Wingspan c. 10 mm.
This species has been found in a number of scattered localities throughout the British Isles, including southern England, South Wales, Scotland and Ireland, but it remains very scarce and local. It was only discovered in 1983 in Cornwall, when it was given the name phaella, but then an earlier record was discovered from the 19th century.
The foodplant is not known, although it is suggested that it may be St. John's-wort (Hypericum).
Adults have been noted in all months between June and September. They have plain blackish forewings with a creamy spot on the costa which merges into the cilia.