The species is quite variable, the forewings being buff or brown, but is always easily identified by the bold whitish apical streak which gives it its common name.

The larva is usually dark green with darker, paler-edged dorsal line, a broad whitish or yellowish subdorsal.

The pupa is red-brown, dorsally rather darker, wings tinged with green.

The moth flies, usually at dusk, in September and October [1] and is sometimes attracted to light.

The larva usually feeds on broom but has been recorded on yellow bush lupin.