Downsiomyia Vargas, 1950

Reinert, John F. & Harbach, Ralph E., 2006, Descriptions of genus Downsiomyia Vargas (Diptera: Culicidae: Aedini) and its type species Do. nivea (Ludlow), Zootaxa 1196 (1196), pp. 33-61 : 34-41

Genus Downsiomyia Vargas, 1950

Type species: Stegomyia nivea Ludlow, 1903

Previous usage

Stegomyia Theobald , of Ludlow (1903), in part of Theobald (1903, 1905a, 1907, 1908, 1910), Blanchard (1905), Ludlow (1905), Leicester (1908), Stone (1957b).

Scutomyia Theobald of Ludlow (1911), in part of Theobald (1905b, 1907, 1910), Banks (1906), Brunetti (1907, 1912).

Ochlerotatus Lynch Arribalzaga , of Shriram et al. (2005), in part of Edwards (1913), Moulton (1914), Brunetti (1920), Senior­White (1923).

Aedes (Ochlerotatus) Group Finlaya , in part of Edwards (1917).

Finlaya Theobald , in part of Barraud (1923, 1924), Senior­White (1927).

Armigeres of Edwards (1926).

Aedes (Finlaya) of Knight & Chamberlain (1948), Peters & Dewar (1956), Stone (1957a), Knight (1978a), Luh & Li (1980), Huang & Rueda (1998), in part of Dyar (1920), Edwards (1921, 1922a, 1922b, 1928, 1929), Brug & Haga (1923), Haga (1924), Dyar & Shannon (1925), Brug (1926, 1931, 1934, 1939), Borel (1930), Brug & Edwards (1931), Barraud (1934), Li & Wu (1935), Bonne­Wepster & Brug (1937, 1939), Causey (1937), Hu (1937), Feng (1938a, 1938 b, 1958), Wu (1940), Bohart (1945, 1946), Hsiao (1945), Bohart & Ingram (1946), Brug & Bonne­Wepster (1947), LaCasse (1948), LaCasse & Yamaguti (1948, 1950), Sasa (1948), Chow (1949a, 1949b, 1950), Carter (1950), Knight & Hull (1951), Monchadskii (1951), Bonne­Wepster (1954a, b), Chow et al. (1954), Horsfall (1955), Stone & Knight (1956), Hsieh & Liao (1956), Hara (1957), Macdonald (1957), Chu (1957), Wattal et al. (1958), Thurman (1959, 1963), Stone et al. (1959), Stone (1961, 1963, 1967, 1970), Omori (1962), Lien (1962, 1968), Kurihara (1963, 1978, 1981, 1999), Delfinado et al. (1963), Loy & Rowland (1963), Rozeboom & Cabrera (1964), Mackie (1964), Joshi et al. (1965), Macdonald et al. (1965), Army Mosquito Project (1965), Scanlon & Esah (1965), Scanlon & Peyton (1965), Stone et al. (1966), Gould et al. (1968), Ramachandran et al. (1970), Aslamkhan (1971), Tanaka (1971, 2002), Basio (1971), Grothaus et al. (1971), Qutubuddin (1972), Rahman et al. (1973), Stone & Delfinado (1973), Ramalingam & Pillai (1973), Ramalingam (1974), Matsuo et al. (1974), Gutsevich et al. (1974), Baisas (1974), Lien et al. (1975), Bhat (1975), Tanaka et al. (1975), Sasa et al. (1977), Lien et al. (1977), Knight & Stone (1977), Knight (1978b), Lee et al. (1980, 1982), Gutsevich & Dubitsky (1981), Jayasekera & Chelliah (1981), O’Connor & Sopa (1981), Ma (1982), Chau (1982), Lu & Li (1982), Gould et al. (1982), Cai (1984), Ward (1984, 1992), Miyagi et al. (1985), Tsukamoto & Horio (1985), Lee & Egan (1985), Toma & Miyagi (1986), Apiwathnasorn (1986), Rudnick et al. (1986), Malhotra et al. (1987), Nagpal & Sharma (1987), Lee (1987), Tsukamoto et al. (1987), Lee & Zorka (1987), Lu & Su (1987), Ahmed (1988), Lu et al. (1988), Debenham & Hicks (1989), Evenhuis & Gon (1989), Townsend et al. (1990), Darsie & Pradhan (1990), Harrison et al. (1991), Darsie et al. (1992, 1993), Malhotra & Mahanta (1994), Stojanovich & Scott (1995, 1996a, 1996b), Reinert (1999a), Peyton et al. (1999), Tanaka (2003), Kaur (2003), Kurihara et al. (2004), Rajavel et al. (2005b).

Aedes (Ochlerotatus) Globus Finlaya , in part of Martini (1931).

Aedes (Finlaya) Group H, in part of Edwards (1932), Bohart (1957).

Aedes Meigen , in part of Riley (1932), Yamada (1932), Hsiao & Bohart (1946), Sasa et al. (1947), Barnett & Toshioka (1951), Osima (1952), Ori & Shimogama (1953), Chu (1957), Barnett (1962), Cabrera & Rozeboom (1964), Sakakibara (1965), Stojanovich & Scott (1965, 1966), Lee & Lien (1970), Basio et al. (1973), Ree et al. (1973), Harinasuta et al. (1974), Wada et al. (1976), Pae et al. (1976), Sarkar et al. (1981), Malhotra et al. (1982), Gandahusada et al. (1984), Lee et al. (1984), Xu (1984), Khamboonruang et al. (1987), Hawley (1988), Darsie et al. (1991), Service (1993), Gerberg et al. (1994), Mogi (1996), Strickman et al. (2000), Ruang­Areerate et al. (2003).

Aedes (Finlaya) niveus complex of Traub & Macdonald (1963).

Aedes (Finlaya) Group H (Geniculatus­Group), Subgroup I, Niveus of Knight & Marks (1952), Colless (1958, 1959), Macdonald & Traub (1960).

Aedes (Finlaya) niveus group of Wharton (1962), Traub & Macdonald (1963), Rao & Rajagopalan (1957), Colless (1957), Harinasuta et al. (1970), White (1979), Lu (1981), Rajput & Singh (1987).

Aedes (Finlaya) niveus subgroup of Sasa & Kakahashi (1952), Knight (1946, 1969), Nakato & Matuo (1960), van Peenen et al. (1975), Furumizo & Rudnick (1979), Amerasinghe (1982), Knight & Harrison (1988), Kulasekera et al. (1990), Rattanarithikul & Panthusiri (1994), Tewari & Hiriyan (1995), Rueda (2004).

Aedes (Finlaya) Nipponicus group of Tanaka et al. (1979).

Aedes (Finlaya) niveus group, niveus subgroup of Lu & Ji (1997).

Ochlerotatus (Finlaya) , in part of Reinert (2000a), Zagaria & Savioli (2002), Rajavel et al. (2005a), Rattanarithikul et al. (2005).

Ochlerotatus (Finlaya) Niveus Assemblage , of Reinert (2002).

Downsiomyia Vargas , of Reinert et al. (2004).

