Culex, Linnaeus, 1758

Simsaa, Mishkat A. A., Harbach, Ralph E., Ali Almalik, Alaa M., Ahmed, Elsheima M., Eisa, Alwia A., Mohamed, Asia H. & Azrag, Rasha S., 2021, Culex mosquitoes (Diptera: Culicidae) recorded along the Nile River in central and northern Sudan, with a key for the identification of all species of the genus known to occur in the country, Zootaxa 4963 (3), pp. 401-411 : 406-408

Key for the adults of Culex and Lutzia species known to occur in northern Sudan

1 Normally 4 or more lower mesepimeral setae; fore- and midfemora and -tibiae each with an anterior row of small pale spots............................................................................................ Lt. tigripes

- A single lower mesepimeral seta (exceptionally 2 or 3) or none; femora and tibiae without rows of pale spots (except Cx. poi- cilipes)............................................................................................. 2

2(1) Acrostichal setae absent.................................................................. Cx. ( Cui.) macfiei

- Acrostichal setae present, may be quite small............................................................... 3

3(2) No lower mesepimeral seta; proboscis and tarsi with pale rings................................................. 4

- 1–3 lower mesepimeral setae............................................................................ 8

4(3) Femora and tibiae with rows of small pale spots anteriorly.................................... Cx. ( Ocu.) poicilipes

- Femora and tibiae without pale spots..................................................................... 5

5(4) Abdominal terga with apical pale bands; wing with numerous scattered pale scales; proboscis with a pair of dorsolateral pale spots before the labella........................................................... Cx. ( Ocu.) bitaeniorhynchus

- Abdominal terga without apical pale bands; wing with few or no pale scales; proboscis dark at the apex (but the labella may be pale)............................................................................................... 6

6(5) Thorax brownish or scutum with many pale scales; scutum usually with anterior 0.5 mainly pale-scaled; wing without pale scales at the apex, length 4.0– 6.5 mm; abdominal terga with basomedian and apicolateral triangular patches of pale scales...................................................................................... Cx. ( Ocu.) annulioris

- Scutal scales form an indefinite mottled pattern, or scales all dark; wing length 2.0–4.0 mm.......................... 7

7(6) Femora with numerous scattered pale scales anteriorly; cell R 2 of wing short, its base distal to the base of cell M 1; pale scales of the proboscis confined to a distinct median ring................................................ Cx. ( Cux.) sitiens

- Femora without or with a few scattered pale scales; cell R 2 longer, its base at least slightly proximal to the base of M 1; pale scaling of the proboscis in a ring with a proximal extension on the ventral surface............ Cx. ( Cux.) tritaeniorhynchus

8(3) Abdominal terga with basal pale bands (except Cx. argenteopunctatus subsp. kingii and some Cx. neavei ) or lateral pale spots; vertex and ocular line of the head with narrow decumbent scales................................................ 9

- Abdominal terga completely dark-scaled or with apical pale scaling............................................ 24

9(8) Tarsi, especially hindtarsi, with narrow pale rings; prealar scales absent; midtibia with a pale anterior stripe; postspiracular scales usually present.................................................................... Cx. ( Cux.) duttoni

- Tarsi entirely dark-scaled; midtibia with or without an anterior pale stripe; postspiracular scales usually absent.......... 10

10(9) Femora of fore- and midlegs and tibiae of all legs with anterior pale stripes running the whole length; hindtibia without a dorsal pale spot at the apex; prealar and upper and lower mesokatepisternal scale-patches contiguous, forming a single patch............................................................................................ Cx. ( Cux.) theileri

- Femora and tibiae either without anterior stripes or if stripes are present on any of them then hindtibia with a dorsal pale spot at the apex; prealar and upper and lower mesokatepisternal scale-patches not continuous, in 3 separate patches.......... 11

11(10) Scutum with 4 spots of silvery-white scales; small dark species, abdominal terga without pale bands...................................................................................... Cx. ( Cux.) argenteopunctatus subsp. kingii

- Scutum without silvery-white spots..................................................................... 12

12(11) Postspiracular and prealar scales present; hindfemur with anterior surface mainly white-scaled, at most distal 0.2 dark-scaled .................................................................................................. 13

- Postspiracular scales absent; prealar scales normally present.................................................. 17

13(12) Hindtibia with distinct or indistinct anterior and posterior pale stripes; wing with or without a short line of pale scales at the base of the costa......................................................................................... 14

- Hindtibia without an anterior pale stripe, apex with a conspicuous white spot; wing entirely dark-scaled............... 16

14(13) Anterior surface of midfemur with distinct or indistinct anterior pale stripe; hindtibia with distinct anterior and posterior pale stripes on proximal 0.8, with distinct apical pale spot; costa of wing with a short line of pale scales at the base; patch of scales covers more or less of the dorsal 0.5 of the postspiracular area; pale bands of abdominal terga with normal basal pale bands.. .................................................................................................. 15

- Anterior surface of midfemur normally without an anterior pale stripe, weakly indicated when present; hindtibia with rather indistinct anterior and posterior pale stripes ending before the base, with rather an indistinct apical pale spot; wing entirely darkscaled, without pale scales at the base of the costa; scales of postspiracular area tend to occur in a small patch near the spiracle; pale bands of the abdominal terga reduced or absent............................................. Cx. ( Cux.) neavei

