Drusilla lativentris, Assing, 2017

Assing, Volker, 2017, On the Lomechusini fauna of the East Palaearctic and Oriental regions, with a focus on the genera Orphnebius and Amaurodera (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 63-106 : 101-102

Drusilla lativentris spec. nov.

urn:lsid:zoobank.org:act:7CAC3239-9821-4DF6-BB7A-C8A564E9AF14

( Fig. 18 , 60 , 117–123 )

Type material: Holotype ♂: “ CHINA: S-Yunnan (Xishuangbanna) 23 km NW Jinghong, vic Na Ben (NNNR) 730 m, N22°09.49, E100°39.92, transition zone, MF1, 10.X.2008, leg. A. Weigel / Holotypus ♂ Drusilla lativentris sp. n., det. V. Assing 2016” ( NME) . Paratype ♀: same data as holotype (cAss) .

Etymology: The specific epithet (adjective) alludes to the broad abdomen, in particular the strongly transverse tergite VII and female sternite VIII.

Description: Body length 4.5–4.8 mm; length of forebody 2.0– 2.2 mm. Coloration ( Figs 18 , 60 ): forebody black; abdomen reddish-brown; legs brown to darkbrown with the bases of the meso- and metafemora and the tarsi slightly paler; antennae blackish; maxillary palpi yellowish.

Head ( Fig. 60 ) transverse, approximately 1.2 times as broad as long, broadest across eyes; posterior angles weakly marked; punctation fine, denser and somewhat more distinct in male than in female. Eyes enormous and bulging, posteriorly nearly reaching posterior margin of head. Antenna ( Fig. 18 ) 1.5–1.6 mm long and moderately massive; antennomere IV weakly transverse; antennomeres V–X of gradually increasing width and increasingly transverse, X less than 1.5 times as broad as long, and XI slightly longer than the combined length of IX and X.

Pronotum ( Fig. 60 ) 1.08–1.13 times as broad as long and 1.07–1.09 times as broad as head, broadest anteriorly; lateral margins straight in posterior half in dorsal view; posterior angles marked; midline with fine and defined sulcus extending from postero-median pit nearly to anterior margin; disc of male pronotum extensively impressed in posterior three-fourths of middle; punctation very dense, somewhat coarser in male than in female; interstices without microsculpture.

Elytra approximately 0.8 times as long as pronotum; punctation even denser than that of pronotum; interstices without microsculpture. Hind wings fully developed. Metatarsomere I slightly longer than II, distinctly shorter than the combined length of II and III.

Abdomen broader than elytra; segments III–VII much more than twice as broad as long; tergites III–VII each with 1–2 lateral setiferous punctures on either side and with several setiferous punctures at posterior margin, otherwise impunctate, and with fine transverse microsculpture; posterior margin of tergite VII with palisade fringe.

♂: tergite VIII ( Fig. 117 ) strongly transverse, posterior margin strongly crenulate and with a distinct lateral tooth on either side; sternite VIII ( Fig. 118 ) longer and less transverse than tergite VIII, posterior margin convex; median lobe of aedeagus 0.6 mm long and shaped as in Figs 119–120 ; paramere 0.48 mm long, with moderately long and unmodified apical lobe.

♀: tergite VIII ( Fig. 121 ) strongly transverse, posterior margin concave in the middle; sternite VIII ( Fig. 122 ) strongly transverse and with broadly convex posterior margin; spermatheca ( Fig. 123 ) minute in relation to body size, its maximal extension 0.18 mm.

Comparative notes: Drusilla lativentris is characterized particularly by the primary sexual characters and the broad abdomen with strongly transverse segments. For an overview of the Drusilla species previously recorded from China see ASSING (2015b).

Distribution and natural history: The type locality is situated in the southwest of Yunnan, not far from the borders with Myanmar and Laos, at an altitude of 730 m. The specimens were collected with a Malaise trap. Witteia tensa and an unidentified species were found in the same locality.

Figures

Figs 1–30: Antenna (1–19), forebody (20, 23, 26), abdomen (21, 24, 27, 29), antero-lateral portion of abdomen in lateral-dorsal view (22, 25, 28), and abdominal segment VII (30) of Orphnebius triacuminatus (1, 20–22), O. gracilis (2, 23–25), O. protuberatus (3, 26–28), O. pertortus (4, 29–30), O. reticulipennis (5), Zyrastilbus almorensis (6), Pheidologitonetes bursata (7), Rabdotodrusilla vara (8), Amaurodera bicarinata (9), A. gilvicornis (10), A. latisulcata (11), A. brevipes (12), A. migritheca (13), A. longisetosa (14), A. calicitheca (15), Drusilla smetanai (16), D. nepalensis (17), D. lativentris (18), and Witteia tensa (19). Scale bars: 1–29: 1.0 mm; 30: 0.5 mm.

Figs 58–61: Forebody of Drusilla smetanai, holotype (58), D. nepalensis, male (59), D. laticeps (60), and Witteia tensa (61). Scale

Figs 101–123: Pheidologitonetes setifer (101–104), P. bursata (105–109), Drusilla obliqua (110–113), D. nepalensis (114–116), and D. lativentris (117–123): male tergite VIII (101, 117); male sternite VIII (102, 118); female tergite VIII (103, 110–111, 114, 121); female sternite VIII (104, 112, 115, 122); median lobe of aedeagus in lateral and in ventral view (105–106, 119–120); apical portion of median lobe of aedeagus in ventral view (107); paramere (108); spermatheca (109, 113, 116, 123). Scale bars: 101–104, 110–112, 114–115, 117–122: 0.5 mm; 105–108, 113, 116, 119–120: 0.2 mm; 109, 123: 0.1 mm.