Culex (Culiciomyia) semibrunneus Edwards, 1927

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 : 490

Culex (Culiciomyia) semibrunneus Edwards, 1927

Male: Wing 2.24 mm. Proboscis 1.50 mm. Forefemur 1.30 mm.

Head: Well-defined row of broad white decumbent scales along eye margin ( Fig. 28A ); narrow pale decumbent scales extend towards back of vertex; a few broad white to translucent decumbent scales pre-laterally on vertex and patch of white decumbent scales on each side of head; erect forked scales quite numerous and appear dark brown to black depending on angle of view. Maxillary palpus slightly longer than proboscis, palpomeres 4 and 5 bearing setae, palpomere 4 about 0.33 length of palpomere 5 (ratio 0.33–0.38); palpal comb scales resemble those of Cx. nebulosus except those of distal set have rounded tips (spatulate or oblanceolate) and lack sharply recurved (hawk beak-like) aristate tips that occur in Cx. nebulosus ( Fig. 28B,D ), 4–6 proximal scales and 6 or 7 distal scales. Antenna and proboscis similar to those of other Culiciomyia .

Thorax: S cutal integument uniformly dark reddish brown ( Fig. 28A ) and scutum and scutellar lobes covered with short brown to shiny translucent setae. Integument of thoracic pleura similar reddish brown as scutal integument ( Fig. 28C ), which gives appearance of males of this species being generally darker than males of other Culiciomyia , lower 0.5 of mesanepimeron, entire metepisternum and mesomeron light brown to yellowish in some specimens ( Fig. 28C ); pleura with scales and setae present as follows: on antepronotum, a row of 6 on posterior margin of postpronotum, 3 on proepisternum, prealar knob, a few on upper and posterior margin of mesokatepisternum, and one lower mesepimeral seta. Capitellum of halter darker than pedicel.

Wing: Scales all dark.

Legs: Coloured similar to those of other Culiciomyia , except for Cx. cambournaci .

Abdomen: Terga dark brown with paler basal lateral spots; sterna lighter brown than terga.

Genitalia: Each tergum IX lobe with irregular row of 8 or 9 setae. Gonocoxite more rounded than in other Culiciomyia , ventral surface with few long setae, each about as long as gonocoxite, positioned in no obvious pattern ( Fig. 29A,C ). Patch of ventrolateral setae less conspicuous than in Cx. nebulosus ; row of 4 setae on dorsal surface of gonocoxite at apex below gonostylus ( Fig. 29B ), otherwise dorsal surface with quite sparsely distributed short setae. Specialized setae attached to an undivided subapical lobe consist of 3 rod-like setae with short hooked apices (a–c), most proximal little shorter than other 2, 1 quite robust seta (e) attached just above a, a short setae above seta e, 2 barbed slightly broadened setae (d 1 –d 2), relatively narrow foliform seta (f) and broader foliform seta (g). Gonostylus with small crest and 2–4 “spinelets” ( Fig. 29B ), 1–3 setae medially, 1 seta below crest, and 1 preapical seta, end of gonostylus curved upward with a small folded apical foliform gonostylar claw; membranous dorsal flange smaller than in Cx. nebulosus . Aedeagus with expanded triangular base with a short basal tooth ( Fig. 30A,B ), lateral plate long and smooth with rounded apex. Paraproct with 3 subapical setae ( Fig. 30A ) and a small rounded basal protrusion ( Fig. 30A,B ); apical region or crest of paraproct typically resembles that of all other Culiciomyia .

Additional notes: This is a small brown mosquito with no obvious features distinguishing it from Cx. nebulosus and allied species except for the rounded tips of the distal scales of the palpal comb of palpomere 3. The phallosome has long smooth lateral plates and the aedeagus has a small basal tooth. The basal protrusion or arm of the paraproct is similar in size and shape to that of Cx. pseudosubaequalis .

Specimens examined: Three males collected by sweep netting through vegetation in the Talangaye Forest , Cameroon . Field accession numbers CAM 132 b1b 31/I/2017 , CAM 132 b1e 31/I/2017 and CAM 132 ki 5/II/2017. One male from Yangambi, Stanleyville, Democratic Republic of the Congo , collected by Dr. Parent, 1944. Specimen held in the insect collection of the National Health Laboratory Services Museum in Johannesburg , South Africa .

Figures

FIGURE 28. External features of Culex semibrunneus. (A) Dorsal view of the head and scutum; (B) lateral view of the maxillary palpus (100x); (C) lateral view of the thorax; (D) lateral view of the palpal comb scales (400x).

FIGURE 29. Gonocoxite of Culex semibrunneus. (A) Drawn depiction; (B) subapical lobe and gonostylus (400x); (C) genitalia (100x).

FIGURE 30. Lateral plates and paraproct of Culex semibrunneus. (A) Drawn depiction; (B) phallosome (400x).