Homoneura (Homoneura) dilatata Chen & Li, 2024

Chen, Xulong, You, Pengyan, Li, Wenliang & Zhang, Zhisheng, 2024, Seven new species of the subgenus Homoneura Malloch (Diptera, Lauxaniidae, Homoneura) from Jiangjin District, southwestern Chongqing, China, ZooKeys 1206, pp. 45-80 : 45-80

Homoneura (Homoneura) dilatata Chen & Li sp. nov.

Figs 11–15 , 16–20 Chinese name: 膨突同脉缟蝇

Type material.

Holotype: ♂, China, Chongqing City, Jiangjin District, Simianshan Natural Reserve , Zhengqiangou , 28 ° 36 ' 59.54 " N, 106 ° 26 ' 25.88 " E, 1273 m, 14. VI. 2022, leg. Xulong Chen. Paratypes: 1 ♂, China, Chongqing City, Jiangjin District, Simianshan Natural Reserve, Dawopu, 28 ° 34 ' 11.28 " N, 106 ° 20 ' 26.96 " E, 1007 m, 6. IX. 2022, leg. Xulong Chen.

Etymology.

The specific name refers to the phallapodeme expanded apically in lateral view.

Diagnosis.

Mesonotum with acrostichal setulae in ten irregular rows. Basal margin of brown apical spot on R 2 + 3 behind vertical level as crossvein dm-cu; brown apical spots on R 2 + 3, R 4 + 5, and M 1 slightly confluent. Syntergosternite with a setula around spiracle. Surstylus furcated into two short, curved processes in lateral view. Hypandrium with one short subuliform ventral process. Phallapodeme expanded apically in lateral view.

Description.

Male. Body length 7.7–8.1 mm, wing length 7.9–8.0 mm.

Head (Fig. 11 ) yellow. Frons as long as wide and parallel-sided; ocellar triangle yellow, ocellar seta developed, as long as anterior fronto-orbital seta, anterior fronto-orbital seta shorter than posterior fronto-orbital seta. Gena ~ 1 / 8 height of eye. Antenna yellow, first flagellomere ~ 2.0 × longer than high; arista black except pale brown at base, long plumose, with longest ray as long as height of first flagellomere. Proboscis and palpus yellow.

Thorax (Fig. 14 ) yellow, with gray pruinosity. 0 + 3 dorsocentral setae, anteriormost postsutural dorsocentral seta far from scutal suture, acrostichal setulae in ten irregular rows. Legs pale yellow. Fore femur with nine posterior dorsal setae, five posterior ventral setae and ctenidium with 16 short setae; fore tibia with one dorsal preapical seta and one short apical ventral seta. Mid femur with five anterior setae and one apical posterior seta; mid tibia with one dorsal preapical seta and three strong apical ventral setae. Hind femur with several weak anterior ventral setae and one preapical anterior dorsal seta; hind tibia with one weak dorsal preapical seta and one short apical ventral seta. Wing (Fig. 12 ) slightly yellow, basal margin of brown apical spot on R 2 + 3 behind vertical level as crossvein dm-cu; brown apical spots on R 2 + 3, R 4 + 5, and M 1 slightly confluent and forming pale brown connecting area between apical spots on R 2 + 3, R 4 + 5, and M 1; brown median spot on R 4 + 5 separated from brown cloud-like spot on crossvein dm-cu; subcostal cell pale brown apically; three short hairs present at base of R 4 + 5; costa with 2 nd (between R 1 and R 2 + 3), 3 rd (between R 2 + 3 and R 4 + 5), and 4 th (between R 4 + 5 and M 1) sections in proportion of 10.5: 2.7: 2.2; r-m before middle of discal cell; ultimate and penultimate sections of M 1 in proportion of 1: 1; ultimate section of CuA 1 ~ 1 / 6 of penultimate. Haltere yellow.

Abdomen (Fig. 15 ) yellow. Male genitalia (Figs 16–20 ): syntergosternite circular with a trapeziform ventral process, with several dorsal setulae and a setula around spiracle. Epandrium broad in lateral view; surstylus hairy, furcated into two short, curved processes in lateral view. Hypandrium H-shaped, with one short subuliform ventral process. Pregonite V-shaped in ventral view, acute apically, postgonite curved, claviform. Phallus with one small, curved hook in lateral view. Phallapodeme expanded apically in lateral view, slightly shorter than phallus.

Female. Unknown.

Distribution.

China (Chongqing).

Remarks.

The new species resembles Homoneura (Homoneura) martini in brown apical spots on R 2 + 3, R 4 + 5, and M 1 slightly confluent, abdominal tergites 2–5 without blackish brown posterior margin and syntergosternite with long hairs around spiracle [see Shi et al. 2017 b: figs 10, 13, 14, 16], but it can be distinguished from the latter by the following: mesonotum with acrostichal setulae in ten rows; fore femur with five posterior ventral setae; syntergosternite with a trapeziform ventral process; surstylus furcated into two short, curved processes in lateral view; phallapodeme expanded apically. In H. (H.) martini , mesonotum with acrostichal setulae in eight irregular rows; fore femur with three posterior ventral setae; syntergosternite without ventral process; surstylus blunt apically; phallapodeme normal apically [see Shi et al. 2017 b: figs 12, 16, 17, 19].

Figures

Figures 11–15. Homoneura (Homoneura) dilatata sp. nov. male 11 head, anterior view 12 wing 13 habitus, lateral view 14 thorax, dorsal view 15 abdomen, dorsal view.

Figures 16–20. Homoneura (Homoneura) dilatata sp. nov. male 16 syntergosternite and epandrium, lateral view 17 epandrial complex, posterior view 18 syntergosternite, anterior view 19 phallic complex, ventral view 20 phallic complex, lateral view. Scale bar: 0.5 mm.