tomato hornworms turn into a pretty butterfly? I won't feel so
bad squishing them if they don't.
Also, I had some moonflower plants
(the poisonous kind that are related to the wild variety, which
grow in pig/cow pastures). Anyway, I had some kind of green hornworm
eat every leaf off every plant. How can a hornworm eat a poisonous
plant and not die?
and tobacco hornworms are large caterpillars, up to four inches
in length. The prominent "horn" on the rear of both gives
them their name. They can quickly defoliate tomatoes, potatoes,
eggplants and peppers. Occasionally, they may also feed on green
fruit. You're likely to notice the damage before you see the culprit.
Hornworms are often difficult to see because of their protective
coloring and their tendency to feed on the interior of the plant
where they are protected from the sun and predators.
tobacco hornworm larva is generally green with seven diagonal white
lines on the sides and a curved red horn. The tomato hornworms
have eight V-shaped marks on each side, and their horn is straighter
and blue-black in color. The adult of the tobacco hornworm is the
sphinx moth. The five-spotted hawk moth is the adult of the tomato
hornworm. Both moths are stout-bodied, grayish-colored insects
with a wing spread of 4 to 5 inches. They're not exactly pretty
butterflies but are large and striking. A quick search on the Web
proved there are many excited butterfly/moth fanciers that think
the hawk moths are fascinating!
If you're interested in tomatoes
and not in moths, you can control them with the following methods:
Handpicking: The large size of hornworms
makes it easy to get hold of them. Once removed from the plant,
they can be destroyed by squishing them, snipping them in half
with shears or dropping them into a bucket of water.
up the soil after harvest will destroy any pupae that may be there.
Biological controls: Bacillus thuringiensis,
or BT (e.g., Dipel, Thuricide), is also considered effective, especially
on smaller larvae. Follow label directions.
Natural enemies, such
as the parasitic wasp that lays its eggs on the hornworm's back,
are common. If you come
across a hornworm with something that looks like fuzzy pieces of
rice on it, leave them in the garden so the emerging wasps can
parasitize other hornworms. The larvae feed on the hornworm.
answer to your question about why hornworms can eat poisonous plants
is just that those plants aren't toxic to them. Some birds, animals
and insects can eat many plants that would be toxic to humans.