Endangered (proposed as a future Red Data Book species) in southern England. Only recorded twice, in West Sussex in June 1995, and in Kent in 1935. Not recorded in Hampshire or on the Isle of Wight to date. Wingspan 10-12 mm. Not unlike the common resident T. luculella
, in which the discal marking is yellow rather than orange and curves in a semicircle so that both ends touch the costa (MBGBI Vol 4 part 2). Larva feeds on Oak, living between leaves spun together with silk.