Geographic location of the bug: Niagara Ontario area
Time: 11:16 PM EDT
Your letter to the bugman: This caterpillar was hanging on my tomato plant with all these white things on it.
Next morning it was on the ground with most of the white things off of it.
How you want your letter signed: Pina
This Tobacco Hornworm or Carolina Sphinx is quite dead, but while it was still alive, it was parasitized by a Braconid Wasp. When the wasp larvae hatched, they feed on the non-vital tissues of the hornworm until they were ready to leave the host and pupate. The white things are the Braconid pupae.