In article .com,
Teech wrote:
Any solution to this besides checking the plants every day? How long
do these things go on? Checking online it looks like they might be
around for a couple of months. Some suggest parasitic wasps...but not
sure how you go about managing those. Another suggestion was "bt"?


Handpicking works well (they are easy to find, you can even hear them
chomping). You could also use Bt (Bacillus thuringiensis) which is a
bacteria which will stop them eating and therefore kill them. Some
formulations of Bt are organic approved and it's considered to be
extremely safe and effective. You can get it as a powder to dust or a
liquid to spray. Check the label to make sure it lists hornworms since
different strains of Bt are used to control different types of
catepillars.

I have always had sufficient parasitic wasps around to take care of all
of the hornworms. If you see one of the hornworms with the wasp pupae
on its back, let it be. The wasps will hatch and then eat the hornworm
from the inside out (leaving a deflated sack of a catepillar). The
hatched wasp will then parasitize more hornworms and will take care of
the problem pretty quickly with no effort on your part.

Here are some photos:

http://chatham.ces.ncsu.edu/growings.../hornworm.html

The bottom photos show the white wasp pupae of a parastized hornworm.

--
Steve