Culex

Azari-Hamidian, Shahyad & Harbach, Ralf E., 2009, Keys to the adult females and fourth-instar larvae of the mosquitoes of Iran (Diptera: Culicidae), Zootaxa 2078, pp. 1-33 : 14-16

Key to subgenera and species of genus Culex : adults

(key characters are illustrated in Figs 1–4 )

1. Proboscis shorter than forefemur; hindtarsomere 1 shorter than hindtibia, not more than 0.85 length of hindtibia; abdominal terga entirely dark-scaled [in males, maxillary palpus generally with short spinelike setae] (subgenus Barraudius )............................................................................................................................................................... 2

- Proboscis longer than forefemur; hindtarsomere 1 usually as long or longer than hindtibia or only slightly shorter, not less than 0.85 length of hindtibia; abdominal terga with pale bands at least on some segments, except Cx. (Cux.) antennatus ...................................................................................................................................................... 3

2(1). Abdominal terga with lateral pale scales more or less developed as spots; postspiracular scales absent ................. ................................................................................................................................................................ Cx. pusillus

- Abdominal terga with pale scales arranged in more or less distinct stripes, sometimes forming triangular spots on anterior margins of terga; postspiracular scales present ..................................................... Cx. modestus (Note 31)

3(1). Abdominal terga with apical pale bands or apicolateral pale patches [lower mesepimeral setae present except in subgenus Oculeomyia ] ............................................................................................................................................. 4

- Abdominal terga with basal pale bands or basolateral pale patches (except Cx. antennatus , which has lateral pale patches on terga VI and VII) [lower mesepimeral setae present in Pipiens Group; absent in Sitiens Group] (subgenus Culex ) ................................................................................................................................................................. 9

4(3). Wing speckled with dark and pale scales, many scales broad ovate; proboscis with ring of pale scales; basal dark area of terga speckled with pale scales; femora and tibiae heavily speckled; tarsi with pale rings; proboscis with pair of dorsolateral pale spots at apex before labella; last palpomere with some pale scales; central part of ocular (orbital) line without scales; anal vein (1A) (vein 6) terminates distal to mediocubital (mcu) crossvein; in males,

proboscis with ventral cluster of setae at false joint; lower mesepimeral seta absent (subgenus Oculeomyia ) (Note 32) ........................................................................................................................................... Cx. bitaeniorhynchus – Wing uniformly dark-scaled, scales narrow clavate; proboscis without ring of pale scales; basal dark area of terga not speckled; femora and tibia not speckled, may have a few pale scales or a row of scales; tarsi without pale rings; proboscis without pair of pale spots at apex before labella; last palpomere without pale scales; central part of ocular (orbital) line with broad scales; 1A terminates before crossvein mcu; in males, proboscis without ventral cluster of setae at false joint; lower mesepimeral seta present ................................................................................ 5

5(4). Prealar and postspiracular scales absent; pale areas of terga clearly reduced, medially narrowed or interrupted; maxillary palpus dark; end of subcosta (Sc) distinctly proximal to furcation of radius-two-plus-three (R2+3) (petiole or stem) and media (M) (vein 4) (subgenus Neoculex ) ....................................................................................... 6

- Prealar and usually postspiracular scales present; terga with broad pale areas of even width or medially extended posteriorly; palpomere 2 usually with pale scales; end of Sc nearly aligned with furcation of R2+3 and M or slightly proximal to them (subgenus Maillotia ) ................................................................................................................... 7

6(5). Apical pale bands of abdominal terga narrow, not interrupted, sometimes represented only by a line of pale scales along border of tergum; in males, last abdominal segment not usually very setose.............................. Cx. territans

- Apical pale bands interrupted at least on some terga, always broader at sides; in males, last abdominal segments with numerous, long setae ................................................................................................ Cx. impudicus * (Note 33)

7(5). Sterna entirely pale-scaled; in males, last palpomere with many setae [pale bands of most abdominal terga with projection].......................................................................................................................................... Cx. deserticola

- Sterna dark with large triangular pale areas at apex of most sterna; in males, last palpomere devoid or nearly devoid of setae .......................................................................................................................................................... 8

