Stegana (Steganina) serrata Zhang & 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 : 41-42

Stegana (Steganina) serrata Zhang & Chen , sp. nov.

( Figs. 4C, 4D , 17 )

Diagnosis. This species differs from the other species of the castanea group in having the aedeagus distomedially with some minute, serrated processes and apically with much pubescence ( Fig. 17B, C ).

Description. Male and female: First flagellomere black. Clypeus yellow. Mesonotum brown, with 1 broad, longitudinal dark brown stripe medially ( Fig. 4C ). Katepisternum yellowish ( Fig. 4D ). Scutellum mostly brown, dark brown anteromedially, and brownish apically ( Fig. 4C ). Fore femur with a row of 5 or 6 long setae on distal part of posteroventral surface. Halter grey ( Fig. 4C ). Abdominal tergites dark brown to black ( Fig. 4C, D ); sternites brown, about 2 times as wide as long. Male terminalia ( Fig. 17 ): Epandrium with ca. 14 setae on dorsal to posterior portions per side ( Fig. 17A ). Surstylus slightly squared, with several minute, serrated processes on outer surface and several setulae along outer margin ( Fig. 17A ). Cercus with much pubescence ( Fig. 17A ). Hypandrium expanded anteromedially ( Fig. 17B, C ). Pregonite with 2 sensilla ( Fig. 17B, C ). Aedeagal sheath nearly erect, slightly dorsad curved, mostly with numerous minute, serrated processes ( Fig. 17C, D ). Subepandrial sclerite deeply split medially ( Fig. 17E ).

Measurements and indices. BL = 3.87 mm in holotype (3.14–3.54 in 5♂, 3.33–4.27 in 5♀ paratypes), ThL = 1.67 mm (1.49–1.67 in ♂, 1.60–1.73 in ♀), WL = 2.67 mm (2.33–3.28 in ♂, 2.33–3.34 in ♀), WW = 1.33 mm (1.05–1.28 in ♂, 1.12–2.07 in ♀), arb = 11/7 (8–11/5–6), avd = 0.85 (0.76–1.17), adf = 1.86 (0.85–2.00), flw = 2.00 (1.50–2.39), FW/HW = 0.45 (0.33–1.46), ch/o = 0.31 (0.19–0.31), prorb = 1.40 (0.97–1.77), rcorb = 0.80 (0.51–0.85), orbito = 1.43 (1.60–2.40), vb = 0.60 (0.29–1.03), sctl = 2.00 (1.36–2.48), sterno = 0.65 (0.64–0.89), sctlp = 1.50 (1.33–1.89), C = 1.90 (1.80–2.15), 4c = 1.05 (1.00–1.26), 4v = 1.75 (1.67–2.00), 5x = 1.25 (1.17–1.88), ac = 10.50 (9.64–14.67), M = 0.50 (0.53–0.70), C3F = 0.76 (0.63–0.85).

Type materials. Holotype ♂ ( SCAU, No. 125242, DNA #1342), CHINA: Menglun, Mengla , Yunnan, 21°47'29''N, 101°22'59''E, alt. 680m, 26–28.ix.2011, ex tree trunk, H.W. Chen . Paratypes: 3♂, 2♀ ( SCAU, Nos. 125246–50, DNA #2642), 16–19.iv.2007, 1♂, 2♀ ( SCAU, Nos. 125251–53), 26–28.ix.2011, H.W. Chen, J.J. Gao, other data same as holotype; 2♂, 1♀ ( SCAU, Nos. 125254–56, DNA #2195), Guanlei, Mengla, Yunnan, 21°38'39''N, 101°09'52''E, alt. 560m, 24.iv.2016, ex tree trunks, Y.L. Wang, L. Zhu; 1♂ ( SCAU, No. 125243, DNA #2605), Longtan Forest Park, Guiping, Guangxi, 23°32'28''N, 110°00'34''E, alt. 1145m, 2.vii.2017, ex tree trunk, H.W. Chen; 1♂ ( SCAU, No. 125244, DNA #2749), Longtan Park , Ximeng , Yunnan, 22°38'55''N, 99°36'02''E, alt. 1150m, 17.iv.2018, ex tree trunk, B.X. Li ; 1♀ ( SCAU, No. 125245, DNA #2715), Nonggang, Longzhou , Guangxi, 22°32'26''N, 106°43'18''E, alt. 230m, 28.xi.2019, ex tree trunk, H.W. Chen.

Distribution. China (Guangxi, Yunnan).

Etymology. From the Latin word " erratus " (= serrate), referring to the aedeagus medially with minute, serrated processes.

Figures

FIGURE 17. Stegana (Steganina) serrata Zhang & Chen, sp. nov., male terminalia.A. Epandrium, surstylus, and cercus in lateral view; B, C. Hypandrium, pregonite, aedeagus, and phallapodeme in ventral and lateral views; D. Aedeagal sheath in ventral view; E. Subepandrial sclerite in ventral view.

FIGURE 1-4. An un-rooted, neighbor-joining (NJ) tree constructed using 435 DNA barcode sequences of 102 Steganina species. Numbers around the nodes are bootstrap percentages (BPs). BPs lower than 50 are not shown. The bars indicate the estimated number of substitutions per site.