Stegana (Oxyphortica) trisetosa, Chen & Wang, 2004

Chen, Hong-wei & Wang, Bao-cheng, 2004, Stegana (Oxyphortica) Nigripennis Species-Group, With Descriptions Of Four New Species From Southeast Asia (Insecta: Diptera: Drosophilidae), Raffles Bulletin of Zoology 52 (1), pp. 29-36 : 33-34

Stegana (Oxyphortica) trisetosa , new species

( Figs. 11-14 )

Material examined. – Holotype - male, MALAYSIA ( BORNEO): Lambir, Sarawak, coll. M. J. Toda, 8 Jan.1999 ( FRC).

Paratypes - MALAYSIA ( BORNEO) : Sabah: 1 male, Poring, 16 Mar.1999 ( KPSP) ; 1 male, Mahua, Crocker Range, coll. M. J. Toda, 18 Oct.1999 ( ITBC) .

Diagnosis. – Paramere apico-medially and subbasally each with 1 distinct incision ( Fig. 13 ); surstylus with dense, irregular scale-shaped processes basally ( Fig. 12 ).

Description. – Thorax: Mesonotum submedially and laterally with black longitudinal stripes, 2 per side; submedial stripes converge on prescutum. Pleura with 2 long, longitudinal

stripes: one of them below wing, the other from fore coxa to metapleura.

Wing: Dark brown, yellow along posterior margin. Halter: stalk grey; apical part white.

Legs: Mid tibia basally with 3 long, strong posterodorsal setae.

Abdominal tergites yellow, black along lateral and posterior margins. Sternites black.

Male terminalia: Epandrium constricted mid-dorsally, with 1 row of long, strong setae and several short setae along posterior margin ( Fig. 11 ). Paramere inter-subbasally with serrated process ( Fig. 14 ), medially with 1 sclerotized projection ( Fig. 13 ). Aedeagus apically broadly separated ( Fig. 14 ).

Measurements: BL = 6.80 mm in the holotype (range in 2 males paratypes: 6.20-7.00); ThL = 2.45 mm (2.00-2.20), WL = 5.70 mm (5.60-5.80); WW = 2.10 mm (2.00-2.10).

Indices: arb = 14/8 (13-14/7-8), avd = 0.80 (0.75-0.80), adf = 3.50 (3.50-3.60), flw = 2.40 (2.40-2.50), FW/HW = 0.40 (0.40-0.45), ch/o = 0.06 (0.06), prorb = 0.70 (0.70-0.75), rcorb = 0.60 (0.60), vb = 0.40 (0.35-040), dcl = 0.40 (0.40-0.50), presctl = 0.70 (0.70), sctl = 0.90 (0.85-0.90), sterno = 0.85 (0.80-0.85), orbito = 1.20 (1.20), dcp = 0.15 (0.15), sctlp = 1.20 (1.20), C = 2.97 (2.86-2.96), 4c = 0.65 (0.62-0.65), 4v = 1.00 (1.00-1.10), 5x = 0.39 (0.40-0.43), ac = 5.50 (5.20- 5.30), M = 0.14 (0.13-0.15), C3F = 1.00 (1.00).

Etymology. – A combination of the Latin words: “tri-” + “setosa” meaning 3 setae, a reference to the setation of the mid tibia.

Distribution. – Malaysia (Borneo).

Remarks. – This species resembles S. (O.) prigenti in the many characters, but can be clearly distinguished from the latter by apico-medially and subbasally each with 1 distinct incision and surstylus with dense, irregular scale-shaped processes basally.

Figures

Figs. 11-14. Stegana (Oxyphortica) trisetosa, new species, male genitalia: 3. epandrium (epand) and cercus (cerc); 4. surstylus; 5. hypandrium (hypd), paramere (pm), gonopod (gon), aedeagus (aed) and aedeagal apodeme (aed a) (ventral view); 6. ditto (lateral view) (scale-line = 0.1 mm).