Insect
Hag Moth
Phobetron pitheciumAlso known as Monkey Slug, Monkey Slug Moth
Hag moth caterpillars, famously called monkey slugs, mimic dislodged tarantulas or dried leaves using pairs of fleshy, hairy lateral projections that detach easily when grabbed by predators. Adult moths display strong sexual dimorphism: heavy-bodied females mimic bumblebees, while smaller males dart through the canopy with translucent wing patches. These insects produce a single generation each year across eastern North American woodlands, overwintering securely inside tough, spherical cocoons wrapped in the larva's own shed appendages.
MimicryWoodlandNocturnal
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & preyOak leaves, Willow leaves, Apple leaves
Predators
- Parasitoid wasps
- Songbirds
- Orb-weaver spiders
ThreatsHabitat fragmentation, broad-spectrum pesticide spraying, and artificial light pollution
HabitatsDeciduous forests, mixed woodlands, orchards, and suburban tree canopies
Life spanAbout 1 year (adults live 5–10 days)
Classification
- OrderLepidoptera
- FamilyLimacodidae
- GenusPhobetron
- SpeciesPhobetron pithecium
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Larval hairs can cause contact dermatitis and stinging; observe without touching.
- Why it is dangerous
- Fine hairs lining the larval projections can pierce skin and trigger burning pain, redness, and itchy welts.
- How to recognize a risky encounter
- Larvae resemble small hairy starfish or tattered brown leaves with curved, disheveled lateral lobes.
- What to do
- Keep hands clear of foliage when pruning, and never handle the hairy caterpillars with bare skin.
Responsible observation
- Spotting: Search the undersides of low oak, cherry, and birch branches during late summer.
- Observation: Use a camera lens or magnifying glass to inspect caterpillars rather than handling them.
- Night Viewing: Hang an illuminated white sheet along forest edges in midsummer to attract adult moths.
Host Plant (c) Alicia Ballard, some rights reserved (CC BY) · cc-by
Close Relative (c) Andy Reago & Chrissy McClarren, some rights reserved (CC BY) · cc-by
Close Relative (c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · cc-by-sa
Close Relative (c) Laura Gaudette, some rights reserved (CC BY) · cc-by
Keep collecting in Fauna
Found in Collections
Species set
Moonlight Marvels
Hag Moth is found in this collection. Identify it in Fauna to fill this slot and continue your progress.
—/7
Help improve the field guideSomething wrong?
Checking your Fauna account…Report a name, category, or profile issue for review.