Stegana (Oxyphortica) dehiscens Cheng and Chen, 2017

Wang, Nannan, Zhang, Yuan, Cheng, Yu & Chen, Hongwei, 2017, Nine new species of the subgenus Stegana (Oxyphortica) from the Oriental region, with morphological and molecular evidence based on Chinese species (Diptera: Drosophilidae), Journal of Natural History 51 (33 - 34), pp. 1943-1970 : 1959-1961

Stegana (Oxyphortica) dehiscens Cheng and Chen , sp. nov.

Diagnosis

This species differs from the other known species of the subgenus in the surstylus large, deeply bilobed subbasally, with six small prensisetae on inner surface ( Figure 11 (a, b)), the gonopods sclerotized basally, anterodistally membranous and bearing dense hair on the inner surface ( Figure 11 (c, d)).

Description

Clypeus and palpus dark brown. Mesoscutum nearly brown. Katepisternum brownish above, yellow below. Scutellum brown, yellow along margin. Wing fuscous anteriorly, pale posteriorly. All abdominal tergites brown in male, black except two basal ones yellow in female. Sternites yellow in male, dark brown to black in female. Male terminalia: Epandrium undeveloped on posterolateral corners, with dense pubescence and setae ( Figure 11 (a)). Cercus lacking pubescence ( Figure 11 (a)). Surstylus with numerous setae on outer surface ( Figure 11 (a)). Parameres fused, with a few sensilla per side ( Figure 11 (c, d)). Aedeagus nearly membranous, with dense pubescence ( Figure 11 (c, d)). Gonopods broadened anteriorly, laterally fused with hypandrium ( Figure 11 (e)).

Measurements

BL = 4.25 mm in holotype (range in two females paratypes: 4.50–4.90 mm), ThL = 2.00 mm (2.25–2.40 mm), WL = 3.70 mm (4.10–4.50 mm), WW = 1.24 mm (1.44– 1.66 mm), arb = 9/6 (10/4–6), avd = 0.84 (0.91–1.04), adf = 2.10 (2.86–3.89), flw = 2.20 (2.71–3.22), FW/HW = 0.41 (0.43–0.44), ch/o = 0.07 (0.08), prorb = 0.73 (0.54–0.63), rcorb = 0.62 (0.54–0.63), vb = 0.50 (0.40–0.45), dcl = 0.44 (0.40–0.42), sctl = 1.26 (1.11– 1.17), sterno = 0.76 (0.75–0.83), orbito = 1.07 (0.79–1.00), dcp = 0.24 (0.22–0.25), presctl = 0.51 (0.52–0.54), sctlp = 1.00 (0.85–1.04), C = 3.23 (3.07–3.13), 4c = 0.56 (0.58–0.59), 4v = 1.18 (1.11–1.21), 5x = 1.03 (0.89–0.94), ac = 3.26 (3.41–3.45), M = 0.27 (0.26–0.28), C3F = 1.00 (1.00).

Type specimen

Holotype male ( KPSP), Malaysia: Mahua , Sabah, 4 October 1999, ex tree trunk, MJ Toda . Paratypes: Malaysia: two females ( KPSP), Ulu Seuagang, Crocker Range, Sabah, 18 October 1999, ex tree trunk, MJ Toda.

Etymology

From the Latin words ‘ dehiscens ’, referring to the bilobed surstylus.

Distribution

Malaysia (Sabah).

Figures

Figure 11. Stegana (Oxyphortica) dehiscens Cheng and Chen, sp. nov., male terminalia. (a) epandrium, cercus and surstylus (lateral view); (b) surstylus (ventral view); (c, d) hypandrium, parameres gonopods, aedeagus and aedeagal apodeme (ventral and lateral views). Scale lines = 0.1 mm.