Description

FEMALES. Head: Vertex with broad, decumbent scales; occiput with numerous erect, forked scales; ocular line narrow, with pale scales; eyes above antennal pedicels contiguous or separated by 1 eye facet or less; interocular space small, with few pale scales, normally 2 dark, interocular setae; antennal pedicel with few small scales and short, dark setae mesally; maxillary palpus and proboscis dark­scaled. Thorax: Scutum with dark integument, covered with narrow, dark scales except bare, median prescutellar space; narrow pale (normally silvery or white) scales on anterior promontory, antedorsocentral area, scutal fossa (normally entire area, rarely pale scales extending posteriorly onto antealar and anterior margin of supraalar area, e.g. Do. nipponica (LaCasse & Yamaguti)) , anterior 0.30–0.70 of acrostichal and dorsocentral areas (some species, e.g. Do. harinasutai (Knight) , Do. litorea (Colless) , Do. nipponica and Do. nivea (Ludlow)) ; prescutellar space mesal to setae rarely with pale scales (e.g. Do. mohani (Knight) , Do. nipponica , Do. saperoi (Knight) and Do. watteni (Lien)) , and normally antealar area, other areas dark­scaled; acrostichal (anterior and posterior) and dorsocentral (anterior and posterior) areas without setae; scutellum with broad scales (normally dark) and several setae on all lobes; mesopostnotum bare; paratergite wide, bare; antepronota widely separated, with broad, pale scales, several setae; postpronotum with few broad scales normally restricted to posterodorsal area, few posterior setae; prespiracular setae absent; postspiracular area without scales, with several setae; hypostigmal and subspiracular areas bare; upper proepisternum with broad scales, several setae; lower proepisternum bare; mesokatepisternum with upper and lower posterior patches of broad, pale scales, few upper and posterior setae; prealar area with patch of broad, pale scales on lower area extending dorsally onto lower part of upper area (except absent in few species, e.g. Do. ganapathi (Knight) , Do. pseudonivea (Theobald) , Do. pexa (Colless) and Do. vana (Colless)) ; mesepimeron with 1 moderately large patch on upper area and extending onto middle, several upper setae, lower setae absent; metameron bare. Wing: Entirely darkscaled; remigium with 1–3 setae distally on dorsal surface; upper calypter with several setae on margin; alula with row of narrow scales on margin; vein R 2 longer than R 2+3; anal vein terminating distal to juncture of CuA and mcu. Legs: Hindfemur dark­scaled distally, with broad, pale­scaled areas on proximal parts of anterior and posterior surfaces; tibiae and tarsi dark­scaled; fore­ and midungues each with 1 tooth, hindungues simple. Abdomen: Terga with basolateral, pale­scaled patches; segments VII and VIII laterally compressed.

Female genitalia. Tergum VIII: Proximal 0.20–0.40 retracted into segment VII; moderately to heavily pigmented, base broad and moderately concave; apex broadly rounded; numerous broad scales covering distal 0.70–0.85; apical margin with number of long, stout setae; several short setae on distal 0.35–0.69; VIII­Te index 0.50–0.76 (0.84 in Do. nipponica ); length 0.26–0.36 mm; width 0.38–0.56 mm. Sternum VIII: Moderately to heavily pigmented; base straight; apex with minute (0.01–0.06 of VIII­S length), median emargination separating pair of broad, flattened lobes or with pair of broad, flattened lobes with apicolateral areas angled posterolaterally; broad scales forming moderately large patches on median, lateral areas on distal 0.76–0.92; numerous short setae on distal 0.84–0.97; apical margin with numerous short, lanceolate setae with apices curved; seta 2–S inserted posterior to 1­S; intersegmental membrane between segments VII and VIII short; VIII­S index 0.81–0.93 (0.74 in Do. inermis (Colless)) ; length 0.32–0.46 mm; width 0.38–0.50 mm. Tergum IX: Heavily pigmented; comprised of 2 narrow, finger­like, lateral lobes connected by very narrow, basal strip; 1–5 (usually 2–4) moderately long, stout setae apically on each lobe; IX­Te index 0.60–1.07; length 0.09–0.14 mm; width 0.10–0.16 mm. Insula: Covered with short spicules; lightly to moderately pigmented; short; wide; liplike; with 3–8 moderately long setae. Lower vaginal lip: Moderately pigmented; narrow, lower vaginal sclerite absent. Upper vaginal lip: Heavily pigmented; narrow; median caudal area flattened; upper vaginal sclerite very small, comprised of narrow, heavily pigmented strip along basolateral area of lip. Spermathecal eminence: Membranous; comprised of few wrinkled, circular folds. Postgenital lobe: Spicules along lateral margins longer, stout and many with basal denticles; short; moderately broad; apex flattened or broadly rounded but usually with minute (0.02–0.08 of dorsal length), median emargination; 12–39 total setae; ventral PGL index 1.42–2.00; ventral length 0.11–0.15 mm (0.17 mm in Do. pexa ). Cercus: Short; broad; apical margin broad and oblique with 5–7 (usually 6) stout setae, setae long on mesal area and tapering in length to moderately long on lateral area, several short, lanceolate setae with apices curved; dorsal surface with scales absent, 2,3 long and few short setae on distal 0.37–0.65; cercus index 1.45–1.89; length 0.14–0.18 mm; width 0.08–0.11 mm. Spermathecal capsules: Nivea Group with one large capsule, Albonivea Group with one large and 2 medium capsules; numerous small spermathecal capsule pores near orifice.

