Tomato Hornworm--3-4 inch long green caterpillar
with diagonal lines on sides, prominent horn on
rear end. Eat foliage and may take bites out of
green fruit. They are the larvae of 2 large moths:
the Hawk moth and the Sphinx moth and over winter
in the soil in the pupal stage. Adult moths appear in
late spring and lay single, pearl colored eggs on the
undersides of plant leaves that hatch in about a
week. Larvae feed on foliage for about a month before
they enter the soil and pupate.
As you can see from this picture the caterpillar
ate a lot of the leaves off this tomato plant before
we discovered the pesky large green caterpillar.