Scutellaris Group

Type species: 

Aedes scutellaris (Walker, 1859), original combination: Culex scutellaris.

Classification: 

Subfamily Culicinae, genus Aedes, subgenus Stegomyia. The Scutellaris Group includes two subgroups, the Albopictus and Scutellaris Subgroups.

Characteristics: 

Species of the Scutellaris Group are distinguished from other species and groups of subgenus Stegomyia by the following combinations of characters. ADULTS ‒ Vertex of head with median stripe of broad pale scales; maxillary palpus with pale scaling; scutum with long median longitudinal pale stripe extending from anterior promontory to near level of wing attachment, scutal fossa without patch of pale scales, acrostichal setae absent, dorsocentral setae present; scutellum with broad pale scales on all lobes; paratergite with broad pale scales; subspiracular area and postspiracular area with or without scales; wing dark-scaled, base of costs with or without small pale spot; all femora with pale knee spot, anterior surface of midfemur usually entirely dark-scaled, without median pale spot but sometimes with median pale stripe; all tibia with anterior surface entirely dark-scaled, without line of pale scales; fore- and midtarsomeres 1‒3 and hindtarsomeres 1‒4 with basal pale bands, hindtarsomere 5 entirely pale-scaled; fore- and midungues of females equal, without tooth, unequal in males, large unguis toothed, smaller one without tooth. FEMALE GENITALIA ‒ Posterior margin of sternum VIII with a deep median U-shaped notch. MALE GENITALIA ‒ Posterior margin of tergum IX rounded, straight or produced into large lobe or median projection; gonostylus simple, elongate, with apical or subapical spiniform gonostylar claw; aedeagus comprised of distinct lateral plates, each with numerous teeth; paraproct without both sternal arm and apical lobed process, cercal setae absent. LARVAE ‒ Comb plate absent, comb scales in a single row; posterior margin of saddle of segment X with small, inconspicuous spicules; ventral brush (seta 4-X) with 4 pairs of setae. PUPAE ‒ Paddle margins with fringe of long hair-like spicules, apex rounded or produced; seta 1-Pa single. See subgenus Stegomyia.

Phylogenetic relationships: 

Knowledge of the Scutellaris Group is too incomplete to fully assess its phylogenetic relationships. Belkin (1962), however, observed that species on eastern islands in the South Pacific appear to be most primitive and hypothesised that species on the larger land masses in western areas of the region evolved more recently. Sota & Mogi (2006) gleaned some insight into evolutionary relationships from analyses of COI mtDNA and 16S and 28S rRNA sequences obtained from 11 species of Stegomyia: one species of the Aegypti Group (Ae. aegypti), one from the Maehleri Group (Ae. maehleri), one of the Pseudonigeria Group (Ae. wadai) and nine of the Scutellaris Group, including three from the Albopictus Subgroup (Ae. albopictus, Ae. flavopictus, Ae. galloisi) and five from the Scutellaris Subgroup (Ae. dybasi, Ae. hensilli, Ae. palauensis, Ae. riversi, Ae. scutellaris). Their interesting results revealed that Ae. maehleri is a distinct lineage within the Scutellaris Group, with closer association with species of the Albopictus and Scutellaris Subgroups than to other species of the subgenus included in the analyses. Two pitcher plant inhabitants of the Scutellaris Subgroup, Ae. dybasi and Ae. palauensis, were recovered as sister species in trees derived from COI mtDNA and 16S rRNA sequences and the combined data set that included 28S rRNA sequences.

Bionomics and disease relations: 

The immature stages of species of the Scutellaris Group are mainly found in tree holes, but larvae are also found in log holes, tree and bamboo stumps, bamboo cups, coconut shells, coconut husks, pitcher plans, crab holes, coral holes, rock holes, rock pools, artificial containers and leaf axils, usually Pandanus but also Allocasia, banana, Colocasia, Nipa and pineapple axils. Females of many species readily bite humans, notably Ae. albopictus, Ae. cooki, Ae. downsi, Ae. malayensis, Ae. polynesiensis, Ae. riversi, Ae. scutellaris and Ae. seatoi. Some species of the group are vectors of microfilariae and dengue viruses (see the Albopictus and Scutellaris Subgroups).

Distribution: 

The Scutellaris Group spans an extensive area from India and Sri Lanka eastward to the Marquesas Islands and the Tuamoto Archipelago in the Pacific and from Russia, China, Korea and Japan southward into northern Australia. The majority of species are recorded from the South Pacific, but are absent from New Caledonia, the Loyalty Islands and New Zealand.

Principal references: 

Belkin, 1962 (South Pacific, description, distribution, bionomics, species treatments); Huang, 1972 (Southeast Asia, taxonomy, description, distribution, bionomic, identification keys, species treatments); Huang, 1979 (Oriental Region, diagnosis, identification keys); Huang & Hitchcock, 1980 (Fiji Islands, Samoan Islands, Tonga Islands and Niue Island, identification keys, descriptions, distributions, bionomics and medical importance); Lee et al., 1987 (Australasian Region, distribution, taxonomy, literature); Huang, 2004 (diagnosis).

Species groups: 

Albopictus Subgroup (see).
Scutellaris Subgroup (see).

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith