taxonID	type	description	language	source
B358B57175158C14D1FEFB5CFA787D6D.taxon	type_taxon	Type species: Diplomesa lapponica Zavřel, 1941 [= Diamesa parva Edwards, 1932], by original designation and monotypy.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175158C14D1FEFB5CFA787D6D.taxon	diagnosis	Generic diagnosis (emended). Based on a new material from the East Palaearctic, the generic diagnosis given by Zavřel (1941), Serra-Tosio (1971), Makarchenko (1985) and Oliver (1989) should be emended as follows.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175158C14D1FEFB5CFA787D6D.taxon	description	Adult male Total length 2.8 – 4.8 mm, wing length 2.4 – 3.9 mm. Antenna. Pedicel with 0 – 3 setae. Flagellum with 13 flagellomeres, plumose, sometimes plume reduced; flagellomeres 1 – 5 or 6 and 13 with sensilla chaetica; terminal flagellomere with 1 – 2 subapical setae. Antennal ratio 0.8 – 2.0 Head. Eye bare or pubescent, slightly to moderately elongate dorsomedially. Temporal setae consisting of inner and outer verticals, frontals and postorbitals. Tentorium swollen basally, with microtrichia. Clypeus with 0 – 6 setae. Thorax. Antepronotal lobes separated medially by V- to U-shaped notch. Acrostichals usually absent but sometimes a few setae in the anterior part of mesonotum; dorsocentrals 7 – 20, erect and uniserial; prealars 3 – 11, ending over median anepisternum II; scutellars 7 – 50, in 1 – 4 rows; preepistemals absent. Wing. Membrane without setae, with moderate punctation. Anal lobe angular or rounded and moderately produced. Costa moderately produced; R 2 + 3 ending closer to R 1 than to R 4 + 5; FCu proximal to MCu. R 4 + 5 with setae. Squama fully fringed. Legs. Fore leg without pseudospurs; mid and hind legs with pseudospurs on tarsomeres 1 and 2; tarsomere 4 cordiform, shorter than tarsomere 5. LR 1 0.66 – 0.73, BV 1 3.40 – 3.80, SV 1 2.43 – 2.69. Hypopygium. Anal point narrow, 65 – 108 μm long, often distally hair-like, sharply pointed, sometimes with 1 – 3 apical setae. Phallapodeme with expanded anterior apex; aedeagal lobe often finger-shaped, sometimes triangular, wedge-shaped or with narrow apex, hook-shaped, bent forward. Gonocoxite with flat, rounded slightly projecting, dorsally bare basal lobe and small lobe-like median field, which continuing basal lobe posteriorly, slightly indistinct, with few setae. Transverse sternapodeme consisting of a narrow arch, without or with expansion in middle. Pars ventralis absent. Gonostylus often with long crista dorsalis, sometimes short subapical crista dorsalis is present; megaseta small.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	description	urn: lsid: zoobank. org: act: A 8382531 - 1 DF 2 - 43 F 0 - 83 B 3 - 7 D 72 FAE 9 A 039 (Figs 1 – 5)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	materials_examined	Type material. Holotype: adult male, Russia, Chukotka Autonomous Okrug, Iultinsky District, Wrangel Island, middle reaches of the Neozhidannaya River, N 71.0167, E 179.1500, 8 – 9. VII. 2019, leg. O. Khruleva. Paratype: 1 adult male, the same data as holotype.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	etymology	Derivatio nominis. The species is named inopinata after the type locality in Neozhidannaya River, which is translated from the Russian word for “ unexpected ”.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	description	Description Adult male (n = 2, except when otherwise stated). Total length 4.2 – 4.3 mm. Total length / wing length 1.1 – 1.17. Coloration. Dark brown. Antennae brown. Wings grayish, with light brown veins. Head. Eyes bare, slightly elongate dorsomedially. Temporal setae including 10 – 11 verticals and 10 frontals. Clypeus with 2 setae, 60 μm long. