Insecta : Lepidoptera : GeometridaeButterflies and Moths

Cosmorhoe ocellata (Linnaeus, 1758)

Purple Bar

Cosmorhoe ocellata

Description: Wingspan 28-30mm. Adults are normally white with a broad bluish black central band tinged with pale ochreous brown at the marginal edge. The basal patch is also dark in colour. From early May right through to late September.

Irish Distribution: Widespread and commonly encountered in all counties.

Ecology: An attractive species associated with a variety of habitats particularly woodland, calcareous grassland, coastal heaths and dunes. Adults come frequently to light, often in good numbers at some of its coastal localities such as Murlough NNR and Killard Point NNR, Down. It is occasionally disturbed by day from bushes and other vegetation. The larvae can be found from summer through to autumn on bedstraws Galium spp. It overwinters as a pupa.

Key Identification Features:

  • White wings
  • Dark blue central band

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

iNaturalist: Cosmorhoe ocellata at iNaturalist World Species Observations database.

 Thompson, R. & Nelson, B. (2023). Cosmorhoe ocellata. (Linnaeus, 1758). [In] Moths of Northern Ireland.
https://habitas.org/moths/species.php?item=5832. Accessed on 2026-11-02.