Here: http://www.hermitlovers.com/HornWorms_care_sheet_PDF.pdf

Only care sheet I could find you on hornworms/tomato worms. The guide mentions that if you keep them at a cooler temperature, you can increase the shell life of them before they pupate. 55-65F. The care sheet also mentions Manduca diet you can feed them which is safe for your herps that can be made at home or purchased in pet stores.