Culex (Culiciomyia) cinereus Theobald, 1901

Cornel, Anthony John, Mayi, Marie Paul Audrey, Kowo, Cyril, Foncha, David, Andongma, Esack, Anong, Damian Nota, Elad, Mirabel, Djomo, Charlene, Tchuinkam, Timoleon, Brisco, Katherine K. & Sehgal, Ravinder, 2020, New species of Culex (Culiciomyia) (Diptera: Culicidae) from Talangaye Forest in Cameroon and descriptions and identification keys for males of the Afrotropical species of the subgenus, Zootaxa 4858 (4), pp. 451-506 : 473-476

Culex (Culiciomyia) cinereus Theobald, 1901

Male. Thoracic pleura generally greyer and with more dusted appearance than males of other Afrotropical species of Culiciomyia . Wing 3.50–3.70 mm. Proboscis 2.10–2.45 mm. Forefemur 2.00 mm.

Head: Decumbent scales of vertex narrow and white to translucent except for single line of broader white scales along eye margin and patch on sides of head ( Fig. 16A ); erect forked scales quite numerous, dark brown, those in middle of vertex with slightly lighter tips. Maxillary palpus slightly longer than proboscis, distal 2 palpomeres bearing setae, palpomere 4 0.34–0.40 length of palpomere 5; palpal comb of palpomere 3 consists of the following scales ( Fig. 16B ): proximal set of 11 or 12 scales needle-like or acicular and 8 or 9 in distal set subulate with sharply downward turned (recurved) apices; no obvious gap between distal and proximal sets, most proximal of proximal set about 0.5 length of other scales of set. Antenna and proboscis similar to those of other Culiciomyia .

Thorax: Scutal integument greyish brown ( Fig. 16A,D ), covered with short brown setae, narrow scales at front and prescutellar area slightly paler, scales on scutellum whitish. Integument of thoracic pleura uniformly greyish brown to beige ( Fig. 16D ), in general paler than scutal integument; pleura lack scales except for a row of whitish to translucent scales among setae on upper mesokatepisternum; setae on antepronotum, a row of 6 on posterior margin of postpronotum, on proepisternum, prealar knob, on all coxae, a patch on upper mesokatepisternum, a row along posterior margin of lower mesokatepisternum and one lower mesepimeral seta.

Wing: Scales all dark.

Legs: Coloured similar to other Culiciomyia except for Cx. cambournaci . Hindfemur as shown in Fig. 16E .

Abdomen: Terga greyish brown with slightly paler small basal lateral spots, but lateral pale scales are absent in many specimens examined; sterna uniformly brownish grey.

Genitalia: Tergum IX lobes each with a row of 6–8 setae ( Fig. 17D ). Ventral surface of gonocoxite with few long setae (slightly longer than gonocoxite) towards outer margin; inner ventral side of gonocoxite with dense ventral lateral patch of 10 rows of setae with about 7 setae in each row ( Fig. 16C ) that in slide mounts obscure and makes setae on subapical lobe difficult to see; prominent subapical lobe with an additional dense patch of shorter setae at base that also can obscure view of setae on lobe ( Fig. 16C ); setae on subapical lobe include 1 or 2 setae below rod-like setae (a–c), seta c more distally positioned than a and c ( Figs 16F , 17A ), 2 barbed appendages (d 1 –d 2) with about 4 barbs on each ( Fig. 17A ), 1 broad foliform seta (g), a second much narrower seta (f) and 2 short and 2 longer setae between bases of b and c, seta b often darker than 2 rod-like setae ( Fig. 16C,F ), upper most seta of patch of setae at base of subapical lobe longer, striated and thicker than others and probably equivalent to seta e in other Culiciomyia , often 3 long setae at apex of gonocoxite below base of gonostylus. Row of 12–14 “spinelets” along crest of gonostylus, gonostylus ends in a small upturned hook, with multiple pre-medially positioned short setae and quite broad dorsal membranous flange. Aedeagus with expanded base with a single dark basal tooth, arms (lateral plates) straight vertically with pointed apices ( Fig. 17B,C ), apices of lateral plates very slightly roughened (it should be noted that lateral plates often pressed sideways or outwards due to the weight of the coverslip in slide mounts). Paraproct with 3 or 4 subapical setae and no obvious sternal process.

Additional notes: The male of Cx. cinereus closely resembles the male of Cx. nebulosus except it is generally larger. Culex cinereus , as described by Edwards (1941), may or may not have flat white scales extending to more than half the length of the mesepimeron and flat scales on the propleuron (proepimeron and proepisternum), mesopleuron (mesokatepisternum) and has flat scales on the coxae. The palpal comb scales differ from those of Cx. nebulosus in lacking an obvious gap between the proximal and distal scale sets. The aedeagus of Cx. cinereus differs from that of Cx. nebulosus by the absence of obvious teeth on the lateral plates. In Cx. cinereus , seta c of the subapical lobe is more obviously separated from the other rods than in Cx. nebulosus . The subapical lobe has a distinctive patch of delicate setae at its base in Cx. cinereus whereas this patch is absent in Cx. nebulosus . Stout seta e is more dorsolaterally positioned than in Cx. nebulosus .

Specimens examined: Several males were collected in the Talangaye Forest in Cameroon. Specimen CAM 85 u 2a 7/XI/2016 was reared from an egg raft that was laid in a bamboo pot. The following males were collected by sweep netting through vegetation on the forest floor. Field accession numbers CAM 86 j1 4/XI/2016 , CAM 86 v 7/XI/2016 , CAM 132 ha 28/I/2017 , CAM 132 hb 28/I/2017 , CAM 132 b 1a 31/I/2017 , CAM 132 b1d 31/I/2017 , CAM 132 a 1 c 1/II/2017 , CAM 132 anb 1/II/2017 , CAM 132 gg 7/II/2017 , CAM 163 kc 10/ V/2017, CAM 202 ta 16/ VII/2017 , CAM 202 tb 16/VII/2017 , CAM 202 nb 21/VII/2017 and CAM 227 q 2/XI/2017 .

Figures

FIGURE 16. External features and genitalia of Culex cinereus. (A) Dorsal view of the head and scutum; (B) lateral view of the palpal comb scales (100x); (C) gonocoxite (100x); (D) lateral view of the thorax; (E) anterior view of the hindfemur; (F) subapical lobe of the gonocoxite (400x).

FIGURE 17. Male genitalia of Culex cinereus. (A) subapical lobe; (B) phallosome (100x); (C) lateral plates; (D) tergum IX lobe (400x).