Body moderately large to large (6–12 mm), mostly dark brown; ventral surface reddish brown; dorsal surface dull and glabrous.

Labroclypeus subtrapezoidal, wider than long, widest at base, lateral margins moderately convex and convergent to strongly rounded anterior angles, anterior margin weakly sinuate medially, margins moderately reflexed; surface weakly convex, moderately shiny, finely and densely punctate; frontoclypeal suture indistinctly incised, flat and weakly curved medially; ocular canthus short and triangular, impunctate, with a single terminal seta. Frons dull, with sparse, fine punctures, with single erect setae beside each eye. Antenna yellowish, with ten antennomeres; club composed of four antennomeres in male, straight, rarely longer than 1.5 times as the remaining antennomeres combined; club in female composed of three antennomeres, as long as the remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum moderately wide and strongly convex, lateral margins evenly convex, more strongly narrowed anteriorly towards sharp and slightly produced anterior angles. Anterior margin of pronotum slightly convex, with fine complete marginal line. Posterior angles blunt or strongly rounded. Surface finely and densely punctate, except minute setae glabrous, lateral and lateral anterior margins sparsely setose. Hypomeron not carinate. Scutellum triangular, finely and densely punctate.

Elytra oblong, widest just behind middle, striae distinctly impressed, finely and moderately densely punctate, intervals distinctly convex, with coarse and dense punctures concentrated along striae, with very minute setae in punctures; epipleural edge robust, ending at weakly curved and slightly blunt external apical angle of elytra, epipleura densely setose, apical border with a broad fringe of microtrichomes (100×).

Ventral surface weakly shiny, finely and densely punctate, metasternum sparsely covered with fine, short, or very minute setae, metacoxa glabrous, with a few single setae laterally; abdominal sternites finely and densely punctuate, with a transverse row of coarse punctures, each bearing a robust seta. Mesosternum between mesocoxae as wide as mesofemur. Pygidium weakly convex and dull, densely punctate, without smooth midline, almost glabrous, but with a few longer setae along apical margin; pygidium without strong sexual dimorphism.

Legs moderately wide; femora finely and sparsely punctate; metafemur wide and moderately shiny or dull, anterior margin acute, posterior margin smooth ventrally and only weakly widened in apical half, posterior margin smooth dorsally, with a few short setae basally. Posterior margin of metafemur generally straight or slightly convex. Metatibia moderately wide to wide and moderately long, widest at half of metatibial length, dorsal margin sharply carinate, with two groups of spines; lateral face finely and sparsely punctate; ventral edge finely serrated, with four robust equidistant setae, medial face smooth, apex interiorly near tarsal articulation with a shallow sinuation. Tarsomeres with fine, very dense setae ventrally on distal half, neither laterally nor dorsally carinate, dorsally smooth; metatarsomeres with a strongly serrated ridge ventrally and glabrous; first metatarsomere slightly shorter than two following tarsomeres combined, one third of its length longer than dorsal tibial spine. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Phallobase with a more or less long median ventral extension (median phallobasal lamina).

Tetraserica differs from closely related genera, Microserica Brenske, 1894 and Trioserica Moser, 1922, by lacking the ventral carina on hypomeron. From Microserica it also differs by lacking the sexual dimorphism of the pygidium, from Trioserica by the bidentate protibia. In contrast to the Microserica, species of Tetraserica are active at night and are attracted by light.

The genus is distributed almost in the entire Oriental region except the southern Indian subcontinent; we know that additional species described by various authors are so far assigned to “Neoserica” from Philippines, Sumatra, and Borneo but that awaits a formal revision (Ahrens 2004).

Holotype: ♂ “Myanmar (Burma) 21 km E Putao, H-550 m Nan S Bon vill., 1-5.5.98 leg S. Murzin & V. Sinaev/ Coll. D. Ahrens/ 215 Sericini Asia spec.” (ZFMK). Paratypes: 1 ♂ “Myanmar (Burma) 25 km E Putao, H-800 m Nan Sa Bon vill., 6-9.5.98 leg S. Murzin & V. Sinaev/ Coll. D. Ahrens” (ZFMK), 1 ♂ “Myanmar (Burma) 21 km S Putao, H-550 m Nan Sa Bon vill., 1-5.5.98 leg S. Murzin & V. Sinaev/ Coll. D. Ahrens” (ZFMK).

Length of body: 8.9 mm; length of elytra: 6.8 mm; maximum width: 5.4 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.67. Ratio of length of metepisternum/metacoxa: 1/1.53. Metatibia moderately long and wide, ratio width/length: 1/3.77; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 1A–D. Habitus: Fig. 1E.

Figure 1. 

A–E Tetraserica finociliata sp. n. (holotype) F–I T. romae sp. n. (holotype) J–N T. neouncinata sp. n. (holotype) A, F, J aedeagus, left side lateral view D, H, M aedeagus, right side lateral view B, G, K parameres, dorsal view C, L parameres, ventral view E, I, N habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.9–10.2 mm; length of elytra: 6.8–7.1 mm; maximum width: 5.4–5.8 mm.

