I think you nailed it. Manduca quinquemaculata. A neat bug. I've decided to keep him as a pet, or rather, a science experiment.digitS' said:Well, I believe that it surely either Manduca quinquemaculata or Manduca sexta.
The former is the tomato hornworm.
Manduca sexta is the tobacco hornworm but often shows up on tomatoes.
You can do a google image search and try to determine which it is.