Large yellow underwing
Its forewings look like plain dead leaf litter at rest, but flicking into flight reveals bright orange-yellow hindwings meant to startle a predator mid-attack.
| Where | Gardens, hedgerows, grassland, waste ground |
|---|---|
| Size | 45 to 55 mm wingspan |
| When | June to October |
At rest it looks like an unremarkable mottled brown moth, but the hindwings are a strong orange-yellow with a black border, visible only when it opens its wings or takes off.
It is one of the most common larger moths, and local numbers are boosted most years by migrants arriving from farther south.
Traits
Habitat
Garden
Colour
Brown, Yellow
Active
Night
To people
Harmless; caterpillars can be a minor garden pest on seedlings
Activity through the year
Often confused with
The broad-bordered yellow underwing has a noticeably wider black border on the hindwing and is on average slightly larger.
Questions
Is the Large yellow underwing dangerous to people?
Harmless; caterpillars can be a minor garden pest on seedlings.
When can you see the Large yellow underwing?
The Large yellow underwing can be seen from June to October, at night.
Plate retouched from a photo by gailhampshire from Cradley, Malvern, U.K, CC BY 2.0, Wikimedia Commons Licence
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Butterflies and moths›Owlet moths›Noctua
Last updated 2026-09-26. Every entry is checked against published sources.