Culex (Culiciomyia) pseudosubaequalis Cornel & Mayi, 2020

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 : 463-464

Culex (Culiciomyia) pseudosubaequalis Cornel & Mayi , sp. n.

Male. Wing 2.70 mm. Proboscis 1.90 mm. Forefemur 1.40 mm. Pleura with an upper dark stripe.

Head: Scaling on vertex same as in Cx. lanzaroi except for more numerous white broad decumbent scales on sides of head ( Fig. 9A ). Maxillary palpus longer than proboscis because of longer palpomere 4, which is little more than 0.5 length of palpomere 5 (ratio = 0.54–0.67; see Fig. 10A,C ); palpomeres 4 and 5 setose; row of 7–9 translucent spearhead-shaped (subulate with a long cuneate base) comb scales on palpomere 3, apices of scales extend into long thin delicate points ( Fig. 10A,C ). Antenna and proboscis identical to those of all other Culiciomyia (see description of Cx. apicopilosus ). Proboscis dark-scaled.

Thorax: S cutal integument light to dark brown, covered with short brown setae, narrow white scales on scutellar lobes. Pleura non-uniform in colour ( Fig. 9B,C ). Integument darker on antepronotum, middle 0.30 of postpronotum, postspiracular area, upper 0.50 of subspiracular area, prealar knob and upper 0.30 of mesanepimeron, giving appearance of an upper dark stripe; lower light brown semi-stripe corresponds to light brown colouring of proepisternum, lower part of subspiracular area and upper mesokatepisternum; one specimen with upper mesokatepisternum not noticeably darkened ( Fig. 9B ); pleura devoid of scales, setae present on antepronotum, posterior margin of postpronotum, 3 on proepisternum, prealar knob, upper and posterior margin of mesokatepisternum and 1 lower mesepimeral seta. Pedicel of halter lighter than capitellum.

Wing: Scales all dark.

Legs: Colouration of legs like legs of Cx. apicopilosus ( Fig. 9D ).

Abdomen: Terga uniformly brown; sterna uniformly brownish grey to greyish beige.

Genitalia: Tergum IX lobes each with a row of 7 seta. Ventral surface of gonocoxite with a few long setae (each as long or a little longer than gonocoxite) in no obvious configuration and a few rows of 3 or 4 narrow setae along inner margin ( Fig. 11 ); dorsal surface with sparsely distributed short setae and a single stouter seta on a slightly raised lobe below base of gonostylus ( Fig. 11 ); a single but not very prominent subapical lobe bearing setae of similar shape and configuration as in Cx. subaequalis that includes 3 rod-like setae (a–c) with a shortest and b longest, a single long quite robust and slightly striated seta (e) less stout than in Cx. subaequalis , 2 small barbed seta (d 1 –d 2), quite broad foliform seta (g) and a smaller less broad membranous seta (f). Gonostylus with crest of approximately 6 “spinelets”, a short rounded dorsal membranous flange, apex upturned and hook-like, and a small broad membranous seta, 1 seta below middle of crest and 1 borne subapically, a single small seta approximately 0.33 from base on upper margin occasionally present ( Fig. 11 ). Aedeagus with expanded base and prominent basal tooth ( Fig. 12A,B ), otherwise devoid of teeth or tubercles, lateral plate quite long and gradually narrowed towards rounded apex, extending upwards and more or less straight. Paraproct with 3 subapical setae and a small rounded basal protrusion ( Fig. 12A,B ).

Additional notes: The thoracic pleura are not uniform in colour. Upper dark grey and lower light brown colouring of some portions of the integument create the appearance of a light grey mid-region ( Fig. 9C ). Other differences distinguishing Cx. pseudosubaequalis from Cx. subaequalis include the lack of rows of ventrolateral setae on the gonocoxite, a smaller basal protuberance on the paraproct and shorter palpomere 4 relative to palpomere 5. The longer palpomere 4 can confuse this species with Cx. subaequalis and Cx. mongiro . In Cx. subaequalis and Cx. mongiro palpomere 4 is 0.75 the length of palpomere 5, whereas in Cx. pseudosubaequalis it is slightly shorter and 0.55–0.65 the length of palpomere 5. Culex mongiro is quite unique among the Afrotropical Culiciomyia by having banded abdominal sterna that are dark basally and lighter apically ( van Someren 1951). Culex mongiro also has no basal protrusion on the paraproct and there are no barbed setae on the subapical lobe of the gonocoxite. Culex subaequalis and Cx. pseudosubaequalis have a basal protrusion on the paraproct and barbed accessory setae on the subapical lobe of the gonocoxite. Culex mongiro shares with Cx. pseudosubaequalis the lack of a ventrolateral patch of long setae on the gonocoxite, which is present in Cx. subaequalis . The mesokatepisternum of both Cx. subaequalis and Cx. pseudosubaequalis lacks white scales. Culex mongiro , on the other hand, has white scales on the mesokatepisternum as in Cx. nebulosus .

Etymology: This species is named Cx. pseudosubaequalis because it closely resembles Cx. subaequalis , with maxillary palpomere 4 longer than half the length of palpomere 5. There are significant differences in structures of the male genitalia of Cx. subaequalis and Cx. pseudosubaequalis .

Specimens examined: The holotype male ( BMEC type # 1921) was collected by sweep netting through forest vegetation in CAMEROON , South-West Region, Nguti Subdivision, Talangaye Forest (5.190397º N; 9.3457790º E) with the following label: Talangaye forest , SE Region, Cameroon, resting in tent. Acc. # CAM132 na 4/ii/2017, date collected 4/ii/2017, Adult ♂, gen and palp mounted, Det. A. J. Cornel. Five paratypes, collected via sweep netting through forest floor vegetation, within 3 km of the holotype. The paratypes have the same label information as the holotype except for different Acc. #s, which are: CAM 62 c 26/VII/2016, CAM 132 b1L 31/I/2017, CAM 132 yF 31/I/2017, CAM 132 d1 6/II/2017 and CAM 202 ma 9/VII/2017 (date on the Acc. #s refers to date they were collected). The holotype and paratypes are deposited in the Bohart Museum , University of California, Davis, California, USA .

Figures

FIGURE 9. External features of the male of Culex pseudosubaequalis. (A) Dorsal view of the vertex; (B,C) lateral views of the thorax; (D) anterior view of the hindfemur.

FIGURE 10. Maxillary palpus of Culex pseudosubaequalis. (A,B,C) Lateral view of palpal comb scales from three individuals (100x).

FIGURE 11. Gonocoxite of Culex pseudosubaequalis.

FIGURE 12. Male genitalia of Culex pseudosubaequalis, lateral plates and paraprocts. (A) drawn depiction; (B) image (400x).