Tribes and genera of Ptiliinae

1. Wing membrane without a clear medial constriction, metacoxae separated by a bifurcate extension of the metaventrum ................................................................ Ptenidiini ( Sindosium Johnson, 2007)

– Wings with a clear median constriction and long peripheral setae ................................................... 2

2. Small, flattened, yellow species with truncated elytra and widely separated metacoxae (usually found in corticular habitats) ................................................................................................................ ............................ Ptinellini ( Niptella gen. nov. (Fig. 12A), Ptinella Motschulsky, 1844 (Fig. 13A))

– More rounded species without truncated elytra ................................................................................ 3

3. Mesoventrum with a large spatulate plate, metacoxae separated by a bifurcate extension of the metaventrum (Fig. 11D) .................................................. Nanosellini ( Kuschelidium Johnson, 1982)

– Without a mesoventral spatulate plate .............................................................................................. 4

4. Species with long legs and antennae clearly adapted for an active lifestyle .................................... 5

– Species with shorter antennae and legs ............................................................................................ 6

5. Antennomere XI with a medial constriction giving the appearance of a dumb-bell or hour-glass, mesoventrum without obvious perforations ....................................................................................... ...................................................................... Discheramocephalini ( Cissidium Motschulsky, 1855)

– Antennomere XI without a medial constriction, pronotum with strongly sculpted linear foveae (Fig. 10B), mesoventrum clearly perforated ....................................................................................... ............................................................ Discheramocepahlini ( Discheramocephalus Johnson, 2007)

6. Small, yellow, fragile species, length <0.7 mm ............................................................................... 7

– Larger, more robust species, length> 0.7 mm .................................................................................. 8

7. Metacoxae contiguous (Fig. 3 A–C) ................................................. Ptiliini ( Bambara Vuillet, 1911)

– Metacoxae separated by ± ¹∕₅ the width of the metaventrum (Fig. 5F) ............................................... ....................................................................................................... Ptiliini ( Ptiliola Haldeman, 1848)

8. Mesoventral collar sharply pointed between the mesocoxae which are contiguous ........................... ................................................................................................................. Ptiliini ( Erro Darby, 2017)

– Mesoventral collar square ended between the mesocoxae which are more widely separated ............ ..................................................................................................... Ptiliini ( Dipentium Johnson, 1982)