Lunar underwing
Despite its plain brown forewings, this moth carries a pale crescent moon shape on each hindwing that only shows when it opens its wings.
| Where | Grassland, downland and gardens |
|---|---|
| Size | 32 to 38 mm wingspan |
| When | September to October |
The Lunar underwing is a variable species ranging from pale buff to dark brown on the forewing, often with clearly defined whitish veins, while the hindwing carries a moon-shaped pale crescent that gives the species its name.
A single generation flies in autumn, with caterpillars feeding afterward on grasses such as cock's-foot, annual meadow-grass and Yorkshire fog through winter and into spring before pupating in the soil.
Traits
Habitat
Grassland
Colour
Brown
Active
Night
To people
Attracted to light; harmless to people.
Activity through the year
Often confused with
A similarly sized autumn moth at around 33 to 38 mm wingspan, but warmer orange brown with a glossy sheen and lacking the Lunar underwing's dark crescent on the hindwing.
Questions
Is the Lunar underwing dangerous to people?
Attracted to light; harmless to people.
When can you see the Lunar underwing?
The Lunar underwing can be seen from September to October, at night.
Plate retouched from a photo by Ben Sale from UK, CC BY 2.0, Wikimedia Commons Licence
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Butterflies and moths›Owlet moths›Agrochola
Last updated 2026-09-26. Every entry is checked against published sources.