here ya go Nova
Step 1
Look for tomato hornworms on the foliage of tomato plants. They are very difficult to spot. One way to find them is to look for the black excrement on the tops of the leaves, then look at the set of leaves above. Usually the caterpillars are right in view, but their effective camouflage makes them very hard to see.
Step 2
Pick the caterpillars by hand and squash underfoot if you have the stomach for this kind of grisly work.
Step 3
Spray Bacillus thuringiensis (or Bt) while the problem is still in the caterpillar state. Bt is a bacteria that is safe to use on food crops and very effective in the control of caterpillars.
Step 4
Purchase parasitic wasps, which will lay eggs on the tomato hornworm caterpillar. The wasp eggs hatch and the young feed on the caterpillar. (Parasitic wasps are not harmful to humans.)