MALES. Head: Antenna about 0.75 length of proboscis, flagellar whorls with numerous long setae directed dorsally and ventrally, distal 2 flagellomeres elongate; maxillary palpus dark­scaled, slightly shorter to approximately equal to proboscis length, palpomere 1 small, palpomere 2 long, narrow, palpomere 3 long, narrow, slightly upturned, with few to several long setae apically on ventral surface, palpomere 4 short, thin, with several to numerous moderately long setae on ventrolateral margins, setae projecting anteroventrally, few moderately long setae dorsoapically, palpomere 5 short, with several short to moderately long setae mainly on ventral and apical areas, palpomeres 4,5 normally slightly down­turned; proboscis longer than forefemur. Thorax: Anterior area of scutum with silvery scales more extensive than in female. Legs: Fore­ and midtarsi with ungues unequal, each with 1 tooth, hindtarsus with ungues equal, both simple.

Male genitalia. Tergum IX: Relatively short, bearing 2 small lobes caudally, each with few to several stout setae. Gonocoxite: Somewhat triangular in outline, proximal part relatively broad, distal part narrow, ventral surface with several to numerous long, broad, fusiform scales on mesal area (except Do. mikrokopion (Knight & Harrison)) ; dorsal surface with numerous short, slender setae on mesal area, and with narrow, thumblike lobe on basomesal area projecting caudoventrally and bearing few to several short setae; dorsal and lateral surfaces with numerous relatively long, dark, broad, spatulate scales. Gonostylus: Narrow, relatively short, with long, narrow gonostylar claw attached apically. Proctiger: Paraproct heavily pigmented and terminating in short, curved, beaklike point; few short, cercal setae. Phallosome: Aedeagus simple, scooplike, apex concave (except Do. axitiosa (Kulasekera, Knight & Harbach) , see Kulasekera et al. 1990) with one or usually 2 or more small teeth on each side laterally; paramere narrow, shorter than aedeagus; basal piece short and broad. Claspette: With moderately long columnar stem bearing 1–3 short, thin setae, with narrow, basolateral extension connected to ventral area of basomesal, thumblike lobe of gonocoxite; claspette filament long, somewhat leaflike, longitudinally striated, expanded on middle part and narrow distally. Sternum IX: With few, normally moderately long setae caudomesally.

PUPAE. Cephalothorax: Seta 1­CT long, moderately stout to stout, normally single (occasionally 2­branched); 2,3­CT short, slender; 5­CT longer than 4­CT, 5­CT often long, moderately stout to stout, single; 11­CT stout, single (distal part rarely forked). Trumpet: With basal tracheoid area weakly developed. Abdomen: Seta 3­I long, single, longer than 6,7­I; 6­I single (rarely 2­branched), longer than 7­I; 7­I normally 2­4 branched (rarely single); 9­III­VI short; 6­VII short, slender, with 2–7 branches, inserted posterior and slightly mesal to 9­VII; 9­VII moderately long, stout, aciculate, normally with 2,3 branches (rarely single on 1 side); 9­VIII long, stout, multiple­branched, aciculate, inserted on posterolateral corner of segment. Paddle: Without fringe of long spicules; midrib well developed, reaching or nearly reaching apex; seta 1­Pa often single (with 2,3 branches in some species, e.g. Do. novonivea ).

