Brunetti, E. 1918. Revision of the Oriental Tipulidae with descriptions of new species, Part 2. Records of the Indian Museum 15: 314.
The genus Trentepohlia is extensive, being represented by nearly 300 species and strongly represented in the Oriental Region. The species of Trentepohlia may be separated from other genera by the characteristic shape of the singular male gonostylus and characters of the wing venation that shows the loss of the R-M crossvein and the deflection of CuA2 towards A1, at times intersecting and closing off cell cup. The subgeneric divisions of Trentepohlia are based on variation in the wing venation and are easily separated based on various combinations of wing characteristics.
Trentepohlia (Plesiomongoma) shows the characteristic bend of CuA2 toward A2, in this case closing cell cup. It is separated from other subgenera of Trentepohlia based on the following combination of wing venation characteristics: the closing of cell cup, cell dm present, two branches of Rs to margin, and two Medial veins present to margin.
Head: Anterior vertex not strongly produced. Rostrum length subequal to remaining head. Maxillary palpus length subequal to remaining head, palpomeres subequal. Antennae: 16 articles, antenomeres suboval to cylindrical.
Wing: Subhyline to lightly suffused; stigma present or absent, additional coloration uncommon; anal angle present. Wing venation: Sc long, Sc1 removed from Sc2, Sc1 ending after split of Rs; Sc2 may be absent; R1+2 subequal to R2, R2 typically directed toward wing base; two branches of Rs (R3, R4+5) attaining wing margin; R-M crossvein absent; two Medial veins (M1+2, M3) attaining wing margin; cell dm present; one Cubital vein (CuA1)attaining wing margin; CuA2 directed intersecting A2 at wing tip, closing cell cup; two Anal veins (A1, A2)attaining wing margin.
Male hypopygium: 9th tergite (9t) and sternite (9s) separated by lateral division. Mesoventral lobe of gonocoxite present or absent. Gonostylus singular; style a broad flattened sclerotized lobe, a tooth present at about 1/3 the length of the style, tip variously produced. Aedeagus simple with one or two terminal openings. Proctriger simple, without modification.
Trentepohlia (Plesiomongoma) a small groups of species (6 species) that is strongly represented in the Oriental Region. Five of the six known species found here and are spread throughout the islands of the region, with the remaining species being found in northern India. The one additional species of T. (Plesiomongoma) not known from the Oriental Region is known from Papua New Guinea of the Australia/Ocenanic Region.
The larval habitat of this subgenus is unknown.