Tomato Hornworms are a serious garden pest. Native to the Northern U.S.,
it is similar to, but different than the Tobacco Hornworm. In the larval,
or caterpillar stage of growth, this insect has a voracious appetite. Their
favorite foods, are the leaves of your tomato plants.
In the adult stage, the tomato hornworm is a moth. It is known by three names:
Hawk moth, Sphinx moth or the Hummingbird moth.
Identifying the Tomato Hornworm
In the larval stage this green grub, or caterpillar, grows up to four inches
long. It has white "V" shaped stripes down it's sides, with a black horn
on its rear. If you see one, you will know, as it is probably the biggest
caterpillar you have ever seen. Hornworms have a green color, which is hard
to spot, blending in with plant foliage.
This hornworm can also be identified, by large black droppings, called frass,
found around the base of affected plants.
Tomato Hornworm Life Cycle:
There are usually two generations of Hornworms per year. One generation
overwinters, while the second goes through it's life cycle much more quickly
in the summer months.
In the fall, the moth burrows into the soil and pupates. This dark brown
pupae overwinters in the soil, and emerges in the spring. It lays eggs on
top and underneath leaves. The eggs hatch in just 4-8 days, and the tomato
hornworm (caterpillar) emerges.
The hornworm grows to full size over 4 weeks. It's main diet is the leaves,
stems and even unripe fruit of tomatoes, eggplants, peppers, and potatoes.
Tomato Hornworm Organic Control
Control methods include:
Hand picking the bugs off the plants.
Tilling soil in late fall and early spring, to disrupt the pupae.
Borage plants deter hornworms.
Plant these companion plants around a tomato plant.
Ladybugs and lacewings eat eggs.
Paper wasps kill hornworms
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