Homoneura (Chaetohomoneura) disciformis, Shi, Li, Wang, Jun Chao & Yang, Ding, 2011

Shi, Li, Wang, Jun Chao & Yang, Ding, 2011, Nine new species from China of the subgenera Chaetohomoneura and Neohomoneura in the genus Homoneura (Diptera, Lauxaniidae), Zootaxa 2975, pp. 1-28 : 5-6

Homoneura (Chaetohomoneura) disciformis sp. nov.

( Figs. 1, 5 , 9–18 )

Diagnosis. Frons slightly longer than wide, with a yellow triangular median spot on anterior margin. Face pale brown except black ventral and lateral margins, with a yellow median spot near ventral margin, rarely absent. Palpus dark brown. Mid femur with 3–4 strong pv. Wing slightly yellow, without spots. Abdominal tergites 1–2 yellow and tergites 3–6 black, protandrium and epandrium yellow.

Description. MALE. Body length 6.0– 6.5 mm, wing length 5.7–6.3 mm.

Head ( Fig. 10 ) pale brown. Frons slightly longer than wide and parallel–sided, with a yellow triangular median spot on anterior margin; ocellar triangle grayish black with two rows of short setulae situated between ocellar triangle and poc; oc developed, longer than posterior or. Face pale brown except black ventral and lateral margins, with a yellow median spot near ventral margin, rarely absent. Gena yellow, about 1/7 height of eye. Antennal scape and pedicel brownish yellow, and 1st flagellomere brown, about 1.6 times as long as high; arista black except pale brown base, plumose with longest setula as long as 2/3 height of 1st flagellomere. Proboscis pale brown, with yellowish and blackish setulae; palpus dark brown, with black setulae.

Thorax ( Fig. 1 , 11 ) brownish yellow with gray pruinosity. Mesonotum with 0+3 dc, acr in 10 rows and prsc longer than anteriormost dc. 2 sa (posterior sa longer than 1/2 length of anterior sa); anepisternum brown with grayish pruinosity, katepisternum yellow, 1 anepst, 2 kepst. Scutellum brownish yellow to pale brown, with grayish pruinosity. Legs mostly brownish yellow, except for fore femur blackish brown, mid and hind femora pale brown, and tarsomeres 3–5 brown. Fore femur with 5–6 strong pv and 10 pd, and ctenidium with 15–17 short setae; fore tibia with 1 strong preapical ad and 1 short apv. Mid femur with 6–7 a, 3–4 strong pv and 1 app; mid tibia with 1 strong preapical ad, 6 short p and 4 strong apv ( Fig. 5 ). Hind femur with a row of strong av ( Fig. 5 ) and 1 preapical ad; hind tibia with 1 strong preapical ad and 1 short apv. Wing ( Fig. 13 ) slightly yellow, without spot; subcostal cell hyaline; 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 3.0 mm: 0.8 mm: 0.6 mm; r-m before middle of discal cell; ultimate and penultimate sections of M 1 in proportion of 2.0 mm: 2.7 mm; ultimate section of CuA1 about 1/7 of penultimate. Halter yellow.

Abdominal tergites 1–2 yellow and tergites 3–6 black, protandrium and epandrium yellow. Male genitalia ( Figs. 14–18 ): protandrium circular with a small rectangular ventral segment; epandrium nearly U–shaped and broad apically in posterior view, with many short setae; surstylus consisting of a short digitiform inner process and a long knee–like curved process with subapical setulae and dorsal teeth; hypandrium nearly H–shaped with apodeme short; gonopod incurved and disciform apically in ventral view; aedeagus consisting of four pairs of teeth on lateral side, a pair of subapical concavity and a deep distal incision in ventral view; aedeagal apodeme nearly as long as aedeagus.

FEMALE. Unknown.

Type material. Holotype ♂ ( IZCAS, IOZ 1665962), CHINA, Yunnan Province: Xishuang banna, Menghai, Mengzhe (870 m), 10. VII. 1958, Zhizi Chen. Paratypes: CHINA, Yunnan Province: 1 ♂ ( IZCAS, IOZ 1665991), Xishuang banna, Menghai, Mengzhe (870 m), 11. VII. 1958, Zhizi Chen; 1 ♂ ( IZCAS, IOZ 1665978), Xishuangbanna, Jinghong, Ganlanba (560 m), 19. IV. 1957, Guangji Hong; 1 ♂ ( IZCAS, IOZ 1665970), Xishuang banna, Jinghong, Damenglong (650 m), 7. X. 1958, Zhizi Chen.

Distribution. China (Yunnan).

Remarks. The species is somewhat similar to Homoneura (Chaetohomoneura) luteoscutellata Sasakawa from Malaysia in the following characters: the scutellum being brownish yellow, the wing lacking spots and the mid femur having 3–4 pv. But it can be separated from the latter by the face having a yellow median spot near ventral margin, rarely absent; the mid tibia having 6 p; the abdominal tergites 1–2 being yellow and tergites 3–6 being black, and the protandrium and epandrium being yellow; the protandrium being circular, the surstylus being distinct with two processes, the hypandrium being nearly H–shaped, the gonopod being disciform apically in the ventral view; the aedeagus having no large acuate processes in the ventral view. In H. (C.) luteoscutellata , the face is entirely black with sparse grayish white pruinosity; the mid tibia has 2–4 p; the abdomen is entirely black with grayish pruinosity (1 holotype Ƥ, No. 15063, Bernice P. Bishop Museum, Honolulu, Hawaii, USA); the protandrium is horseshoe–shaped, the surstylus is absent, the hypandrium is Y–shaped, the tip of the gonopod is narrow and blunt in the ventral view, the aedeagus has three pairs of acuate processes in the lateral view. ( Sasakawa, 1992).

Etymology. Latin, disciformis , meaning disciform, referring to the gonopod being incurved and disciform apically in the ventral view; a feminine adjective.

Figures

FIGURES 1 – 8. Thorax, lateral view and leg. Homoneura (Chaetohomoneura) disciformis sp. nov. 1. thorax, 5. mid and hind femosa; Homoneura (Chaetohomoneura) umbrosa Malloch, 1929. 2. thorax, 6. mid tibia and femur; Homoneura (Neohomoneura) nadaensis Yang, Hu & Zhu, 2002. 3. thorax, 7. mid tibia; Homoneura (Neohomoneura) setuligera Gao & Yang, 2005. 4. thorax, 8. mid tibia.

FIGURES 9 – 13. Homoneura (Chaetohomoneura) disciformis sp. nov. Male. 9. habitus, lateral view; 10. head, anterior view; 11. mesonotum, dorsal view; 12. abdomen, dorsal view; 13. wing.

FIGURES 14 – 18. Homoneura (Chaetohomoneura) disciformis sp. nov. Male. 14. protandrium and epandrium, lateral view; 15. protandrium, anterior view; 16. epandrial complex, posterior view; 17. aedeagal complex, ventral view; 18. aedeagal complex, lateral view. Scale 0.1 mm.