15(14) Proboscis with pale scales on middle of ventral surface; midfemur with a complete distinct or indistinct anterior pale stripe; anterior and posterior pale stripes of hindtibia separated ventrally by a complete dark stripe; wing vein 2A (posterior to vein 1A) of female usually with a line of scales................................................. Cx. ( Cux.) univittatus

- Proboscis pale-scaled ventrally except at base, weakly on distal 0.25; midfemur with or without an incomplete faint or distinct anterior pale stripe; anterior and posterior pale stripe of hindtibia partly separated on proximal 0.5 or less by a weak ventral dark stripe; wing vein 2A of female occasionally with a few scales.................................. Cx. ( Cux.) perexiguus

16(13) Hindfemur with complete or nearly complete anterodorsal dark stripe; females: abdominal sterna with apical dark bands; forecoxa with some dark scales; males: abdominal sterna mainly dark-scaled, with basolateral pale spots, maxillary palpus normal.................................................................................... Cx. ( Cux.) simpsoni

- Hindfemur with an anterodorsal dark stripe on distal 0.5 or less; females: abdominal sterna usually entirely pale-scaled; scales of forecoxa usually all pale; males: abdominal sterna mainly pale-scaled, posterior sterna usually with dark scales posteriorly, maxillary palpus sparsely setose......................................................... Cx. ( Cux.) sinaiticus

17(12) Abdominal terga with basal pale bands................................................................... 18

- Abdominal terga, at least the first few, without pale bands; mesepimeron with a distinct scale-patch in the middle....... 20

18(17) Thorax pale; proboscis entirely dark-scaled; abdominal sterna pale-scaled; 2–4 lower mesepimeral setae frequently present; hindtibia with conspicuous apical pale spot................................................ Cx. ( Cux.) laticinctus

- Thorax darker; proboscis pale beneath in the middle; only 1 lower mesepimeral seta; hindtibia with inconspicuous apical pale spot............................................................................................... 19

19(18) Scutal scales golden brown with reddish tint; wing of female with cell M 2 more than 3 times as long as its stem (vein R 2+3), subcosta normally intersects the costa at or beyond the furcation of R 2+3; basal bands of abdominal terga yellowish, usually same color as the sternal scales; tergal bands of female distinctly darker than basolateral white spots........... Cx. ( Cux.) pipiens

- Scutal scales more or less buff-colored; wing of female with cell R

2

2.8–3.3 times as long as vein R

2+3

, subcosta normally in- tersects the costa before the furcation of R 2+3; basal bands of abdominal terga nearly white, usually slightly paler than sternal scaling, tergal bands of female slightly if at all darker than basolateral white spots............. Cx. ( Cux.) quinquefasciatus

20(17) Antenna of female normal, each flagellomere with 4–6 long setae; knob of halter usually dark-scaled.................. 21

- Antenna of female sub-verticillate; first few flagellomeres each with 10–20 long setae; halter entirely yellow-scaled...... 23

21(20) Small brown species; abdominal terga without basal pale bands, terga VI and VII with lateral pale stripes; sterna pale-scaled.................................................................................... Cx. ( Cux.) antennatus

- Larger species; abdominal terga with or without narrow basal pale bands, with basolateral pale patches; sterna with apical dark bands............................................................................................. 22

22(21) Erect scales of head all or nearly all dark; scutum with evenly dispersed uniform reddish-brown scales, anterior and lateral margins and prescutellar area with pale scales; hindfemur with 0.2 or less of anterior surface dark-scaled; hindtibia with a pale spot at the apex.......................................................................... Cx. ( Cux.) decens

- Erect scales of head all dark; scales on margins of scutum and prescutellar area creamy-white; hindfemur with anterior dark area at apex longer than broad; hindtibia entirely dark-scaled....................................... Cx. ( Cux.) perfuscus

23(20) Proboscis dark-scaled; 2 lower mesepimeral setae; hindtibia with a spot of pale scales at the apex; abdominal sterna with dark apical bands.......................................................................... Cx. ( Cux.) grahamii

- Proboscis pale beneath; usually only 1 lower mesepimeral seta; hindtibia entirely dark-scaled; abdominal sterna entirely palescaled or with only a few dark scales on the apical margins...................................... Cx. ( Cux.) weschei

24(8) Vertex of head with narrow whitish decumbent scales; mesepimeron with very few or no scales....... Cx. ( Eum.) kingianus

- Vertex with some moderately broad scales, at least on the ocular line........................................... 25

25(24) Only ocular line of head with broad scales, the scales white; abdominal terga with apical lateral pale spots or all dark; thoracic pleura gray-dusted................................................................................... 26

- Vertex of head usually with more numerous broad scales, and these usually dark.................................. 27

26(25) Small species; length of wing 3–4 mm; mesepimeron usually without distinct scale-patch; gonocoxite of male genitalia with few short setae........................................................................ Cx. ( Cui.) nebulosus

- Larger species; length of wing 4–5 mm; mesepimeron usually with a large patch of scales; gonocoxite of male genitalia with dense patch of soft pale setae............................................................. Cx. ( Cui.) cinereus

27(25) Dorsum of head almost entirely clothed in broad decumbent scales; legs mainly dark-scaled; hindfemur only indistinctly palescaled ventrally.................................................................. Cx. ( Eum.) inconspicuosus

- Dorsum of head with a fairly broad band of decumbent scales in front adjoining the eyes; hindfemur more extensively palescaled, ventral surface distinctly paler................................................. Cx. ( Eum.) simpliciforceps