Subject: Giant Caterpillar Found!
Geographic location of the bug: Mexico, Guanajuato State
Time: 12:58 AM EDT
Your letter to the bugman : Hi there! I was in my yard today and was shocked when I discovered this huge, mauvey colored, black striped caterpillar. I tried searching around the internet to indentify it but I had no luck. It seemed to have a single eye-like pattern in the middle of its butt, which made me think maybe it was a swallowtail, but again I can’t find anything like it. I am really interested in knowing what it is and would be so grateful if you could help! It’s also the summer/hot/rainy season here in Mexico if that helps! Thanks for your efforts!
How you want your letter signed: Emma
The “single eye-like pattern in the middle of its butt is known as a caudal bump, a mark at the tip of the abdomen that marks the spot where a caudal horn was shed from a prior molt. Because of that caudal bump, we correctly guessed the genus and then quickly located matching images of a Typhon Sphinx Caterpillar, Eumorpha typhon, on Sphingidae of the Americas where it states the larval food plant is grape. Do you have a nearby grape vine?
Wow thank you for identifying it so quickly! That’s so fascinating! We initially believed that it had fallen off from a vine that runs along our fence and into our courtyard, so that makes perfect sense. Not sure if it is a grape vine however. Yesterday I put it back on the vine, so I’m glad that’s where it wanted to be. Thank you again!
It might have left the vine to find a place to pupate. Many Sphinx Caterpillars burrow underground to pupate.