Isabella tiger moth vs Virginian tiger moth
These two are easy to mix up. Here's how to tell an Isabella tiger moth from a virginian tiger moth, and whether either one bites or stings.
Isabella tiger moth
Pyrrharctia isabella
Virginian tiger moth
Spilosoma virginica
≠The key differences
Spilosoma virginica caterpillars are uniformly coloured (often yellowish to orange-brown) with longer, softer hairs and no black-brown-black banding; adults are white with a few small black dots.
Pyrrharctia isabella caterpillar typically has distinct black end bands with a broad reddish-brown middle band; Spilosoma virginica larvae are more variable and often more uniformly coloured.
⚖︎Side by side
| Isabella tiger moth | Virginian tiger moth | |
|---|---|---|
| To humans | Irritating hairs | Irritating hairs |
| Size | 45-65 mm wingspan | 30-50 mm wingspan |
| Colours | Orange, Reddish-brown, Black | Cream, White, Pale yellow, Rusty orange (larva), Black (larva) |
| Family | Erebidae | Erebidae |
| Habitat | Open areas, fields, meadows, roadsides, gardens and edges of woodlands throughout towns and countryside | Open woodlands, gardens, fields, roadsides and disturbed areas; larvae feed on a wide range of herbaceous and woody plants. |
| Range | Widespread across North America: most of the United States and southern Canada; also reported in parts of northern Mexico. | Across most of North America, from southern Canada south through the United States; widespread in suitable habitats. |
| Active | Adults: late spring to late summer (two broods in the south). Larvae commonly seen in late summer and autumn; they overwinter and pupate the next spring. | Spring through fall; adults mainly at night (nocturnal) and attracted to lights. Multiple generations per year in warmer parts of its range. |
| Pest? | No | Yes |
🔍How to spot an Isabella tiger moth
- Woolly bear caterpillar: dense bristly hairs with black ends and a reddish-brown middle band.
- Adult moth: pale orange forewings with variable darker markings and orange hindwings; wingspan about 45-65 mm.
- Location and season: common in North America, especially late summer and autumn for caterpillars.
🔍How to spot a virginian tiger moth
- Adults: white moth with a 30-50 mm wingspan, a few small black dots on the wings, and a yellow-orange abdomen with rows of black spots.
- Larvae: very hairy 'woollybear' caterpillar, colour variable from orange/rust to black and densely covered in long setae.
- Cocoon: loose silk cocoon incorporating larval hairs in soil or leaf litter.
- Flight: nocturnal and commonly attracted to porch and street lights in summer.
?Frequently asked questions
What is the difference between an Isabella tiger moth and a virginian tiger moth?
Spilosoma virginica caterpillars are uniformly coloured (often yellowish to orange-brown) with longer, softer hairs and no black-brown-black banding; adults are white with a few small black dots. Pyrrharctia isabella caterpillar typically has distinct black end bands with a broad reddish-brown middle band; Spilosoma virginica larvae are more variable and often more uniformly coloured.
Is an Isabella tiger moth or a virginian tiger moth more dangerous?
Isabella tiger moth: Irritating hairs. Virginian tiger moth: Irritating hairs. Adults are harmless. Adults are harmless and do not bite or sting.
Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.