The Triple-Spotted Clay moth is unknown in Ireland since 1956. From Red List 9 Macro-moths:
There is a single generation of adults in late June to early August with larvae from August to the following spring. Adults come to light and sugary attractants. The foodplants include herbaceous plants such as Primrose Primula vulgaris but also trees and shrubs in damp, open woodland. There are just a few Irish records, the last being in 1956. This species is therefore assessed as Regionally Extinct. There are many claims of this species annually which to date have all been shown to be misidentifications of a common species.
Séamus Sweeney 