Tetroxyrhina tengchongenisis, Shi, Li, Gaimari, Stephen D. & Yang, Ding, 2017

Shi, Li, Gaimari, Stephen D. & Yang, Ding, 2017, Five new species of the genus Tetroxyrhina Hendel from China (Diptera, Lauxaniidae), Zootaxa 4247 (3), pp. 246-280 : 258-260

Tetroxyrhina tengchongenisis sp. nov.

( Figs 21–24 , 79–83 )

Diagnosis. Frons with three narrow blackish brown stripes (two lateral stripes weak). Face with pale brown triangular spot under each antennal base. Arista black, pubescent. Fore tarsus pale brown, mid and hind tarsomeres 4–5 pale brown. Wing slightly darkened, with darker tinged brown apical spots on R2+3, R4+5 and M1 confluent, forming a wide stripe and extending to posterior margin; three pale brown spots on R4+5 divided by two indistinct hyaline spots; a narrow hyaline stripe present between R2+3 and R4+5; brown spot on each of crossveins r-m and dmcu; subcostal cell brown. Abdomen mostly blackish brown except yellow on two lateral margins in dorsal view, tergites 1–5 each with a pale yellow median spot on anterior margin; male tergite 6 and female tergites 6–7 yellow on anterior 1/2 and blackish brown on posterior 1/2.

Description. MALE. Body length 3.4–3.8 mm, wing length 3.6–4.1 mm. FEMALE. Body length 4.1–4.4 mm, wing length 3.8–4.5 mm.

Head ( Figs. 79–80, 83 ) yellow. Frons with broad brown area consisting of three narrow dark brown stripes (two lateral stripes weaker) extending to ocellar triangle, and black short setulae on anterior 1/2, nearly 1.4 times longer than wide and parallel-sided; ocellar triangle grayish black; anterior fronto-orbital setae reclinate, slightly shorter than posterior. Facial keel distinct on upper part between bases of antennae; pale brown triangular spot under each antennal base; gena about 1/2 height of eye, with wide dark brown stripe. Antenna yellowish brown, 1st flagellomere rounded apically, nearly 1.4 times longer than high; arista black, pubescent. Orbito-antennal spot distinct, present as a brown round spot between eye and base of antenna. Proboscis mostly yellow except brown at tip, with yellow and blackish setulae; palpus yellow with black setulae.

Thorax ( Figs. 79–80 ) brown, with sparse grayish white pruinosity. Mesonotum with narrow yellow dorsocentral vittae and a narrow yellow median vitta, all of which extend through otherwise brown scutellum, with median stripe widening posteriorly to edge; 0+3 dorsocentral setae, acrostichal setulae in 4 rows; prescutellar acrostichal seta shorter than 1st postsutural dorsocentral seta; anepisternum and katepisternum mostly dark brown with sparse grayish white pruinosity, upper margin of anepisternum pale yellow to lemon yellow; 1 anepisternal seta, 1 katepisternal seta. Legs mostly yellow, except fore tarsus pale brown, mid and hind tarsomeres 4–5 pale brown. Fore femur with 4–5 posteroventral setae and 6 posterodorsal setae; fore tibia with 1 preapical anterodorsal seta and 1 weak apicoventral seta. Mid tibia with 1 strong preapical anterodorsal seta, 1 strong apicoventral seta. Hind femur with 1 weak preapical anterodorsal seta; hind tibia with 1 preapical anterodorsal seta and 1 short apicoventral seta. Wing ( Fig. 81 ) slightly darkened, with darker tinged brown apical spots on R2+3, R4+5 and M1 confluent, forming a wide stripe and extending to posterior margin; three pale brown spots on R4+5 divided by two indistinct hyaline spots; narrow hyaline apical stripe present between R2+3 and R4+5 distally; brown cloud on each of crossveins r-m and dm-cu; subcostal cell brown; costa with 2nd (between R1 and R2+3), 3rd (between R2+3 and R4+5) and 4th (between R4+5 and M1) sections in proportion of 7.7:1.3:1; crossvein r-m beyond middle of discal cell; ultimate and penultimate sections of M 1 in proportion of 1: 1.2; ultimate section of CuA1 about 1/5 of penultimate. Halter yellow except knob black.

Abdomen ( Figs. 79, 82 ) blackish brown, tergites 1–5 each with a pale yellow median spot on anterior margin; male tergite 6 (female 6–7) yellow on anterior 1/2 and blackish brown on posterior 1/2; male sternite 6 membranous with associated pair of rhombic sclerites. Male genitalia ( Figs 21–24 , 82 ): epandrium nearly triangular, with four pairs of dorsal setae on brown protruding subbasal area, with pair of black conical dorsoapical processes with setae, and tiny ventral incision on anterior margin, and incision on ventral margin; hypandrium narrow, with distinct auricular lateral process; phallus with a pair of subbasal teeth in ventral view, funnel-shaped and truncate apically in lateral view.

Type material. CHINA, Yunnan Province: Holotype male ( CAUC), Tengchong autonomic village, 2000 m, 31. V. 2007, Xingyue Liu . Paratypes: CHINA, Yunnan Province: 1 male ( CAUC), Tengchong autonomic village, 2200m, 31. V. 2007, Yanlei Li ; 1 female ( CAUC), Xishuangbanna, Mengla, Yaoqu , 1200 m, 5. VI. 2006, Shan Huo ; 1 female ( CAUC), Longling, Xiaoheishan station , 1528 m, 16. V. 2006, Xingyue Liu.

Distribution. China (Yunnan).

Remarks. The new species is very similar to Tetroxyrhina gressitti Sasakawa from China ( Taiwan) in the following characters: wing with brown cloud on each of crossveins r-m and dm-cu, and abdominal pattern; epandrium nearly triangular, with a pair of black conical dorsoapical processes with setae, but it can be separated from the latter by the wing being dark brown from the anterior costal margin to M1, and subcostal cell brown; the epandrium having four pairs of dorsal setae in a brown protruding subbasal area; and the phallus being funnelshaped and truncate apically in lateral view. In Tetr. gressitti , the wing is hyaline from the costal margin to M1, with a hyaline subcostal cell; the epandrium has no dorsal setae in a dark subbasal area; and the phallus is conical apically ( Sasakawa, 2002).

Etymology. The new species is named after the type locality, Tengchong.

Figures

FIGURES 21 – 24. Tetroxyrhina tengchongensis sp. nov., male genitalia. 21 – 22. Epandrial complex: 21. lateral view; 22. posterior view. 23 – 24. Phallus complex: 23. ventral view; 24. lateral view. Scale 0.1 mm.

FIGURES 79 – 83. Tetroxyrhina tengchongensis sp. nov., holotype male. 79. Habitus, lateral view. 80. Head and thorax, dorsal view. 81. Wing. 82. Abdominal apex, posterolateral view. 83. Head, Anteroventral view.