23-25mm, 20-21mm. The facies is very different from all other Bertula, as the wings are a uniform dark greenish brown with irregular, broken submarginals and fine, linear postmedials in a much paler colour, almost white. The forewing postmedial is gently curved, weakening towards the costa, and that of the hindwing forms a curve or slight angle subtornally but does not extend forwards beyond the midpoint of the wing. The chevrons of the submarginal are also restricted to the dorsal half. The male antennae are fasciculate, and the labial palps are recurved to the thorax and tufted as in other Bertula. The foretibia is thickly scaled. The male abdomen has the eighth segment as in Bertula and allied genera. The genitalia have an unusual spatulate uncus with a slender neck. The valves are large, triangular, expanding towards the distal end where the costal and ventral angles are produced, incurved, a feature shared with B. picta (p. 43), where the valves are much shorter. The aedeagus vesica is consistent with placement in Bertula, and has a complex scobinate diverticulum on the distal side. The female has the ostium set within an extensive horseshoe-shaped, crinkled and scobinate area of the eighth segment. The ductus is very slender, the corpus bursae elongate, distinctly pyriform, with both neck and bulb of the pear scobinate over their basal part, the bulb having a small signum, an umbonate concentration of scobination, within this. The slightly coiled ductus seminalis arises from the distal part of the neck of the pear.
Holotype. Kina Balu, N. BORNEO (J. Waterstradt), BM noctuid slide 19493.
Paratypes: 1 (abdomen missing) as holotype; 1 Kina Balu (ex Staudinger) 1896; 1 Kina Balu, N. BORNEO; 1 (slide 20166; foreleg), 2 (one abdomen missing) NORD BORNEO: Mont Kina Balu, 5-8.1903 (John Waterstradt); 1 SARAWAK: Gunong Mulu Nat. Park, R.G.S. Exped. 1977-8 (J.D. Holloway et al.), W. Melinau Gorge, 100m, 428563, to light in camp [alluvial forest]. 15.3.1978; 1 (slide 19823) SARAWAK as previous but Site 10, February, Camp 1, Mulu, 160m, 386470, mixed dipt. for.
Taxonomic note. This species is only tentatively assigned to Bertula as it lacks the orbicular stigma of the hindwing underside that characterises this and related genera. The male foreleg has a tibial sheath but lacks a spur on the first tarsal segment. Other features, however, are consistent with such a placement.
Geographical range. Borneo.
Habitat preference. Recent survey records are from lowland forest; the Kinabalu specimens lack altitude data.
