Description: Wingspan 38-48 mm. A very distinctive moth, which is not easily confused with any other species. Forewings mainly brown with a bright metallic yellow-green patch running from the basal area to the apex of the wing. Hindwings dark fuscous, paler towards the basal area. Recorded once in October in N.Ireland. Skinner gives mid-August to late October as the normal flight period in Britain.

World Distribution: Tropical; found commonly from the Azores to the East Indies. In western Europe it appears as a migrant.

Irish Distribution: A very rare migrant from southern Europe that has only been recorded once in N. Ireland at Seaforde, Down in 1989. There have been only three other Irish records from Timoleague, Cork in 1946, Connemara, Galway 1964 and Fountainstown, Cork in 1978.

Ecology: A Mediterranean species that occasionally in favourable years appears in very small numbers in southern England. It is rarely found elsewhere.

Key Identification Features:

• Its flight period and scarcity in N. Ireland
• Bright yellow-green metallic coloration on the forewing

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

iNaturalist: Diachrysia orichalcea at iNaturalist World Species Observations database.