19-21mm. This species is similar in size and forewing facies to I. duplicifascia Hampson comb. n. (see generic account). However, the male labial palps are as in the typical members of Isana rather than with a very long third segment extending to beyond the centre of the abdomen as in duplicifascia. The features of the hindwing, including the stigmata on the underside, are as in the previous species, features also shared with duplicifascia. The antennae are fasciculate, and the foreleg has the generic features. The forewing postmedial band is broader and more distal than in duplicifascia, with its darkest component on the basal (rather than distal) side. There is a medium brown basal area bounded by an oblique antemedial and a dark brown medial zone that narrows towards the dorsum as illustrated. The male abdomen has the eighth segment unmodified except for apodemes on the tergite. The genitalia have the valves expanding distally, with their distal margin excavated in a smooth curve, the former more produced. The aedeagus vesica is similar in shape to that of eugenes, with a similar distal mixture of fine scobination and larger globular spines, though the latter are more elongate, and the whole field is set on a distinct distal diverticulum.
Holotype. SARAWAK: Gunong Mulu Nat. Park, R.G.S. Exped. 1977-8 (J.D. Holloway et al.), Site 2, January, Camp 4, Mulu, 1790m. 452463 [upper] montane (moss) forest, BM noctuid slide 19497.
Paratypes: 1 as holotype; 1 (slide 20198; foreleg) as holotype but Site 5, 1780m. 451463 [stunted upper] montane forest.
Geographical range. Borneo.
Habitat preference. All three specimens are from upper montane forest.
