Aedes kochi (Dönitz, 1901), original combination: Culex kochi.
Subfamily Culicinae, tribe Aedini, genus Aedes. Subgenus Finlaya includes 36 species. Subgenus abbreviation – Fin.
ADULTS ‒ The following characteristics easily distinguish the adults of subgenus Finlaya from other aedine taxa. Maxillary palpus and proboscis with pale-scaled areas; maxillary palpus of males long with distal part of palpomere 3 slightly swollen, upturned and bearing several long setae on ventrolateral area, palpomeres 4 and 5 short and downturned; few setae on upper proepisternum; postpronotum with a large patch of broad scales; postspiracular area with a few setae and normally no scales; veins of wing covered with broad scales arranged in pale and dark areas (spots), costa with 3 or more pale areas, wing fringe with pale areas at ends of veins; fore-, mid- and hindfemora and -tibiae with pale bands and/or spots [pale bands or spots, or both bands and spots, also occur on the femora and tibiae of some species of subgenera Diceromyia and Mucidus]; fore-, mid- and hindtarsi with extensive pale areas, hindtarsomere 1 with basal, median and apical pale bands (median band rarely reduced to a pale spot), hindtarsomeres 2 and 3 with apical pale bands (nearly completely pale in some species), hindtarsomere 5 always white-scaled; larger fore- and midunguis of males with 2 teeth, smaller fore- and midunguis with 1 tooth; abdominal terga with white-scaled areas. FEMALE GENITALIA ‒ Distinctive; tergum VIII and sternum VIII with large patches of broad scales; tergum IX composed of 2 long, narrow lateral sclerites connected basally by a lightly pigmented strip, bearing 1–5 short setae apically (absent in Ae. knighti); upper vaginal sclerite well developed and heavily pigmented; cercus short with a broadly rounded or flattened apex bearing a few moderately long and long, stout setae, several short, lanceolate setae and a number of broad scales on dorsal surface. MALE GENITALIA ‒ Distinctive; aedeagus scoop-shaped with distal third expanded; dorsal surface of gonocoxite with large patch of numerous tightly packed setae on basomesal area, ventral surface with patch of long to very long fusiform scales on dorsomesal margin [males of subgenus Downsiomyia, genus Haemagogus and Ae. (Och.) albotaeniatus also have long fusiform scales on the ventral surface but they extend more distad in Downsiomyia and Haemagogus]; claspette with columnar stem usually bearing a single short seta on both proximal and distal third, claspette filament long, foliform and normally annulated transversely [an annulated claspette filament is also found in some species of the Gubernatoris and Papuensis Groups of subgenus Ochlerotatus]; tergum IX consists of broad lateral plates, each with a very small subapical lobe on posterior margin bearing 1‒3 moderately long setae, lateral plates connected mesally by a narrow membranous strip. LARVAE ‒ Fourth-instar larvae of subgenus Finlaya display a number of unusual features, including seta 1-C stout proximally and branched distally [branched seta 1-C also occurs in Ae. (Dow.) axitiosus, Ae. (How.) walkeri and Ae. (Stg.) pandani]; seta 3C absent; development and positions of setae 4‒7-C distinctive; seta 13-C inserted mesad of seta 12-C; seta 14-C displaced caudally, longer than and posterior or lateral to seta 15-C; seta 2-A noticeably longer than setae 3‒6-A; seta 0-P displaced laterally; seta 2-P very long and single; setae 1,3-P short, stellate and multiple branched; setae 5,10,12-M and 10-T very long; seta 5-T inserted mesad and slightly caudad of seta 6-T; seta 8-T displaced anteriorly; seta 11-M,T relatively moderately long and usually with 5 or more branches; seta 5-I‒VI large, stellate and inserted noticeably anterior to seta 6-I‒VI; seta 5-III‒VI inserted anterior to seta 8-III‒VI; seta 9-II‒VI long, displaced anteriorly and multiple branched; setae 6,8-S very long, single; spiracular apodeme of siphon with distinctive shape; ventral brush (seta 4-X) comprised of long pectinate setae borne on a boss; comb scales and pecten spines distinctively developed [larvae of Ae. (Cts.) meronephada have setae 14,15-C, 5-I‒VI and 9-II‒IV similarly developed to larvae of Finlaya, and larvae of subgenus Lorrainea have seta 5-I‒VI slightly anterior to seta 6-I‒VI but they are small and simple]. PUPAE ‒ Cephalothorax and/or abdomen with clear unpigmented spots (present also in Ae. (Ala.) brevitibia and Ae. (Blk.) aurotaeniatus but otherwise unique within tribe Aedini); other unusual or unique features of Finlaya pupae include seta 2-II inserted anterior and usually slightly mesad of seta 1-II, seta 5-II inserted mesad of seta 4II, presence of seta 8-II, seta 9-VI inserted anterior to seta 8-VI and setae 8,9-VI inserted dorsal and far anterior on tergum. See Aedes.
Subgenus Finlaya appears to be most closely related to subgenera Danielsia and Downsiomyia, which comprise species previously included in the traditional polyphyletic concept of Aedes (Finlaya), as well as the Neotropical genus Haemagogus, based on the cladistic analysis of extensive morphological data by Reinert et al. (2009) that generated relationships of these genera expressed parenthetically as (Finlaya + Danielsia) + (Downsiomyia + Haemagogus). Finlaya was also recovered as the sister of Danielsia in the study of Wilkerson et al. (2015). Pao & Knight (1970) recognised the Marshallii Group of Aedes (Aedimorphus) to include Ae. (Elp.) apicoannulatus, Ae. (Elp.) simulans, Ae. (Adm.) grjebinei and eight species of Finlaya, but there is no evidence of a close phylogenetic relationship between the first three species and Finlaya. The internal relationships of genus Finlaya and its genealogical association with other aedine genera require further study.
Larvae are found almost exclusively insmall collections of water in leaf axils of plants, especially species of Pandanaceae and Araceae. Belkin (1962) noted that at least four species on Guadalcanal may be found in a single host plant [Pandanus] at the same time but each species occurred predominantly in certain leaf axils and generally at a specific level of the plant. He also noted that the immature stages are sometimes found in extremely shallow water, and the larvae can crawl out of the water and move into a more suitable niche. Females of Ae. fijiensis, Ae. kochi, Ae. oceanicus and Ae. samoanus are known to bite humans. They appear to be predominantly nocturnal feeders but there are some records of diurnal attacks (Belkin, 1962).
Species of subgenus Finlaya do not appear to be of medical or economic importance to humans.
Southern areas of the Oriental Region and northern and eastern areas of the Australasian Region.