An immigrant species, normally found at coastal localities, attracted to light, but does turn up inland.
In some years there are reasonable influxes, and subsequently larvae can be found in some areas, feeding on bedstraw (Galium) and willow herb (Epilobium).
The attractive caterpillars are dark green or brownish with bright yellow spots.
The forewing is dark olive brown with lighter brown along the outer margin and a tan band running from the wing tip to the inner margin. The hindwing is dark brown with a pale narrow outer margin and a reddish median band, which becomes white at the inner margin.
If found report to MWHG/County Lepidopterist as soon as possible and provide photographic proof if possible.