Subgenus Geoskusea Edwards, 1929
Aedes fimbripes Edwards, 1924.
Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Geoskusea includes 10 species. Subgenus abbreviation – Geo.
The presence of fine setae on the metameron of Geoskusea adults is a particularly distinctive feature of this subgenus of aedine mosquitoes. Characters that diagnose Geoskusea (as genus) in the phylogenetic analyses of Reinert et al. (2009) are indicated by an asterisk (*).
ADULTS – Vertex with broad decumbent scales; erect scales numerous, scattered over vertex in females, usually concentrated on occiput in males; eyes contiguous above antennal pedicels; antenna of females about as long as proboscis; antenna of males distinctly shorter than proboscis, flagellomeres 12 and 13 together about as long as rest of flagellum; proboscis dark-scaled, about 1.3 length of forefemur; maxillary palpus of females about 0.15 length of proboscis, palpomere 5 minute; maxillary palpus of males 0.2–0.7 length of proboscis; scutum with narrow scales; acrostichal setae and dorsocentral setae strongly developed; scutellum with narrow or broad scales or both; paratergite bare; antepronotum usually without scales; postpronotum with broad or narrow scales; pleural scaling restricted to upper mesokatepisternal and upper mesepimeral patches, latter may extend posteriorly onto lower half of sclerite; lower mesepimeral setae absent but numerous *fine setae borne posteriorly near middle of sclerite; *metameron with fine setae (distinctive feature); wing dark-scaled, alula with fringe of hair-like or moderately broad scales; tarsi dark-scaled, ungues of females simple, fore- and midungues of males toothed, *midungues both toothed, larger one with 1 tooth; tergum I dark-scaled, *laterotergite without scales, other terga entirely dark-scaled, with basolateral pale spots or basal pale bands; lateral abdominal setae of males sparse, short. FEMALE GENITALIA – Segment VIII largely retracted, without scales, *tergum with long setae on lateral margins of proximal 0.40; cercus long, without scales; insula with 2 setae on either side of midline; 1 large and 2 smaller spermathecal capsules. MALE GENITALIA – Segment VIII reduced, tergum with long median sclerotised lobe extending into caudal membrane; tergum IX poorly sclerotised, *some or all setae stout, with *pair of close-set posterior lobes; gonocoxite *without dorsomesal basal lobe, without distinct mesal membrane; *claspette developed as single basal setose plaque, columnar lobe absent; aedeagus small, simple, poorly sclerotised; proctiger small, paraproct with simple short apical spine; cercal setae usually in 2 or 3 pairs. LARVAE – Antenna long, spiculate; seta 1-A branched; palatal brushes filamentous; dorsomentum with numerous narrow denticles; seta 4-C very small, inserted cephalad of seta 6-C; setae 5,6-C very long, single to triple; setae 4–7-C inserted caudad of antennal base; *seta 7-C 0.21–0.38 length of dorsal apotome; seta 8-C long, single; setae 12,13-C widely separated; *seta 19-C present; seta 13-P absent; *seta 7-M as long or longer than seta 5-M; seta 12-I present; comb comprised of small fringed scales in large patch; siphon short, acus present; pecten long, spines evenly spaced; *seta 1-S short, length ≤ 0.40 diameter of siphon, inserted beyond pecten; saddle small, incomplete; seta 1-X not inserted on saddle; seta 2-X multi-branched; ventral brush (seta 4-X) with 6 pairs of setae, all on grid. PUPAE – Seta 8-CT inserted at level of trumpet bases, with numerous delicate terminal branches; setae 2,3-I approximated; seta 9-VI small, similar to seta 9-II–V; seta 5-V very long, single; seta 6-VII very small, single, inserted posterior to seta 7; genital lobe of males very long; paddle short, broadly ovate; seta 1-Pa very long, single. See Aedes.
Belkin (1962) noted that adults of subgenus Geoskusea share a number of characters with the adults of subgenera Levua and Rhinoskusea, and the pupae are very similar to those of Levua. Based on the cladistic analysis of extensive morphological data by Reinert et al. (2009), Geoskusea appears to be related to three other subgenera of Aedes – the four subgenera comprised a clade expressed parenthetically as Sallumia + (Geoskusea + (Levua + Rhinoskusea)). In the phylogeny of Wilkerson et al. (2015), Geoskusea formed a polytomy along with subgenera Levua, Rhinoskusea and Sallumia, and this group was sister to subgenus Cancraedes. A single species of Geoskusea (Ae. baisasi) was recovered in a sister relationship with a single species of Kenknightia (Ae. dissimilis) in the maximum likelihood phylogeny of Soghigian et al. (2017) based on a single molecular marker.
The immature stages of all species of subgenus Geoskusea appear to be associated with crab holes, where resting adults can also be found. Larvae and pupae may be found in ground pools in the immediate vicinity of crab holes. Females of some species attack humans readily, mainly at night.
Species of subgenus Geoskusea are not known to be of medical importance.
Species of subgenus Geoskusea are recorded from Indonesia (Kabaena, Timor and Saparoea), Philippines Islands, New Guinea and the Bismarck Islands, Solomon Islands and New Hebrides in the South Pacific.
Mattingly, 1959 (taxonomy, bionomics); Belkin, 1962 (taxonomy, bionomics); Lee et al., 1984 (taxonomy, bionomic); Reinert, 2002 (female genitalia); Reinert et al., 2004, 2006, 2008, 2009 (as genus, morphology, phylogeny); Wilkerson et al., 2015 (phylogeny, classification); Soghigian et al., 2017 (phylogenetic relationships).
baisasi Knight & Hull, 1951
becki Belkin, 1962
daggyi Stone & Bohart, 1944
fimbripes Edwards, 1924
kabaenensis Brug, 1939
longiforceps Edwards, 1929 (in Paine & Edwards, 1929)
lunulatus King & Hoogstraal, 1946
perryi Belkin, 1962
timorensis (Miyagi, Toma & Lien, 2004)
tonsus Edwards, 1924