Simulium (Montisimulium) wulaofengense Chen and Zhang

Han-Bin, Chen, Guo-Sheng, Lian & Chun-Lin, Zhang, 2011, A faunal summary of Simulium (Montisimulium) with descriptions of five new species from China (Diptera: Simuliidae), Zootaxa 3017, pp. 51-68 : 62-64

Simulium (Montisimulium) wulaofengense Chen and Zhang , sp. nov.

( Fig. 44–53 )

Male. Body length 3.2 mm.

Head. Width equal to that of thorax, with large upper-eye facets arranged in 16 vertical and 17 horizontal rows. Clypeus black with sparse brown hairs. Antenna composed of 2+9 segments, which are dark brown except scape yellowish brown; 1st flagellomere about 1.9 times as long as following one. Maxillary palp blackish, with 5 segments, proportional length of 3rd to 5th segments 5.2:5.7:11.4; sensory vesicle elongate about 2.0 times as long as wide.

Thorax. Scutum dark brown, covered densely with golden pubescence as well as sparse erect black hairs on prescutellar area. Scutellum greyish yellow with sparse golden pubescence and black hairs. Postscutellum black and bare. Pleural membrane and katepisterum bare. Legs. All coxae and trochanters dark brown except fore trochanter pale. Fore and mid femora pale with distal 1/4 dark brown; hind femur pale with distal 1/3 brownish. All tibiae brown except median large portion of outer surface which is pale yellow. All tarsi brown except hind basitarsus and basal 1/2 of second tarsomere which are pale yellow. Fore basitarsus slender, about 9.0 times as long as wide. Hind basitarsus somewhat inflated, W:L ratio 1.0:4.0. Calcipala and pedisulcus developed. Wing: Costa with spinules as well as hairs. Subcosta with distal 2/3 hairy. Basal section of radius fully haired. Base of radius with a tuft of black hairs.

Abdomen. Basal scale brown with a fringe of brownish hairs. Terga brownish black with dark hairs. Genitalia: Gonocoxite in ventral view nearly rectangular, about 1.4 times as long as wide. Gonostyle much short than gonocoxite, rather wide in middle, abruptly benst inward, and much narrowed subapical toward apex, with apical spine. Ventral plate in ventral view butterfly shaped, with distal margin concave and proximal median margin distinctly produced forward, setose medially, basal arms about 2/3 length of plate body and converging apically. Parameres each with about 10 strong hooks. Median sclerite rod shaped with apex widened.

Female. Only one specimen dissected from pupa and limited characters are described. Body length 3.5 mm.

Head. Slightly narrower than thorax. Frons and clypeus brownish, grey-dusted. Frontal ratio 7.2:5.5.6:6.1; frons-head ratio 7.2:25.7. Antenna composed of 2+9 segments, which are brownish black except scape brownish yellow, first flagellomere about 1.6 times as long as the second one. Maxillary palp with 5 segments, proportional lengths of 3rd to 5th segments 5.0:4.7:10.8; 3rd segment enlarged, sensory vesicle ellipsoidal, which is about 0.6 length of respective segment. Maxilla with 9 inner teeth and 12 outer ones. Mandible with 33 inner teeth and lacking outer ones.

Thorax. Scutum black, covered uniformly with golden yellow pubescence as well as sparse black hairs on prescutellar area. Scutellum greyish brown, with sparse golden yellow pubescence. Postscutellum black and bare. Pleural membrane and katepisternum bare. Legs and wing nearly as in female except hind basitarsus slender, nearly parallel-sided, about 7.0 times as long as wide and subcosta of wing hairy.

Abdomen. Nearly as in female except genitalia unknown.

Pupa. Body length about 4.0 mm.

Head and thorax. Integument pale yellow, sparsely covered with disc-like tubercles. 3 pairs of head trichomes simple and minute, whereas thorax with 6 pairs of slender and simple trichomes. Gill with 12 filaments approximately 2/3 length of pupal body, arranged in groups of 2+3+3+4 from dorsal to ventral; all filaments widely divergent and distally tapering and with conspicuous tubercles as well as minute ones.

Abdomen. Arrangement of setae, spines and hooks of both dorsal and ventral surfaces of abdomen similar to those of S. (M.) xinzhouense sp. nov. Cocoon: Slipper-shaped, tightly woven, and without a definite anterior margin.

Mature larva. Body length about 7.0 mm. Cephalic apotome with faint positive head spots. Antenna with 3 segments in proportions of 6.5:8.0:3.4. Labral fan with 28 main rays. Mandible with a large and a small mandibular tooth but lacking any supernumerary serrations. Hypostomal teeth 9 in number, median and corner teeth strongly prominent and intermediate ones smallest. Hypostomal bristles 4 in number on each side. Postgenal cleft very minute. Thoracic and abdominal integument bare. Anal sclerite X-formed with anterior arms short, about 0.8 times as long as posterior ones. Posterior circlet with about 76 rows of up to 16 hooklets per row. Ventral papillae prominent.

Type materials. Holotype 3, reared from pupa, slide-mounted with pupal exuviae and cocoon. Paratype, Ƥ, dissected from pupa, 2 pupae and 2 larvae, collected from stone in a small stream from Wulaofeng, Yongji city (34°18ʹN, 110°61ʹE, 1100 m) Shanxi Province, China, 10 July 2007, by Lian Guo-Sheng.

Distribution. Shanxi Province. China.

Remarks. This new species belongs to Simulium (Montisimulium) . It is characterized by having 12 filaments in the pupa. This character is shared with several known species. The new species is most closely related to S. (M.) taishanense Sun and Li, 2000 from China, but the latter species differs by the small female sensory vesicle, the shape and structure of the male genitalia and segment 2 of the antenna with 4 pale rigs in the larva.

Etymology. The specific name was given for its type locality.

Figures

FIGURES 44 – 53. S. (M.) wulaofengense Chen and Zhang, sp. nov. 44. Gonocoxite and gonostylus of male; 45. Ventral plate; 46. Median sclerite; 47. Male sensory vesicle; 48. Female sensory vesicle; 49. Cocoon in dorsal view; 50. Filaments; 51. Larval head capsule in ventral view; 52. Larval mandible; 53. Larval anal sclerite.