Orthocladiinae
Creators: name: Cranston, Peter S.
name: Tang, Hongqu
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Chironomidae

description: Orthocladiinae: genera
This large subfamily, which is second only to Chironominae in diversity, clearly is less dominant in subtropical and tropical rainforests comparing to temperate zones. The Orthocladiinae includes taxa with larvae living in the marine / intertidal/ splash zone, including Clunio, Thalassosmittia and Semiocladius (Tang et al. 2022b). Selected terrestrial (or semi-terrestrial) larvae are included only if at least one sp. is suspected from aquatic habitat(s): these are not illustrated. Some genera, notably Cricotopus (including Paratrichocladius) and Orthocladius lack unambiguous diagnostic larval characters to separate unequivocally. These key in several places: none include their subgenera.
1 Anal end lacks procercus; if present, without distinct anal setae and posterior parapods; anal setae present or absent (Fig. 16A). Anterior parapods often partially fused.................................................................... 2
1’ Procercus present, perhaps reduced; variable number of anal setae (Fig. 16T). Anterior parapods separated............. 15
2(1) Pecten epipharyngis scales each subdivided into 2–3 teeth, forming row of c. 8 teeth; S1 nearly palmate... Antillocladius Saether [seeps, wet terrestrial moss. Thailand, A. zhengi Wang & Saether (Hainan), A. tokarameneus (Sasa & Suzuki) Ryukyu, Japan, Korea; Nearctic, Neotropics; Mendes et al. 2004]
2’ Pecten epipharyngis consisting of 3 scales. S I palmate only in Parasmittia and Smittia ............................. 3
3(2) Preanal and anal segments and posterior parapods bent ventrally at right angles to body axis (Fig. 16A)................. 4
3’ Preanal and anal segments in same horizontal axis as body.................................................... 5
4(3) Posterior parapods undivided. Anal tubules present. Usually lacking anal setae............ Bryophaenocladius Thienemann [largely terrestrial,>8 spp. Oriental China, B. fujidecimus (Sasa), common; chaos in Asian spp. (M. Yamamoto, pers. comm. 2017), Kong et al. 2021, Lin et al. 2012. Japan, Korea, global]
4’ Posterior parapods divided, anterior part with small claws, posterior bare. Anal tubules small or absent. Single anal seta................................................................................. Gymnometriocnemus Edwards [semi-aquatic, terrestrial moss. Adults of several spp. inc. oriental China; global]
5(3) Anal tubules absent (Fig. 16D). Marine / maritime spp........................................................ 6
5’ Anal tubules present (Fig. 16T). Not marine, few marine littoral Pseudosmittia .................................... 8
6(5) Basal antennal segment squat, much wider than high. Ventromental plate protruding, rounded, with second more posterolateral plate. Premandible with brush. S I bifid............................................ Semiocladius Sublette & Wirth [marine coastal. S. endocladiae (Tokunaga), Korea, oriental China (Guangdong, Fujiang); Japan; Australia, western S. Pacific, Seychelles. Tang et al. 2022b].
