Wingspan 18 to 24 mm. Eupithecia innotata is a rather complex taxonomic group, consisting of a number of forms previously thought to be separate species, but now believed to be different forms of the same species using different foodplants. Ash Pug, originally given specific status Eupithecia fraxinata, is now known as Eupithecia innotata f. fraxinata, and as its name suggests, feeds on Ash (Fraxinus). The forewings are generally dark brown or grey with few distinguishing marks apart from a small white tornal spot which may not be present on the frequent melanic forms.

In areas where Ash is plentiful.

The moths fly in two generations, from May to June and again in August.

Larva feeds mainly on Ash, over-wintering as a pupa.

It is widely distributed throughout much of Britain where the foodplant occurs. In a recent survey to determine the status of all macro moths in Britain this species was Unconfirmed.

Fairly frequent but not common in Leicestershire and Rutland. L&R Moth Group status = B (scarce resident or restricted distribution or regular migrant).