Eastern tiger swallowtail vs Red-spotted purple
These two are easy to mix up. Here's how to tell an eastern tiger swallowtail from a red-spotted purple, and whether either one bites or stings.
Eastern tiger swallowtail
Papilio glaucus
Red-spotted purple
Limenitis arthemis
≠The key differences
Dark female tiger swallowtails may look superficially similar at a distance but have characteristic swallowtail tails and different wing shape and markings.
⚖︎Side by side
| Eastern tiger swallowtail | Red-spotted purple | |
|---|---|---|
| To humans | Non-toxic | Non-toxic |
| Size | 80-140 mm wingspan | 6-8 cm wingspan |
| Colours | Yellow, Black, Blue (hindwing band), Orange (submarginal spot) | Glossy blue, Black, Red-orange, Brown (underside), White (band, white admiral form) |
| Family | Papilionidae | Nymphalidae |
| Habitat | Woodland edges, riversides, suburban gardens, fields and parks throughout eastern North America | Deciduous and mixed woodlands, forest edges, parks, suburban gardens and riparian corridors. |
| Range | Eastern North America from Ontario and Maine south to Florida and west to the Great Plains; range overlaps with related tiger swallowtails in northern and western areas | Eastern and central North America, from southern Canada through much of the eastern United States; distribution of forms varies geographically. |
| Active | Spring to early autumn (generally March-September; earlier in southern range); active by day, especially sunny periods | Spring through early autumn (peak in summer); diurnal, most active during warm daylight hours. |
| Pest? | No | No |
🔍How to spot an eastern tiger swallowtail
- Large yellow wings with bold black 'tiger' stripes across both fore- and hindwings
- Characteristic tail-like extensions on each hindwing
- Blue band and orange submarginal spots on the hindwing; females may be dark melanic form lacking yellow ground color
🔍How to spot a red-spotted purple
- Look for glossy blue-violet sheen on the upper wings with small red-orange marginal spots (red-spotted purple form).
- Note absence of tails (distinguishes from many swallowtails) and the overall dark, glossy ground colour.
- Compare the white-banded form (white admiral) which has a broad white band across both wings; both forms belong to the same species.
- Underside is mottled brown and camouflaged; check for reddish marginal spots on the underside in the red-spotted purple form.
?Frequently asked questions
What is the difference between an eastern tiger swallowtail and a red-spotted purple?
Dark female tiger swallowtails may look superficially similar at a distance but have characteristic swallowtail tails and different wing shape and markings.
Is an eastern tiger swallowtail or a red-spotted purple more dangerous?
Eastern tiger swallowtail: Non-toxic. Red-spotted purple: Non-toxic. Not dangerous. Harmless to people.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.