Cecropia moth vs Io moth
These two are easy to mix up. Here's how to tell a Cecropia moth from an Io moth, and whether either one bites or stings.
Cecropia moth
Hyalophora cecropia
Io moth
Automeris io
≠The key differences
Much larger and different wing shape and banding; cecropia lacks the Io moth's single central eyespot and has more complex red and white bands.
⚖︎Side by side
| Cecropia moth | Io moth | |
|---|---|---|
| To humans | Non-toxic | Stinging caterpillar |
| Size | Wingspan 120-160 mm (12-16 cm) | 50-80 mm wingspan |
| Colours | Reddish-brown, Cream, Black, Orange, Green (larva) | Yellow, Reddish brown, Green (caterpillar), Blue (eyespots), Black (eyespot center) |
| Family | Saturniidae | Saturniidae |
| Habitat | Deciduous woods, woodland edges, parks, suburbs and gardens where host trees grow | Woodlands, forest edges, fields, gardens and riparian areas where host plants grow |
| Range | Widespread across much of North America: from southern Canada through much of the United States (ranges vary by local populations) | Eastern and central North America — from southern Canada through the United States and into parts of Mexico |
| Active | Adults on wing late spring through summer (timing varies by latitude); mostly night-active (nocturnal) | Spring to late summer depending on latitude; adults are nocturnal |
| Pest? | No | Yes |
🔍How to spot a Cecropia moth
- Very large wingspan (12-16 cm) with rounded wings and bold bands of white, black and reddish-brown.
- Crescent-shaped pale spots and small crescent eyespots on each wing.
- Males with large feathered antennae; females with somewhat less plumose antennae.
- Large green caterpillars with rows of colored tubercles; pupae inside a brown, papery silken cocoon.
🔍How to spot an Io moth
- Hindwings with a single large eyespot on each side: black-and-blue center with a white mark, on a yellow background
- Sexual dimorphism: males bright yellow, females reddish-brown on forewings
- Caterpillars bright green with branched stinging spines and a red-and-white stripe along each side
?Frequently asked questions
What is the difference between a Cecropia moth and an Io moth?
Much larger and different wing shape and banding; cecropia lacks the Io moth's single central eyespot and has more complex red and white bands.
Is a Cecropia moth or an Io moth more dangerous?
Cecropia moth: Non-toxic. Io moth: Stinging caterpillar. Adults and caterpillars are not poisonous and do not sting. Io moth caterpillars have urticating spines that inject irritant when they break the skin.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.