6’ Basal antennal segment not squat, higher than wide (Fig. 16C). Ventromental plate single. Premandible without brush (Fig. 16B). S I simple, pectinate or plumose..................................................................... 7
7(6) Anal seta single. S I and S II broad, feathered. Seta submentum simple ... Clunio Haliday [marine, C. tsushimensis Tokunaga, C. tuthilli Tokunaga, C. setoensis Tokunaga, C. pacificus Edwards, e. coastal China, Japan, Tang et al. 2022b; global]
7’ Anal setae 2 or 3, rarely 1 (Fig. 16D). S I simple, S II always simple. Seta submentum simple or plumose...................................................................................... Thalassosmittia Strenzke & Remmert [marine, shores T. nemalione (Tokunaga), oriental China; Japan, Tang et al. 2022b. Holarctic]
8(5) Commensal on Ephemeroptera (Fig. 16E). Mandible with spine-like teeth (Fig. 16F). Mentum with broad median depressed area (Fig.16G)....................................................................... Symbiocladius Keffer [S. rhithrogenae Zavr ̌el, oriental China (Sichuan) Liu et al. 2023. Holarctic, Neotropical, Australia]
8’ Rarely commensal/ectoparasitic. Mandibular teeth typical, rounded to subtriangular (Fig. 16I). Mentum medially toothed (Fig. 16J) or with narrower median untoothed part (Fig. 16N)...................................................... 9
9(8) S I and S II bifid..................................................................................... 10
9’ S II never bifid....................................................................................... 13
10(9) Posterior parapods, procercus, anal setae and anal claws absent. Terminal antennal segment as long as preceding segment................................................................................... Camptocladius v.d. Wulp [coprophagous, aquatic only in (cattle) faecal-contaminated water, C. stercorarius (De Geer), nr global]
10’ Anal claws and posterior parapods present; if posterior parapods vestigial and without claws then terminal antennal segment about 3 x length of preceding segment................................................................... 11
11(10) Posterior parapod with 0–5 claws, 0–18 μm long. Mandible with 3 inner teeth. Antennal blade extending beyond flagellum 1 to 4 x as long as the width of basal segment................................................ Pseudosmittia Edwards [speciose, few aquatic; P. littoralis (Tokunaga) marine coastal, Tang et al. 2022b; speciose, global]
11’ Posterior parapod with 7–12 claws, 15–80 μm long. Mandible with 3 or 4 inner teeth. Antennal blade as long as width of basal segment, at most slightly extending beyond flagellum....................................................... 12
12(11) Mandible with 4 inner teeth, lacking seta interna, mentum with 5 pairs of lateral teeth. If 3 inner mandibular teeth, then mentum with 4 pairs of lateral teeth, blade as long as flagellum and seta submenti bifid ...................... .. Allocladius Kieffer [A. caspersi Ferrington & Saether oriental China (Sichuan)., A. aizaiensis (Wang) (Hunan); Japan. Holarctic, Neotropical, Afrotropical]
12’ Mandible with 3 inner teeth or when with 4 teeth, mentum with 4 pairs of lateral teeth. Seta interna occasionally present. Antennal blade extending beyond flagellum. Seta submenti simple.................... Hydrosmittia Ferrington & Saether [aquatic H. oxoniana (Edwards) oriental China (Yunnan); H. continalinea & H. sipinata both Zhang et al. (Sichuan), Zhang et al. 2016; global]
13(9) Mandible without seta interna. S I simple.................................................. Mesosmittia Brundin L, some on wet surface of rainforest leaves (Australia, Brazil); M. patrihortae Saether, oriental China 4 spp. (inc. Guangxi, Guizhou, Yunnan), seeming widespread. Holarctic, Neotropical, Afrotropical, Australia]
13’ Mandible with seta interna. S I palmate or plumose.......................................................... 14
14(13) Antenna very short, 4 segmented, distal segments indistinct, blade extending beyond antenna......... Parasmittia Strenzke [terrestrial, 1–2 undescribed spp. oriental China; Holarctic; Japan]
14’ Antenna even if reduced, with 4–5 distinct segments; blade less extended............................ Smittia Holmgren [terrestrial, modest but largely unknown diversity; global]
15(1) Antenna at least 1/2 length of head (less blade) (Fig. 16N, P)................................................. 16
