Pseudostegana Okada, 1978

Li, Tong, Gao, Jianjun & Chen, Hongwei, 2010, Six new species of the genus Pseudostegana (Diptera: Drosophilidae) from the Oriental region, Journal of Natural History 44 (23 - 24), pp. 1401-1418 : 1402-1406

Pseudostegana Okada, 1978

Stegana (Pseudostegana) Okada 1978: 392 ; Okada 1982: 39. Type species: Stegana (Parastegana) grandipalpis Takada and Momma 1975: 12 .

Pseudostegana: Sidorenko 2002: 14 (as a genus); Chen et al. 2005: 407.

Diagnosis

Postvertical and prescutellar setae absent; ocellar setae outside triangle made by ocelli; arista with one ventral branch except for terminal fork; anterior dorsocentral seta minute; wing hyaline, mostly with dark band(s); all femora, tibiae and first tarsomeres slender; foreleg first tarsomere with four to six black, short, thick setae; abdominal tergites mostly glossy; seventh tergite present in male ( Chen et al. 2005).

Description

Head ( Figure 1 ). Eye brownish red. Ocellar triangle mostly, broadly or narrowly elongated to anterior margin of frons. Frons mostly glabrous, lacking minute, interfrontal setulae. Anterior reclinate orbital seta minute; posterior reclinate orbital seta situated nearer to proclinate seta than to inner vertical. Arista with long, dorsal branches. Clypeus brown to black. Subvibrissa mostly longer than half length of vibrissa. Palpus slender in female, variable in male.

Thorax. Scutum and scutellum dorsally convex. Katepisternal setae two or three; medial one shortest. Scutellum usually pale at tip; subscutellum swollen.

Wing ( Figure 2 ). Basal medial-cubital cross-vein absent. Costal vein extending beyond tip of R 4+5 vein, with five to seven peg-like spinules on ventral surface between veins R 2+3 and R 4+5. R 2+3 vein slightly curved to costa at tip; M vein strongly convergent to R 4+5 vein.

Haltere. Stalk greyish; knob white.

Legs. Mostly yellow, slender. Midleg tibia basally without strong, posterodorsal setae.

Abdomen. Sternites usually yellow to brown.

Male terminalias. Epandrium broad, sometimes slightly constricted middorsally, pubescent except for anterior margin. Surstylus separated from epandrium, mostly lacking pubescence, with several setae on outer and inner surfaces. Cercus separated from epandrium, pubescent and setigerous. Hypandrium broad, large, laterally mostly with one pair of paramedian setae, midanteriorly connected with apical part of aedeagal apodeme by aedeagal guide. Paramere with two long sensilla distally and several, small sensilla. Gonopods forming posteromedian lobe, basolaterally contiguous to parameres. Aedeagus usually with one pair of flap-like, serrated processes basally. Aedeagal apodeme long, rod-shaped, basally laterally flattened.

The latiparma species group

Diagnosis

Wing basally with distinct, cross band ( Figures 2A–D ).

Included species

Pseudostegana albinotata ( Okada 1982) from Philippines, Pseudostegana angustifasciata Chen and Wang 2005 from China, Pseudostegana bifasciata Chen and Wang 2005 from China, Pseudostegana dactylis Chen and Toda 2005 from Malaysia, Pseudostegana hirta ( Okada 1982) from Philippines, Pseudostegana latiparma ( Okada 1982) from Philippines and Papua New Guinea, Pseudostegana latizonaria ( Okada 1982) from Philippines, Pseudostegana lineoparma ( Okada 1982) from Papua New Guinea, Pseudostegana orbicapitata Chen and Toda 2005 from Malaysia, Pseudostegana pallidimaculata Chen and Wang 2005 from China, Pseudostegana philoga Chen and Toda 2005 from Malaysia, Pseudostegana acutifoliolata sp. nov., Pseudostegana bilobata sp. nov. and Pseudostegana minutipalpata sp. nov. from China, Pseudostegana bipartita sp. nov. from Indonesia.

Key to species of the latiparma group

1. R-m cross-vein clear............................................ 2 R-m cross-vein clouded........................................ 10

2. Ocellar triangle narrower than one-sixth of frontal width.... P. lineoparma Ocellar triangle medially as broad as one-third of frontal width......... 3

3. Palpus expanded, medially one-third to half as wide as long............ 4 Palpus slender, rod-shaped...................................... 6

4. Paramere distally deeply bifurcated, without lobe-like process; aedeagus apically roundly expanded in ventral view, broadened on distal half in lateral view, about three times basal width................. P. bipartita sp. nov. Paramere apically shallowly bifurcated at most, with expanded lobe-like process; aedeagus apically not expanded in ventral view, distally narrowed and curved in lateral view....................................... 5

5. Paramere apically shallowly bifurcated, subapically lacking small projection, dorsomedially slightly roundly protruded in lateral view...... P. bifasciata Paramere apically not bifurcated, subapically with one small, acute projection, dorsomedially triangularly protruded in lateral view......................................................... P. acutifoliolata sp. nov.

6. Medial band broader than length of dm-cu cross-veins................ 7 Medial band narrower than length of dm-cu cross-veins............... 8

7. Paramere apically pointed, without lobe-like process............ P. hirta Paramere apically with expanded lobe-like process and strongly sclerotized, acute projection............................ P. minutipalpata sp. nov.

8. Paramere distally narrowed, without expanded part......... P. latiparma Paramere distally with expanded part.............................. 9

9. Paramere subapically triangularly expanded in ventral view; basal process of aedeagus membranous, lacking finger-like processes..... P. angustifasciata Paramere subapically roundly expanded in ventral view; basal process of aedeagus with finger-like processes................... P. pallidimaculata

10. Palpus slender, rod-shaped; ocellar triangle distinct, medially broader than a quarter of frontal width.........................................11 Palpus expanded, medially a half as wide as long; ocellar triangle narrower than a quarter of frontal width...................................12

11. Paramere submedially curved, not expanded in ventral view, apically not shallow split......................................... P. latizonaria Paramere submedially expanded, not curved in ventral view, apically shallow split....................................... P. bilobata sp. nov.

12. Medial band confluent with r-m patch.................... P. albinotata Medial band separated from r-m patch.............................13

13. Wing medial band narrower than basal band; paramere apically pointed, subapically with one small projection; distal half of aedeagus expanded in lateral view, about three times basal width................... P. dactylis Wing medial band broader than basal band.........................14

14. Paramere bifurcated from middle, submedially with two small projections; aedeagus medially slightly broader than apical part in ventral view; basal process slightly sclerotized, with about three finger-like processes.......................................................... P. orbicapitata Paramere apically bifurcated; aedeagus medially broader than two times of apical part in lateral view; basal process of aedeagus membranous, lacking processes.............................................. P. philoga

Figures

Figure 1. Frons and palpus of male. (A, B) Pseudostegana acutifoliolata sp. nov.; (C,D) Pseudostegana bilobata sp. nov.; (E,F) Pseudostegana bipartita sp. nov.; (G,H) Pseudostegana minutipalpata sp. nov.; (I,J) Pseudostegana insularis sp. nov.; (K,L) Pseudostegana silvana sp. nov.

Figure 2. Wing of male: (A). Pseudostegana acutifoliolata sp. nov.; (B) Pseudostegana bilobata sp. nov.; (C) Pseudostegana bipartita sp. nov.; (D Pseudostegana minutipalpata sp. nov.; (E) Pseudostegana insularis sp. nov.; (F) Pseudostegana silvana sp. nov. Scale bars: 1 mm.