Spongy moth vs White-marked tussock moth
These two are easy to mix up. Here's how to tell a spongy moth from a white-marked tussock moth, and whether either one bites or stings.
Spongy moth
Lymantria dispar
White-marked tussock moth
Orgyia leucostigma
≠The key differences
Also a defoliator (formerly called gypsy moth), but its caterpillars lack the white toothbrush tufts of Orgyia species and have paired blue and red spots along the back.
⚖︎Side by side
| Spongy moth | White-marked tussock moth | |
|---|---|---|
| To humans | Irritating hairs | Irritating hairs |
| Size | Male wingspan 35-50 mm; female wingspan 50-75 mm | Male wingspan 20-35 mm; female body length about 10-18 mm (flightless, wing-reduced) |
| Colours | Brown, Cream, Black, Blue (larval spots), Red (larval spots) | Brown, White, Yellow, Orange, Black |
| Family | Erebidae | Erebidae |
| Habitat | Forests, woodlands, parks and urban areas where host trees are present | Deciduous and mixed forests, orchards, shade trees and urban landscapes where host trees and shrubs occur |
| Range | Native to Europe, parts of Asia and North Africa; established as an invasive species in eastern North America, with isolated introductions elsewhere | Native to North America: widespread across eastern and central Canada and the United States, west to the Great Plains, with scattered records farther west. |
| Active | Caterpillars active in spring and early summer; adults emerge mid to late summer depending on climate | Larvae active in late spring and summer (region-dependent). Adults typically appear for a short period in summer; one generation per year in most of its range, sometimes two in warmer regions. |
| Pest? | Yes | Yes |
🔍How to spot a spongy moth
- Caterpillars with five pairs of blue dorsal spots followed by six pairs of red dorsal spots.
- Spongy, tan egg masses 40-70 mm long attached to bark, wood, vehicles or outdoor objects.
- Adult females are white or cream with dark markings and often poor fliers; males are brown and fly readily.
🔍How to spot a white-marked tussock moth
- Look for hairy caterpillars with a red head, four white toothbrush-like tufts in a row on the back, and long black hair pencils at the front and rear.
- Adult males: small moth with mottled brown-gray wings and a small white spot near the rear corner of each forewing.
- Adult females: wingless, stout and grayish-white, usually found sitting on their cocoon or egg mass.
- Check for white, frothy egg masses on old cocoons on tree bark, fences or under eaves in fall and winter.
?Frequently asked questions
What is the difference between a spongy moth and a white-marked tussock moth?
Also a defoliator (formerly called gypsy moth), but its caterpillars lack the white toothbrush tufts of Orgyia species and have paired blue and red spots along the back.
Is a spongy moth or a white-marked tussock moth more dangerous?
Spongy moth: Irritating hairs. White-marked tussock moth: Irritating hairs. Caterpillar hairs and scales can cause skin irritation or an itchy rash (contact dermatitis) in sensitive people; inhalation of large numbers of hairs or scales may irritate the respiratory tract. Caterpillar hairs are urticating and can cause skin irritation, rashes or eye irritation in sensitive 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.