Insecta : Lepidoptera : NoctuidaeButterflies and Moths

Xylena vetusta (Hubner, 1813)

Red Sword-grass

Xylena vetusta

Description: Wingspan 52-62 mm. Adults are distinctive at rest as they wrap their wings tightly around their body so resembling a dead piece of wood. The forewings are straw-coloured with a reddish flush along the dorsal half of the wing. There is a small white mark in the central area of the forewing and an irregular subterminal line. Hindwings are fuscous with a small discal lunule. Early September to late October and again after hibernation from mid-January to late April.

World Distribution: Throughout western Europe from Spain to the Arctic Circle.

Irish Distribution: Generally widespread across all counties, but usually more common in the south where recording is more frequent during the early part of the year.

Ecology: A large distinctive species found in a variety of habitats including damp woodland, bogs, fens and moorland. Adults come regularly to light and will also feed on overripe berries, rotten fruit and Ivy Hedera helix blossom. The larvae feed during the day, often fully exposed from May until the beginning of July on a variety of woody and herbaceous plants, including Bog Myrtle Myrica gale, dock Rumex spp., Yellow Iris Iris pseudacorus and various grasses.

Key Identification Features:

  • Resembles a dead piece of wood
  • Resting posture and time of year
  • Dark hairy thorax
  • Small discal lunule on hindwing

Distribution Map from NBN: Xylena vetusta at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Xylena vetusta at iNaturalist World Species Observations database.

 Thompson, R. & Nelson, B. (2023). Xylena vetusta. (Hubner, 1813). [In] Moths of Northern Ireland.
https://habitas.org/moths/species.php?item=6334. Accessed on 2026-11-02.