Small Square-spot Diarsia rubi
Wingspan 28-33 mm.
A common species throughout Britain, occurring in any suitable habitat, but perhaps preferring damp and marshy places.
South of Scotland, it is double-brooded, flying in May and June, and again in August and September. In Scotland there is one generation, flying in July and August, when it is difficult to tell apart from the very similar, and possibly conspecific, Fen Square-spot (D. florida).
Where there are two broods, the first generation generally produces larger moths.
The larval foodplants are a range of herbaceous species.