Culex pipiens Linnaeus, 1758.
Subfamily Culicinae, genus Culex. Subgenus Culex, as presently defined, includes 215 extant species and one extinct (fossil) species. Subgenus abbreviation – Cux.
ADULTS – Generally medium-sized mosquitoes; decumbent scales of vertex predominantly narrow; eyes narrowly separated or contiguous above antennae; antenna slightly longer than proboscis, antenna of males without tufts of specialised setae or scales; maxillary palpus of females with 3 palpomeres, palpus of males with 5 palpomeres, usually distinctly longer than proboscis, palpomere 3 with row of ventral setae and variable number of longer ventrolateral setae, palpomeres 4 and 5 upturned and usually with numerous setae; proboscis usually as long or slightly longer than forefemur, with or without median pale ring or pale scaling on ventral surface, proboscis of males with or without median ventral cluster of setae but usually with false joint before mid-length; scutal scaling varied; acrostichal setae present in more or less double row, sometimes short; dorsocentral setae, scutal fossal setae, antealar setae and supraalar setae well developed; thoracic pleura usually with extensive scaling, usually present at least on antepronotum, postpronotum, upper proepisternum, mesokatepisternum and mesepimeron, present or absent on lower proepisternum, anteprocoxal membrane, postspiracular area and prealar area; pleural setae varied, postspiracular setae rarely present, lower mesepimeral setae present or absent; wing most often entirely dark-scaled, sometimes with scattered pale scales or distinct pale spots; legs varied, tarsi with or without pale bands; ungues small, equal and simple in females, outer unguis of fore- and midlegs toothed and larger than inner unguis in males; pulvilli well developed; abdominal terga usually with basal pale bands and basolateral pale spots, sometimes with apical pale bands, apicolateral pale patches or entirely dark. MALE GENITALIA – Ninth tergal lobes usually short and broad, with 1 or 2 rows of setae; gonocoxite with or without scales; subapical lobe not distinctly divided, setae a-c rod-like, setae d-f and seta h varied, 1 or all of setae d-f sometimes absent, seta g foliform or simple; gonostylus generally simple, curved and tapered; gonostylar claw weak, subapical, usually shoehorn-shaped; phallosome complex, varied, lateral plate usually with distinct inner and outer divisions bearing variously developed teeth and processes; paraproct with crown of numerous spicules of varying size and character, basal sternal process varied, sometimes absent; cercal setae present. LARVAE – Antenna shorter or as long as head; seta 1-A usually strongly developed; setae 2,3-A single, usually subapical, sometimes apical; median labral plate usually distinctly delimited from dorsal apotome; seta 1-C slender or stout; setae 1–3-P subequal and long, usually single, seta 3-P rarely distinctly shorter than setae 1,2-P; abdominal chaetotaxy varied; setae 6-I,II and 7-I strongly developed; seta 6-III–VI moderately to strongly developed; seta 7-II large like seta 7-I or small like seta 7-III–V; seta 1-III-VII varied; comb varied from numerous fringed scales to a few strong spines; siphon varied, short and stout to long and slender; pecten varied from a few to many spines, denticulation varied; seta 1-S in 3–7 posterolateral pairs, 1 or more distal elements sometimes out of line; seta 2-S single, sometimes hook-like and large; saddle usually complete, rarely incomplete; seta 1-X varied, not very long; setae 2,3-X strongly developed, seta 2-X branched, seta 3-X single; ventral brush (seta 4-X) comprised of 6 or 7 pairs of setae, all inserted on grid. PUPAE – Trumpet varied in length, generally cylindrical or distally flared with large pinna; meatus usually without slit; tracheoid area variable; cephalothoracic setae varied in development, all shorter than trumpet; abdominal chaetotaxy varied, seta 1-III–VII and 5-IV–VI varied in development; seta 2-III–VI single, very small, always inserted mesad of seta 1, seta 2-VII usually inserted laterad of seta 1, sometimes variable in position; seta 6-I,II usually distinctly longer than seta 7-I,II; paddle generally broad and oval, apex rounded, slightly produced or slightly emarginate, outer margin minutely spiculate proximally; seta 1-Pa and seta 2-Pa small and usually single, seta 2-Pa sometimes absent. See genus Culex.
