Description: Wingspan 17-22mm. Adults have a distinctive whitish sheen to the wings with greyish cross lines, which are straight on the forewings and curved on the hindwings. Skinner (1998) gives June and July as the main flight period.

Irish Distribution: The absence of recent records for this species may indicate that it has become extinct. There are old early 20th century records from the Kilkeel area in Down and from Whitehead Antrim. More recently it was recorded from Murlough NNR in 1978 by Capt W.S. Wright. There have been several other recent records claimed, but since no specimens exist these must be regarded as doubtful.

Ecology: A species normally associated with woodland, although the older records are mainly from coastal localities. Adults are attracted to light but appear only sparingly. The moth is more commonly encountered in southern Ireland reaching as far north as Dublin. Larvae have been reared in captivity on Dandelion Taraxacum officinale, Knotgrass Polygonum aviculare and plantain Plantago spp. It overwinters as a larva.

Key Identification Features:

• Whitish sheen to the wings
• Curved crosslines on the hindwings

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

iNaturalist: Idaea subsericeata at iNaturalist World Species Observations database.