Key: Step 642. Orthocladiinae 54 Hydrobaenus

642a. Armament of abdominal tergites denser and stronger, e.g. median points of tergite IV 12µm long; points of apical band IV about as strong as those on III.

Hydrobaenus lugubris

642b. Armament of abdominal tergites less dense and weaker, e.g. median points of tergite IV 8µm long; points of apical band IV much smaller than those on III.

Hydrobaenus rufus
Decision path