Fauna
Insect · GBIF taxon 1783008

American Dagger

Acronicta americana

Also known as American Dagger Moth

American dagger moths are famous for their bristly yellow caterpillars, which feature five prominent long black hair pencils extending along the body. While the grey-brown adults blend seamlessly into hardwood tree bark during the day, larvae actively feed on deciduous foliage throughout late summer. In autumn, caterpillars descend tree trunks to spin tough, silk-reinforced cocoons beneath loose bark or leaf litter where they overwinter.

NocturnalCaterpillarNative
American Dagger reference1 / 7
Licensed reference(c) Kimberely G., some rights reserved (CC BY) · cc-by
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Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & prey
  • Maple leaves
  • Oak leaves
  • Birch leaves
Predators
  • Songbirds
  • Bats
  • Parasitoid wasps
ThreatsPesticide application, artificial light pollution, severe habitat loss
HabitatsDeciduous forests, woodlands, suburban parks, orchards
Life span1 year (full cycle from egg to adult)
Classification
  1. OrderLepidoptera
  2. FamilyNoctuidae
  3. GenusAcronicta
  4. SpeciesAcronicta americana
Range & activity
Range data is not available yet.
Safe observation
Interaction riskLow
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is low
Caterpillar setae cause skin irritation; avoid handling larvae with bare skin.
Why it is dangerous
Late-instar caterpillars possess stinging setae embedded within dense yellow hairs that easily break off, causing localized dermatitis, swelling, and itchiness.
How to recognize a risky encounter
Recognize the larvae by their bright yellow or whitish coat paired with five distinct long, slender black hair pencils along the back.
What to do
Observe without touching, or use a leaf or stick to gently relocate caterpillars off walkways.
Responsible observation
  • Caterpillar Safety: Do not touch the furry larvae directly, as breaking their bristles triggers skin rashes.
  • Spotting Adults: Scan deciduous tree trunks during the daytime for flat, bark-patterned moths resting at rest.
  • Winter Protection: Keep fallen leaves and loose bark undisturbed near hardwood trees to safeguard overwintering pupae.
Related species
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