Cacoxenus (Nankangomyia) gani, Chen, 2007

Chen, Hong-Wei, 2007, Two new species of the subgenus Cacoxenus (Nankangomyia) from the Oriental Region (Diptera, Drosophilidae), Journal of Natural History 41 (41 - 44), pp. 2701-2706 : 2702-2704

Cacoxenus (Nankangomyia) gani sp. nov.

( Figures 1–7 )

Diagnosis

Surstylus distally elongated, apically pointed, lacking prensiseta ( Figures 2, 3 ); paramere apically pointed ( Figures 4, 5 ); aedeagus basally much expanded, distally sclerotized, slightly curved dorsad, apically pointed ( Figures 4, 5 ).

Description

Head. Eye brown-red. Postvertical setae as small as interfrontal setulae, slightly behind top of vertex ridge. Ocellar triangle brown, with three (two to four) pairs of small setae above ocellar setae. Frontal vitta dark brown, yellow anteriorly, with several thick interfrontal setulae ( Figure 1 ). Proclinate orbital seta before anterior reclinate, nearer to frontal margin than to inner vertical seta. Pedicel dark brown; first flagellomere grey-yellow; arista short plumose, with pubescence ( Figure 1 ). Face dark brown; facial carina slightly bulged. Clypeus dark brown. Palpus rod-shaped, grey-yellow, with several stout setae on lateral margin. Vibrissa prominent; other orals small ( Figure 1 ). Gena yellow; postgena brown. Occiput black.

Thorax. Yellow, with brown-black patches, grey pollinosity, and dark patches around setal sockets. Postpronotal lobe with a long humeral seta and a few small setae. Acrostichal setulae in ca 12 irregular rows. Anepisternum lacking setulae. Katepisternal setae two. Scutellum yellow, with brown patch; basal scutellar setae divergent; apicals cruciate.

Wing. Hyaline; veins grey-yellow. C 1 setae two, less differentiated. Basal medial-cubital crossvein present. Costal vein lacking minute spinules on ventral surface between R 2+3

and R 4+5. R 2+3 slightly curved to costa at tip; R 4+5 and M 1 distally nearly parallel. Halters white.

Legs. Yellow. Apical and preapical setae present on all tibiae. Fore femur with one to two row(s) of setae on posterior surface. Hind tarsus without a row of minute cuneiform setulae ventrally.

Abdomen. All tergites brown with grey pollinosity, pale on median of first and second; third to six with narrow, silver-grey bands along posterior margins. Sternites yellow-grey.

Male terminalia. Epandrium pubescent, with about 15 setae near posterior margin; anteroventral corners not protruded ( Figure 2 ). Surstylus separated from epandrium, basally with strong setae, submedially protruding with several setulae ( Figures 2, 3 ). Cercus separated from epandrium, entirely pubescent and setigerous. Membrane between epandrium and cercus pubescent. Hypandrium broad, plate-like, lacking pubescence and paramedian setae ( Figures 4, 5 ). Parameres sclerotized, basally articulated with aedeagal apodeme; with ca 10 sensilla arranged longitudinally ( Figures 4, 5 ). Gonopods anteriorly not fused to aedeagus, forming posteromedian low plate, posterolaterally contiguous to posterior ends of hypandrium and anteroventral corners of epandrium ( Figures 4, 5 ). Aedeagal apodeme lobe-like, horizontally flattened, with a pair of arms fused to base of parameres ( Figures 4, 5 ).

Female terminalia. Epiproct with a few setae ( Figure 6 ). Circus setigerous, lacking pubescence ( Figure 6 ). Spermatheca deeply introverted ( Figure 7 ).

Measurements. BL 53.35 mm in holotype, range in 3 „ paratypes: (3.20–3.35); ThL 51.70 mm (1.65–1.70), WL 53.20 mm (2.90–3.20); WW 51.50 mm (1.40–1.50).

Indices. arb58–10/7–8 (8–11/7–9), avd50.50 (0.50–0.60), adf51.10 (1.00–1.20), flw52.20 (2.10–2.20), FW/HW50.30 (0.30), ch/ o50.14 (0.12–0.14), prorb51.00 (0.94–1.00), rcorb50.86 (0.76–0.86), vb50.35 (0.30–0.35), dcl50.50 (0.45–0.50), presctl50.75 (0.70–0.80), sctl51.10 (1.10), sterno50.92 (0.90–0.95), orbito51.90 (1.80–1.90), dcp50.24 (0.24), sctlp51.00 (1.00), C52.33 (2.46–2.73), 4c51.00 (0.96– 1.00), 4v51.86 (1.85–2.11), 5x51.00 (0.92–1.00), ac51.76 (1.58–1.75), M50.46 (0.46– 0.53), C3F50.65 (0.63–0.64).

Type material

Holotype: „, China: Qiongzhusi, Kunming , Yunnan, alt. 2100 m, 21 July 2004, H. W. Chen leg. ( SCAU). Paratypes: 3 „, 2♀, same data as holotype except for 13 July 1986, Y. X. Gan leg. (2 „, 1♀, KIZ; 1 „, 1♀, SCAU).

Distribution

China (Yunnan).

Relationship

This species is very similar to Ca. (Na.) academicus in the arista short plumose and shape of paramere, but can be distinguished from the latter in surstylus and aedeagus (in academicus : surstylus neither distally elongated nor apically pointed; aedeagus neither basally expanded nor distally sclerotized).

Etymology

Patronym, in honor of Prof. Yunxing Gan (KIZ).

Figures

Figures 1–7. Cacoxenus (Nankangomyia) gani sp. nov., „. (1) Head. (2) Epandrium, cercus and surstylus, lateral view. (3) Surstylus, frontal view. (4, 5) Hypandrium (hypd), gonopod (gon), parameres (pm), aedeagus (aed), and aedeagal apodeme (aed a), ventral and lateral views, respectively. (6) Epiproct and circus, lateral view. (7) Spermatheca.