Hummingbird Moths: A Gardeners Dilemma

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During the summer late in the day or early evening you can often find what looks like a fuzzy small hummingbird at flowers in your garden. These are called Hummingbird Moths and also sphinx moths and hawk moths. These insects have tongues which can be up to four inches long, allowing them to drink nectar while they hover over flowers.

These beautiful moths lay their eggs on a variety of plants. The Hummingbird moth we often see are the parent of the tomato hornworm caterpillar. These caterpillars and their cousins tobacco hornworm are voracious eaters, doing damage to plants in a short period of time. Tomato hornworm is a pest of not only tomatoes, but also eggplant, pepper and potato plants. Because of their green color, the caterpillars are often hard to see in the plants. Here is the dilemma, we like the hummingbird moth, but can’t tolerate tomato hornworms. As a side note, hummingbird moths are parents of a variety of different caterpillars that feed on different plants. If you see hummingbird moths, enjoy their beauty!

Nature can come to the rescue and balance things out. Parasitic wasps often will lay their eggs on the caterpillars. The eggs will grow and pupate using the hornworm as their home. If you see a caterpillar with these egg casings, leave them alone. This is nature’s way of destroying pests. If you cannot tolerate tomato hornworms, be sure to till your garden in the spring. This may help destroy some of the pupating insects. You can also hand pick and drop the caterpillars into soapy water or spray Bacillus thuringiensis (Bt) which is a naturally occurring bacteria that only targets caterpillars. Bt does not harm other insects, such as beneficial insects.

Hummingbird moths are a beautiful addition to any garden. Not only are they pretty to look at but are native pollinator.