Amaurodera migritheca, 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 : 95-96

Amaurodera migritheca spec. nov.

urn:lsid:zoobank.org:act:AAE44C1B-FD1A-49CF-B08B-C6F067F54F09

( Figs 13 , 52–54 , 141–146 )

Type material: Holotype ♂: “ SUMATRA: Jambi, Mt Kerinci , 1900 m, 13.XI.1989, Agosti, Löbl, Burckhardt / Holotypus ♂ Amaurodera migritheca sp. n., det. V. Assing 2016” ( MHNG) . Paratypes: 12 exs.: same data as holotype ( MHNG, cAss) ; 1 ex.: “ SUMATRA: Jambi Prov., Mt. Kerinci , footpath to summit , W of Kersik Tua 2160 m, 17–18.ii.2000 Sum00-13, P. Schwendinger ” ( MHNG) .

Etymology: The specific epithet (noun in apposition) is composed of the Latin adjective migrus (minute) and the Greek noun theca. It alludes to the conspicuously small spermatheca.

Description: Body length 4.7–5.7 mm; length of forebody 2.2–2.6 mm. Other measurements: head width: 0.63–0.68 mm; length of pronotum: 0.85–0.99 mm; width of pronotum: 0.66–0.75 mm; elytral length at suture: 0.48–0.53 mm; elytral width: 0.90–1.07 mm. Coloration ( Figs 13 , 52, 54 ): forebody dark-brown with the elytra often slightly paler; abdomen dark-brown to blackishbrown with the posterior margins of the segments dark-reddish to reddish-brown; legs yellowish with the apices of the meso- and metafemora often slightly darker; antennae dark-brown to blackish-brown with the basal 2–3 antennomeres and often also (the apex of) antennomere XI pale-brown; yellowish; maxillary palpi pale-brown to dark-brown with the terminal palpomere yellowish.

Head ( Fig. 52 ) weakly oblong, 1.05–1.10 times as long as broad, broadest across eyes; postero-lateral outline between eyes and posterior constriction convex in dorsal view; median dorsal portion not impressed; punctation moderately sparse and very fine; interstices with very shallow, indistinct microreticulation and glossy. Eyes large and convex, approximately 0.7 times as long as distance from posterior margin of eye to posterior constriction. Antenna ( Fig. 13 ) long and slender, 2.6–2.8 mm long; antennomere IX approximately twice as long as broad and antennomere X approximately 1.5 times as long as broad.

Pronotum ( Fig. 53 ) moderately slender, approximately 1.3 times as long as broad, without sexual dimorphism; dorsal surface, except for the glossy median sulcus, with very dense microgranules and opaque, antero-median portion often with reduced shine; midline with narrow median sulcus reaching neither anterior nor posterior margins; antero-lateral portions with numerous moderately short setae.

Elytra ( Fig. 52 ) 0.55–0.60 times as long as pronotum; punctation fine and moderately dense; microreticulation practically absent (indistinct traces may be visible at high magnification). Hind wings fully developed. Legs including tarsi long and slender; metatarsomere I barely as long as the combined length of II and III.

Abdomen ( Fig. 54 ) narrower than elytra; tergites III–V with moderately deep anterior impressions; tergites III– VII with sparse punctures on disc (especially laterally) and at posterior margin; tergite VIII with sparse setiferous punctation in posterior third; tergal surfaces with indistinct microsculpture visible only at high magnification (100 x); posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII weakly convex and serrate.

♂: median lobe of aedeagus approximately ( Figs 141–144 ) 0.68–0.72 mm long; ventral process weakly curved and acute apically (lateral view).

♀: spermatheca ( Figs 145–146 ) minute, maximal extension 0.11 mm.

Comparative notes: Amaurodera migritheca is readily distinguished from other Amaurodera species recorded from Sumatra by the minute spermatheca. In external characters and in the shape of the aedeagus it is most similar to A. spinans , whose female sexual characters are unknown. It differs from this species by apically darker antennae ( A. spinans : apical 2–3 antennomeres darkyellowish), paler femora, and by the morphology of the aedeagus ( A. spinans : ventral process basally more slender in ventral view and apically more acute; crista apicalis larger and of different shape). For illustrations of A. spinans see ASSING (2016b).

Distribution and natural history:The known distribution is confined to two localities in Mt. Kerinci, West Sumatra, Indonesia. The specimens were collected at altitudes of 1900 and 2160 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.