Description: Wingspan 42-50 mm. Forewings broad and normally dark greyish brown. Stigmata similar to the ground colour and not clearly defined; in some cases the reniform stigma takes the form of a small colon mark. There is a series of small black dots along the termen. Crosslines pale and indistinct. Subterminal line irregular and poorly defined. Hindwings pale whitish brown, darker towards the terminal margin. The fringe is normally white. Unknown in N. Ireland. Late July and early August in Britain according to Skinner.

World Distribution: Holarctic: generally confined to coastal localities in western Europe from northern France to the Baltic coast of Finland.

Irish Distribution: Currently unknown as there have been no records since 1978 of this coastal species. It was last recorded from Murlough National Nature Reserve, Down, although no specimen exists to validate the record. The loss of saltmarsh habitat may be a contributing factor to its rarity and apparent decline. There has been targeted fieldwork carried out in the saltmarshes on Carlingford Lough, in south Down, but without success. In Ireland it is mainly confined to the east coast from Waterford to Antrim.

Ecology: A rare species of which little is known about its habits and requirements in N. Ireland. Elsewhere is generally associated with saltmarshes, mudflats and brackish areas. Adults are attracted to light and flowers especially Sea Campion Silene uniflora and thistles. The larvae, which overwinter, feed on the roots of saltmarsh grasses from September until June.

Key Identification Features:

• Small colon mark in some cases on the forewing
• Small black dots
• Pale hindwings with darker veining

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

iNaturalist: Apamea oblonga at iNaturalist World Species Observations database.