FOURTH­INSTAR LARVAE. Head: Seta 1­C single, distal part attenuate ( Do. axitiosa split distally, see Kulasekera et al. 1990); 4­7­C well developed, multiplebranched, aciculate; 4­C slightly shorter than 5­7­C, inserted mesal to 6­C; 5­7­C approximately equal in length; 5­C inserted posterior to 4,6,7­C; 13­C single (single or 2­ branched in Do. mikrokopion , see Knight & Harrison 1987), long, inserted lateral to 12­C; 18­C present; 19­C absent; antenna with spicules, 1­A multiple­branched, aciculate; 6­Mx branched; labiogula width greater than length; ventromedian cervical sclerite present. Thorax: Setae 1­3­P normally inserted on common setal support plate; 8­P branched, shorter than 4­P; 5­M longer than 7­M; 6­T single. Abdomen: Seta 12­I present; 6­I­VI long, 6­II,III branched, 6­II shorter than 6­III; 7­I long, stout, single or 2­branched; 7­II short, multiple­branched; 8­II branched; 2­VI at same level or mesal to 1­VI (2­VI slightly lateral to 1­VI in Do. litorea ); 1­VII long; 2­VII inserted near 1­VII; 3­VII branched; 4,10,12­VII, 2,4­VIII single; comb scales in single row (except small patch in Do. axitiosa ); segment X with saddle incomplete ventrally, normally with several moderately long to long, stout spicules on posterior margin dorsal to insertion of 1­X, acus absent, 1­X inserted on saddle, 2­X normally with few branches, much shorter than 3­X, 3­X long, single, ventral brush with several setae, posterior setae normally with several long branches arising from short stem, inserted on grid normally with transverse and lateral bars (lateral bar weekly developed or absent in some species, e.g. Do. harinasutai and Do. mohani ), 2,3 shorter precratal setae. Siphon: Pecten comprised of numerous, evenly spaced spines, inserted on approximately proximal 0.50 of siphon, acus present, seta 1­S branched, aciculate, inserted distal to pecten, 6,8­S short, 9­S short, slightly curved.

EGGS. Matsuo et al. (1974) provided photographs and the following description of the egg of Do. albolateralis (Theobald) . Size: Length 470–510 (495 ± 2); width 120–170 (151 ± 3). Outer chorion: Reticulation composed of pattern of quadrilateral, pentagonal, or sometimes hexagonal cells (at 200x magnification), ridge of reticulation high, hence cells appearing concave, many small papillae in each cell, irregular in shape, occasionally confluent with each other and ridge (at 1,000x magnification).

Species included in Downsiomyia

Specimens examined in parenthesis, F = female, Fg = female genitalia, M = male, Mg = male genitalia, P = pupa, and L = fourth­instar larva. Nivea Group: Do. albolateralis (F, Fg, M, Mg, P, L), Do. axitiosa , Do. dorseyi (Knight) (F, Fg, M, Mg, L), Do. ganapathi (F, Fg, M, Mg, P, L), Do. harinasuti (F, Fg, M, Mg, P, L), Do. idjenensis (Brug) , Do. inermis (F, Fg, M, Mg, P, L), Do. lactea (Knight) (F, L), Do. laoagensis (Knight) (F, Fg, M, P, L), Do. leonis (Colless) (F, Fg, M, Mg, P, L), Do. litorea (F, Fg, M, Mg, P, L), Do. mikrokopion (F, Fg, M), Do. mjoebergi (Edwards) (F, Fg), Do. mohani (F, Fg, M, P, L), Do. nipponica (F, Fg, M, Mg, P, L), Do. nippononivea (Sasa & Nakahashi) (F, M), Do. nishikawai (Tanaka, Mizusawa & Saugstad) (F, M, P, L), Do. niveoides (Barraud) (F, Fg, M, Mg, P, L), Do. nivea (F, Fg, M, Mg, P, L), Do. novonivea (Barraud) (F, Fg, M, Mg, P, L), Do. omorii (Lien) (F, M, Mg, P, L), Do. pexa (F, Fg, M, Mg, P, L), Do. pseudonivea (F, Fg, M, Mg, P, L), Do. shehzadae (Qutubuddin) , Do. sinensis (Chow) (M, Mg), Do. subnivea (Edwards) (F, Fg, M, Mg, P, L), Do. vana (F, Fg, M, Mg, P, L), Do. watteni (F, M, Mg, P, L), and Albonivea Group: Do. albonivea (Barraud) (F, Fg, M, Mg) and Do. saperoi (F, Fg, M, Mg, P, L).

