Common Rustic Noctuidae

Mesapamea secalis (Linnaeus, 1758)

Description: Wingspan 31-36 mm. Adults can be variable in colour. Forewings range in colour from light to dark brown. The reniform stigma is large, usually lobed, with a smaller white-lined stigma inside. The orbicular stigma is generally inconspicuous. Antemedian and post median lines irregular and strongly indented. The termen area is normally darker and clearly seen on paler individuals. Hindwing dark fuscous becoming lighter towards the base with a paler fringe. Requires examination of the genitalia to confirm identification due to close similarity to Lesser Common Rustic M. didyma.

Similar Species: Small Clouded Brindle A. unanimis which has a dark basal streak on the forewing and a paler hindwing. Separation from Lesser Common Rustic M. didyma requires examination of genitalia.

Key Identification Features:

Sets:  male upperside female upperside

Flight Period: Beginning of July to the start of September.

Status: This species was previously considered to be variable and has in recent times been separated into two species M. secalis and M. didyma. The distinction between both can only be conclusively determined by genital examination of the specimen. The M. secalis/didyma aggregate is common and widespread in N. Ireland but the current abundance and precise distribution of both species is not known. The old records of M. secalis can only be accepted if a voucher exists.

Ecology: A grassland species found in a wide variety of habitats. Adults rest concealed among ground vegetation by day and become active after dark. They come frequently to light and also to flowers, especially Common Ragwort Senecio jacobaea, Buddleia Buddleja davidii and marsh grasses. The larvae feed from autumn until May on Cock's-foot Dactylis glomerata and other grasses. It overwinters as a larva.

World Distribution: Eurasiatic: widespread and generally common in western Europe from Spain to central Scandinavia.

Bradley & Fletcher number: 2343 Agassiz number: 73.169

Additional information:

UK Moths account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland