Key to adult males of the genus Psectrotanypus
1. AR = 1.8 ........................................................................................................................ 2
AR = 1.8... ..................................................................................................................... 3
2. Tergites with lateral bands (Oriental) .................................................. P. lateralis sp. n.
Abdomen uniformly brown (Afrotropical) .................................. P. schwetzi (Freeman)
3. Abdomen uniformly brown (Nearctic) .................................. P. pictipennis (Zetterstedt)
Abdomen with dark bands............................................................................................. 4
4. AR> 2.1 (Palaearctic) ............................................................ P. yoshimurai (Tokunaga)
AR = 2.1 ........................................................................................................................ 5
5. Fore tibiae without apical setae (Nearctic) ................................. P. discolor (Coquillett)
Fore tibiae with apical setae .......................................................................................... 6
6. Tergites II–V with transverse, anterior brown band, without additional spots (Nearctic) ......................................................................................................... P. dyari (Coquillett)
Tergites I–V each with anterior brown band and 2 additional rounded median dark spots (Oriental, Palaearctic) ............................................................ P. varius (Fabricius)