Acrobasis tumidana
Tufted Oak Knot-horn

Wingspan 19-24 mm.

A poorly-known species in the British Isles, it is a scarce and local species in southern and south-eastern England, with a few records elsewhere in the country north to Lancashire. It seems probable that some of these are migrants.

The adult resembles A. repandana, but rather redder and with more prominent scale tufts.

It flies between July and early September, and can be attracted to light. The larvae are reputed to feed on oak (Quercus), amongst spun leaves, though this stage has rarely, if ever, been observed in Britain.