Bionomics

Immatures of Downsiomyia species normally inhabit water in treeholes but have been collected occasionally from bamboo stumps, fallen bamboo and bamboo internodes ( Mcdonald & Traub 1960). Macdonald (1957) reported Fl. albolateralis biting humans in the forest canopy (75 feet high) and less commonly at ground level in Malaysia. Finlaya niveoides and Fl. vana were collected biting humans in a swamp­forest in Malaysia ( Wharton 1962) and Macdonald et al. (1965) reported small numbers of Fl. nivea ­ subgroup species biting humans by day and early evening in Malaysia. Shriram et al. (2005) found 96 of 3,625 Fl. nivea (identification?, see discussion below under Fl. nivea ) naturally infected with Wuchereria bancrofti filarial parasites in the Andaman and Nicobar Islands of India.

Distribution

Species of the genus occur in the Oriental Region and adjoining areas of the Australasian and Palaearctic Regions.

Discussion

Downsiomyia is diagnosed and distinguished from other generic­level taxa of Aedini by the following combinations of characters: females by (1) vertex with only broad, decumbent scales whereas erect, forked scales restricted to occiput, (2) antennal pedicel with few small scales and short setae mesally, (3) eyes contiguous or separated by one eye facet or less, (4) maxillary palpus and proboscis dark­scaled, (5) acrostichal and dorsocentral areas without setae, (6) scutal fossa entirely covered (or rarely nearly covered) with narrow, curved, pale scales, (7) supraalar area dark­scaled (rarely pale scales extending to anterior margin of supraalar area, e.g. Do. nipponica ), (8) scutellum with broad scales on all lobes, (9) paratergite, postspiracular area, subspiracular area and metameron without scales, (10) wing entirely dark­scaled, and (11) hindtibia, hindtarsus and distal part of hindfemur dark­scaled; female genitalia by (1) both tergum VIII and sternum VIII with numerous broad scales, (2) tergum IX comprised of two narrow, lateral lobes connected by narrow, basal strip and each lobe with 1–5 setae apically, (3) insula liplike with few long setae in lateral patches, (4) upper vaginal sclerite small, (5) cercus short, broad, with lateral part of distal margin oblique and bearing 5–7 stout setae that decrease in length laterally, and (6) only single large spermathecal capsule (Nivea Group) or one large and two smaller spermathecal capsules (Albonivea Group); males by (1) flagellar whorls of antenna with numerous long setae directed dorsally and ventrally and distal two flagellomeres elongate, (2) maxillary palpus slender, dark­scaled and slightly shorter to approximately equal to length of proboscis, (3) fore­ and midtarsi with unequal ungues, each with one tooth, whereas hind ungues are equal, simple; male genitalia by (1) gonocoxite somewhat triangular in outline, proximal part relatively broad, distal part narrow and bearing several to numerous long, broad, fusiform scales (except Do. mikrokopion ) on mesal area of ventral surface, and basomesal area of dorsal surface with narrow, thumblike lobe bearing several short setae, (2) gonostylus relatively narrow, short and with long, narrow gonostylar claw apically, (3) aedeagus simple, scooplike and with one or usually two or more small teeth apically on each side, and (4) claspette developed as moderately long column bearing one long, somewhat leaf­like, longitudinally striated, claspette filament apically; pupae by (1) seta 1­CT long, moderately stout to stout and normally single whereas setae 2,3­CT are short and slender, (2) seta 5­CT noticeably longer than seta 4­CT and often long and single, (3) seta 11­CT long, stout and single, (4) seta 3­I long and stout, longer than seta 6­I, (5) seta 6­VII short, with few slender branches, inserted posterior to seta 9­VII which is moderately long, stout and normally with 2 or 3 aciculate branches, (6) seta 9­VIII long, stout, multiple­branched, aciculate and inserted on posterior lateral corner of segment, and (7) paddle without hairlike spicules on margin and midrib well developed; and fourth­instar larvae by (1) seta 1­C single with distal part attenuate, (2) setae 4­7­C well developed, multiple­branched and aciculate, (3) antenna with spicules and seta 1­A with multiple aciculate branches, (4) seta 12­I present, (5) seta 7­I long, stout, single or 2­branched whereas seta 7­II is short and multiplebranched, (6) seta 6­II shorter than seta 6­III, (7) setae 2­VIII and 4­VIII both single, (8) segment X with saddle incomplete ventrally and seta 1­X attached, and (9) pecten on siphon with numerous, evenly spaced spines and seta 1­S branched, aciculate and inserted distal to pecten.

