MSB,
Tomato hornworms are very common in all parts of North America. They are the caterpillar form of an adult Sphinx moth that looks very much like a small hummingbird.
The tomato hornworm is green with diagonal white bars on each side and a black horn at the tail end. The tobacco hornworm is very similar, but has a red horn instead of a black one.
The hornworm's favorite diet is the leaves of the tomato plant, but they also will dine on any of the tomato related plants, such as peppers, eggplant, potatoes and tobacco. A favorite trap crop for hornworms is dill, because they are easier to spot on dill than on tomatoes, especially in the earlier stages.
To find hornworms, you look for their distinctive droppings, which resemble tiny hand grenades. Find the droppings on the ground, and look above in the plant for the worm. Hornworms grow quite large and fat, up to 4 or maybe five inches long and very plump at that length. You can control them by handpicking and destroying, trap crops, such as dill, repellent plants such as marigolds and basil, or disguise the tomatoes amongst other plants. You can also use Bacillus thuringiensis (marketed under various labels as Bt; widely available in any garden center) which is a bacteria that makes them sick and eventually starves them to death. You can also use hot pepper sprays to discourage the adult moth from laying eggs.
You find them mostly at the tops of the plants because that may be where the eggs were laid (on the underside of the leaves) or that is the direction that the caterpillar has migrated to.
KJC |