Culex is almost certainly polyphyletic and will remain a "taxon of convenience" until the monophyly, phylogeny and classification of the included taxa and their relationships with other genera are resolved. Subgenera Phenacomyia, Oculeomyia, Phytotelmatomyia and Sirivanakarnius have been placed among species of subgenus Culex in both morphological and molecular studies that included species of these subgenera (Deus, 2009; Vesgueiro et al., 2011; Demari-Silva et al., 2011; Harbach et al., 2012; Laurito & Almirón, 2013). Analyses of the mitochondrial genomes of four species of the Coronator Group suggest that the ATP6, ATP8 and NADH5 genes may be useful for resolving phylogenetic relationships within the subgenus (Demari-Silva et al., 2015).
Harbach et al. (2017) conducted a phylogenetic analysis of the subgenus using implied and equally weighted parsimony methods to analyse a data set comprised of 286 characters of the larval, pupal and adult stages of 150 species of the subgenus and an outgroup of 17 species. The analyses largely failed to resolve relationships among the species and the informal groups in which they are currently placed; thus, the internal classification of the subgenus based on the intuitive assessment of morphological similarities and differences does not seem, in large part, to reflect evolutionary relationships. It is notable that the phylogenetic analysis of Sun et al. (2019) based on the nucleotide sequences of 13 protein-coding genes obtained from the complete mitochondrial genomes of 10 species of Culex strongly supported the suppositions of Edwards (1932), Sirivanakarn (1976) and Harbach et al. (2017) that the Sitiens Group possibly should be recognized as a genus-group taxon. It is also interesting to note that their study did not support the monophyly of the Pipiens Group, which was recovered as a polyphyletic group in the studies of Laurito & Almirón (2013) and Harbach et al. (2017), but did support the monophyly of the Coronator Group.
The immature stages typically occur in ground-water habitats, but several species are frequently found in large artificial containers. A number of species inhabit rock holes, crab holes, tree holes, bamboo and the leaf axils of plants. Many species are notorious pests of humans and domesticated animals. Females are primarily active during crepuscular or nocturnal periods. The hosts of most species are unknown but probably principally include birds and mammals.
The subgenus includes most of the medically important and pest species of Culicini. Many species vector pathogens that cause human diseases, including Japanese encephalitis in the Oriental Region, several encephalitic diseases in North America, Murray Valley encephalitis and Ross River fever in Australia, West Nile fever in Africa, Europe and North America, and Rift Valley fever in Africa. A few species are important vectors of Wuchereria bancrofti, and some species may be involved in the transmission of Brugia malayi.
Cosmopolitan.
Belkin, 1962 (South Pacific, keys, taxonomy, bionomics, distributions); Bram, 1967 (Thailand, keys, taxonomy, bionomics, distributions); Bram, 1967 (Neotropical Region, keys, taxonomy, distributions); Sirivanakarn, 1976 (Oriental Region, keys, taxonomy, bionomics, distributions); Harbach, 1988 (southwestern Asia and Egypt, taxonomy, bionomics, distributions); Lee et al., 1989 (Australasian Region, keys, literature, distributions, bionomics); Laurito & Almirón, 2013 (morphology, phylogenetic relationships of species of the subgenus in Argentina); Harbach et al., 2017 (World, morphology, phylogeny): Sun et al. 2019 (phylogenetic relationships based on mitochondrial genomes); González et al., 2023 (Neotropical subgenera of Culex, comparative morphology, molecular associations).
