Culex
Creators: name: Azari-Hamidian, Shahyad
name: Harbach, Ralf E.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Culicidae
Culex

description: Key to subgenera and species of genus Culex: fourth-instar larvae
(key characters are illustrated in Figs 5 and 6)
1. Seta 4-X (ventral brush) with 1 or more precratal setae; thorax and abdomen spiculate [siphonal trachea narrow, less than 0.5 width of siphon] .................................................................................................................................. 2
- Seta 4-X without precratal setae; thorax and abdomen not spiculate, except Cx. (Cux.) vishnui (with thorax spiculate) ........................................................................................................................................................................... 6
2(1). Seta 3-P more than 0.5 length of setae 1,2-P; siphon with 2 or more (usually more) anterolateral setae on each side; seta 1-S (siphonal tufts) unpaired, occurring in single median posterior row; seta 2-S (apicodorsal seta of siphon) large and hooked; siphon not expanded at apex; seta 6-C (median frontal seta) with at least 2 branches; seta 1-C (preclypeal seta) pale, more or less stout, never strongly tapered or filamentous (subgenus Maillotia) ... 3
- Seta 3-P about 0.5 or less length of setae 1,2-P; siphon without anterolateral setae; seta 1-S more or less paired, occurring in 2 posterolateral rows; seta 2-S small and straight, not hooked; siphon slightly expanded at apex; seta 6-C single; seta 1-C dark, otherwise same as above (subgenus Neoculex) ............................................................. 5
3(2). Siphon with numerous strong setae on subdorsal part of distal 0.67; siphon index (SI) less than 5.0 (4.4); seta 1-S (siphonal tuft) inserted beyond pecten [PTF 3–4:1:2:3:1:1:3] .............................................................. Cx. arbieeni
- Siphon without such setae; SI more than 5.0; usually at least 1 pair of seta 1-S (siphonal tufts) inserted within pecten........................................................................................................................................................................ 4
4(3). Seta 3-P (prothoracic seta 3) bifid; seta 8-P (prothoracic seta 8) usually single; seta 1-S (siphonal tuft) often less than 0.3 length of siphon; anal papillae (gills) longer than saddle; siphon more than 4.0 length of saddle; siphon index (SI) 6.5 or greater (6.5–8.0) [PTF 1:1:2–3:4:1:1:3] ................................................................... Cx. hortensis
- Seta 3-P single; seta 8-P usually with 2 or 3 branches; seta 1-S often more than 0.3 length of siphon; anal papillae shorter than saddle; siphon less than 4.0 length of saddle; SI less than 6.5 (6.0–6.4) [PTF 1:1:1:3:1:1:4] ............... ........................................................................................................................................................... Cx. deserticola
5(2). Length of seta 1-S (siphonal tuft) usually more than 2.0 (1.5–3.0) width of siphon at point of attachment; more distal pecten spines evenly spaced, each with 3 long ventral denticles; anal papillae (gills) about 0.5 length of saddle, blunt tipped [SI 6.1–8.5; PTF 1:1:3:2:1:1:3] ............................................................ Cx. impudicus * (Note 33)
- Seta 1-S at most 2.0 (usually less than 1.5) width of siphon at point of attachment; more distal pecten spines often more widely spaced and somewhat irregularly inserted, each with 1 or 2 ventral denticles; anal papillae nearly as long or longer than saddle, pointed [SI 6.0–7.0; PTF 1:1:3:2:1:1:3] .................................................... Cx. territans
6(1). Seta 1-S (siphonal tufts) in single row, with all elements arranged in more or less straight line; seta 3-C absent [siphonal trachea broad, more than 0.5 width of siphon; at least one pair of seta 1-S inserted within pecten; seta 1- C (preclypeal seta) pale, very slender and distally strongly tapered or filamentous] (subgenus Barraudius)......... 7
