a. $1 ULIGINOSUS
b.
c. MEUNIER 1904A: 213, 215 - as CHIRONOMUS, on basis of adult males and females.
d. PALEARCTIC - Baltic region (Eocene/Oligocene amber).
e. MEUNIER 1912B: 169; KEILBACH 1982: 353 (notes two different descriptions by MEUNIER; but one is misspelling of CALIGINOSUS); EVENHUIS 1994: - as CHIRONOMUS.

a. $2 ULIGINOSUS
b. CHIRONOMUS (S.S.).  Junior homonym of ULIGINOSUS MEUNIER 1904.  NEW NAME: VALLENDUUKI - ASHE & O'CONNOR 2015: 231.
c. KEYL 1960A: 191 - AS CHIRONOMUS.
d. EUROPE - Sehestedter Moor, GERMANY.
e. KEYL 1962B: 480 - cytology of arms A, E & F.

a. $2a ULIGINOSUS2
b. CHIRONOMUS (S.S.).  As subspecies or sibling species of ULIGINOSUS sensu KEYL.
c. BROSHKOV, KIKNADZE, ISTOMINA & GUNDERINA 2008: 57 - on basis of cytology.
d. EUROPE - Latka River, Borok, Yaroslav Prov. RUSSIA.
e. KIKNADZE et al. 2016: 443 - cytology.

a. $ UMBROSUS
b.
c. MEUNIER 1904A: 212 - as CHIRONOMUS, on basis of adult female.
d. EUROPE - Baltic region (Eocene/Oligocene amber).
e. MEUNIER 1912B: 169; KEILBACH 1982: 353; SPAHR 1985: 24; EVENHUIS 1994: - as CHIRONOMUS.

a. * UNCINUS
b. Unlikely to be CHIRONOMUS - could be new genus?
c. KONAR 2018: 14 - as CHIRONOMUS, on basis of adult male.
d. ASIA - Kaligram, Burdan, West Bengal (to be deposited to the National Zoological Collections, Kolkata)
e.

a. * UNDINE
b. PARACLADOPELMA - BECK & BECK 1969B: 302.
c. TOWNES 1945A: 149 - as HARNISCHIA (CLADOPELMA). Transferred to CHIRONOMUS (CRYPTOCHIRONOMUS) by BECK 1961A: 125.
d. HOLARCTIC - Snake River, Ontario, OREGON, U.S.A.; SWEDEN?
e. SUBLETTE & SUBLETTE 1965A: 168 - as C. (CRYPTOCHIRONOMUS).  JACKSON 1977A: 1342; ASHE & CRANSTON 1990: 297 - as PARACLADOPELMA.

a. * UNGUICULATUS
b. STICTOCHIRONOMUS - TOWNES 1945A: 82 (as TANYTARSUS (STICTOCHIRONOMUS).
c. MALLOCH 1934A: 16 - as CHIRONOMUS (CHIRONOMUS), on basis of adult male.
d. AMERICAN ARCTIC - Southampton Island, Keewatin, N.W.T., CANADA.
e.

a. $ UNUGLATUS
b. Nomen nudem - SPAHR 1985: 24.
c. KEILBACH 1982: 351 - attributes to LOEW 1850: 30, who didn't publish name.  On basis of adult female.
d. EUROPE - Fossil species.
e. EVENHUIS 1994: - as Nomen nudum.

a. $ UNGULINUS
b. Nomen nudem - SPAHR 1985: 24.
c. KEILBACH 1982: 351 - attributes to LOEW 1850: 30, who didn't publish name.
d. EUROPE - Fossil species.
e. EVENHUIS 1994: - as Nomen nudum.

a. * UNICALCAR
b. PARACHIRONOMUS - SÆTHER 1977B: 89; FREEMAN & CRANSTON 1980A: 194.
c. FREEMAN 1957A: 401 - as CHIRONOMUS (CRYPTOCHIRONOMUS) & new name for KRIBIOCRYPTUS FLAVIVENTRIS KIEFFER 1921A.
d. AFRICA - South of Khartoum, SUDAN.
e.

a. #1 UNICOLOR
b. SYN: PENTANEURA MELANOPS - SUBLETTE & SUBLETTE 1965A: 147.
c. WALKER 1848A: 19 - as CHIRONOMUS, on basis of female.
d. NORTH AMERICA - Nova Scotia, CANADA.
e. JOHANNSEN 1926A: 274 - as syn. TANYPUS MELANOPS.  ROBACK 1966 : 124 - as THIENMANNIMYIA or RHEOPELOPIA.