15’ Antenna shorter than 1/2 length of head.................................................................. 20
16(15) Ventromental plate well developed. Mandible with globose base............................................... 17
16’ Ventromental plate weak or indistinguishable. Mandible with normal base....................................... 18
17(16) Dorsomentum with numerous fine anterior and lateral teeth (Fig. 16K)............... nr. ‘Orthocladiinae sp. C’. of Saether [lotic, undescr. L, P, oriental China (Hainan); (? = Parakiefferiella gp), Nearctic, Andersen et al. 2013]
17’ Dorsomentum with few rudimentary median teeth (Fig. 16L, M)............................ Nanocladius Kieffer (part) [few spp. with long antenna key here, see couplet 32]
18(16) Antenna with 4 segments, longer than head (Fig. 16N). Head capsule sometimes with surface sculpturing. Seta at base of posterior parapod with accessory spinelets (Fig. 16O)....................................... Corynoneura Winnertz [lentic, lotic. widespread regional, speciose, oriental China, Fu et al. 2019, 2022, global]
18’ Antenna with 5 distinct segments or 5–6 indistinct segments, at most as long as head, usually shorter. Head capsule without surface sculpturing. Seta at base of posterior parapod simple.................................................. 19
19(18) Antenna with 5 distinct segments, third segment frequently darkened (Fig.16P). Mentum without paired hypopharyngeal scales dorsal to it. Simple spine-like seta at base of posterior parapod (Fig. 16Q)..................... Thienemanniella Kieffer [lentic, lotic. widespread regional, speciose, oriental China, Fu et al. 2010a, 2013, 2020, global]
19’ Antenna with second antennal segment unevenly sclerotised, with alternate Lauterborn organs (Fig. 16S). Multitoothed mentum with paired hypopharyngeal scales (Fig. 16R). No basiventral spine on posterior parapod............ Rheosmittia Brundin [psammophilic, R. yakytriangulata (Sasa & Suzuki), oriental China (Guangdong); Japan, Holarctic]
20(15) One anal seta as long as 25% body length (Fig. 16T)........................................................ 21
20’ All anal setae shorter than 20% body length............................................................... 23
21(20) Mentum with 6 pairs of narrow, sharply pointed lateral teeth and single median tooth with small median nipple (Fig. 16U). Premandible with 2 apical teeth. Maxillary palp long. Anal setae of procercus directed dorsally................................................................................................. Krenosmittia Thiennemann & Krüger [krenobiont, lotic, Thailand, Indonesia (Sulawesi), 3 spp. oriental China (Fujian, Guangdong, Yunnan); Holarctic, esp. e. Palaearctic, Japan]
21’ Mentum with 4 pairs of lateral teeth, median tooth without median projection. Premandible with 1 apical tooth. Maxillary palp short. Preanal segment projects over anal segment, directing anal setae posteriorly................................. 22
22(21) Mandible with 3 inner teeth (Fig. 16V)........................................... Pseudorthocladius Goetghebuer [springs, hyporheic, mosses; speciose, 10+ spp. 3-4 as Pe, oriental China (Fujian, Guangdong, Guizhou, Hainan, Hunan, S. Shaanxi, Sichuan, Zhejiang) (Ren et al. 2014), errors/synonymy high in Asian spp. Japan, Holarctic, Afrotropical]
22’ Mandible usually with only 1–2 inner teeth............................................. Parachaetocladius Wülker [lotic, krenobiont, 2Pe, oriental China (Guangdong), P. akanoctavus Sasa & Kamimura (Sichuan), P. squamula Liu & Cao (Zhejiang) Liu et al., 2020. Japan, Holarctic]
23(20) Mentum with at least 16 teeth, strongly arched, giving impression of only 4–6 central teeth; lateral teeth visible only on compression of mentum (Fig. 16W). Phoretic / parasitic on ephemerid mayflies.............. Epoicocladius Sulc & Zavřel [2 L / P spp. China / Japan, Hayashi & Kobayashi 2000. Holarctic, Neotropical]
23’ Mentum with fewer than 15 teeth. Rarely phoretic / parasitic.................................................. 24
24(23) Beard beneath (dorsal) to or closely laterally adjacent to ventromental plate (may be few setae, and require high magnification optics) (Fig. 17B).................................................................................... 25
24’ Beard absent, although 1–4 vestigial setae may be present.................................................... 30