- Seta 1-S in 1 or 2 rows, with 1-3 elements distinctly out of line with the others (inserted laterally); seta 3-C usually present (may be absent in some species, such as Cx. (Cux.) pipiens and Cx. (Cux.) vishnui) .......................... 8
7(6). Siphon index (SI) about 3.0 (2.6–3.2); pecten at least 0.5 length of siphon; 2 apical seta 1-S (siphonal tufts) at least as long as width of siphon at point of attachment; 2 pairs of seta 1-S inserted within pecten; anal papillae (gills) about 0.5 length of saddle, scarcely longer than diameter, dorsal pair slightly longer than ventral pair; seta 8-P (prothoracic seta 8) usually single [PTF 1:1:1:2:1:1:3] ................................................................... Cx. pusillus
- SI about 4.0 or more (3.8–5.0); pecten less than 0.5 length of siphon; 2 apical seta 1-S shorter than width of siphon at point of attachment; 1 pair of seta 1-S inserted within pecten; anal papillae slightly shorter than saddle, slender and tapering, same length; seta 8-P with 2 or 3 branches [PTF 1:1:1:1–2:1:1:3].................... Cx. modestus
8(6). Dorsomentum of head a straight-sided triangle with minutely serrate margins; pecten very short, with 7–9 spines grouped at base of siphon, less than 0.1 length of siphon; seta 1-A (antennal tuft) inserted near mid-length of antenna; median labral plate (preclypeus or labrum) indistinguishably fused to dorsal apotome (frontoclypeus) [comb with 4–8 large scales, each with distinct main spine; distal pecten spines with 7 or more ventral denticles; seta 1-C (preclypeal seta) stout, distinctly thicker than branches of setae 5,6-C; SI 6.8 (5.0–8.4); PTF 1:1:1:1–2:1:1:3] (subgenus Oculeomyia) (Note 32)................................................................ Cx. bitaeniorhynchus
- Dorsomentum an imperfect triangle with large teeth; pecten much longer, about 0.33 length of siphon; seta 1-A inserted near apex of antenna; median labral plate distinct, separated by suture from dorsal apotome (subgenus Culex) ..................................................................................................................................................................... 9
9(8). Some or all comb scales spiniform, with pointed apex and fringe at sides ........................................................... 10
- All comb scales evenly fringed at sides and apex .................................................................................................. 14
10(9). Comb with fewer than 25 spiniform scales (usually fewer than 20), each with distinct main spine [seta 1-C (preclypeal seta) pigmented, stout, distinctly thicker than branches of setae 5,6-C] (Note 33) .................................. 11
- Comb with more than 25 spiniform scales, without distinct main spine................................................................ 12
11(10).Comb with 4–8 (rarely up to 19) large spiniform scales in single row; thorax not spiculate; seta 1-S (siphonal tufts) with 5 or fewer branches; distal pecten spines with 7 or more ventral denticles of similar size arising along entire length [SI 5.4 (4.4–6.9); PTF 1:1:1:1–3:1:1:3] ................................................................. Cx. pseudovishnui
- Comb with 16–22 small spiniform scales in 3 or 4 rows; thorax spiculate; seta 1-S with 6 or more branches; distal pecten spines with 2–5 ventral denticles of different size arising proximally [PTF 1:1:1:2:1:1:3] .... Cx. vishnui *
12(10).Seta 2-S long and curved; antenna with setae 2,3-A (subapical setae) arising at 0.3–0.5 distance between apical setae and seta 1-A (antennal tuft); seta 7-I about as long as 6-I, usually single; seta 14-C single; distal pecten spines with 7 or more ventral denticles; seta 1-C (preclypeal seta) stout, distinctly thicker than branches of setae 5,6-C (inner and median frontal setae), dark [siphonal trachea narrow, less than 0.5 width of siphon; SI 6.0 (4.5–7.4); PTF 1:1:1:1:1:1:2–3] ....................................................................................................... Cx. mimeticus
