Chusaris signicosta Walker comb. n.

Enea signicosta Walker, [1863] 1864, J. Proc. Linn. Soc. (Zool.), 7: 63.

Diagnosis

The forewings are an ashy grey, the hindwings a duller medium grey. The forewing costa is marked by three evenly spaced black triangles, the most distal one being the largest. There may also be a black discal mark in a relatively central position, just basal to the central triangle, and heavily marked specimens may have a postmedial arc of small black spots running from this triangle and around the discal mark on its distal side.

Taxonomic note

Enea Walker is placed as a synonym of Chusaris in the generic account, so the type species is automatically transferred. The next two species are closely related to signicosta. There is a further species in Sulawesi (slide 20366) with valves tapering acutely apically but without a marginal spur ventrally. The valve costa is strongly bowed over its ventral two-thirds, but the ventral margin is straight. There is a small triangular process on the interior of the sacculus.

Geographical range

Borneo.

Habitat preference

The species is frequent in a range of lowland forest types including heath and coastal forest. It has also been recorded more infrequently in lower montane forest up to 1000m, with one record from 1500m.

Genitalia: