Are American Dagger Moth Caterpillars Dangerous?

Dagger moth caterpillar is a larval stage of the American dagger moth. It’s poisonous and dangerous and can sting with the long black bristles it has on its body.

American dagger moth caterpillar identification

Dagger moth caterpillar
Dagger moth caterpillar

The American dagger moth (Acronicta Americana) belongs to family Noctuidae, order LepidopteraThe American dagger moth caterpillars reach 0.19 inches (5 cm), while the adult moths have a wingspan of 0.19 to 0.25 inches (5 to 6.5 cm).

Dagger moth caterpillar is a fuzzy, bright yellow caterpillar with white or yellow setae (hair-like outgrowths). All instars have upright, long black hairs. Four of those black bristles stick out from the first and third abdominal segments, and a tuft of black hairs is on the eighth abdominal segment of the caterpillar’s body.

What are some of the colors the dagger moth caterpillar can turn into?

Dagger moth larvae are dark yellow in the early instars and can turn pale green in the later stages. They also change the color of their setae through the instars – from lemon yellow in the early stages to white in the late stages. Adult moths are brown-grayish and characterized by a zigzag black line pattern on their forewings.


American dagger moth caterpillars are widely spread through Eastern North America. They can be found in the following areas in the US:

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  • South Carolina
  • North Carolina
  • New Jersey
  • New York
  • Michigan
  • Tennessee
  • The Rocky Mountains

Moreover, they are also seen in Alabama, Arkansas, Colorado, Connecticut, and many other US territories.

What do dagger moth caterpillars eat?

Dagger moth caterpillar
Dagger moth caterpillar lives among deciduous trees

American dagger moth caterpillars’ host plants are deciduous trees, such as:

  • Alders
  • Birches
  • Hickories
  • Elms
  • Poplars
  • Maples
  • Oaks
  • Walnuts
  • Willows

After they hatch from the eggs, these caterpillars will eat their host plants to gain energy.

Is the dagger moth caterpillar poisonous?

The Dagger moth caterpillar is a poisonous stinging caterpillar. The venom is located in its black bristles.

The American dagger moth caterpillars are poisonous to humans and pets, although more dangerous for humans, especially children, who can pick them up while playing at a park.

Symptoms of getting stung by a dagger moth caterpillar include:

  • A stinging sensation
  • Skin irritation
  • Hives

Most people have a mild, short-lasting reaction to the toxin. In dogs, it usually just leaves a sting. The adult moth is not poisonous.

What to do if you get stung by an American dagger moth caterpillar?

Getting stung by a Dagger moth caterpillar isn’t an emergency, but you can do a couple of things to soothe your skin:

  1. Remove the toxic bristles with tape.
  2. Wash your skin with soap and water.
  3. Apply an ice pack to the affected area to reduce a burning sensation.

If it’s itchy, you can use a baking soda paste.

What to do if you see American dagger moth caterpillars?

If you need to remove a Dagger moth caterpillar, don’t touch it with your hands. Use a stick or a similar object instead. To get rid of these caterpillars in your yard, spray them with soapy water or oil spray if you can reach them. Alternatively, knock them down with a strong garden water hose and then spray them or leave them to the birds and other predators.

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