Key to females of Thai Aposthonia

1. Head light brown. Prothorax brown, meso- and metathorax dark brown. Forelegs concolorous with pronotum, middle and hind legs entirely dark brown. Abdomen brownish with terga of segments 3–6 somewhat reddish brown. Cerci entirely medium brown (Fig. 3 B)..................................................................... A.ceylonica (Enderlein)

- Head dark brown or black............................................................................... 2

2. Head blackish brown. Prothorax light brown orange, cream-white intersegmental banding anterior and posterior to mesoscutum. All legs brown, except middle and hind coxae and trochanters whitish. Abdomen chestnut-brown throughout. Cerci entirely medium brown (Fig. 3 A)........................................................ A. borneensis (Hagen)

- Head dark. Thorax entirely dark. All legs concolorous with thorax. Abdomen very glossy, dark. Cerci pale (Fig. 3 C)............................................................................................... A. problita sp. n.