- Seta 2-S always straight; setae 2,3-A arising adjacent to apical setae; seta 7-I distinctly shorter than 6-I, usually double; seta 14-C with 2 or more branches, rarely single; distal pecten spines with 2–5 ventral denticles of different size arising proximally; seta 1-C slender, usually not thicker than branches of setae 5,6-C, dark or pale....... 13
13(12).Siphon with all elements of seta 1-S (siphonal tufts) arising laterally and posterolaterally, with 1–4 branches; siphonal trachea narrow, less than 0.5 width of siphon; pecten spines not large and curved; some anterior scales of comb evenly fringed at sides and apex; seta 5-C (inner frontal seta) with 1 or 2 branches (usually single), shorter than seta 6-C (median frontal seta); seta 14-P double on at least one side; siphon index (SI) more than 5.5 (6.9; 5.9–8.1); seta 1-C (preclypeal seta) pale, very slender and strongly tapered or filamentous [PTF 1:1:1:1–4:1:1:3]. ............................................................................................................................................................. Cx. sinaiticus
- Siphon with most elements of seta 1-S arising relatively close to posterior midline, with 4–11 branches; siphonal trachea broad, more than 0.5 width of siphon; more distal pecten spines very large and curved; all scales of comb spiniform; seta 5-C with 3 or 4 branches, about as long as seta 6-C; seta 14-P single; SI less than 5.5 (4.7; 4.1–5.4); seta 1-C dark, more or less stout, never strongly tapered or filamentous [PTF 1:1:1:2:1:1:3–4]............... ................................................................................................................................................................ Cx. theileri
14(9). Distal pecten spines with 7 or more ventral denticles of similar size arising along entire length; seta 1-C (preclypeal seta) dark, stout, spiniform or foliform, abruptly pointed or blunt apically, distinctly thicker than branches of setae 5,6-C (inner and median frontal setae) ......................................................................................................... 15
- Distal pecten spines with 2–5 ventral denticles of different size arising proximally; seta 1-C usually pale or pigmented, never dark, slender, scarcely if at all thicker than branches of setae 5,6-C ............................................. 16
15(14).Seta 1-S (siphonal tufts) mostly inserted in irregular row on posterior margin of siphon; anal papillae (gills) very small and globular, about 0.5 length of saddle or less; siphon index (SI) less than 5.0 (3.8, 3.6–4.6); seta 5-C (inner frontal seta) with at least 6 (6–8) branches; seta 6-C (median frontal seta) with at least 4 (4–7) branches; seta 1-X (saddle seta) usually single; seta 1-C (preclypeal seta) markedly flattened, or somewhat foliform, with blunt apex [PTF 1:1:1:2:1:1:2–3] ............................................................................................................. Cx. sitiens
- Seta 1-S in posterolateral pairs; anal papillae elongate, never globular; SI more than 5.0 (6.3, 5.7–7.0); seta 5-C with 4 or fewer branches; seta 6-C with 3 or fewer branches; seta 1-X usually triple (2–4); seta 1-C slender and spiniform, with acuminate apex [PTF 1:1:1:1–2:1:1:2–3] ..................................................... Cx. tritaeniorhynchus
16(14).Siphon with 6–8 pairs of seta 1-S (siphonal tufts), with one pair arising laterally and 5–7 irregular pairs arising relatively close to posterior midline; seta 1-S with 2 pairs arising within pecten [seta 1-C (preclypeal seta) pale, more or less stout, never strongly tapered or filamentous; SI 3.5 (2.8–4.6); PTF 1:1:1:2:1:1:3–4] ... Cx. laticinctus
- Siphon with 3–6 pairs of seta 1-S, with 1-3 pairs arising laterally and 2–4 pairs arising posterolaterally; seta 1-S at most with 1 pair arising within pecten ................................................................................................................... 17
