Tomato Hornworm and the Sphinx Moth

This year, we discovered five enormous green hornworms happily eating our pepper plants.

A single hornworm can eat an impressive amount of foliage, so they are not always welcomed by gardeners. Instead of killing them, we moved ours away from the vegetable garden and placed them near the pond. There, they could become food for the birds or, if they were mature enough, burrow into the soil and begin their transformation.
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Hornworms found on peppers are usually tomato or tobacco hornworms. Both feed on plants in the nightshade family, including tomatoes, peppers, potatoes and eggplants. When fully grown, they leave the plant and burrow into the soil, where they become pupae before emerging as large moths.

What Does a Hornworm Become?

A tomato hornworm transforms into a five spotted hawkmoth, while a tobacco hornworm becomes a Carolina sphinx moth.

Both belong to the sphinx moth family. They are large, strong flying moths with long wings and thick bodies. Adults hover in front of flowers and use a long, tube shaped mouthpart to drink nectar. As they move between flowers, they can carry pollen and become valuable evening and nighttime pollinators.

You can sometimes tell the caterpillars apart by their markings. Tomato hornworms have white V shaped markings and a dark horn. Tobacco hornworms have straight diagonal lines and usually a reddish horn.

Is a Sphinx Moth the Same as a Hummingbird Moth?

This is where it becomes confusing.

Sphinx moths are sometimes called hawkmoths or hummingbird moths because they can hover over flowers and even fly backwards. Their rapid wings and long feeding tube make them look surprisingly similar to a tiny hummingbird.

However, the moth most people recognize as a hummingbird moth is the hummingbird clearwing moth. It is a different species within the same large sphinx moth family.

The hummingbird clearwing is smaller, often active during the day and has transparent wings with a fuzzy green and reddish body. The moths that develop from tomato and tobacco hornworms are generally larger, grey or brown, with solid wings, and are most active around dusk or after dark.

A Garden Pest or Part of the Ecosystem?

As caterpillars, hornworms can quickly damage vegetable plants. As adults, they become remarkable moths that visit flowers and help move pollen through the garden.

They are also part of the farm’s food chain. Hornworms provide food for birds and beneficial insects, while the adult moths become food for bats and other nighttime animals.

We certainly did not want five hungry hornworms finishing our pepper plants, but we also did not feel that they needed to be destroyed. Moving them gave nature the opportunity to decide what happened next.
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Sometimes the creature eating your garden today may become one of its pollinators tomorrow.