Stegana (Steganina) flabella Li & Chen

WANG, YA-LIAN, LI, BING-XUE, CUI, MENG-DI, ZHANG, YUAN, WANG, LE, ZHANG, CAI-HONG, TSAUR, SHUN-CHERN, CHEN, HONG-WEI & HUANG, JIA, 2023, Revision of the subgenus Stegana (Steganina) from China, with assessment of species delimitation using DNA barcodes (Diptera, Drosophilidae), Zootaxa 5250 (1), pp. 1-109 : 68-69

Stegana (Steganina) flabella Li & Chen , sp. nov.

( Figs. 8C, 8D , 37 )

Diagnosis. This species closely resembles S. (S.) euryphylla Chen & Chen, 2009 in the shape of male terminalia (as figs. 14–20 in Chen & Chen 2009, Fig. 37 ), but can be distinguished from the latter by having the aedeagus distomedially and subdistolaterally lacking much pubescence ( Fig. 37 ).

Description. Male and female: First flagellomere black. Clypeus yellow. Mesonotum brown to dark brown medially, yellow to brownish laterally ( Fig. 8C ). Katepisternum yellowish ( Fig. 8D ). Scutellum dark brown ( Fig. 8C ). Halter mostly brownish ( Fig. 8D ). Fore femur with 3 or 4 long setae on distal part of posteroventral surface. Abdominal tergites dark brown to black ( Fig. 8C, D ); sternites brown, slightly wider than long. Male terminalia ( Fig. 37 ): Epandrium with ca. 11 setae on dorsal to posterior portions per side ( Fig. 37A ). Surstylus with minute, serrated processes and numerous setulae on outer surface, 1 peg-like tooth near distal margin ( Fig. 37A, B ). Cercus lacking pubescence ( Fig. 37A ). Hypandrium expanded anteromedially ( Fig. 37C, D ). Pregonite small, with 3 sensilla ( Fig. 37C, D ). Aedeagus distally broadened and with numerous minute, serrated processes, with a row of serrated processes laterally and some pubescence distoventrally ( Fig. 37C, D ). Aedeagal sheath distally dorsad curved and with several minute, serrated processes ( Fig. 37E, F ). Subepandrial sclerite rounded distally ( Fig. 37G ).

Measurements and indices. BL = 2.37 mm in holotype (2.19–2.39 in 3♂, 2.34–2.41 in 3♀ paratypes), ThL = 1.09 mm (1.09–1.12 in ♂, 0.95–1.21 in ♀), WL = 2.12 mm (2.03–2.13 in ♂, 1.91–2.32 in ♀), WW = 0.95 mm (0.87–0.97 in ♂, 0.84–1.01 in ♀), arb = 6/4 (6–7/4–5), avd = 0.71 (0.71–0.86), adf = 1.46 (1.05–1.34), flw = 1.85 (1.67–2.05), FW/HW = 0.44 (0.38–0.42), ch/o = 0.32 (0.25–0.38), prorb = 0.83 (0.68–1.32), rcorb = 0.67 (0.59– 0.92), vb = 0.51 (0.50–0.71), dcl = 0.76 (0.53–0.81), presctl = 0.65 (0.55–0.78), sctl = 1.96 (1.61–2.13), sterno = 0.71 (0.55–1.39), orbito = 2.00 (1.50–2.08), dcp = 0.29 (0.27–0.42), sctlp = 1.39 (1.39–1.82), C = 1.99 (1.71–2.13), 4c = 1.25 (1.00–1.59), 4v = 2.25 (1.57–2.37), 5x = 1.34 (1.32–1.75), ac = 8.44 (8.87–12.29), M = 0.71 (0.59–0.96), C3F = 0.60 (0.47–0.61).

Type materials. Holotype ♂ ( SCAU, No. 125710, DNA #2659), CHINA: Wangtianshu, Mengla , Yunnan, 21°36'09''N, 101°35'06''E, alt. 670m, 25.iv.2017, ex tree trunk, H.W. Chen . Paratypes: 3♂, 3♀ ( SCAU, Nos. 125711–16, DNA #2691), other data same as holotype.

Distribution. China (Yunnan).

Etymology. From the Latin word " flabellum " (= knife), referring to the distally broadened aedeagus.

Figures

FIGURE 8. A, B. Stegana (Steganina) dendrophila Zhang & Chen, sp. nov.; C, D. S. (S.) flabella Li & Chen, sp. nov.; E, F. S. (S.) flavipes Li & Chen, sp. nov.; G, H. S. (S.) formosa Zhang & Chen, sp. nov.; I, J. S. (S.) fusca Li & Chen, sp. nov.

FIGURE 37. Stegana (Steganina) flabella Li & Chen, sp. nov., male terminalia. A. Epandrium, surstylus, and cercus in lateral view; B. Surstylus in ventral view; C, D. Hypandrium, pregonite, aedeagus, and phallapodeme in ventral and lateral views; E, F. Aedeagal sheath in ventral and lateral views; G. Subepandrial sclerite in ventral view.