Genus Trichactia Stein, 1924

Trichaetia Becker, 1908: 118. Type species: Trichaetia nubilinervis Becker, 1908, by monotypy. A junior homonym of Trichaetia Swinhoe, 1892.

Trichactia Stein, 1924: 138 . Type species: Thryptocera securicornis Egger, 1865, by monotypy [= pictiventris (Zetterstedt, 1855) (Herting 1984)].

Diagnosis. Arista bare, first and second aristomeres each at least 3 times as long as wide; parafacial with setulae on upper half or less; facial margin visible in lateral view; palpus well developed; back of head with some rows of black setulae behind postocular row; prosternum bare; postpronotum with 2–3 setae not arranged in a triangle; scutellum with a pair of strong, crossed apical setae; basicosta yellowish-orange; wing cell r 4+5 without a petiole; wing vein R 4+5 with basal setulae dorsally, reaching at least halfway to crossvein r–m; hind tibia with 3 preapical dorsal setae, and anteroventral and posteroventral preapical setae subequal; middorsal depression of syntergite 1+2 extending to posterior margin of that segment.

Remarks. The genus Triarthria is the closest relative of Trichactia, from which it can be separated by the following combination of character states: parafacial entirely covered with proclinate setae and setulae, facial margin not visible in lateral view and scutellum without crossed apical setae.