Plinachtus

Key to the Madagascar and Aldabra Atoll species of Plinachtus

1- Posterior third of antennal segment III black; posterior margin of pleural abdominal sterna II to IV black....................................................................................................... 2

1’- Posterior third of antennal segment III yellow or reddish orange; posterior margin of pleural abdominal sterna II to IV yellow ...................................................................... 3

2- Rostral segments II to IV black; posterior third of antennal segment II reddish; basal half of costal margin of corium black; abdominal spiracles yellow ............................... ................................................................................... P. scitulus Brailovsky and Barrera

2’- Rostral segments II to IV yellow (apex of IV black); posterior third of antennal segment II black; basal half of costal margin of corium yellow; abdominal spiracles black ............................................................................. P. vermiculus Brailovsky and Barrera

3- Abdominal sternite V with black discoidal spot; humeral angles of pronotum flattened, and relatively thin at base ......................................... P. madagascariensis (Kiritshenko)

3’- Abdominal sternite V without black discoidal spot; humeral angles of pronotum thick at base............................................................................................................................ 4

4- Mesopleura with small black discoidal spot; posteroventral edge of male genital capsule with lateral arms wider, stout, gently conical, and large u-shaped concavity (Fig. 4) ..................................................................................................... P. aldabrensis n. sp.

4’- Mesopleura without black discoidal spot; posteroventral edge of male genital capsule differentiated into prominent asymmetrical arms; inner arms with large setae-like hairs (Fig. 6) ................................................................................................ P. contortus n. sp.