Key to species of Hemisphaeriini known from Borneo
1 Metope narrow, dark brown red with pale lateral margins (Fig. 19). ................................ .............................................................................. Gergithus niger niger (Walker, 1857)
– Metope wide (Fig. 13), with different coloration. .......................................................... 2
2 Fore wings elongate, each with three separate light spots (Figs 11, 12). .......................... .......................................................................... Bruneastrum cardinale gen. & sp. nov.
– Fore wings relatively wider (Figs 16, 18); if spots are present, then two of them are partly fused posteriorly (Fig. 18). ............................................................................................. 3
3 Fore wings unicoloured, without spots or bands. ........................................................... 4
– Fore wings with spots or bands. ..................................................................................... 6
4 General coloration dark brown to black. ......... Hemisphaerius bacculinus Butler, 1875
– General coloration pale. ................................................................................................. 5
5 Fulvous, mesonotum with two wide red stripes (Figs 15, 16). ......................................... ......................................................................... Hemisphaerius rufovarius Walker, 1858
– Brown yellowish, mesonotum without stripes. .... Hemisphaerius torpidus Walker, 1857
6 Fore wings testaceous with two wide, irregular, parallel, transverse dark brown to black lines (see BUTLER 1875: pl. 4, fig. 14). ................. Hemisphaerius typicus Walker, 1857
– Fore wings dark brown, each with three large light spots, two of which are partly fused posteriorly (Figs 17, 18). ............................. Hemisphaerius maculatus Melichar, 1906