Wingspan 11 - 14mm.
A rare immigrant from Central and Southern Europe. The first authenticated British record was made at Minsmere, Suffolk, in 2009; the few other authenticated records have been from Suffolk (three) and Norfolk (one) and have all occurred in late May and June.
The larvae feed within the seeds of Field Maple (Acer campestre) and Sycamore (A. pseudoplatanus) but as yet there is no evidence of breeding in the UK.
The specific scientific name means "polluted" or "dirty", somewhat harsh for quite a distinctive-looking moth with a broad white/yellow dorsal patch.