Culex pipiens Linnaeus, 1758. [Meigen (1818) introduced the first family-group name (Culiciformes) that established the date of priority for Culicidae and the coordinate tribal name Culicini (International Commission on Zoological Nomenclature, 1999: Article 36.1).]
Subfamily Culicinae. The tribe includes 796 species classified in four genera. Culex is by far the largest genus with 769 species divided between 26 subgenera. In comparison, Deinocerites has 18 species, Galindomyia one species and Lutzia eight species. Navarro & Liria (2000) formally reduced genus Deinocerites to subgeneric status in genus Culex, but this action has not been widely accepted because this group of species is diagnosed by many unique (autapomorphic) features in the immature and adult stages.
The immature stages of Culicini are very similar to the immature stages of some groups of Culiseta. As far as known, the cibarial armature of the females is developed elsewhere only in subfamily Anophelinae. The absence of spiracular setae and postspiracular setae is rather distinctive of Culicini, but the latter are present in at least two species (see genus Culex). The tribe is unique in the development of more or less distinct pulvilli at the base of the ungues, but this character is rather difficult to observe. The crown of spicules on the paraprocts of the male genitalia is also a unique feature of Culicini, but the spicules are reduced in some subgenera of Culex. See Culicinae.
The monophyly of Culicini has never been disputed. The tribe was recovered as the sister of Sabethini in the cladistic analysis of Harbach & Kitching (1998). Mattingly (1981) noted that certain Culex share characters with sabethines, but there is no substantial evidence to support a relationship between Culicini and Sabethini. Belkin (1962) considered Culicini to be a natural and ancient group that shares some similarities in the immature stages with certain groups of Culiseta. Adames (1971) considered Deinocerites and Galindomyia as a monophyletic group based on shared characteristics of the antennae and male genitalia, and regarded this clade as the sister group of Culex. These relationships were supported in the generic analysis of Harbach & Kitching (1998).
A number of published and unpublished phylogenetic studies based on morphological and molecular data support the monophyly of all of the generic-level groups of Culicini except subgenera Culex, Eumelanomyia and Neoculex (Mallampalli, 1995; Miller et al., 1996; Isoe, 2000; Navarro & Liria, 2000; Juthayothin, 2004; St John, 2007; Deus, 2009; Vesgueiro et al., 2011; Demari-Silva et al., 2011; Harbach et al., 2012; Laurito & Almirón, 2013; Harbach et al., 2016, 2017). The results of these studies, however, provide conflicting support for the generic status of Lutzia and the subgeneric statuses of Oculeomyia, Phenacomyia, Phytotelmatomyia and Sirivanakarnius. With the exception of Mallampalli (1995), analyses based solely on morphological data support the generic status of Lutzia (Navarro & Liria, 2000; St John, 2007; Harbach et al., 2012; Laurito & Almirón, 2013) by placing it outside the clade comprised of the subgenera of Culex, whereas the analyses based on DNA sequence data (ITS1 and ITS2 rDNA and COI mtDNA) do not, because Lutzia is placed among species or subgenera of genus Culex (Miller et al., 1996; Vesgueiro et al., 2011; Demari-Silva et al., 2011). The morphological analysis of Navarro & Liria (2000) recovered subgenus Phenacomyia in a basal relationship relative to all other subgenera of Culex (a clade that also included genus Deinocerites). In contrast, Phenacomyia and Phytotelmatomyia, and also subgenera Oculeomyia and Sirivanakarnius, have been placed among species of subgenus Culex in other studies, both morphological and molecular, that included species of these subgenera (Deus, 2009; Vesgueiro et al., 2011; Demari-Silva et al., 2011; Harbach et al., 2012; Laurito & Almirón, 2013; Harbach et al., 2016).
Species of Culex are found primarily in more or less permanent bodies of ground water, but many species inhabit the leaf axils of plants, tree holes, rock holes and crab holes. A few species that normally occur in ground water or tree holes also utilise artificial containers. The eggs of most Culex species are laid in rafts on the water surface, but species that inhabit axils of plants are likely to lay their eggs individually, possibly in individual gelatinous coverings like species of subgenus Microculex. The females of the majority of species attack humans, other mammals and birds. Some species appear to feed primarily on birds, and some are known to feed on frogs and lizards. Several species, primarily of subgenus Culex, are more or less closely associated with humans.
Several species of subgenera Culex and Melanoconion are involved in the transmission of agents that cause human diseases, particularly filariasis and arboviral encephalitis.
Culex has a cosmopolitan distribution, Deinocerites and Galindomyia occur in the Neotropical Region and Lutzia is represented by species in all zoogeographical regions except the western Palaearctic and Nearctic Regions.
Harbach et al., 2012 (phylogeny). See the references listed for genera Culex, Deinocerites, Galindomyia and Lutzia.