abnormalis Lane, 1936 abyssinicus Edwards, 1941 acharistus Root, 1927 aenescens Edwards, 1941 alani Forattini, 1965 alienus Colless, 1957 alis Theobald, 1903 ameliae Casal, 1967 andersoni Edwards, 1914 annulirostris Skuse, 1889 annuliventris (Blanchard, 1852) antennatus (Becker, 1903) aquarius Strickman, 1990 archegus Dyar, 1929 argenteopunctatus (Ventrillon, 1905) articularis Philippi, 1865 asteliae Belkin, 1968 astridianus de Meillon, 1942 atriceps Edwards, 1926 australicus Dobrotworsky & Drummond, 1953 bahamensis Dyar & Knab, 1906 banksensis Maffi & Tenorio, 1977 barraudi Edwards, 1922 beta Séguy, 1924 bhutanensis Somboon, Namgay & Harbach, 2021 (in Somboon et al., 2021) bickleyi Forattini, 1965 bidens Dyar, 1922 bihamatus Edwards, 1926 bilineatus Theobald, 1903 bonneae Dyar & Knab, 1919 brami Forattini, Rabello & Souza Lopes, 1967 brethesi Dyar, 1919 brevispinosus Bonne-Wepster & Bonne, 1920 brumpti Galliard, 1931 bukavuensis Wolfs, 1947 bwambanus Edwards, 1941 calurus Edwards, 1935 camposi Dyar, 1925 carcinoxenus de Oliveira Castro, 1932 carleti Brunhes & Ravaonjanahary, 1971 castelli Hamon, 1957 chidesteri Dyar, 1921 chitae Duret, 1967 chorleyi Edwards, 1941 comorensis Brunhes, 1977 coronator Dyar & Knab, 1906 covagarciai Forattini, 1965 crinicauda Edwards, 1921 curvibrachius Angulo, 1993 (in Angulo & Olivares, 1993) cuyanus Duret, 1968 decens Theobald, 1901 declarator Dyar & Knab, 1906 delys Howard, Dyar & Knab, 1915 demeilloni Doucet, 1950 diengensis Brug, 1931 diplophyllum Dyar, 1929 dohenyi Hogue, 1975 dolosus (Lynch Arribálzaga, 1891) draconis Ingram & de Meillon, 1927 duplicator Dyar & Knab, 1909 duttoni Theobald, 1901 eduardoi Casal & García, 1968 edwardsi Barraud, 1923 elgonicus Edwards, 1941 erikae Szadziewski & Szadziewska, 1985 (fossil species, 33.9–40.4 Mya, Cenozoic, Late Eocene) erythrothorax Dyar, 1907 eschirasi Galliard, 1931 farakoensis Hamon, 1955 fasyi Baisas, 1938 fernandezi Casal, García & Cavalieri, 1966 foliaceus Lane, 1945 fuscocephala Theobald, 1907 gameti Bailly-Choumara, 1966 garciai Broche, 2000 gediensis Edwards, 1941 gelidus Theobald, 1901 globocoxitus Dobrotworsky, 1953 grahamii Theobald, 1910 guayasi Leví-Castillo, 1953 guiarti Blanchard, 1905 guizhouensis Chen & Zhao, 1985 habilitator Dyar & Knab, 1906 hancocki Edwards, 1930 hopkinsi Edwards, 1932 huangae Meng, 1958 hutchinsoni Barraud, 1924 incognitus Baisas, 1938 inflictus Theobald, 1901 ingrami Edwards, 1916 interfor Dyar, 1928 interrogator Dyar & Knab, 1906 invidiosus Theobald, 1901 iyengari Mattingly & Rageau, 1958 jacksoni Edwards, 1934 (in Barraud, 1934) janitor Theobald, 1903 kartalae Brunhes, 1977 kesseli Belkin, 1962] kingii (Theobald, 1913) lahillei Bachmann & Casal, 1962 laticinctus Edwards, 1913 laticlasper Galindo & Blanton, 1954 levicastilloi Lane, 1945 litoralis Bohart, 1946 litwakae Harbach, 1985 longitubus Somboon, Namgay & Harbach, 2021 (in Somboon