Aedes palpalis (Newstead, 1907) (in Newstead et al., 1907), original combination: Neomelaniconion palpale.
Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Neomelaniconion includes 28 species, one represented by two subspecies. Subgenus abbreviation – Neo.
Species of subgenus Neomelaniconion are comparatively darkly ornamented species, usually with bright yellow or whitish scales of the vertex and sides of scutellum. The following features, for the most part, distinguish subgenus Neomelaniconion from other generic-level taxa of Aedini. Characters that diagnose Neomelaniconion in the phylogenetic analysis of Reinert et al. (2009) are indicated by an asterisk (*).
ADULTS – Decumbent scales of vertex all narrow; erect scales fairly numerous but not reaching front of vertex; *ocular scales both narrow and broad; *6 or more interocular setae present; eyes contiguous or nearly so; antenna of females normal, antenna of males strongly verticillate with flagellar whorls directed mainly dorsally and ventrally; maxillary palpus of females about 0.2 length of proboscis, maxillary palpus of males slightly longer than proboscis, distinctive, palpomere 4 large, upturned and densely setose, palpomere 5 minute or absent; proboscis usually entirely dark-scaled, sometimes pale below (with complete pale ring in Ae. taeniarostris); scutum and scutellum with narrow scales; *scutal fossa with contrasting pale scales in large patch; dorsocentral and acrostichal setae present; scutellar scales all narrow; paratergite bare; *antepronotal scales absent; prealar scales absent; mesokatepisternal scale-patches well separated; *lower anterior mesepimeral setae present; wing with narrow dark scales (*costal scales all dark), *remigium without dorsal setae; alula with narrow fringe scales; tarsi dark-scaled; foreungues toothed in females and males; abdominal terga with basal pale bands, sometimes also with apical pale scaling. FEMALE GENITALIA – Abdominal segment VIII small, completely retractile, *tergum VIII longer than wide; cercus long, narrow; postgenital lobe deeply emarginate apically. MALE GENITALIA – Tergum IX lobes shallowly separated, setose; *gonocoxite without mesal membranous area, basal dorsomesal lobe a short process bearing 2 stout setae, *ventromesal surface with longitudinal row of few to several short blunt-tipped spiniforms (unique character); gonostylus inserted subapically, *narrow basally, enlarged medially; claspette absent; phallosome with toothed lateral plates; proctiger triangular, *with sternal arm; apex of paraprocts sclerotised and pointed. LARVAE – Antenna spiculate; seta 1-A small with few branches; seta 4-C small, inserted slightly anterior to seta 6-C; setae 4–6-C inserted caudad of seta 7-C; dorsomentum with numerous small teeth (except in Ae. bolensis); comb scales stout, in 1 or 2 irregular rows; pecten extends beyond mid-length of siphon, with 1 or more distal spines more widely separated; seta 1-S small, inserted distal to pecten; saddle incomplete; ventral brush (seta 4-X) with precratal setae. PUPAE – *Seta 5-CT >1.3 length of seta 4-CT; seta 10-CT inserted laterad and markedly posterior to seta 11-CT; setae 2,3-I widely separated, *seta 3-I with 3 or more branches; seta 1-II with at least slightly expanded base and 4 or more primary branches; seta 7-VI minute, seta 7-VII small, at least somewhat darkened and thickened; paddle with several rows of minute spicules on distal edge; midrib weakly developed; seta 1-Pa small, single or branched. See Aedes.
Mattingly (1961) observed that Neomelaniconion “shows marked affinities” with subgenera Aedes and Paraedes in all life stages and surmised a close relationship with the former based on similarities of the male genitalia, particularly the subapical attachment of the gonostylus to the gonocoxite. In the morphology-based phylogeny of tribe Aedini recovered by Reinert et al. (2009), Neomelaniconion (based on characters coded for Ae. lineatopennis and Ae. palpalis) was placed in a clade comprised of Neomelaniconion + (subgenus Edwardsaedes + (subgenus Aedes + (subgenus Paraedes + genus Verrallina))). Neomelaniconion was recovered as the sister of a clade comprised of subgenus Aedes + (subgenus Paraedes + genus Verrallina) in the study of Wilkerson et al. (2015). It was not recovered as a monophyletic lineage in the maximum likelihood phylogeny of Soghigian et al. (2017) based on seven molecular markers because the clade with nine species of Neomelaniconion included a branch with Aedes (Aedimorphus) dentatus. It seems likely, however, that the specimen of Ae. dentatus was a misidentified specimen of a species of subgenus Neomelaniconion; thus, the subgenus comprises a monophyletic group. Kengne et al. (2009) investigated the relationships of members of the Circumluteolus and Sylvaticum Groups in Madagascar based on ITS2 rDNA sequence.
The immature stages of Neomelaniconion species are found in various ground-water habitats, such as stream pools, ground pools, flood pools, marshy ground and ponds. Adult females of several species are avid blood-suckers and readily attack humans. In general, very little is known about the bionomics of species of the subgenus.
Subgenus Neomelaniconion includes a number of species that have been implicated in the transmission of numerous arboviruses, including viruses of the families Flaviviridae, Togaviridae and Bunyaviridae. Specific isolations have been documented from Ae. mcintoshi, Ae. circumluteolus, Ae. luridus and other species (see e.g. Worth et al., 1961; McIntosh, 1971; McIntosh et al., 1972).
Species of subgenus Neomelaniconion predominantly occur in the Afrotropical Region. One species, Ae. lineatopennis, extends through the Oriental Region into the Australasian Region. In the Australasian Region it is known from Timor, Amboina and northern Australia.
Edwards, 1941 (taxonomy, keys); Mattingly, 1961 (taxonomy, bionomics, keys); Lee et al., 1984 (taxonomy); Jupp, 1996 (South Africa, taxonomy, keys); Reinert et al., 2004, 2009 (as genus, morphology, phylogeny); Rattanarithikul et al., 2010 (as genus, Thailand, keys, bionomics); Wilkerson et al., 2015 (phylogeny, classification); Soghigian et al., 2017 (phylogenetic relationships).