My tomato hornworm is turning a brownish color on it's back! What is happening? Is it dying or is it forming?

Question

My tomato hornworm caterpillar has a brownish color on it's back. When I touch the caterpillar it doesn't move. It only stays there and starts to breath. Is it dying or is it making a cacoon?

Answer 1

If it is forming a cocoon then it will be attached by a silk cord to a silk spot on something. If you touched the ground and then touched your caterpillar then you probably infected it with a bacteria that can kill it. That is why you never find caterpillars crawling on the ground on dirt. Think Bacillus thuringiensis. I never tried to cure a caterpillar. I don't know if antibiotic ointment would work or not. It would be sad if it died of an infection before it metamorphosed. If I had one and it died then I would cry I think.

Answer 2

yes, it is starting its change into a pupae.... at this time his skin is hardening and turning brown... he is not responisve to your touch because he can no longer move very well as his skin is starting to harden and he can no longer bend as he used to.  Not all caterpillars make a silky cacoon, and he is likely one of this type.  If you want to watch him turn, give him some shade or he may overheat if he is left in the light.