25(24) 6 th antennal segment hair-like, usually distinct (Fig. 17A). Mentum with single broad median tooth (Fig. 17B)..................................................................................... Parakiefferiella Thienemann (part.) [lotic, lentic, speciose in palaearctic, perhaps less so in s.e. Asia. Thailand, Indonesia (Sulawesi), P. yakykelea Sasa & Suzuki, oriental China (Guangdong), Japan; Holarctic, Neotropical, Afrotropical]
25’ Antenna with 4 or 5 segments, never with 6 th (Fig. 17E)...................................................... 26
26(25) S I simple. Mentum with 2–3 median, equally sized, elongate teeth; beard well developed, radiating from a common area. Seta interna absent; seta subdentalis large..................................................................... 27
26’ S I simple, bifid, coarsely pectinate, palmate or plumose. Mentum, beard and mandible not as above. Abdomen without alternating simple and plumose setae, but single pair of tufts may be present posterolaterally......................... 28
27(26) Mentum with 2 median teeth; beard with apically branched filaments (Fig. 17C). Mandible with inner spine. Abdominal segments with alternating simple and plumose setae (Fig. 17D)........................... Synorthocladius Thienemann [S. semivirens (Kieffer) wide range inc. oriental China; S. bifidus Liu & Wang, oriental China (Guangdong, Yunnan) Liu & Wang 2005. Holarctic, Neotropical, Afrotropical]
27’ Mentum with 3 median teeth; beard with simple filaments (Fig. 17G). Mandible without inner spine (Fig. 17F). Abdominal segments with simple and bifid or plumose setae, if plumose then only 1 on each posteroventral corner except for last abdominal segment....................................................................... Parorthocladius Thienemann [small waterbodies, P. unicentrus Liu & Wang, oriental China (Guangdong). Holarctic, inc. Korea, Japan; Afrotropical]
28(26) S I broadly trifid, palmate or with 4 long, narrow teeth, seldom bifid (Fig. 17I, J). Procercus with small to large spurs (Fig. 17H)......................................................................... Psectrocladius Kieffer (part.) [lentic, L. key to subgenera Andersen et al. 2013, sp. Thailand, uncertain in oriental China; global exc. Australia; Oceania]
28’ S I simple, bifid, apically split, plumose or coarsely serrate. If procercus with spurs, S I bifid........................ 29
29(28) Beard strong. Procercus with basal spurs. S I deeply bifid. (Fig. 17K, L)........................ Rheocricotopus Brundin [rheophilic, speciose, L keys to subgenera, s.s. & Psilocricotopus Saether in Andersen et al. 2013; widespread, Thailand, Indonesia (Kalimantan, Sulawesi, Sumatra), Malaysia (Sabah), speciose in oriental China (e.g. 8 spp. Guangdong). Holarctic (c. 35 spp.), Neotropical. Afrotropical, Australia]
29’ Beard weak. Procercus smooth, without spurs. SI simple, apically serrate (Fig. 17M, N)............ Paracladius Hirvenoja [P. antennarius Yan & Wang, P. alpicola (Zetterstedt) both oriental China (Sichuan), P. ovatus Fu et al. (Yunnan) Fu et al. 2010b; Japan, Holarctic]
30(24) Ventromental plate extending laterad of mentum (Fig. 17O) or broad, non-extended................................ 31
30’ Ventromental plate small, not extending laterad of mentum, or plate very narrow.................................. 38
31(30) All S setae simple. Mentum with small paired median teeth often well separated from 0–6 pairs of lateral teeth which may be small, fused or closely adpressed (Fig. 17O); s.g Plecopteracoluthus Steffan with broad plate..... Nanocladius Kieffer (part) [lotic, lentic, rheophilic, or phoretic or parasitic on range of aquatic insects (N. (Plecopteracoluthus) asiaticus Hayashi) Hayashi & Kobayashi 2000, Nanocladius s.s. nr. global, Andersen et al., 2013]
31’ S I never simple. Mentum not as above. Not phoretic........................................................ 32
32(31) Antenna 7 segmented; 7th segment fine; 3rd minute, 1/3 length of 4th (Fig. 16H).................................. 33
32’ Antenna 5–6 segmented; 3rd not minute relative to 4th (Fig. 16M, P)........................................... 34
33(32) Mentum with 5 pairs of lateral teeth, ventromental plate wide. Premandible bifid.............. Heterotrissocladius Spärck [lotic, littoral, H. marcidus (Walker) China (o. & p.), Tibet, Holarctic. 3 spp (as nov.) oriental China (Zhejiang, Guizhou, Fujian, Guangxi); Tibet, Kong & Wang 2011. Holarctic,? India).
