Fauna
Insect

Saddleback Caterpillar Moth

Acharia stimulea

Also known as Saddleback Caterpillar, Saddleback Slug Moth

Saddleback caterpillars are famous for their vibrant green bodies wrapped in a dark central saddle pattern, but their striking appearance serves as a clear warning. Dense clusters of hollow horns inject venom upon contact, causing severe burning and skin irritation. Adults transform into unassuming, velvety chocolate brown moths that fly short distances at night without feeding.

StingingCaterpillarNocturnal
Saddleback Caterpillar Moth reference1 / 7
(c) Andy Reago & Chrissy McClarren, 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 & preyOak Leaves, Maple Leaves, Apple Leaves
Predators
  • Braconid Wasps
  • Assassin Bugs
  • Songbirds
ThreatsHabitat fragmentation and broad-spectrum pesticide usage
HabitatsDeciduous forests, woodlands, suburban gardens, and orchards
Life span1 year total life cycle; adults live 1–2 weeks
Classification
  1. OrderLepidoptera
  2. FamilyLimacodidae
  3. GenusAcharia
  4. SpeciesAcharia stimulea
Range & activity
Range data is not available yet.
Safe observation
Interaction riskVery high
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is very high
Spines inject stinging venom upon contact; observe without touching.
Why it is dangerous
Larvae possess hollow spines that inject venom on contact, causing intense burning pain, swelling, and localized blistering.
How to recognize a risky encounter
Recognize larvae by their bright green sweater-like body with a dark brown central saddle patch bordered in white.
What to do
Never touch larvae directly; if contact occurs, use sticky tape to pull remaining spines out of skin.
Responsible observation
  • Identification: Check broadleaf foliage in late summer for distinct green and brown larvae.
  • Safety: Avoid brushing against garden shrubs where caterpillars rest beneath leaves.
  • Relocation: Move caterpillars using a twig rather than gloves to prevent spines penetrating fabric.
Related species
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Found in Collections

Species set

Moonlight Marvels

Saddleback Caterpillar Moth is found in this collection. Identify it in Fauna to fill this slot and continue your progress.

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