Subfamily Culicinae, tribe Culisetini. Culiseta is the only genus of tribe Culisetini. It includes 39 species. One species is not placed in a subgenus; the other species are divided between seven subgenera (number of species in parentheses): Allotheobaldia (1), Austrotheobaldia (1), Climacura (6), Culicella (14), Culiseta (12), Neotheobaldia (2), Theomyia (1) and subgenus uncertain (2). Genus abbreviation – Cs.
Culiseta are rather large mosquitoes which bear a superficial resemblance to Culex. They lack perceptible pulvilli, possess prespiracular setae and bear a patch of setae at the base of the subcosta (absent in subgenus Theomyia) on the ventral surface of the wing. The subcostal setae are virtually diagnostic for the genus. They are known to occur in only three other mosquitoes, Coquillettidia (Austromansonia) tenuipalpis (New Zealand), Opifex (Nothoskusea) chathamicus (Chatham Island) and Opifex (Opifex) fuscus (New Zealand). Culiseta are distinguished from these species by the presence of prespiracular setae. With one exception (Cs. littleri, subgenus Austrotheobaldia, Australia), larvae have seta 1-S inserted at the base of the siphon. The only other genera that have seta 1-S in this position are Ficalbia and Hodgesia. Larvae of Culiseta differ from Ficalbia in having a complete hypostomal suture. They differ from Hodgesia in having seta 5-VIII located far below the dorsal margin of abdominal segment X. Larvae of Austrotheobaldia are unique in having the antennae and head setae 5,6-C unusually long, with seta 6-C single and about twice as long as the head. See Culisetini.
The affinities of Culiseta are unknown. Culiseta was paired with Toxorhynchites in the implied weighting analysis of Harbach & Kitching (1998) based on morphological data, but this relationship seems unlikely. Culiseta appears to be an ancient group that shares similarities with a number of other genera. From divergence times based on sequence data for nuclear protein-coding genes and fossil calibration points, it appears that Culiseta may have appeared as early as 191.0 Mya (CL = 154.7–218.8 Mya) during the Jurassic (Reidenbach et al., 2009).
Most Culiseta are cold-adapted species which only occur in warmer climates during the colder parts of the year or at higher elevations where temperatures are low. The larvae of most species are found in ground waters such as bogs, marshes, ponds, streams, ditches and rock pools, but an African species occurs in tree holes, a common eastern Palaearctic species occurs in wells and rock pools, and several Australian species occur underground. Little is known about the blood-feeding habits of females. Most species feed on birds and mammals, but a few feed on reptiles. Several species attack domestic animals and occasionally humans.
Three species, Cs. inornata, Cs. melanura and Cs. dyari, are vectors of both Eastern and Western equine encephalitis virus in North America.
Most species of Culiseta occur in the Palaearctic, Nearctic and Australasian Regions, but some also occur in the Afrotropical and Oriental Regions. Two species are found in Central America, but none occur in South America.
Belkin, 1962 (taxonomy, South Pacific); DuBose & Curtin, 1965 (keys, Mediterranean area); Forattini, 1965 (Neotropical Region); Belkin, 1968 (New Zealand); Dobrotworsky, 1971 (Southeast Asia); Gutsevich et al., 1974 (former USSR); Tanaka et al., 1979 (Japan); Wood et al., 1979 (Canada); Darsie & Ward, 1981, 2005 (keys, North America); Lu & Li, 1982 (China); Lee et al., 1988 (Australasian Region); Maslov, 1967, 1989 (world); Service, 1990 (Afrotropical Region); Lu Baolin et al., 1997 (China); Becker et al., 2003, 2010.