33’ Mentum with 4 pairs of lateral teeth, ventromental plate modest. Premandible with apical tooth, 1 low accessory tooth...................................................................................... Paratrissocladius Zavřel [tubicolous in lotic sediment, P. excerptus (Walker) ssp. pubis Saether & Wang Burma, sp. Thailand, oriental China (Henan, Fujian, Anhui) (Saether & Wang 2000). L common, widespread, Japan; Holarctic, Afrotropical]
34(32) Ventromental plate appears double (Fig. 17Q). Seta submenti located anterior to posterior margin of plate (Fig. 17Q, S)... 35
34’ Ventromental plate simple. Seta submenti at posterior margin of ventromentum plate or more posteriad................ 36
35(34) Basal segment of antenna long. AR> 1.25. Blade shorter than flagellum (Fig. 17R)........ Parametriocnemus Goetghebuer [lotic, lentic, P. nigrescens (Johannsen) Indonesia (Java), regionally abundant, 7 spp, widespread oriental China, Li et al. 2013; Japan, global]
35’ Basal segment of antenna short. AR <1.1. Bade equal to or longer than flagellum (Fig. 17U)... Paraphaenocladius Thienemann [lotic, lentic, seeps, Indonesia (Java). P. discretus (Johannsen), P. impensus (Walker), P. exagitans (Johannsen), oriental China (Guangdong). Holarctic, Neotropical, Afrotropical. Saether & Wang 1995]
36(34) Ventromental plate covers most or all of lateral teeth of mentum, median tooth broad and dome-shaped (Fig 17B). Antenna with 6 segments, sixth segment hair-like (Fig. 17A)................................... Parakiefferiella Thienemann (part.) [comments, see couplet 26]
36’ Most lateral teeth of mentum outside ventromental plate, median tooth broad or narrow. Antenna 4–6 segmented........ 37
37(36) Antenna with 5 segments. Premandible with brush..................................... Chaetocladius Kieffer (part.) [♂ only, oriental China (Zhejiang); Tibet; Holarctic, Afrotropical]
37’ Antenna with 6 segments, sixth segment vestigial (Fig. 17U). Premandible without brush.............. Hydrobaenus Fries [in lentic sediment, H. kondoi Saether, oriental China (Jiangxi). Holarctic]
38(30) Antenna with 6–7 segments, terminal segment, hair-like. Ventromental plate wide........... Parakiefferiella Kieffer (part.) [see couplet 26]
38’ Antenna with 5 or fewer segments, last segment normal. Ventromental plate modest to vestigial...................... 39
39(38) Abdomen with setal tufts in fringe, or 2 or 4 pairs per segment................................................ 40
39’ Abdomen without fringe or paired setal tufts, although individual setal tuft or long setae may be present............... 42
40(39) Abdominal segments with many setal tufts (Fig. 17W). Antenna with 5 segments, 2nd complete (Fig. 17X).... Xylotopus Oliver [lotic, wood-mining, X. burmanensis Oliver Burma, oriental China (Yunnan), X. amamiapiatus (Sasa) oriental China (Guangdong, Hainan), Liu et al. 2019, 2021b, Japan, Nearctic]
40 Abdominal segments each with 2 or 4 setal tufts. 2nd antennal segment divided into 2 parts......................... 41
41(40) Antenna with 4 segments, Abdominal segments with 4 setal tufts.................................. Neobrillia Kawai [lotic, wood-miner, N. longistyla Kawai (= N. komorii (Niitsuma) oriental China (Guangdong, Hainan); Japan]
41’ Antenna with 5 segments, Abdominal segments with 2 setal tufts....................... Tokyobrillia Kobayashi & Sasa [lotic, wood-miner, one common sp., T. tamamegaseta Kobayashi & Sasa, oriental China (Guangdong, Hainan, Yunnan); Japan]
42(39) Abdomen with long simple setae, some at least 1/2 as long as segment (Fig. 18D)................................. 43
42’ Abdomen without long setae, or if present, arranged as pairs of single tufts, one posterolateral on each side on many body segments........................................................................................... 47
43(42) S I simple or with indistinct apical dentations. Procercus short / stout, <2× width................................. 44
43’ S I bifid, with several apical teeth or plumose. Procercus long, usually> 2× width................................. 46
44(43) Antennal blade longer than flagellum (Fig. 18A). Mandible with 4 inner teeth (Fig. 18B). Premandible with 2 apical teeth and brush (Fig. 18C). Abdominal setae about as long as the segment bearing them................... Paralimnophyes Brundin [eutrophic pools, P jii Wang & Saether oriental China (Hubei), undesc. spp., Wang & Saether 2002; Holarctic, Australia]
44’ Antennal blade shorter than flagellum. Mandible with 3 inner teeth. Premandible simple, without brush.Abdominal setae about 1/2 length of segment bearing them..................................................................... 45
45(44) Inner margin / mola of mandible with several spines. Setae submenti adjacent to posterad mentum or slightly posterior from the mentum (Fig. 18G). Procercus without spurs (Fig. 18H)............................. Eukiefferiella Thienemann (part.) [eurythermic, lotic, speciose, widespread, regional endemism low, Pe common, 8+ spp from oriental China (Guangdong) Japan - errors/synonymy high), spp. groups Andersen et al. 2013; global exc. Australia].
