Chironomidae: subfamily key 1 Antenna retractile within head (Fig. 2A). Hypopharynx with toothed ligula (Fig. 2B). Mentum weak......... Tanypodinae 1’ Antenna non-retractile. Hypopharynx lacking toothed ligula. Mentum is dominant toothed plate....................... 2 2(1) Ventral (median) mentum laterally expanded into ventromental plate, usually striate (Fig. 2C, D), never with beard beneath [Exceptionally ventromental plate lacks striae in Xiaomyia, Shangomyia (Fig.2E) (tribe Xiaomyiini), Harrisius, Stenochironomus (tribe Chironomini) (Fig. 2F)................................................................. Chironominae 2’ Ventromental plate, if developed, never striate, sometimes with beard beneath..................................... 3 3(2) Labrum without premandibles (Fig. 2H)................................................................... 4 3’ Labrum with distinct premandibles (Fig. 2J)............................................................... 5 4(3) Procercus well developed (Fig. 2K). Antenna well-developed with 4 or 5 segments, 2nd and/or 3rd annulate (Fig. 2L).............................................................................................. Podonominae 4’ Procercus absent (Fig. 2I). Antenna weak, 3rd segment smooth.................................... Buchonomyiinae [lotic, commensal/ectoparasitic, B. burmanica Brundin & Saether, adults from Myanmar (Burma), oriental China (Yunnan)] 5(3) Antennal segment 3 annulate (Fig. 2O). Ligula and paraligula (of prementum) forming 3 setal brushes (Fig. 2P). Diamesinae 5’ Antennal segment 3 smooth (Fig. 2M, N).................................................................. 6 6 Head capsule densely setose (Fig. 13C, D). Anterior labrum with transverse row of overlapping serrate lamellae (Fig. 13E, F), Prementum medially deeply divided into lamellae (Fig. 13H)..................................... Protanypodinae 6’ Head rarely with more than basic cephalic setae. Labrum without row of lamellae, or restricted to paired labral lamellae close to S1 setae. Prementum distinctive only in Telmatogetoninae ................................................... 7 7(6) Ventromental plate with setal beard beneath (Fig. 2G). Antenna long, 4-segmented (Fig. 2N)............. Prodiamesinae 7’ Ventromental plate, if developed, without setal beard beneath. Antenna, if 4-segmented, very short.................... 8 8(7) Antenna squat, 4-segmented (Fig. 2M). Premandible with strong beard (Fig. 2J). Anal tubules absent, usually maritime.......................................................................................... Telmatogetoninae 8’ Antenna if short, rarely 4-segmented or indistinctly segmented. Premandible bare or with sparse beard. Anal tubules usually present in freshwater groups................................................................. Orthocladiinae

Published as part of Cranston, Peter S. & Tang, Hongqu, 2024, An identification guide to the genera of aquatic larval Chironomidae (Diptera) of south-east Asia, pp. 151-193 in Zootaxa 5497 (2) on page 154, DOI: 10.11646/zootaxa.5497.2.1, http://zenodo.org/record/13618241