8(7). Pale bands of most abdominal terga with projection; upper proepisternal area with many prominent scales; relatively darker species; palpomere 2 usually with prominent pale scales on dark background; in males, gonocoxite of genitalia with unusually broad, sclerotized, flattened process at apex............................ Cx. hortensis (Note 34)

- Pale bands of abdominal terga of more or less even width, at most a few terga with weak projection; upper proepisternal area with fewer prominent scales; paler species; palpomere 2 with pale scales less prominent; in males, gonocoxite of genitalia otherwise .............................................................................................. Cx. arbieeni

9(3). Proboscis with pale ring in middle; lower mesepimeral setae absent; tarsi with narrow pale rings ( Sitiens Group). ................................................................................................................................................................................ 10

- Proboscis without pale ring; lower mesepimeral setae present; tarsi without pale rings ( Pipiens Group)............. 14

10(9). Wing with 3 conspicuous pale areas on costa (C) and pale markings on other veins; midtibia with anterior pale stripe.................................................................................................................................................... Cx. mimeticus

- Wing without pale areas, occasionally with scattered pale scales; midtibia without anterior pale stripe ............. 11

11(10).Anterior surface of fore- and midfemur speckled with pale scales; scutum with indefinite mottled pattern; cell M2 (posterior forked cell of vein 4) long, furcation of radius-two-plus-three (R2+3) (petiole or stem) distal to furcation of media (M) (vein 4); scutal integument dark ......................................................................................... Cx. sitiens

- Anterior surface of fore- and midfemur not speckled; scutum without mottled pattern; furcation of R2+3 proximal to furcation of M; scutal integument pale brown ( Vishnui Subgroup) (Note 35)................................................... 12

12(11).Pale ring of proboscis usually with proximal extension on ventral surface; hindfemur pale with an apical dark ring; erect scales on vertex all dark, dirty yellow to brown in middle; cell R2 (anterior forked cell of vein 2) more than 3.0 length of radius-two-plus-three (R2+3) (petiole or stem); in males, proboscis with ventral cluster of 10 or more setae at false joint ......................................................................................................... Cx. tritaeniorhynchus

- Pale ring of proboscis without proximal extension on ventral surface; hindfemur with dark and pale areas, with or without speckling, without apical dark ring; vertex with mixture of pale (cream, pale yellow, or beige) and dark erect scales, rarely all dark; cell R2 less than 3.0 length of R2+3; in males, proboscis with at most 10 (usually fewer) setae at false joint.................................................................................................................................................... 13

13(12).Anterior surface of hindfemur with pale stripe contrasting well with dark-scaled area; in males, proboscis usually without ventral cluster of setae at false joint, 1 or 2 setae sometimes present ............................ Cx. pseudovishnui

- Anterior surface of hindfemur with pale stripe not distinctly contrasting with dark-scaled area; in males, proboscis with ventral cluster of 5–10 setae at false joint ................................................................................... Cx. vishnui *

14(9). At least forefemur with pale stripe on anterior surface, stripe usually present on fore- and midfemur and all tibiae ................................................................................................................................................................................ 15

- Fore- and midfemur without anterior pale stripe ( Cx. univittatus and Cx. perexiguus usually have an anterodorsal pale stripe on midtibia) ........................................................................................................................................... 16

15(14).Basal pale bands of abdominal terga usually produced posteromedially into triangular patches; prealar and postspiracular scales present; hindfemur with a dark ventral stripe in apical third; prealar and upper and lower mesokatepisternal scale-patches confluent ............................................................................................. Cx. theileri

- Basal pale bands of abdominal terga more or less of even width, not produced posteriorly; prealar and

postspiracular scales absent; ventral surface of hindfemur completely pale-scaled; prealar and upper and lower mesokatepisternal scale-patches not confluent ..................................................................... Cx. vagans * (Note 36) 16(14).Postspiracular scales present; hindtibia with pale ring or well-developed and prominent pale spot at apex [prealar scales present] ......................................................................................................................................................... 17

- Postspiracular scales absent; hindtibia without pale ring or spot at apex (except Cx. laticinctus , which has a weak apical pale spot) [prealar scales present or absent] ................................................................................................ 19

