Fauna
Insect

Isabella Tiger Moth

Pyrrharctia isabella

Also known as Banded Woolly Bear, Woolly Bear, Woolly Worm

Banded woolly bear caterpillars are famous across North America for their thick coats of black and rust-orange bristles and their remarkable ability to freeze solid over winter. In spring, they thaw out, pupate inside silk cocoons, and emerge as understated yellowish-buff moths marked with small dark spots. These nocturnal adults live only a week or two, devoting their brief lives to finding mates and laying eggs on low-growing plants.

Fuzzy CaterpillarNocturnalCold-Tolerant
Isabella Tiger Moth reference1 / 7
"Woolly Bear Caterpillar Spotted!" by soomness is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/. · 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 & preyDandelion Leaves, Plantain Leaves, Clover
Predators
  • Birds
  • Rodents
  • Parasitoid Wasps
ThreatsPesticide application, habitat destruction, and vehicle mortality during autumn caterpillar movements.
HabitatsMeadows, fields, pastures, roadsides, lawns, and forest edges.
Life spanUp to 1 year total (larvae overwinter; adults live 1–2 weeks).
Classification
  1. OrderLepidoptera
  2. FamilyErebidae
  3. GenusPyrrharctia
  4. SpeciesPyrrharctia isabella
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
Bristles can cause mild skin irritation in sensitive individuals; handle gently or observe without touching.
Responsible observation
  • Autumn Spotting: Look for caterpillars crawling across footpaths in autumn as they search for shelter under logs and bark.
  • Nighttime Attraction: Attract adult moths during summer nights using a porch light or blacklight set against a white sheet.
  • Gentle Handling: Allow caterpillars to crawl onto a flat hand or leaf rather than squeezing, as stiff hairs can prick skin.
Related species
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