Amaurodera gilvicornis, 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 : 93-94

Amaurodera gilvicornis spec. nov.

urn:lsid:zoobank.org:act:8AD61DB5-D227-4158-93B3-0F902BFF8C8F

( Figs 10 , 47–48 , 127–128 )

Type material: Holotype ♂: “ Thailand; Phang Nga Prov., Tone Chong–Fah Waterfall , 20 km S Takuapa, 100–200 m, 11.–14.I.1996, leg. Schulz & Vock / Holotypus ♂ Amaurodera gilvicornis sp. n., det. V. Assing 2016” (cAss).

Etymology: The specific epithet (Latin, adjective) alludes to the uniformly yellow antennae.

Description: Body length 4.6 mm; length of forebody 2.3 mm. Other measurements: head width: 0.59 mm length of pronotum: 0.77 mm; width of pronotum: 0.64 mm; elytral length at suture: 0.48 mm; elytral width: 0.83 mm. Coloration ( Figs 10 , 47–48 ): forebody reddishbrown, with the postero-lateral portions of the elytra indistinctly and diffusely darker; abdomen blackish with segments II–III and the anterior margin of segment IV pale-yellowish; legs: profemora and apical halves of meso-and metafemora dark-brown, basal halves of meso- and metafemora pale-yellowish, tibiae dark-brown with the apical portion dark-yellowish, tarsi dark-yellowish; antennae yellow; maxillary palpi dark-yellowish with the terminal palpomere pale-yellowish.

Head ( Fig. 47 ) 1.05 times as broad as long, broadest across eyes; postero-lateral outline between eyes and posterior constriction broadly convex in dorsal view; median dorsal portion not impressed; median and anterior dorsal portions extensively without punctation, lateral and posterior portions of dorsal surface with few scattered punctures; interstices with distinct microreticulation, but glossy. Eyes strongly convex, approximately 0.7 times as long as distance from posterior margin of eye to posterior constriction. Antenna ( Fig. 10 ) conspicuously elongate and very slender, 2.9 mm long; antennomeres IX and X 3 and 2.5 times as long as broad, respectively.

Pronotum ( Fig. 47 ) 1.24 times as long as broad and 1.0 times as broad as head; dorsal surface opaque due to very dense microgranules; midline with long and narrow furrow reaching neither anterior nor posterior margins; antero-lateral portions with few short setae.

Elytra ( Fig. 47 ) approximately 0.6 times as long as pronotum; punctation fine and very sparse; interstices with distinct microreticulation. Hind wings present, but apparently of reduced length. Metatarsomere I as long as the combined length of II and III.

Abdomen ( Fig. 48 ) narrower than elytra; tergites III–V with moderately deep anterior impressions; tergites III–VII with fine punctation only at and near posterior margins, otherwise impunctate; tergite VIII with sparse setiferous punctation in posterior third; tergites III–V with distinct, VI–VII with very indistinct or obsolete microreticulation; posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII truncate and with eight tooth-like projections.

♂: posterior margin of sternite VIII broadly and weakly convex, in the middle nearly truncate; median lobe of aedeagus ( Figs 127–128 ) 0.55 mm long; ventral process weakly curved apically (lateral view); crista apicalis narrow in lateral view.

♀: unknown.

Comparative notes: Amaurodera gilvicornis is readily distinguished from all other congeners previously recorded from Thailand by the relatively longer, more slender, and uniformly yellowish antennae and by the morphology of the aedeagus (crista apicalis narrower; ventral process of different shape), from most of them also by the coloration of the abdomen. It is additionally distinguished from A. reticulata ASSING, 2016 , the only other species known from Thailand with distinct microreticulation on the elytra and together with which A. gilvicornis would key out in the key provided by ASSING (2016b), by the absence of a median impression on the male head and by the coloration of the legs ( A. reticulata : tibiae and profemora yellow; meso- and metatibiae only indistinctly bicoloured).

From the two Amaurodera species known from Peninsular Malaysia, the new species is distinguished as follows: from A. plena PACE, 2003 by larger size, a dark abdominal apex (reddish-yellow in A. plena ), bicoloured legs (reddish in A. plena ), paler antennae, more distinct microreticulation on the head and elytra, and an aedeagus of different shape; from A. pahangensis PACE, 2003 (male unknown) by larger size ( A. pahangensis : 3.6 mm), darker coloration of the forebody, an extensively dark tergite IV (yellowish in A. pahangensis ), and different coloration of the legs ( A. pahangensis : tibiae yellow; profemur bicoloured).

For illustrations of A. plena and A. pahangensis see PACE (2003), for figures of the species previously recorded from Thailand see ASSING (2016b).

Distribution and natural history: The type locality is situated in Khaolak-Lumru National Park (approximately 8°38'N, 98°18'E), South Thailand, Malay Peninsula. The holotype was collected at an altitude of 100– 200 m.

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 43–57: Amaurodera bicarinata (43–46), A. gilvicornis (47–48), A. latisulcata (49–50), A. brevipes (51), A. migritheca (52–54), A. longisetosa (55–56), and A. calicitheca (57): forebody (43, 47, 49, 51, 52, 55, 57); pronotum in dorsal view (44, 50, 53); pronotum in dorso-lateral view (45, 56); abdomen (46, 48, 54). Scale bars: 43, 46–49, 51–52, 54–55, 57: 1.0 mm; 44–45, 50, 53, 56: 0.5 mm.

Figs 124–149:AmauroderaschuelkeifromAssam(124–126),A. gilvicornis(127–128),A. bicarinata(129–132),A. latisulcata (133–135), A. brevipes (136–140), A. migritheca (141–146), A. frondium (147–148), and Zyrastilbus almorensis (149): median lobe of aedeagus in lateral and in ventral view (124–125, 127–134, 136–139, 141–144); spermatheca (126, 135, 140, 145–148); median portion of pronotum (149). Scale bars: 124–125, 127–134, 136–139, 141–144:0.5 mm; 126, 135, 140, 145, 147–148: 0.2 mm; 146, 149: 0.1 mm.