Culex pusillus Macquart, 1850.
Subfamily Culicinae, genus Culex. Subgenus Barraudius includes four species. See Culex classification, Subgenus Barraudius). Subgenus abbreviation – Bar.
ADULTS – Small yellowish-brown mosquitoes; vertex of head with narrow scales only; proboscis shorter than forefemur, entirely dark-scaled; maxillary palpus with 3 palpomeres in females (palpomere 4 vestigial or absent), 5 in males; acrostichal setae and dorsocentral setae present; thoracic pleura with distinct pale scale-patches; lower mesepimeral seta present; tarsi entirely dark-scaled, foretarsomere 5 equal or longer than tarsomere 4, hindtarsomere 1 distinctly shorter than tibia; abdominal terga dark-scaled but basolateral pale patches may be present. MALE GENITALIA – Tergum IX lobes poorly developed, widely separated, with setae; gonocoxite with scales; subapical lobe median in position, divided, each division bearing 1–3 specialised setae of uncertain homology; gonostylus simple, tapered distally, with rather long claw at apex; phallosome elongate, lateral plate narrow, tapered, apically pointed and bent laterad; paraproct with crown of numerous short thorn-like spicules, basal lateral arm not developed; cercal setae present. LARVAE – Palatal brushes normal; seta 1-A large, distad of middle of antenna; seta 4-C single, setae 4,5,6-C inserted at mid-length of head capsule, seta 3-P nearly as long as setae 1,2-P; seta 8-P well develop, double; seta 7-I subequal to seta 6-I, seta 7-II small, similar to 7-III–V, seta 7-VI single; siphon moderately long, pecten spines long and slender, seta 1-S with 8–11 long multi-branched elements in posterior zigzag row extending from within length of pecten to apex; saddle complete; seta 2-X with 2 or 3 branches, seta 3-X single, longer than seta 2-X; ventral brush (seta 4-X) with 5.5–6.5 pairs of long setae inserted on grid. PUPAE – Setae of cephalothorax generally short, subequal; seta 6-I longer than seta 7-I; 5-IV–VI shorter or slightly longer than following tergum; seta 1-Pa and seta 2-Pa present. See genus Culex.
The affinities of Barraudius are not clear, but the group appears to be closely related to the Afrotropical Afroculex and Maillotia and the Neotropical Allimanta. When Edwards (1921) established subgenus Barraudius, he pointed out that species of the subgenus “appear to be more distinct from typical Culex than any other groups occurring in the Old World”. The basal placement of Barraudius relative to taxa traditionally included in subgenus Culex in the morphology-based phylogenetic analyses of Harbach et al. (2012) support Edwards’s observation.
Immature stages inhabit a variety of ground-water habitats, especially brackish water marshes, swamps and rice fields. Females are known to bite humans and domesticated animals during day and night.
Culex modestus vectors arboviruses and is regarded as a potential vector of West Nile virus. It has been found naturally infected with tularaemia (Gutsevich et al., 1974).
Palaearctic (principally) and Afrotropical Regions.