Tribe Aedini Neveu-Lemaire, 1902
Aedes Meigen, 1818. [The subfamily name Aedinae was established by Neveu-Lemaire (1902) (as Aedeinae). In accordance with the Principle of Coordination (International Commission on Zoological Nomenclature, 1999: Article 36.1), Neveu-Lemaire (1902) is considered to have simultaneously established the coordinate tribal name Aedini.]
Subfamily Culicinae. Aedini is the largest tribe of mosquitoes with 1,268 species classified in 10 genera. The genera are as follow (number of species in parenthesis): traditional Aedes sensu Wilkerson et al. 2015 (940), Armigeres (58), Eretmapodites (49), Haemagogus (28), Heizmannia (40), Opifex (2), Psorophora (49), Udaya (3), Verrallina (95) and Zeugnomyia (4). Species of this tribe are referred to as ‘aedines’.
Tanaka (2014, 2018), in a catalogue of the mosquitoes of Japan, ranked the tribe Aedini as a subtribe of a more encompassing tribe Culicini, and included 17 generic-level taxa for aedine species known to occur in the country: Aedes, Aedimorphus, Armigeres, Bruceharrisonius, Collessius, Downsiomyia, Edwardsaedes, Empihals, Geoskusea, Hopkinsius, Hulecoeteomyia, Neomelaniconion, Ochlerotatus, Phagomyia, Stegomyia, Tanakaius and Verrallina. Five of these taxa, Aedimorphus, Bruceharrisonius, Phagomyia, Ochlerotatus and Stegomyia, included subgeneric groups that are not currently recognised. Ecculex and Lepidotomyia (synonyms of Aedimorphus) were listed as subgenera for species of Aedes (Aedimorphus) and Quasistegomyia (a synonym of Stegomyia) was listed as a subgenus for species of Aedes (Stegomyia), all without indication of formal change of status. However, Tanaka listed associated species names for those subgenera in both publications and differentiated them from other generic-level taxa of Japanese aedine mosquitoes in a dichotomous key included in his 2018 publication. Traditionally, these acts would have been considered to validate the subgeneric names, but in the absence of evidence for the monophyly of the groups based on comparative morphological or phylogenetic analyses of a larger selection of taxa, their listing as subgenera should be rejected pending more comprehensive study. The following further supports this position. Tanaka resurrected Ecculex for Ae. (Aedimorphus) vexans nipponii and Ae. (Adm.) vexans nocturnus, which he listed as a species without explanation, description or formal change of status; and resurrected Lepidotomyia for Ae. (Adm.) alboscutellatus. In the phylogeny of Aedini generated in the extensive morphology-based study of Reinert et al. (2009), Ae. vexans was recovered in a basal relationship to 17 other species of the subgenus, with low support, and Ae. alboscutellatus formed a weakly supported sister pair with Ae. culicinus. Those results do not provide evidence for recognising new subgenera for species currently classified in subgenus Aedimorphus. Similarly, Tanaka resurrected Quasistegomyia for Ae. (Stg.) albopictus, Ae. (Stg.) daitensis, Ae. (Stg.) flavopictus, Ae. (Stg.) galloisi and Ae. (Stg.) riversi. In the study of Reinert et al. (2009), two of these species, Ae. (Stg.) albopictus and Ae. (Stg.) riversi, were recovered in a paraphyletic relationship with several other Oriental species of Stegomyia; thus indicating the need for a much broader study to support the removal of Quasistegomyia from synonymy and its possible subgeneric status.
Species of tribe Aedini are extremely varied, and many are difficult to identify to subgenus because of overlapping suites of shared anatomical features. Hence, combinations of characters are required to define the majority of the subgenera and species. General features of the tribe include the presence of toothed ungues (tarsal claws) and a pointed abdomen in most females. Although toothed ungues are not universally present, they are not found in any other tribe of Culicinae. Larvae have relatively short, stout siphons with a single pair of seta 1-S (except for species of subgenus Aedes and the Rusicoidus Group of subgenus Ochlerotatus of Aedes) inserted well above the base, usually beyond the middle of the siphon. A comb is always present on segment VIII and the ventral brush is usually represented by five or more pairs of setae.
