Identification

Very similar to Common Rustic. No reliable external features have been found and examination of the genitalia is required to distinguish the two species.

Undissected specimens should be recorded as Common Rustic agg.(Mesapamea secalis agg.).

Recording Method.

Attracted to light, also comes to sugar and flowers.

Life cycle

One generation. Overwinters as a larva during September to May, feeding inside a stem and pupating in a cocoon underground.

Larval foodplants

Grasses.

Habitat

A wide variety of grassland sites.

History 

It wasn’t until 1983 that it was realised that there were two different species under M. secalis and so M. didyma was born.

The first confirmed record came in August 1987, when Bernard Skinner trapped it at Sandhead, Wigtownshire. Since then Tony Davis caught it and confirmed it at Torrs Warren (VC74) in August 1997, Fleet Forest, Gatehouse of Fleet and Wood of Cree (both VC73), all in August 1997.