Zyras (Zyras) ambulans, Assing, 2017

Assing, Volker, 2017, On Zyras sensu strictu in the East Palaearctic and Oriental regions, with a focus on the faunas of the Himalaya, India, Sri Lanka, Thailand, and Sulawesi (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 117-192 : 154

Zyras (Zyras) ambulans spec. nov.

urn:lsid:zoobank.org:pub:FD33C1AE-F7D9-4E3A-A053-A2CAA7261CFE

( Figs 34 , 70 , 107 , 212–215 , Map 10 )

Type material: Holotype ♂: “ Thailand, Satun Prov., Thale Ban N.P. , 20 km E Satun, 200–400 m, 1.–4.I.1996, leg. Schulz & Vock / Holotypus ♂ Zyras ambulans sp. n., det. V. Assing 2016” (cAss).

Etymology: The specific epithet is the present participle of the Latin verb ambulare (to walk) and alludes to absence of functional hind wings.

Description: Body length 6.2 mm; length of forebody 2.5 mm. Coloration ( Figs 34 , 70 , 107 ): head blackishbrown; pronotum and elytra dark-brown; abdomen with segments III–V reddish, tergite VI dark-brown with reddish margins, VII and VIII dark-brown with the anterior and posterior margins narrowly paler; legs yellowish with the apices of the meso- and metafemora brown; antennae dark-brown with antennomeres I–II reddish and XI yellow; maxillary palpi dark-yellowish with the terminal palpomere pale-yellowish.

Head ( Fig. 70 ) moderately transverse, middle extensively impunctate; punctation in lateral dorsal portions sparse and fine. Eyes large and bulging, much longer than postocular region in dorsal view. Antenna ( Fig. 34 ) 2.3 mm long; antennomeres IV–V oblong, VI weakly oblong, VII as long as broad or weakly oblong, VIII–IX very weakly transverse, X less than 1.5 times as broad as long, and XI approximately as long as the combined length of IX and X. Pronotum ( Fig. 70 ) weakly transverse, approximately 1.1 times as broad as long and 1.2 times as broad as head, broadest anteriorly, distinctly tapering posteriad; lateral margins straight in posterior two-thirds (dorsal view); punctation shallow and sparse; midline broadly impunctate; lateral margins anteriorly with two very long, stout, dark setae.

Elytra ( Fig. 70 ) short, approximately 0.7 times as long as pronotum; punctation moderately dense, moderately coarse, and regularly distributed. Hind wings reduced. Metatarsomere I longer than the combined length of II and III, but shorter than the combined length of II–IV.

Abdomen ( Fig. 107 ) broader than elytra, with moderately deep anterior impressions on tergites III–V; anterior impressions of tergites III–V without non-setiferous punctures; tergites III–VI with a lateral puncture bearing a long black seta on either side and with a transverse row of approximately 10 setiferous punctures at or near posterior margins, at least the lateral punctures of these rows bearing long black setae; tergite VII anteriorly with a cluster of rather sparse shallow non-setiferous punctures and posteriorly with sparse setiferous punctures, posterior margin with narrow palisade fringe; tergite VIII with sparse setiferous punctures only in posterior portion, posterior margin smoothly convex, without median excision or other modifications.

♂: sternite VIII with convex posterior margin; median lobe of aedeagus 0.65 mm long and shaped as in Figs 212–213 ; paramere ( Fig. 214 ) much longer than median lobe (0.9 mm), with long, flattened, and somewhat club-shaped apical lobe ( Fig. 215 ).

Comparative notes: Zyras ambulans is distinguished from all the species previously known from Thailand and Peninsular Malaysia by the reduced hind wings and the morphology of the aedeagus (shape of median lobe; modifications of paramere). It is additionally characterized by the coloration (body, legs, and antennae), a slender pronotum, short elytra, and the punctation pattern of the abdomen.

Distribution and natural history: Thale Ban National Park is situated in the extreme south of Thailand at approximately 6°43'N, 100°10'E, close to the border with Malaysia ( Map 10 ). The holotype was collected at an altitude between 200 and 400 m. Since one of the collectors is a myrmecologist, it may have been found associated with ants.

Figures

Map 10: Revised distributions of Zyras preangeranus (black circles), Z. brevilobatus (white star), Z. parvicollis (white star), Z. ambulans (white circle), Z. densissimus (black star), Z. titan (black star), Z. densihirtus (black star), and Z. nigrihirtus (black star) in the southern East Palaearctic and Oriental regions.

Figs 1–41:Antennae of Zyrasspp.:kraatzi(1),exasperatus(2),pindarae (3–5),perforatus(6),championi(7),pallipes (8),condignus (9), nitens (10), truncatus (11), nilgiriensis (12), hirsutiventris (13), russiceps (14), brignolii (15), hastatus (16), parageminus (17–18), latilobatus (19), alternans (20), hirtus (21), nigroaeneus (22), luteipes (23), longilobatus (24), morvani (25), gratellus (Malaysia) (26), castaneus, lectotype (27),proximus (28–29),novinversus (30–31), brevilobatus(32), parvicollis(33), ambulans (34),matangensis (35), densissimus (36), densihirtus (37), nigrihirtus (38), gratellus (Sulawesi) (39), gardneri (40), titan (41). Scale bar: 1.0 mm.

Figs 68–81: Forebody (68–77), head and pronotum (78), and abdomen (79–81) of Zyras spp.: brevilobatus (68), parvicollis (69), ambulans (70), nitens, holotype (71), gratellus (Malaysia) (72), matangensis (73), gratellus (Sulawesi) (74), densissimus (75), titan (76), densihirtus (77), nigrihirtus (78), kraatzi (79), asperatus (80), nigroaeneus (81). Scale bar: 1.0 mm.

Figs 100–116: Abdomen of Zyras spp.: luteipes (100), nilgiriensis (101), brevilobatus(102), brignolii (103), parvicollis (104), proximus, holotype (105), novinversus (106), ambulans (107), matangensis (108), nitens (109), gratellus (Malaysia) (110), densissimus (111), gratellus (Sulawesi) (112), titan (113), russiceps (114), densihirtus (115), nigrihirtus (116). Scale bar: 1.0 mm.

Figs 208–226: Zyras parvicollis (208–211), Z. ambulans (212–215), Z. nitens, holotype (216–221), and Z. gratellus (Malaysia) (222–226):medianlobeofaedeagusinlateralandinventralview(208–213,216–217,222–223);paramere (214,218,224); male tergite VIII (219, 225); male sternite VIII (220, 226); apical lobe of paramere (215); postero–median portion of male sternite VIII (221). Scale bars: 208–214, 216–220, 222–226: 0.5 mm; 215, 221: 0.1 mm.