This moth is very difficult to differentiate from its close relative Pancalia schwarzella, with forewing differences relating to the angulation of the lines and antennae colour and size. In leuwenhoekella, the antennae in both sexes have a broad subapical white section. In schwarzella, the male antenna is brown, the female antenna has a thickened area in the middle before the white section.
The larvae feed on hairy violet (viola hirta) or dog violet (viola canina), with the adults flying in sunshine from April to June, in its chalk and limestone habitats.
The moth is locally common in southern England, and sparsely distributed throughout the rest of the UK.