Key to the species of the Acidiella longipennis species group

1. Male (discernible by not having oviscape; Figs. 3 E, F, H, J).................................................... 2

- Female (discernible by conspicuous oviscape; Figs. 3 G, I; A. spinipenis female not available)......................... 4

2. Abdominal tergite 3 (2nd visible tergite; Fig. 3 H) entirely dark brown............................ A. spinipenis, sp. nov.

- Abdominal tergite 3 largely yellow brown.................................................................. 3

3. Abdominal tergite 5 dark brown with narrow yellow brown medial longitudinal band (Figs. 3 E, F).... A. longipennis Hendel

- Abdominal tergite 5 entirely dark brown (Fig. 3 J)........................................ A. kambaitiensis, sp. nov.

4. Abdominal tergite 3–4 largely dark brown with narrow medial longitudinal medial band (Fig. 3 G); oviscape about as long as two preceding abdominal segments...................................................... A. longipennis Hendel

- Abdominal tergite 3–4 almost entirely yellow brown with narrow dark brown lateral bands (Fig. 3 I); oviscape much longer than two preceding abdominal segments............................................... A. kambaitiensis, sp. nov.