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 738 μm; terminal flagellomere with 1 subapical setae, ca 50 μm long; pedicel with 2 setae, 60 – 68 μm long. AR 1.96. Palpomere length (μm): 48 – 52, 80, 140 – 168, 104 – 152, 180 – 196. Palpomere 3 in distal part with sensilla capitata with diameter 12 μm. Head width / palpal length 1.07 – 1.30. Thorax. Antepronotum with 6 – 8 ventrolateral setae. Dorsocentrals 11, prealars 5. Scutellum with ca 40 – 50 setae in 3 – 4 rows. Wings. Length 3.6 – 3.9 mm, width 1.2 mm. Anal lobe developed and rounded. Squama with ca 60 setae, 84 – 120 μm long. R and R 1 with 23 – 43 setae, R 4 + 5 with 0 – 2 setae in distal part. RM / MCu 3.0. Legs. Spur of front tibia 96 μm long. Spurs of mid tibia 64 μm and 72 μm long. Spurs of hind tibia 96 μm and 56 μm long. Hind tibial comb with 12 setae. Length (μm) and proportions of leg segments are as in Table 1. Hypopygium (Figs 1 – 5). Tergite IX with 19 – 20 setae from one side, 24 – 28 μm long and with anal point, 92 – 108 μm long, distally hair-like (Fig 2). Laterosternite IX with 7 setae, 60 – 92 μm long. Transverse sternopodeme narrow, slightly curved, 216 μm long, 44 μm wide, without expansion in middle. Aedeagal lobe 112 – 132 μm long, distally triangular, with pointed apex (Fig 5); phallapodeme 136 μm long. Gonocoxite 328 – 340 μm long, basal lobe rounded, dark brown, without setae, median field light brown, with 10 – 15 setae, 28 – 40 μm long (Figs 3, 5). Gonostylus massive, 168 μm long, subapical with short and rounded crista dorsalis and the thorn that is behind it (Fig. 4), apex with macroseta, 12 μm long; HR 1.36 – 1.40. Pupa and larva unknown.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	diagnosis	Diagnosis. Total length 4.2 – 4.3 mm. Wing length 3.6 – 3.9 mm Clypeus with 2 setae. AR 1.96. Dorsocentrals 11, prealars 5. scutellars ca 40 – 50 (in 3 – 4 rows). LR 1 0.70, BV 1 3.47, SV 1 2.52. Anal point 92 – 108 μm long, distally hair-like. Aedeagal lobe 112 – 132 μm long, distally triangular, with pointed apex. Basal lobe of gonocoxite rounded, dark brown, without setae, median field light brown, with 10 – 15 setae. Gonostylus subapical with short and rounded crista dorsalis. HR 1.36 – 1.40. The adult male of P. inopinata sp. nov. differs from all known species of the genus by its high AR value (1.96), large number of setae on scutellum (40 – 50), arranged in 3 – 4 rows, short subapical rounded crista dorsalis of gonostylus and some other characters listed in Table 5 and key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175168C12D1FEFB42FC247AD0.taxon	distribution	Distribution. Known only from the type locality in Wrangel Island.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	description	urn: lsid: zoobank. org: act: 7914 AD 72 - 63 C 1 - 4 CB 5 - A 54 C- 01 D 8607 FD 4 F 5 (Figs 6 – 10)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	materials_examined	Type material. Holotype: adult male, Russia, Republic of Sakha (Yakutia), Bulunsky District, spurs of the Kharaulakh Ridge, Ust-Lensky State Nature Reserve, Lena River Delta, kordon Belaya Scala, 29. VI. 1990, leg. N. Zelentsov. Paratypes: 2 adult males, the same data as holotype.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	etymology	Derivatio nominis. The species is named in honor and memory of the organizer and participant of polar expeditions, Arctic explorer Alexander Vasilyevich Kolchak. The name is a noun in apposition.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	description	Description Adult male (n = 2, except when otherwise stated). Total length 4.6 – 4.8 mm. Total length / wing length 1.23 – 1.35. Coloration. Brown, dark brown. Wings white, with brownish veins. Head. Eyes bare, slightly elongate dorsomedially. Temporal setae including 6 verticals and 7 – 8 frontals. Clypeus with 4 setae, 40 – 64 μm long. