Rhaphiocerina chinensis, Li, Zhu, Yang, Ding & Zhang, Tingting, 2016

Li, Zhu, Yang, Ding & Zhang, Tingting, 2016, Review of the genus Rhaphiocerina Lindner (Diptera: Stratiomyinae), with description of a new species, Zootaxa 4111 (1), pp. 53-60 : 57-59

Rhaphiocerina chinensis sp. nov.

( Figs 13–15 , 17–23)

Diagnosis. Postocular rim mostly shiny black, only with a subsquare ivory white spot on each outside of vertex. Thoracic notum shiny black without any spots. Vein M3 incomplete, not reaching wing margin, but distinct and visible. Abdomen shiny black without yellow lateral margin, postero-lateral margins of tergites 3–4 with subsquare yellow lateral spots.

Description. Female ( Figs. 13–15 ). Body length 6.9 mm; wing length 5.6 mm. Head shiny black. Eyes dichoptic, brown and bare. Frons narrow, about 1/5 as wide as head and slightly narrower towards antenna. Frons shiny black and bare. Lower frons swollen above antennae, with a subtriangular ivory white spot reaching eyes. Postocular rim wide, mostly shiny black, only with a subsquare ivory white spot on each outside of vertex. Face shiny black with sparse black hairs. Gena shiny black with pale long hairs. Antenna fulvous, scape nearly as long as pedicel; flagellum spindle-shaped with long slender apical arista. Antennal length ratio of scape: pedicel: flagellum (exclude arista) = 1: 2: 3. Arista twice as long as rest of antenna. Proboscis short and small, yellow with pale hairs.

Thorax shiny black with sparse pale short hairs. Mesonotum without any spots, only thin brown line along upper margin of pleuron running from humeral callus to postalar callus. Lateral and hind margins of scutellum yellow and blackish brown in the middle. Scutellar spines yellow and short. Legs slender and unmodified. All coxae black, the rest fulvous with yellow short hairs. Wing hyaline, tinged with yellow, veins brown to pale yellow with crossvein m-cu distinct. Vein R4 present, three M veins arising from discal cell, vein M3 incomplete, not reaching wing margin, but slightly longer than 1/2 of vein M2. Haltere yellow.

Abdomen shiny black without yellow lateral margin, only with 2 pairs of yellow lateral spots. Tergites 1–2 black; postero-lateral margin of tergites 3–4 with subsquare yellow spots; hind margin of tergite 5 yellow. Sternite blackish brown. Tergite and sternite of abdomen with pale hairs. Female terminalia ( Figs. 18–23 ) with onesegmented cercus, long oval with hairs. Tergite 8 trapezoid with broad and deep V-shaped incision at basal margin. Tergite 9 trapezoid, about three times as wide as long. Tergite 10 triangular, wider than long. Genital furca distinctly longer than wide with straight basal margin; basal part of gentital furca rectangular, longer than wide; postero-lateral projections spindle-shaped in lateral view, tapered towards apex; postero-median projections obtuse triangular. Sternite 10 subtriangular with a small middle incision on basal margin.

Male. Unknown.

Specimen examined. Holotype: ♀, CHINA, Guangxi, Longzhou, Xiangshui, 2006. V. 15, Yin-Xia Liao (CAU). Paratype: 1♀, CHINA, Guangxi, Longzhou, Nonggang, 2006. V. 16, Yin-Xia Liao (CAU).

Distribution. China (Guangxi).

Etymology. The species is named after the type locality China.

Remarks. Although sexual dimorphism occurs in Stratiomyinae , for the genus Rhaphiocerina , there are not too many differences in external characters between males and females except head characters. For R. hakiensis , eyes are contiguous in males and separated in females, resulting in sexually dimorphic frons characteristics. Other head characteristics are the same in both sexes.

The new species is similar to Rhaphiocerina hakiensis ( Matsumura, 1916) from Japan, but may be separated from the latter in the following characters: postocular rim is mostly shinning black, only with a subsquare ivory white spot on each outside of vertex; mesonotum has not any yellow spots and stripes; vein M3 slightly longer than 1/2 of vein M2; abdomen has no yellow lateral margin, only with yellow lateral spots on tergites 3–4. In Rhaphiocerina hakiensis , upper 2/3 of postocular rim is yellow and lower 1/3 is black; mesonotum has a pair of yellow longitudinal stripes; vein M3 no longer than 1/2 of vein M2; abdomen has the broad yellow lateral margin, tergites 2–4 have stripe-like yellow lateral spots.

Figures

FIGURES 13 – 15, 17. Rhaphiocerina chinensis sp. nov. 13. Female body, dorsal view. 14. Female frons, frontal view. 15. Female head, lateral view. 16. Wing (Rhaphiocerina hakiensis). 17. Wing.

FIGURES 18 – 23. Rhaphiocerina chinensis sp. nov. 18 – 23. Female terminalia: 18. Tergite 8, dorsal view. 19. Tergite 9, dorsal view. 20. Tergite 10 and cerci, dorsal view. 21. Genital furca, ventral view. 22. Genital furca, right lateral view. 23. Sternite 10, ventral view.