The heterogeneity of the tribe is illustrated by the following description of principal taxonomic features (excluding those above) found in the adult and larval stages. ADULTS ‒ Compound eyes contiguous or separated above antennae; erect scales of head numerous, restricted to a single posterior row, or absent; clypeus with or without scales, never setae; proboscis variable in length and development; antennae distinctly shorter to slightly longer than proboscis; scutal scales and setae varied; mesopostnotum with or without setae; paratergite with or without scales; antepronota large or small, sometimes close together; pleural setae and scales varied; base of hindcoxa in line with or below base of mesomeron; pulvilli not evident; tarsi normal; wing membrane with distinct microtrichia; cell R2 longer than vein R2+3; vein Rs without basal spur; vein 1A ending distal to base of mediocubital crossvein; base of subcosta without setae ventrally except in genus Opifex; scales of alula varied; upper calypter usually with complete line of setae or hair-like scales, sometimes reduced in number or absent; laterotergite varied, completely or partially covered with scales or bare. LARVAE ‒ Occipital foramen normal, circular; collar varied, usually distinct; hypostomal suture complete; seta 2-C absent; seta 3-C dorsal in position; seta 13-P rarely present; no plumose or palmate setae on thorax or abdomen; seta 12-I present or absent; pecten usually present, sometimes absent; saddle usually incomplete.
Morphological and molecular evidence indicates that Aedini is a monophyletic taxon (see review of Harbach, 2007; Reidenbach et al., 2009). Based on the assumption that annectant forms may have been derived by hybrid origin, Belkin (1962) believed that Aedini differentiated in the Indomalayan area of the Old World where the majority of annectant forms presently exist. Aedini was recovered as a paraphyletic assemblage with respect to Mansonia in the morphology-based phylogeny of Harbach & Kitching (1998), as the sister of Mansonia in the studies of Reinert et al. (2004, 2006, 2009) and as sister to Orthopodomyia + Mansonia in the study of Reinert et al. (2008) based on morphological data. Aedini was recovered as the sister to Orthopodomyia + Coquillettidia in the study of Reidenbach et al. (2009) based on combined molecular (six nuclear genes) and morphological data. Aedini was not recovered as a monophyletic group in the analyses of Wilkerson et al. (2015) based on equal weighting of the data set of Reinert et al. (2009) ‒ Mansonia + Psorophora was recovered in a sister relationship to the other generic-level taxa of the tribe. Interestingly, Psorophora was found to be the sister to all other aedines included in the molecular phylogenetic study of Soghigian et al. (2017). Their study included two or more species for each of 26 genus-group taxa: Acartomyia, Aedes, Aedimorphus, Bothaella, Bruceharrisonius, Catageiomyia, Collessius, Diceromyia, Dobrotworskyius, Downsiomyia, Georgecraigius, Halaedes, Howardina, Hulecoeteomyia, Jarnellius, Lorrainea, Macleaya, Mucidus, Neomelaniconion, Ochlerotatus, Paraedes, Phagomyia, Rhinoskusea, Rusticoidus, Stegomyia and Tanakaius. All but six of these groups were recovered as monophyletic. Aedimorphus, Catageiomyia and Neomelaniconion of the Aedes Genus Group (their Clade A) and Collessius, Ochlerotatus and Phagomyia of the Ochlerotatus Genus Group (their Clade B) were not monophyletic. However, the monophyly of Collessius, Neomelaniconion and Phagomyia was violated by species with only a single genetic marker. The authors cautioned against drawing firm conclusions about the classification of Aedini because sampling of genetic markers for taxa included in the study relied heavily on incomplete coverage of nucleotide sequeces in GenBank.
Aedine larvae inhabit a diversity of habitats. Some species utilise temporary ground waters such as pools, puddles, hoof prints, wallows and the margins of swampy or marshy areas. Other species utilise rock holes, crab holes, tree holes, leaf axils and flower bracts, pitcher plants and man-made containers. The females of many species readily attack humans. Both daytime and night-time biters are known.
Certain members of the tribe are of great importance in the transmission of viruses and helminths to humans and other animals (see Wilkerson et al., 2015: Table 1).
Aedini are world-wide in distribution, but are better represented in the Old World and the Nearctic Region.
Belkin, 1962 (South Pacific, systematics, bionomics, distribution); Belkin et al., 1970 (West Indies); Huang, 2001 (Afrotropical Region, key to subgenera of Aedes); Reinert et al., 2004, 2006, 2008, 2009 (phylogeny, classification); Reidenbach et al., 2009 (phylogeny); Rattanarithikul et al., 2010 (keys, Thailand); Wilkerson et al., 2015 (phylogeny, classification); Soghigian et al., 2017 (phylogenetic relationships).