Culex (Culiciomyia) cinerellus Edwards, 1922

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 : 471-473

Culex (Culiciomyia) cinerellus Edwards, 1922

Male. The integument of the thoracic pleura has the appearance of two dark brown stripes contrasting against a middle pale beige stripe. Wing 2.30 mm. Proboscis 1.60 mm. Forefemur 1.20 mm.

Head: Narrow white decumbent scales confined to mid-frontal area of vertex, line of broad white decumbent scales along eye margin, small patches of broad white scales on sides of head ( Fig. 14A ), light brown erect forked scales have slightly paler apices. Maxillary palpus slightly longer than proboscis, palpomeres 4 and 5 with setae, palpomere 4 approximately 0.4 length of palpomere 5 (ratio 0.39–0.46, mostly 0.4), palpomere 3 with 12–15 comb scales shaped as described by Edwards (1941) —all lanceolate with distal scales slightly closer together than more proximal scales, in all specimens examined most proximal scale is shortest (a in Fig. 14B ), scales gradually increase in length to middle scales, which are longest (b in Fig. 14B ), more distal 6 or 7 scales (c in Fig. 14B ) each of equal length and slightly broader than preceding scales. Antennae and proboscis similar to those of other Culiciomyia .

Thorax: Scutal integument greyish brown and covered with short brown setae, narrow white scales on scutellar lobes. Thoracic pleura with middle region obviously paler ( Fig. 14C,D ), antepronotum dark, middle 0.33 of postpronotum, postspiracular area and upper 0.5 of subspiracular area, prealar knob and upper 0.33 of mesanepimeron form an upper dark stripe, lower dark brown stripe corresponds to dark integument of proepisternum, lower 0.5 of subspiracular area, upper mesokatepisternum, lower margin of mesanepimeron and entire mesomeron. Pleura devoid of scales except a few specimens with 3 or 4 scales medially between setae on upper mesokatepisternum and some along lower 0.50 of posterior margin of lower mesokatepisternum. Setae on antepronotum, row of 6 on posterior margin of postpronotum, 3 on proepisternum, several on prealar knob, a few on upper and posterior margins of mesokatepisternum, and a single lower mesepimeral seta.

Wing: S cales all dark.

Legs: Colouration similar to the legs of other Culiciomyia , except Cx. cambournaci .

Abdomen: Terga greyish brown with slightly paler small apical lateral spots, sterna uniformly brownish grey.

Genitalia: Tergum IX lobes each with a row of 9 or 10 setae. Ventral surface of gonocoxite with a few long setae in no obvious configuration ( Fig. 15A ), dorsal surface with sparsely distributed short setae; a single subapical lobe with 3 rod-like setae (a–c), most anterior longest and most posterior shortest, a single long slightly stout seta (e), 3 small barbed setae (d 1 –d 3), 1 small seta (d 4), 1 relatively narrow foliform seta (g) and a smaller slightly narrower foliform seta that is often folded and looking like a slightly flattened blade (f). Gonostylus with a crest of 3–6 “spinelets” and devoid of setae except for 1 near crest and 1 borne subapically ( Fig. 15A ); gonostylus without dorsal membranous flange where it bends downwards, apex upturned and hook-like and with a small apical downward projecting scale-like seta. Aedeagus with expanded base with a row of 5 or 6 rounded tubercles, most proximal larger than the others, which Edwards (1941) probably referred to as “without a well-marked tooth at base” (a in Fig. 15B, C ); tubercles end where lateral plate narrows sharply, arm of lateral plate long, thin and narrow with blunt apices (b in Fig. 15B,C ). Paraproct with 2 or 3 subapical setae. Without obvious sternal process.

Additional notes: Edwards (1941) described this species as lacking the grey dusting of the thoracic pleura with the integument “mainly pale yellowish with the upper region more or less obviously darker”. While we agree that this species lacks the greyish colouring, the pleura in fact have two quite distinct dark bands or regions, with the middle 0.33 appearing light brown to almost pale yellowish (much like that seen in some species of the subgenus Eumelanomyia ). Specimens of this species examined in the National Health Laboratory Services Museum (Johannesburg, South Africa), while being generally paler than those from the Talangaye Forest, still had two visibly darker pleural regions, which makes us consider that the “bicolour” appearance of the pleura is normal for this species. Edwards (1941) omitted to mention the presence of setae d 1 –d 3 on the gonocoxite, but two of these appendages were drawn as non-barbed setae in Jupp (1996).

Specimens examined: Several males collected from the Talangaye Forest in Cameroon by sweep netting through forest vegetation, except for specimen CAM 226 b 28/X/2017 which was found resting in an un-baited net trap. Field accession numbers of the other specimens are CAM 132 L1b 2/II/2017, CAM 132 kb 5/II/2017, CAM 163 kb 10/V/2017, CAM 202 mc 9/VII/2017, CAM 202 q 21/VII/2017, CAM 227 ob 7/X/2017, CAM 226 b 28/X/2017, CAM 227 K 31/X/2017, CAM 227 d 17a 7/XI/2017 and CAM 227m 8/XI/2017. Some adults reared from larvae collected from a fallen banana leaf in a banana plantation, with accession numbers CAM 12.18 .2 3/IX/2011, CAM 12.18 pq.1 3/IX/2011 and CAM 12.18 pq.2 3/IX/2011 were also examined .

For comparative purposes, a few specimens previously collected by one of us ( AJC), and a few deposited in the insect collection of the National Health Laboratory Services Museum in Sandringham , Johannesburg , South Africa, were also examined. These were from: (i) Felixton , Kwazulu Natal, South Africa. Cx. cinerellus — 1 male. Collected in 1927. No further information on the label. (ii) Yangambi, Stanleyville, Democratic Republic of the Congo. Cx. cinerellus — 4 males. Collected by Dr. Parent; identified by Botha De Meillon, 1943. (iii) Embotyi, Kwazulu Natal, South Africa. Cx. cinerellus— 1 male. Collected and identified by Jim Muspratt, 1952. Between the cities of Tiko (4.0786° N; 9.3590° E), and (iv) Douala (4.0511° N, 9.7679° E) in western coastal Cameroon. Cx. cinerellus — 3 males. Collected and identified by AJC in 2011 .

Figures

FIGURE 14. External features of Culex cinerellus. (A) Dorsal view of the head; (B) lateral view of the palpal comb scales (100x); (C,D) lateral views of the thorax.

FIGURE 15. Male genitalia of Culex cinerellus. (A) Gonocoxite; (B) lateral plates and paraprocts (100x); (C) lateral view of the phallosome (400x).