45’ Inner margin of mandible usually smooth. Insertion of seta submenti always clearly posterior from the mentum, gap about 1/2 length of mentum height. Procercus with spurs........................................... Paracricotopus Brundin [lotic, bogs, L/Pe, Indonesia (Sulawesi), Thailand, Singapore; P. irregularis Niitsuma, oriental China (Guangdong); Japan. Holarctic]
46(43) Mandible with 3 inner teeth and inner margin / mola with several spines.............................. Tvetenia Kieffer [lotic, T. calvescens (Edwards), T. tamaflava (Sasa) (possibly synonymous) oriental China (Guangdong). Japan, Holarctic, Afrotropical]
46’ Mandible with 4 inner teeth and inner margin / mola smooth. (Fig. 18O).................. Metriocnemus v.d. Wulp (part.) [microaquatic habitats, esp. pitcher plants in tropical forest, speciose,?12+ spp. oriental China Saether 1995, Li & Wang 2014, inc. M. tristellus Edwards (Guangdong), M. brusti Saether (Yunnan); Japan; global exc. Australia]
47(42) Mentum with 3 median teeth and 5 pairs of lateral teeth, first pair of lateral teeth closely adpressed to outer median teeth (Fig. 18E). Antenna 1/4–1/3 as long as head. S II strong, on tubercle......................... Onconeura Andersen & Saether [O. togamijika (Sasa & Okazawa) Spies et al. 2022, Holarctic, Neotropical]
47’ Mentum with1–2 median teeth and 4–5 pairs of laterals. Antenna at most ¼ as long as head. S II not on tubercle......... 48
48(47) S I simple.......................................................................................... 49
48’ S I bifid, serrate, pectinate or plumose.................................................................... 55
49(48) Antenna 4-segmented. Weak labral lamellae of 2 small, well separated, apically serrate lobes........ Eurycnemus v.d. Wulp [lotic, possibly all inhabit caddis cases, E. cf. nozakii Kobayashi, oriental China (Fujian, Yunnan), Li & Tang 2017; Palaearctic, inc. Japan]
49’ Antenna 5-segmented. If labral lamellae absent, then 2 small separated lobes..................................... 49
50(49) Inner margin of mandible with spines (may be small)........................................................ 51
50’ Inner margin of mandible usually smooth................................................................. 53
51(50) Procercus reduced, with 2 setae thicker than others on each procercus. Seta interna of mandible with long stalk, branching apical. Mentum with 5 pairs of lateral teeth (Fig. 18F)........................................ Cardiocladius Kieffer [fast lotic, Indonesia (Sulawesi, Kalimantan), Thailand, oriental China, taxonomy problematic; global]
51’ Procercus conventional, at least as long as wide, setae about equally thick. Seta interna of mandible usually divided to near base, if divided near apex. Mentum with 4 pairs of lateral teeth..................................................... 52
52(51) Supraanal setae much longer than anal tubules. Abdomen with setae c. 1/2 as long as segment.... Eukiefferiella Thienemann (part) [see comments under couplet #44]
52’ Supraanal setae shorter than anal tubules. Abdominal setae short................................. Tokunagaia Saether 1 [lotic, in mosses, hygropetric, 5 spp oriental China (Yunnan, Sichuan, Guizhou) Liu & Wang 2006; speciose e. Palaearctic, inc. Japan, few Holarctic]
53(50) Body with posterolateral tufts (Fig. 18J). Mentum with single median tooth (Fig. 18K)......... Cricotopus v.d. Wulp (part) [lotic, lentic, speciose, subgenera Anderson et al. 2013, includes some Paratrichocladius Santos Abreu; regionally widespread, e.g. 13 spp. oriental China (Guangdong); global] [Occasionally, a few Orthocladius (Symposiocladius) will key here]
53’ Body without posterolateral tufts. Mentum with bifid median tooth............................................. 54
54(53) Premandible apically simple. Mentum with median teeth strongly projecting anteriorly; ventromental plate not rounded posterolaterally (Fig. 18I)......................................................... Chaetocladius Kieffer (part) [semi-aquatic, spp. groups, Andersen et al. 2013; speciose, temperate. C. oyabevenustus Sasa, oriental China (Zhejiang, Guangdong). Holarctic, Afrotropical]
