Setostylus triumphus Qi, Huang et Wang, 2022

Qi, Lei, Huang, Junhao, Wu, Hong & Wang, Qingyun, 2022, Two new species of Setostylus Matile, 1990 (Diptera: Keroplatidae) from China, Zootaxa 5165 (3), pp. 443-450 : 446-448

Setostylus triumphus Qi, Huang et Wang sp. n.

( Figs 3–4 )

Diagnosis. This new species resembles the type species of the genus, S. singularis (Lane) in the male adult appearance, but it can be easily distinguished from the latter by the suboval and brown maxillary palpus of the male, and the gonocoxites having raised posteromesal part in the male terminalia. In S. singularis , the maxillary palpus is globose and black, and the gonocoxites have emarginated posteromesal part.

Type material. Holotype. Male, CHINA: Zhejiang, Mt. Longwang (30.24° N, 119.26° E), 980 m, 27.VII.2018, coll. Caixia Liu, slide no. LWS-5-59 . Paratype. Male, CHINA: Guangdong, Mt. Dinghu (23.10° N, 112.32° E), 235 m, 12.VI.2020, coll. Lei Qi, slide no. DHS-8-67 .

DNA barcode. The DNA barcode sequences from holotype and paratype are deposited in BOLD and GenBank. The BIN number is AEJ 6195 in BOLD. The GenBank accession numbers for holotype and paratype are ON190027 and ON190028 , respectively .

Description Male ( Fig. 3 ). Body length (without antennae) 5.0 mm. wing length 1.4 mm, width 3.0 mm.

Head ( Fig. 4a ) pale brown, with width 1.2 times of its height. Vertex with numerous dark setae, frons and face bare. Three ocelli in approximately linear arrangement, medial ocellus about 1/3 diameter of lateral one. Compound eyes almost hemispheric, covered with pointed setae. Clypeus pale brown with 12–16 dark brown setae. Mouthparts reduced, maxillary palpus with two segments, segment 2 erecting forward, suboval, with 8–10 setae laterally. Antenna ( Fig. 4c ) brown and strongly compressed; scape and pedicel nearly funnel-shaped, bearing several subapical and apical setae; flagellum pectinate and 14-segmented, each flagellomere bearing 6–10 setae on dorsal edge, segments 1–8 with a few microtrichia ventrally, subtriangular apically.

Thorax ( Figs 4d–e ) pale brown to brown. Scutum brown, bearing dense setae, with a V-shaped streak. Scutellum brown, with a row of marginal setae. Mediotergite pale brown, bare. Anepisternum dark brown, with several setae on top corner. Laterotergite pale brown and subrectangular, bare. Halter length 0.3 mm, stem translucent; knob dark brown, bearing sparse setae.

Wing ( Fig. 4b ) brown, without pattern, bearing dense microtrichia on surface. Wing margin with short brown setae. R 1 and R 4+5 with dark setae arranged along the veins. Vein C stops at nearly middle of R 4+5 to M 1. Sc ends at basal 1/3 of C, about half length of R 1. Vein m-cu and R+M fusion subequal in length; Rs about twice of m-cu in length. CuA curved. CuP free, with end approaching to outer margin.

Legs ( Fig. 3 ) pale brown to dark brown. Fore coxa brown. Mid coxa with basal 2/3 pale brown and bare, distal 1/3 dark brown and setose. Hind coxa dorsally covered with sparse setae. Femur, tibia and tarsus brown, covered with numerous setae. Hind tibia with two combs apically, in linear arrangement.

Abdomen ( Fig. 3 ) pale brown to dark brown, bearing dense dark setae. Tergite 1 brown, tergites 2–4 somewhat transparent, tergites 5–8 dark brown.

Terminalia ( Figs 4f–h ) brown. Tergite 9 subtrapezoidal, with abundant setae. Gonostylus curved, narrowed gradually from base to end; basal 1/2 bearing abundant dark brown setae on surface, 8–10 black spines on inner margin medially, and having a triangular projection distal-laterally; distal 1/2 hyaline, bare, with a dark brown apical bristle; hyaline part about twice length of bristle. Gonocoxites brown, bearing dense setae; posterior margin raised and divided medially, with 8–10 black strong spines posteriorly. Cercus thinly digitate, bearing setae.

Female. Unknown.

Etymology. The name of this new species is derived from the Latin word triumphus (victory), referring to the V-shaped streak on the scutum.

Figures

FIGURE 3. Setostylus triumphus sp. n., holotype, mlae, lateral view.

FIGURE 4. Setostylus triumphus sp. n., holotype. a. head (frontal view), antennae removed; b. wing; c. antenna; d–e. thorax (d. lateral view; e. dorsal view); f–h. terminalia (f. vertral view, with a close-up of gonostylus in the upper right; g. dorsal view; h. lateral view). Slide No. LWS-5-59.