Illustrations and descriptions of Downsiomyia species are found in articles listed above in the “previous usage” section.

Downsiomyia females have large, pale­scaled patches covering the scutal fossae, which also occur in females of the Gubernatoris Group of “ Ochlerotatus ” (“ Finlaya ”). However, the latter group is easily distinguished by the presence of an elongate, transverse patch of pale scales anterior to the wing base that extends mesally. In contrast, the supraalar area is dark­scaled in Downsiomyia . The pale­scaled scutal fossa of Downsiomyia is also superficially similar to some Stegomyia , as evidenced by the type species, Do. nivea , which was originally assigned to that genus. Stegomyia are readily distinguished by possessing white­scaled areas on the supraalar area of the scutum, apex of the maxillary palpus and the hindtarsomeres, as well as numerous differences in the other life stages. The simple aedeagus bearing small teeth apically in Downsiomyia males is somewhat similar to some species of Ochlerotatus Lynch Arribalzaga , e.g. Oc. cantans (Meigen) and Oc. excrucians (Walker) , but these species differ in numerous other characters.

We conducted an extensive search of the literature on Culicidae , but were unable to find the formal synonymy of Downsiomyia with Finlaya . This synonymy was listed, without explanation in A Synoptic Catalog of the Mosquitoes of the World by Stone et al. (1959), and again in Knight & Stone (1977). Downsiomyia , as the Niveus Subgroup, was last reviewed by Colless (1958, 1959), who treated 19 species. Knight (1946) previously reviewed nine species, including Do. nivea . Reinert (2002) indicated that the female genitalia could be easily separated into two assemblages of species that are similar but distinguished as follows: “Niveus Assemblage” with a single, large, spermathecal capsule, and tergum IX usually with three or four setae on each lateral lobe apically (at least on one lateral lobe); and the “Alboniveus Assemblage” with one large and two medium­sized spermathecal capsules, and tergum IX with only one or two setae apically on each lateral lobe. These two “Assemblages” of species are treated herein as Species Groups. Reinert (2002) separated species treated here from other groups of Finlaya based on features of the female genitalia. Reinert (1981, 2000c) noted that groups of species in Paraedes Edwards also possess different numbers of spermathecal capsules.

Rozeboom & Cabrera (1964) incriminated Do. nivea as a vector of nocturnally periodic Wuchereria bancrofti (Cobbold) in the Philippine Islands and Gould et al. (1982) indicated that Do. harinasutai was the primary vector of subperiodic Wuchereria bancrofti in Thailand. Zagaria & Savioli (2002) also list these two species as vectors of filariasis. Rudnick et al. (1986) reported that species of Downsiomyia (as “Niveus Subgroup”) were canopy vectors of dengue virus in Malaysia.