Isocossus marginimaculatus sp. n.

♂♂ 15mm, 17mm. The male antennae are filiform. The forewing ground is a rather dirty white that is irrorated with a pale, dull, reddish brown extensively over the basal two‐thirds and more narrowly at the margin. The basal brown area is heavily mottled with dark grey that almost obscures it, but is much reduced in the submarginal zone of ground colour. The marginal brown zone contains a row of round black spots in the spaces at the very margin. These are present but fainter and greyer on the hindwing, which is otherwise completely irrorated with the reddish brown colour apart from sparse spotting of grey. The male gentalia are of the standard cossine type, perhaps most similar to those of I. telisai, but with the unusual wing facies being diagnostic.