17(16).Hindtibia without anterior pale stripe; wing entirely dark-scaled; basal pale bands of terga straight, 0.3–0.4 length of tergum, slightly produced laterally, especially on terga VI and VII; anterior surface of forecoxa pale-scaled or with a few dark scales in middle.......................................................................................................... Cx. sinaiticus

- Hindtibia with anterior pale stripe; wing with pale scales at base of costa (C); basal pale bands on terga narrower and convex; anterior surface of forecoxa with numerous dark scales in middle ................................................... 18

18(17).Anterior surface of midfemur dark-scaled or with incomplete narrow pale stripe; wing seldom with few scales on anal vein 2A ....................................................................................................................................... Cx. perexiguus

- Anterior surface of midfemur with complete narrow pale stripe; wing usually with row of scales on anal vein 2A ......................................................................................................................................... Cx. univittatus * (Note 37)

19(16).Abdominal terga unbanded, terga VI and VII with lateral pale stripes; in male, proboscis with ventral cluster of setae at false joint............................................................................................................................... Cx. antennatus

- Basal pale bands present on terga of most segments; in male, proboscis without ventral cluster of setae at false joint ........................................................................................................................................................................ 20

20(19).Basal pale bands of abdominal terga very broad, 0.50–0.67 length of segment, not narrowed toward sides; scales of forecoxa mostly pale; wing with short line of pale scales at base of costa (C); proboscis all dark or faintly pale beneath; 2–4 lower mesepimeral setae present; hindtibia with apical pale spot [prealar scales present or absent] ... ............................................................................................................................................................ Cx. laticinctus

- Basal pale bands of abdominal terga narrower, less than 0.5 length of segment, often narrower at sides, sometimes reduced to lateral spots or even absent from some terga; forecoxa with some dark scales; wing entirely darkscaled; proboscis usually distinctly pale beneath in middle; 1, rarely 2, lower mesepimeral setae present; hindtibia without apical pale spot (Note 38).......................................................................................................................... 21

21(20).Scutal scales more or less buff-colored; basal bands of abdominal terga nearly white, usually slightly paler than sternal scaling; tergal bands slightly if at all darker than basolateral white spots; subcosta (Sc) normally intersects costa (C) before furcation of radius-two-plus-three (R2+3) (petiole or stem) [prealar scales absent].......................... ................................................................................................................................................ Cx. quinquefasciatus

- Scutal scales golden brown with reddish tint; basal bands of abdominal terga yellowish, usually same colour as sternal scaling; tergal bands distinctly darker than basolateral white spots; Sc normally intersects C at or beyond furcation of R2+3 ...................................................................................................................................................... 22

22(21).Cell R2 (anterior forked cell of vein 2) more than 4.0 length of radius-two-plus-three (R2+3) (petiole or stem); integument and scales between supraalar and posterior dorsocentral setae usually noticeably darker than surrounding integument and scales, evident as pair of ovoid spots [prealar scales normally absent] ............................ ...................................................................................................................... Cx. pipiens (including form molestus)

- Cell R2 less than 4.0 length of R2+3; integument and scales between supraalar and posterior dorsocentral setae not appreciably darker than surrounding integument and scales [prealar area normally with 4 scales or more, occasionally absent] .................................................................................................................................. Cx. torrentium

Figures

FIGURE 1. Characters of adult mosquitoes used in the keys. A, Lateral aspect (left side) of a culicine female (diagrammatic). B, Dorsal aspect of female anopheline cibarium. C, Ventral aspect of the posttarsis of an aedine female. (A, B Modified from Harbach & Knight, 1980; C modified from Edwards, 1941).

FIGURE 2. Lateral aspect (left side) of the head of an Anopheles female showing characters used in the keys. (Modified from Harbach & Knight, 1980).

FIGURE 3. Characters of the mosquito thorax used in the keys. A, Lateral aspect (left side) of an aedine male. B, Dorsal aspect of the same. (Modified from Harbach & Knight, 1980).

FIGURE 4. Characters of the mosquito wing used in the keys. A, Left wing (ventral aspect) of an aedine female. B, Costal wing spots (dorsal aspect) of anopheline wings. (A Modified from Harbach & Knight, 1980; B modified from Glick, 1992).