a. *2 UNICOLOR
b. PARACHIRONOMUS - LEHMANN 1970A: 146. NEW NAME: MONOCHROMUS - VAN DER WULP 1874A: 129.
c. VAN DER WULP 1858A: 5 - as CHIRONOMUS. Name preoccupied by WALKER 1848A, changed to MONOCHROMUS by VAN DER WULP 1874A: 129.
d. HOLARCTIC - NETHERLANDS (Location of types unknown?)
e. TOWNES 1945A: 160 - as HARNISCHIA (HARNISCHIA) MONOCHROMUS.

a. * UNIFASCIA (UNIFASCIUM)
b. POLYPEDILUM - SASA & YAMAMOTO 1977A: 313.
c. TOKUNAGA 1938A: 335 - as CHIRONOMUS (POLYPEDILUM), on basis of adult female.
d. ASIA - Yamashina, Kyoto, JAPAN.
e. ASHE & CRANSTON 1990: 307 - as POLYPEDILUM.

a. * UNIFASCIATUS
b. ?SYN: CRICOTOPUS ALBIFORCEPS (KIEFFER, 1916) - EDWARDS 1929A: 321; HIRVENOJA 1973A: 231 (Questionable senior synonym).
c. MACQUART 1826A: 204.
d. EUROPE - FRANCE.
e.

a. * URBANUS
b. Nomen dubium in MICROTENDIPES - ASHE & CRANSTON 1990: 291.
c. KIEFFER 1911B: 26 - as TENDIPES, on basis of adult.
d. EUROPE - GERMANY.
e. GOETGHEBUER 1937-54(13c): 55; FITTKAU, SCHLEE & REISS 1967A: 373 - as MICROTENDIPES.

a. * URSINUS
b. METRIOCNEMUS - KIEFFER 1906C: 32.
c. HOLMGREN 1869A: 30 - as CHIRONOMUS.
d. HOLARCTIC - SPITZBERGEN; GREENLAND; Quebec, CANADA.
e. GOETGHEBUER 1937-54(13g); 28; SUBLETTE & SUBLETTE 1965A: 161; ASHE & CRANSTON 1990: 200 - as METRIOCNEMUS.

a. $ USENICUS
b. CHIRONOMUS PLUMOSUS GROUP
c. LOGINOVA & BELYANINA 1994: 93 - as CHIRONOMUS, on basis of all stages and cytology.
d. EUROPE - Saratov, RUSSIA; POLAND
e. JABLONSKA-BARNA & MICHAILOVA 2006: 959 - cytology.

a. * USMAENSIS
b. CRYPTOTENDIPES - BECK & BECK 1969A: 294 (as type of genus).
c. PAGAST 1931A: 219 - as CHIRONOMUS (LEPTOCHIRONOMUS)
d. EUROPE - Kurlandia, U.S.S.R.
e. GOETGHEBUER 1937-54(13c): 47- as T. (CRYPTOCH. Gp. PARACHIRONOMUS).  LENZ 1941B: ; KUGLER 1971A: 341 - as CRYPTOTENDIPES.  FITTKAU, SCHLEE & REISS 1967A: 374 - as PARACHIRONOMUS.  ASHE 1983:19 - generic position.

a. * USSOURIENSIS
b. CRYPTOCHIRONOMUS - FITTKAU, SCHLEE & REISS 1967A: 371.
c. GOETGHEBUER 1933B: 116 - as CHIRONOMUS (CRYPTOCHIRONOMUS).
d. PALAEARCTIC - Rjabovonj, Lake Chanka, SIBERIA.
e. GOETGHEBUER 1937-54(13c): 41 - as T. (CRYPTOCHIRONOMUS).

a. $ UTAHENSIS
b. CHIRONOMUS (S.S.) - SUBLETTE & SUBLETTE 1965A: 166.
c. MALLOCH 1915A: 438 - as CHIRONOMUS, on basis of adult.
d. NEARCTIC - Kaysville, UTAH, U.S.A.
e. EGGLETON 1931A: 255.  BONNELL & MOTE 1941A: 324; 1942A: 3 - eggs & larva.  TOWNES 1945A: 127 - Redescription as TENDIPES.

a. $ UTTARPRADESHENSIS
b. CHIRONOMUS (S.S.)
c. SINGH & KULSHRESTHA 1976A: 156 - on basis of male and female (although female was that of C. BHARATI).
d. ASIA - Khandari Agricultural Farm, Agra, UTTAR PRADESH, INDIA.
e. CHAUDHURI & GUHA 1987: 27; MAHESHWARI 1989: 253 - male, female and immatures, as CHIRONOMUS.