American Dagger Moth Caterpillar
Scientific Name: Acronicta americana
Order & Family: Order: Lepidoptera, Family: Noctuidae (or Erebidae, depending on recent reclassification)
Size: Caterpillars typically range from 1.5 to 2 inches (3.8 to 5 cm) in length when fully grown. The adult moths have a wingspan of about 2 to 2.5 inches (5 to 6.5 cm).
Natural Habitat
Found in deciduous forests, woodlands, suburban areas, and gardens where their host trees are present. They are widespread across North America.
Diet & Feeding
The caterpillars are polyphagous, meaning they feed on the leaves of a wide variety of deciduous trees including oak, maple, willow, birch, elm, ash, and various fruit trees.
Behavior Patterns
As caterpillars, they feed on various host plants. When mature, they pupate and later emerge as moths. The caterpillars are known to be solitary feeders. They are not typically aggressive but their hairs can cause irritation upon contact, which serves as a defense mechanism.
Risks & Benefits
Potential risks include skin irritation (dermatitis) due to contact with their urticating hairs, which can cause itching, redness, and a rash in sensitive individuals. They are not typically considered a significant pest to healthy trees. As moths, they can be pollinators and are part of the food chain for birds and other animals, contributing to ecosystem biodiversity.
Identified on: 9/3/2025