54’ Premandible apically bifid.Mentum with median teeth not strongly projecting anteriorly; with ventromental plate posterolaterally rounded (Fig. 18U, W, X)................................................................. Limnophyes Eaton [semi-terrestrial, speciose, L. minimus (Meigen) widespread, 4+ spp. oriental China (Guangdong, Sichuan, Hubei), Liu et al. 2021a; global]
55(48) S I bifid............................................................................................ 56
55’ S I serrate, apically fringed, pectinate or plumose........................................................... 57
56(55) Inner margin of mandible serrate (Fig. 18L). Some abdominal segments with posterolateral setal tuft.................................................................................................. Cricotopus v.d. Wulp (part) [see couplet 52 for comments]
56’ Inner margin of mandible smooth. Without abdominal setal tufts.......................... Cricotopus v.d. Wulp (part) [Includes some Paratrichocladius Santos Abreu. L, Pe inseparable, synonymised Cranston & Krosch 2015] [any Orthocladius larva will key here]
1 At least on immature stages doubtfully distinguished from Eukiefferiella, Tang pers. obs. 2024
57(55) Anal tubules twice or more as long as posterior parapods, with many constrictions. Procercus vestigial or consisting of 2 nearly contiguous, flat cones with basal, low plates, each with 2–3 hair-like setae (Fig. 18M). Labral lamellae simple, rounded, weakly sclerotised. Blade extending well beyond terminal antennal segment........................ Doithrix Saether & Sublette [small streams, seeps, D. emeiensis Wang, oriental China (Sichuan), Japan, Holarctic, Afrotropical]
57’ Anal tubules short or normal, without constrictions. Procercus weak to well developed, not vestigial. Labral lamellae well developed, vestigial or absent. Blade shorter or longer than flagellum........................................... 57
58(57) Labral lamellae well developed......................................................................... 59
58’ Labral lamellae absent or vestigial....................................................................... 61
59(58) 2–4 subequal median mental teeth. Setae submenti located near base of mentum (Fig. 18O).......... Metriocnemus (part.) [see comments couplet #45]
59’ Mentum with 2 elongate median teeth, often small central tooth between median teeth (Fig. 18P). Setae submenti posterior from base of mentum..................................................................................... 59
60(59) Second antennal segment complete (Fig. 18Q)................................................ Euryhapsis Oliver [lotic, E. fuscipropes Saether & Wang, Holarctic)
60’ Second antennal segment with weakly sclerotised area near base (Fig. 18R, S).......................... Brillia Kieffer [lotic, lentic, springs, hygropetric, B. japonica Tokunaga, oriental China (Guangdong), Holarctic]
61(58) Mentum with 2 broad median teeth, separated medially by U- or wide V-shaped space (Fig. 18V). Second antennal segment weakly divided near base, antennal blade much longer than flagellum (Fig. 18T). Mandible with 3 inner teeth. (Fig. 18V)......................................................................................... Heleniella Gowin [H. nebulosa Andersen & Wang, Thailand, oriental China (Guangdong), sp. (Sichuan). Holarctic]
61’ Median teeth of mentum not separated by such a U- or V- shaped gap (Fig. 18W). Second antennal segment not weakly divided near base (Fig. 18U). If blade longer than flagellum, then mandible with 4 inner teeth (Fig. 18Y)..................... 62
62(61) Mandible with 3 inner teeth (Fig. 18X). Supraanal setae subequal to anal setae....................... Limnophyes (part.) [see comments #53]
62’ Mandible with 4 inner teeth (Fig. 18Y). Supraanal setae c. 1/3 as long as anal setae............... Compterosmittia Saether [some spp. phytotelmic, speciose, 7+ spp. oriental China (Guangdong, Fujian); e. Palaearctic, Japan, Nearctic, Neotropical, Australia (inc., Oceania). Lin et al. 2013]
description: 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 pages 179-187, DOI: 10.11646/zootaxa.5497.2.1, http://zenodo.org/record/13618241