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 620 μm; terminal flagellomere with 1 subapical seta, 28 μm long; pedicel with 2 setae, 100 – 116 μm long. AR 1.58 – 1.69. Palpomere length (μm): 44 – 60, 76 – 100, 156 – 160, 132 – 140, 192 – 204. Palpomere 3 in distal part with sensilla capitata with diameter 12 μm. Head width / palpal length 1.07 – 1.30. Thorax. Antepronotum with 8 – 12 ventrolateral setae. Dorsocentrals 14 – 20, prealars 5. Scutellum with 20 – 25 setae in 1 – 2 rows. Wings. Length 3.5 – 3.9 mm, width 1.2 mm. Anal lobe developed and rounded. Squama with 60 – 64 setae, 48 – 80 μm long. R and R 1 with 30 setae, R 4 + 5 with 4 setae in distal part. RM / MCu 3.0 – 3.2. Legs. Spur of front tibia 60 – 96 μm long. Spurs of mid tibia 60 μm and 64 μm long. Spurs of hind tibia 96 – 108 μm and 56 – 72 μm long. Hind tibial comb with 16 – 18 setae. Length (μm) and proportions of leg segments are as in Table 2. Hypopygium (Figs 6 – 10). Tergite IX with 16 – 22 setae from one side, 40 – 100 μm long and with anal point, 96 – 104 μm long, distally hair-like (Fig. 9). Laterosternite IX with 8 – 18 setae, 60 – 136 μm long. Transverse sternopodeme consisting of a narrow arch 240 – 260 μm long, 28 – 36 μm wide. Aedeagal lobe 136 – 144 μm long, with long finger-shaped distal part (Figs 6 – 8); phallapodeme 150 – 156 μm long. Gonocoxite 336 – 348 μm long, basal lobe rounded, without setae, median field with 20 – 21 setae, 32 – 36 μm long (Figs 6 – 8). Gonostylus massive, 168 – 200 μm long, 64 μm wide, with long and low crista dorsalis, which occupies about half length of gonostylus; apex with macroseta, 8 – 12 μm long (Figs 6 – 7, 10); HR 1.74 – 2.0. Pupa and larva unknown.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	diagnosis	Diagnosis. Total length 4.6 – 4.8 mm. Wing length 3.5 – 3.9 mm Clypeus with 4 setae. AR 1.58 – 1.69. Dorsocentrals 14 – 20, prealars 5. scutellars 20 – 25 (in 1 – 2 rows). LR 1 0.66, BV 1 3.70, SV 1 2.69. Anal point 96 – 104 μm long, distally hair-like. Aedeagal lobe 136 – 144 μm long, with long finger-shaped distal part. Basal lobe of gonocoxite rounded, without setae, median field with 20 – 21 setae. Gonostylus with long and low crista dorsalis, which occupies about half length of gonostylus. HR 1.74 – 2.0. The adult male of P. kolchak sp. nov. differs from all known species of the genus by larger sizes (4.6 – 4.8 mm), number of clypeals (4) and dorsocentrals (14 – 20), length of aedeagal lobe (136 – 144 μm) and some other characters listed in Table 5 and key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175108C10D1FEFB97FEC47BFC.taxon	distribution	Distribution. Known only from the type locality in Ust-Lensky State Nature Reserve of Sakha (Yakutia), Lena River Delta.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	description	urn: lsid: zoobank. org: act: FDB 98 EDB- 25 E 1 - 4 FDC-A 89 D- 93494705 A 2 C 6 (Figs 11 – 17)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	materials_examined	Type material. Holotype: adult male, Russia, Magadan Region, Susuman District, Okhandya Ridge, unnamed stream in the Yug Lake basin, 17. VII. 2024, N 63.79986, E 147.68961, alt. 1137 m a. s. l., leg. A. Krasheninnikov. Paratypes: 8 adult males, the same data as holotype.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	etymology	Derivatio nominis. The species is named in honor of Russian chironomidologist Dr. Andrei Borisovich Krasheninnikov (Institute of Biological problems of North FEBRAS, Magadan, Russia) who collected type material of new species.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	description	Description Adult male (n = 4, except when otherwise stated). Total length 3.6 – 4.1 mm. Total length / wing length 1.23 – 1.59. Coloration. Brown, dark brown. Antennae brownish grey. Wings grayish. Head. Eyes bare, slightly elongate dorsomedially. Temporal setae including 4 – 10 verticals and 7 – 9 frontals. Clypeus without setae. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 560 μm; terminal flagellomere with 1 – 2 subapical setae, 52 – 60 μm long; pedicel with 2 setae, 60 – 68 μm long. AR 0.97 – 1.24. Palpomere length (μm): 40 – 44, 60 – 73, 146 – 156, 108 – 128, 160 – 184. Palpomere 3 in distal part with sensilla capitata with diameter 16 μm. Head width / palpal length 1.38. Thorax. Antepronotum with 4 – 6 ventrolateral setae. Dorsocentrals 9 – 13, prealars 5 – 7. Scutellum with 8 – 10 setae in 1 row. Wings. Length 2.8 – 2.9 mm, width 0.84 – 0.88 mm. Anal lobe developed and rounded. Squama with 18 – 22 setae, 40 – 80 μm long. R and R 1 with 21 – 23 setae, R 4 + 5 with 3 – 4 setae in distal part. Costal extension 90 – 98 μm. RM / MCu 3.0 – 3.2. Legs. Spur of front tibia 60 – 68 μm long. Spurs of mid tibia 40 – 48 μm and 44 – 56 μm long. Spurs of hind tibia 56 – 68 μm and 32 – 48 μm long. Hind tibial comb with 14 – 16 setae. Ta 4 cardioform. Length (μm) and proportions of leg segments are as in Table 3. Hypopygium (Figs 11 – 17). Tergite IX with 8 – 17 setae from one side, 36 – 56 μm long and with anal point, 72 – 92 μm long, distally hair-like (Figs 11, 13) sometimes with 1 apical seta, 26 μm long. Laterosternite IX with 5 – 8 setae, 60 – 80 μm long. Transverse sternopodeme 172 – 200 μm long, 40 – 60 μm wide, with oval expansion in middle (Fig. 12). Aedeagal lobe 100 – 118 μm long, distal part finger-shaped, sometimes with pointed apex (Fig. 12); phallapodeme 100 – 120 μm long. Gonocoxite 276 – 324 μm long, basal lobe rounded, with 1 – 4 setae, 20 – 28 μm long, median field narrow, with 6 – 8 setae, 28 – 48 μm long (Fig. 12). Gonostylus is long, narrow and almost straight, 148 – 184 μm long, 32 μm wide, with long crista dorsalis which occupies about two-thirds of gonostylus; apex with macroseta, 8 – 12 μm long (Figs 11, 14 – 17); HR 1.54 – 1.88. Pupa and larva unknown.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	diagnosis	Diagnosis. Total length 3.6 – 4.1 mm. Wing length 2.8 – 2.9 mm. Clypeus without setae. AR 0.97 – 1.24. Dorsocentrals 9 – 13, prealars 5 – 7, scutellars 8 – 10 (in 1 row). LR 1 0.65 – 0.68, BV 1 3.40 – 3.62, SV 1 2.60 – 2.68. Anal point 72 – 92 μm long, distally hair-like, sometimes with 1 apical seta. Transverse sternopodeme with oval expansion in the middle. Aedeagal lobe 100 – 118 μm long, with long, finger-shaped distal part. Basal lobe rounded, with 1 – 4 setae, median field narrow, with 6 – 8 setae Gonostylus as in Figs. 14 – 17, long, narrow, and almost straight, with long crista dorsalis that occupies about two-thirds of gonostylus; apex with macroseta. HR 1.74 – 2.0. The adult male of P. krasheninnikovi sp. nov. differs from all known species of the genus by absence of setae on the clypeus, presence of oval expansion in the middle of transverse sternapodema, 1 – 4 setae on basal lobe of gonocoxure and long narrow gonostylus with long crista dorsalis that occupies about two-thirds of gonostylus. Some other characters listed in Table 5 and key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B57175128C1ED1FEFCFAFB707C76.taxon	distribution	Distribution. Known only from the type locality in the upper stream of Kolyma River.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751C8C1CD1FEFA74FBE07A8C.taxon	description	(Figs 18 – 21)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751C8C1CD1FEFA74FBE07A8C.taxon	materials_examined	Material examined. 2 adult males, 1 pupa (male), 4 pupal exuviae, 7 larvae Russia, Trans-Baikal Territory, environs of the Chita Сity, Kaydalovka River, upper stream, N 52.039058, E 113.560243, 18. VIII 2003, leg. P. Matafonov; 8 larvae, the same data, except 31. V. 2022, N 52.039988, E 113.562473, leg. P. Matafonov; 1 larva, the same data, except Karpovskyi Stream, 2. VII. 2004, leg. O. Klishko.