17(16).Seta 1-S (siphonal tufts) no longer than width of siphon at point of attachment, usually in 5 pairs; all seta 1-S subequal in length; seta 6-VI normally single; seta 5-C (inner frontal seta) usually double or triple (occasionally with 4 branches); seta 6-C (median frontal seta) at most with 3 (2 or 3) branches; seta 1-C (preclypeal seta) more or less stout, never strongly tapered or filamentous ................................................................................................... 18
- Seta 1-S longer than width of siphon at point of attachment, usually in 4 pairs; at least basal 2 pairs of seta 1-S distinctly longer than apical setae; seta 6-VI normally double; seta 5-C with 4 or 5 branches; seta 6-C usually with more than 3 branches; seta 1-C pale, very slender and distally strongly tapered or filamentous ......................... 20
18(17).Siphon with 3 lateral pairs of seta 1-S (siphonal tufts); seta 1-M usually double or triple, sometimes single; seta 5- C (inner frontal seta) usually with 2 branches; distal pecten spines usually with 2 ventral denticles; seta 1-C (preclypeal seta) long, thin and pale [SI 6.8 (5.4–8.2); PTF 1:1:1:2:1:1:3]............................................ Cx. antennatus
- Siphon with 2 lateral pairs of seta 1-S (siphonal tuft); seta 1-M usually single, sometimes double; seta 5-C usually with 3 branches; distal pecten spines usually with 3 or more ventral denticles; seta 1-C not as long, slightly stouter and pigmented ....................................................................................................................................................... 19
19(18).Seta 1-S (siphonal tufts) as long as width of siphon at point of attachment [SI 6.8 (5.4–7.9); PTF 1:1:1:2:1:1:3–4] Cx. perexiguus
- Seta 1-S distinctly shorter than width of siphon at point of attachment [SI 5.7 (4.9–7.2); PTF 1:1:1:2:1:1:2–3] ..... ........................................................................................................................................ Cx. univittatus * (Note 37)
20(17).Seta 1-III–V with 3–6 branches (usually 4 or 5), sum of their branches on one side of abdomen 10 or more (usually more); seta 1-M normally double or triple; seta 1-X (saddle seta) usually double [SI 5.2 (4.4–5.7); PTF 1:1:1:2:1:1:2–3] ............................................................................................................... Cx. torrentium (Note 38)
- Seta 1-III–V with 1–4 branches (usually 1 or 2), sum of their branches on one side of abdomen not exceeding 10 (usually 6 or fewer); seta 1-M normally single; seta 1-X usually single............................................................... 21
21(20).Integument of thorax and abdomen with rows of minute vesicles; seta 13-T as long as 12-T; seta 1-C (preclypeal seta) pigmented, usually spiculate in middle [SI 5.4 (3.9–6.7); 1:1:1:2:1:1:2–4] ................ Cx. vagans * (Note 36)
- Integument of thorax and abdomen without vesicles; seta 13-T distinctly shorter than 12-T; seta 1-C usually not pigmented, sides smooth ........................................................................................................................................ 22
22(21).Siphon usually widest in middle, tapering more strongly apically than basally; width of siphon at apex more than 0.5 width at base; siphon index (SI) never more than 4.6 usually about 4.0 (3.7; 2.8–4.6); siphonal saddle index less than 3.45; seta 1-III, IV usually single [PTF 1:1:1:2:1:1:2] ............................................ Cx. quinquefasciatus
- Siphon widest at base, tapering towards apex, slightly sigmoid in lateral view; SI usually about 5.0 (4.6; 3.0–5.8); siphonal saddle index greater than 3.45; seta 1-III, IV usually double [PTF 1:1:1:2–3:1:1:2–3].............................. ..................................................................................................................... Cx. pipiens (including form molestus)
description: Published as part of Azari-Hamidian, Shahyad & Harbach, Ralf E., 2009, Keys to the adult females and fourth-instar larvae of the mosquitoes of Iran (Diptera: Culicidae), pp. 1-33 in Zootaxa 2078 on pages 21-23, DOI: 10.5281/zenodo.187282