et al., 2021) lygrus Root, 1927 maracayensis Evans, 1923 macrophyllus Edwards & Gibbins, 1939 marianae Bohart & Ingram, 1946 marquesensis Stone & Rosen, 1953 mattinglyi Knight, 1953 mauesensis Lane, 1945 maxi Dyar, 1928 mimeticus Noè, 1899 mimuloides Barraud, 1924 mimulus Edwards, 1915 miraculosus Bonne-Wepster, 1937 mirificus Edwards, 1913 mollis Dyar & Knab, 1906 murrelli Lien, 1968 musarum Edwards, 1932 nakuruensis Mattingly, 1951 neavei Theobald, 1906 nigripalpus Theobald, 1901 nilgiricus Edwards, 1916 ninagongoensis Edwards, 1928 omani Belkin, 1962 orientalis Edwards, 1921 ornatothoracis Theobald, 1909 ousqua Dyar, 1918 pacificus Edwards, 1916 pajoti da Cunha Ramos & Ribeiro, 1982 pallens Coquillett, 1898 palpalis Taylor, 1912 paramaxi Duret, 1968 perexiguus Theobald, 1903 perfidiosus Edwards, 1914 perfuscus Edwards, 1914 perplexus Leicester, 1908 pervigilans Bergroth, 1889 philipi Edwards, 1929 philippinensis Sirivanakarn, 1976 pinarocampa Dyar & Knab, 1908 pipiens Linnaeus, 1758 plicatus Olivares, 1993 (in Angulo & Olivares, 1993) propinquus Colless, 1955 prosecutor Séguy, 1927 pruina Theobald, 1901 pseudopruina van Someren, 1951 pseudostigmatosoma Strickman, 1990 pseudovishnui Colless, 1957 quasiguiarti Theobald, 1910 quinquefasciatus Say, 1823 quitensis Levi-Castillo, 1953 restuans Theobald, 1901 riojanus Duret, 1968 roseni Belkin, 1962 rotoruae Belkin, 1968 salinarius Coquillett, 1904 saltanensis Dyar, 1928 scheuberi Carpintero & Leguizamón, 2004 schwetzi Edwards, 1929 scimitar Branch & Seabrook, 1959 scottii Theobald, 1912 sechani Brunhes & Boussès, 2009 secutor Theobald, 1901 seldeslachtsi Wolfs, 1947 shoae Hamon & Ovazza, 1954 sinaiticus Kirkpatrick, 1925 sitiens Wiedemann, 1828 solitarius Bonne-Wepster, 1938 sphinx Howard, Dyar & Knab, 1913 spinosus Lutz, 1905 stenolepis Dyar & Knab, 1908 stigmatosoma Dyar, 1907 striatipes Edwards, 1941 summorosus Dyar, 1920 surinamensis Dyar, 1918 tamsi Edwards, 1934 tarsalis Coquillett, 1896 tatoi Casal & García, 1971 telesilla de Meillon & Lavoipierre, 1945 (in De Meillon et al., 1945) tenagius van Someren, 1954 terzii Edwards, 1941 thalassius Theobald, 1903 theileri Theobald, 1903 thriambus Dyar, 1921 tianpingensis Chen, 1981 toroensis Edwards & Gibbins, 1939 torrentium Martini, 1925 toviiensis Klein, Rivière & Séchan, 1984 trifilatus Edwards, 1914 trifoliatus Edwards, 1914 tritaeniorhynchus Giles, 1901 tsengi Lien, 1968 ugandae van Someren, 1967 umbripes Edwards, 1941 univittatus Theobald, 1901 usquatissimus Dyar, 1922 usquatus Dyar, 1918 vagans Wiedemann, 1828 vansomereni Edwards, 1926 ventrilloni Edwards, 1920 verutus Harbach, 1987 vexillatus Edwards, 1941 vicinalis de Meillon & Lavoipierre, 1944 vicinus (Taylor, 1916) vishnui Theobald, 1901 watti Edwards, 1920 weschei Edwards, 1935 whitei Barraud, 1923 whitmorei (Giles, 1904) whittingtoni Belkin, 1962 yojoae Strickman, 1990 zombaensis Theobald, 1901