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751C8C1CD1FEFA74FBE07A8C.taxon	description	Description Adult male (n = 2, except when otherwise stated). Total length 3.6 – 3.9 mm. Total length / wing length 1.06 – 1.16. Coloration. Brown, dark brown. Head, thorax, and abdomen with hypopygium brown or dark brown. Legs yellowish brown. Wings greyish. Head. Eyes pubescent, slightly elongate dorsomedially. Temporal setae including 13 – 19 verticals and 12 – 13 postorbitals. Clypeus with 2 – 5 setae. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 540 μm; terminal flagellomere with 1 subapical seta, 60 – 64 μm long; pedicel with 2 setae, 60 – 72 μm long. AR 1.35 – 1.57. Palpomere length (μm) (n = 1): 44, 84, 156, 120, 156. Palpomere 3 in distal part with sensilla capitata with diameter 8 μm. Head width / palpal length 1.0. Thorax. Antepronotum with 7 ventrolateral setae. Dorsocentrals 12 – 13, prealars 5 – 6. Scutellum with 9 – 18 setae in 1 row. Wings. Length 3.3 – 3.4 mm, width 0.92 mm. Anal lobe developed and rounded. Squama with 30 – 46 setae, 75 – 100 μm long. R and R 1 with 18 – 20 setae, R 4 + 5 with 4 – 5 setae in distal part. RM / MCu 2.3 – 2.5. Legs. Spur of front tibia 76 – 84 µm long. Spurs of mid tibia 60 – 64 µm and 64 µm long. Spurs of hind tibia 84 – 96 µm and 60 – 64 µm long. Hind tibial comb with 16 setae. LR 1 0.71, BV 1 3.53 – 3.56, SV 1 2.43 – 2.46. Hypopygium (Figs 18 – 21). Tergite IX with 17 – 18 setae from one side, 32 – 36 µm long, and with anal point, 80 µm long and 16 µm wide in base, apically with 3 setae, 24 – 26 µm long (Fig. 19). Laterosternite IX with 8 setae, 64 – 76 µm long. Transverse sternopodeme consisting of a narrow arch 216 – 240 µm long. Aedeagal lobe 116 – 132 µm long, wide in basal third and narrow finger-shaped in distal two-thirds (Fig. 21); phallapodeme 120 µm long. Gonocoxite 308 – 310 µm long, basal lobe rounded, with 2 – 4 setae, median field with 7 – 10 long setae (Fig. 20). Gonostylus massive, 168 – 176 µm long and 56 – 60 µm wide, with long crista dorsalis which occupies about two-thirds length of gonostylus; apex with macroseta, 16 µm long (Fig. 18); HR 1.75 – 1.76. Pupa and larva were described by Makarchenko & Semenchenko (2023).	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751C8C1CD1FEFA74FBE07A8C.taxon	discussion	Remarks. Adult male of S. matafonovi differs from all known species of the genus by the presence of three setae in apex of anal point and some other characters listed in Table 5 and key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751E8C1DD1FEFC6AFC8378A0.taxon	description	(Figs 22 – 25)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751E8C1DD1FEFC6AFC8378A0.taxon	materials_examined	Material examined. 2 adult males, Russia, Khabarovsk Territory, Solnechnyi District, environs of Gornyi Village, Miao Chan Ridge, valley of the Levaya Silinka River, Amur River basin, 27. VII. 2006, N 50.710861, E 136.365278, light trap, leg. E. Makarchenko.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751E8C1DD1FEFC6AFC8378A0.taxon	description	Description Adult male (n = 2, except when otherwise stated). Total length 2.7 – 2.8 mm. Total length / wing length 1.16. Coloration. Grayish brown. Head, thorax, and abdomen with hypopygium grayish brown or brown. Legs brownish gray. Wings greyish. Head. Eyes pubescent, slightly elongate dorsomedially. Temporal setae including 7 – 8 verticals and 12 postorbitals. Clypeus with 2 setae, 52 – 68 μm long. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 558 μm; terminal flagellomere with 1 subapical seta, 36 μm long; pedicel with 2 setae. AR 0.81. Palpomere length (μm): 32 – 40, 48 – 56, 88 – 108, 92 – 96, 132 – 160. Palpomere 3 in distal part with sensilla capitata with diameter 8 μm. Head width / palpal length 1.0. Thorax. Antepronotum with 2 – 4 ventrolateral setae, 32 – 40 μm long. Dorsocentrals 7 – 10, 84 – 88 μm long, prealars 3 – 4, 72 – 80 μm long. Scutellum with 7 – 8 setae in 1 row. Wings. Length 2.3 – 2.4 mm, width 0.64 mm. Anal lobe developed and rounded. Squama with 14 setae, 52 – 68 μm long. R and R 1 with 17 setae, R 4 + 5 with 5 setae in distal part. RM / MCu 2.5. Legs. Spur of front tibia 40 – 60 µm long. Spurs of mid tibia 40 – 44 µm and 40 µm long. Spurs of hind tibia 56 – 60 µm and 40 – 44 µm long. Hind tibial comb with 14 – 15 setae. LR 1 0.66, BV 1 3.51, SV 1 2.68. Hypopygium (Figs 22 – 25). Tergite IX with 12 – 14 setae, from one side, 28 – 40 µm long and with narrow, sharply pointed anal point, 68 – 80 µm long (Fig. 22). Laterosternite IX with 5 – 8 setae, 60 – 72 µm long. Transverse sternopodeme consisting of a narrow arch 176 µm long, slightly expanded in the middle (Fig. 23). Aedeagal lobe wedge-shaped, 68 µm long (Fig. 23). Gonocoxite 212 µm long, with basal lobe in the form of rounded or rounded triangular tubercles, with 3 – 4 setae; median field with microtrichia and 10 – 12 long setae (Fig. 24). Gonostylus narrow, 100 – 104 µm long, with long and low crista dorsalis which occupies about half length of gonostylus; apex with short macroseta, 8 – 12 µm long (Figs 22, 25); HR 1.9 – 2.2. Pupa and larva unknown.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751E8C1DD1FEFC6AFC8378A0.taxon	discussion	Remarks. Adult male of S. silinka differs from all known species of the genus by the wedge-shaped aedeagal lobe, structure of the basal lobe, and median field which is in the form of rounded or rounded triangular tubercles. Other distinguishing characters are listed in Table 5 and the key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751F8C18D1FEFE46FE9D7BA4.taxon	description	urn: lsid: zoobank. org: act: E 85 E 5 E 54 - 6 B 1 C- 4090 - 8 B 3 B- 9 DB 71404951 B (Figs 26 – 37)	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751F8C18D1FEFE46FE9D7BA4.taxon	materials_examined	Type material. Holotype: adult male, Russia, Chukotka Autonomous Okrug, Iultinsky District, Wrangel Island, Rogers Bay area, vicinity of Atherton Mount, 13. VII. 2019, N 70.983, E. 178.683, leg. O. Khruleva. Paratypes: 3 adult males, the same data, except Lavrentiya Village, 1800 m from the village, 26. VI. 1972, N 65.586470, W 171.046964, leg. I. Chereshnev; 1 adult male, the same data, except 17. VII. 1981, leg. E. Makarchenko; 3 adult males, the same data, except Chegitun River, 31. VII. 1981, N 66.563333, W 171.078611, leg. E. Makarchenko; 4 adult males, Krasnoyarsk Territory, urban settlement of Dikson, Taimyr Dolgano-Nenets municipal district, Ragozinka River, 5 – 7. VII. 1990, leg. V. Lantsov; 3 adult males, Novaya Zemlya archipelago, Yuzhny Island, Sakhanin Peninsula, 03. VIII. 2015, N 70.628111, E 54.992722, leg. A. Krasheninnikov.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751F8C18D1FEFE46FE9D7BA4.taxon	etymology	Derivatio nominis. The species is named for its transarctic distribution.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751F8C18D1FEFE46FE9D7BA4.taxon	description	Description Adult male (n = 5, except when otherwise stated). Total length 3.7 – 4.0 mm. Total length / wing length 1.25 – 1.41. Coloration. Brown, dark brown. Antennae brownish grey. Wings white to grayish, with brownish veins. Head. Eyes bare, slightly elongate dorsomedially. Temporal setae including 8 – 12 verticals and 5 – 14 frontals and 8 – 9 postorbitals. Clypeus with 2 setae, 44 – 52 μm long. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 705 μm; terminal flagellomere with 2 subapical setae, 32 – 44 μm long; pedicel with 2 setae, 66 – 80 μm long. AR 1.33 – 1.56. Palpomere length (μm): 36 – 44, 60 – 76, 116 – 140, 100 – 108, 120 – 164. Palpomere 3 in distal part with sensilla capitata with diameter 12 μm. Head width / palpal length 1.11 – 1.22. Thorax. Antepronotum with 4 – 9 ventrolateral setae. Acrostichals 2 (n = 1), dorsocentrals 10 – 12, prealars 6 – 11. Scutellum with 10 – 18 setae in 1 row. Wings. Length 2.76 – 2.96 mm, width 0.68 – 0.84 mm. Anal lobe developed and rounded. Squama with 24 – 36 setae, 40 – 104 μm long. R and R 1 with 14 – 35 setae, R 4 + 5 with 5 – 20 setae. Costal extension 68 – 96 μm long. RM / MCu 3.2 – 3.5. Legs. Spur of front tibia 68 – 80 μm long. Spurs of mid tibia 44 – 52 μm and 44 – 68 μm long. Spurs of hind tibia 72 – 84 μm and 40 – 56 μm long. Hind tibial comb with 13 – 16 setae. Ta 4 cardioform. Length (μm) and proportions of leg segments are as in Table 4. Hypopygium (Figs 26 – 37). Tergite IX with 9 – 12 setae from one side, 32 – 40 μm long and with anal point, 76 – 80 μm long, distally hair-like (Figs 27, 29). Laterosternite IX with 12 setae, 96 – 136 μm long. Transverse sternopodeme 176 – 224 μm long, with triangle outgrowth expansion in middle (Figs 28, 32 – 37). Aedeagal lobe 112 – 124 μm long, as in Figs. 28, 32, 33 – 37, apex narrow, hook-shaped, bent forward, apically uncinate; phallapodeme 104 – 144 μm long. Gonocoxite 252 – 276 μm long, basal lobe rounded, with 1 – 2 setae, 20 – 28 μm long, median field narrow, with 14 – 21 setae, 32 – 56 μm long (Figs 28, 31 – 32). Gonostylus 153 – 160 μm long, 32 μm wide, in position pressed against gonocoxite, it is slightly curved in middle, with long and high crista dorsalis which occupies about two-thirds of gonostylus; apex with macroseta, 8 – 12 μm long (Figs 26, 28, 30 – 31); HR 1.66 – 1.98. Pupa and larva unknown.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751F8C18D1FEFE46FE9D7BA4.taxon	diagnosis	Diagnosis. Total length 3.7 – 4.0 mm. Wing length 2.76 – 2.96 mm Clypeus with 2 setae. AR 1.33 – 1.56. Dorsocentrals 10 – 12, prealars 6 – 11. scutellars 10 – 18 (in 1 row). LR 1 0.68 – 0.73, BV 1 3.50 – 3.80, SV 1 2.44 – 2.69. Anal point 76 – 80 μm long, distally hair-like. Transverse sternopodeme with triangular outgrowth expansion in the middle. Aedeagal lobe 112 – 124 μm long, apex narrow, hook-shaped, bent forward, apically uncinate. Basal lobe rounded, with 1 – 2 setae, median field narrow, with 14 – 21 setae. Gonostylus in position pressed against gonocoxite is slightly curved in middle, with long and high crista dorsalis which occupies about two-thirds of gonostylus. HR 1.74 – 2.0. The adult male of P. transarctica sp. nov. differs from all known species of the genus by aedeagal lobe, which with narrow apex, hook-shaped, bent forward, apically uncinate. Other distinguishing characters are listed in Table 5 and the key.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751A8C18D1FEFD42FDF17D9C.taxon	discussion	Remarks. Based on several characters, it does not correspond to the diagnosis of the genus Pseudokiefferiella. These features include the absence of anal point on tergite IX, a different shape of the gonostylus and transverse sternapodema, and the structure of the gonocoxite. We agree with opinion of Yamamota & Yamamoto (2014) that this species is closely related to Potthastia longimanus Kieffer but further comparative studies of the adult males of these species are needed.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
B358B571751A8C18D1FEFD42FDF17D9C.taxon	distribution	Distribution. Japan, Honshu.	en	Makarchenko, Eugenyi A., Semenchenko, Alexander A. (2026): A review of the East Palaearctic Pseudokiefferiella Zavřel, 1941 (Diptera: Chironomidae: Diamesinae), with description of new species and DNA barcoding of known species. Zootaxa 5782 (3): 509-526, DOI: 10.11646/zootaxa.5782.3.5, URL: https://doi.org/10.11646/zootaxa.5782.3.5
