (do they all rear up or thrash about in unison if disturbed)?


---------- FOLLOW-UP ----------

QUESTION: Im afraid im not going to be much help in telling you what the tree is that they have decided to snack on. But as far as size goes, they are all about the length of a regular writing pen and the width of persons finger (they are very large) thats really all I can tell you... and of course I got the image to up load
I hope this helps


Ah, ok, the image gives a conclusive answer as to both the caterpillar and the tree.

The tree is a catalpa, and the caterpillars the "Catalpa Hornworm," Ceratomia catalpae .  Here's more about them:


I have seen small catalpa trees in a Cincinnati vacant lot completely defoliated by the caterpillars, and yet rebound just fine the next year.  So, I would not call the Catalpa Hornworm a pest.  In fact, they are plagued by parasitic wasps:


So, I wouldn't worry much, especially since they have pretty much finished eating leaves and are about ready to pupate underground in the soil.

Would you consider sharing your image(s?) with me?  I would like to do a blog post on this species at some point, but don't have pictures of the caterpillars.  You can e-mail me at:
Bugeric24ATyahooDOTcom if this is agreeable.  Remember to include your name so I can give you credit for the images, and a geographic location.  Thanks!



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.

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

Past/Present Clients
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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