Tetraserica finociliata sp. n. differs from all other Tetraserica species by the long and robust distal lobe of right paramere being strongly curved upwards (lateral view), and having a strong subapical ventral tooth.

The species name (adjective in the nominative singular) is derived from the combined Latin words fino- (fine) and ciliatus (ciliate), with reference to the fine comp of trichomes at the base of the right paramere.

Holotype: ♂ “Vietnam-N (Na Hang) 160 km NW Ha Noi, NE env. of Na Hang 26.5-6.6.1996 150–200 m lg. A. Napolov & I. Roma/ CNa Riga” (ZFMK). Paratype: 1 ♂ “X-DA4501 labcode: VD 023 Vietnam: Tuyn Quang pr. SE-E env. of Na Hang, 200–700 m 22°17'30"–22'30"N, 105°26'–28'E, 1-12.v.2010 L. Dembický leg. (VN2/2010 MZM EXPEDITION) Tetraserica sp VI_V1” (ZFMK), 2 ♂♂ “Vietnam-N Tuyen quang pr. SE-E env. of Na Hang 22°17'30"–22'30"N, 105°26'–28'E, 200–700 m L. Dembicky leg., 1.-12.V.2010” (ZFMK).

Length of body: 7.3 mm; length of elytra: 5.3 mm; maximum width: 4.6 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.46. Ratio of length of metepisternum/metacoxa: 1/1.65. Metatibia moderately long and wide, ratio width/length: 1/3.81; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 1F–H. Habitus: Fig. 1I.

Female unknown.

Length of body: 7.3–8.1 mm; length of elytra: 5.3–5.8 mm; maximum width: 4.6–5.0 mm.

Tetraserica romae sp. n. differs from all other Tetraserica species by the right hammer-shaped paramere, which has a sharply pointed double spine at apex, one directed dorsally, and a larger one ventrally.

The new species is named after one of its collectors, Ilona Roma (noun in genitive singular).

Holotype: ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v. 2012, 1300–1900 m leg. C. Holzschuh - ZFMK Ankauf 2012” (ZFMK). Paratypes: 1 ♂ “X-DA4582/ X-DA4582 labcode VD049 Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 15-30.iv.2014 leg. C. Holzschuh Ankauf 2014/ Tetraserica spLA_V22/ sp-LA-V22” (ZFMK), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5’-104°01'E, Ban Saluei- Phou Pane Mt., 1340–1870 m, 10.v.-16.vi.2009, M. Brancucci & local coll. leg./ NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň” (NHMB), 2 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.iv.- 14.v.2008, Vít Kubán leg.” (ZFMK), 1 ♂ “Myanmar, Mandalay prov. Kyaukpadanng 10.6.2009 From Li Jingke” (ZFMK).

Length of body: 8.8 mm; length of elytra: 7.9 mm; maximum width: 6.1 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.55. Ratio of length of metepisternum/metacoxa: 1/1.76. Posterior margin of metafemur with blunt tooth. Metatibia moderately long and wide, ratio width/length: 1/3.31; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 1J–M. Habitus: 1N.

Female unknown.

Length of body: 8.8–9.8 mm; length of elytra: 7.1–7.9 mm; maximum width: 5.8–6.1 mm.

The new species differs from the similar T. daqingshanica by the dorsal lobe of the right paramere being wide and straight in the basal half and curved in the apical half; the apex of left paramere gently narrows towards apex in T. neouncinata.

The species name (adjective in the nominative singular) is derived from the combined Greek word neo- (new) and Latin word uncinatus, with reference to the uncinated shape of the right paramere.

Holotype: ♂ “X-DA4693 labcode: VD086 China, Guangxi A.R., Schiwandashan National Forest Park (forested river valley; at light), 290–360 m, 21°54.4'N, 107°54.2'E, 5-9.iv.2013, M. Fikáček, J. Hájek, J. Růžička leg. Tetraserica spCH_V47/ sp-CH-V47/ X-DA4693“ (ZFMK).

Length of body: 9.3 mm; length of elytra: 6.9 mm; maximum width: 5.9 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.58. Ratio of length of metepisternum/metacoxa: 1/1.7. Posterior margin of metafemur with blunt tooth. Metatibia moderately long and wide, ratio width/length: 1/3.31; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 2A–D. Habitus: Fig. 2E.

Figure 2. 

A–E Tetraserica pseudouncinata sp. n. (holotype) F–J T. falciformis sp. n. (holotype) K–N T. sculptilis Liu et al., 2014 (holotype). A, F, K aedeagus, left side lateral view D, I, M aedeagus, right side lateral view B, G, L parameres, dorsal view C, H parameres, ventral view E, J, N habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Tetraserica pseudouncinata sp. n. differs from T. neouncinata by the left paramere being two thirds as wide as length of the antennal club (rather than one quarter as wide as in T. neouncinata).

The species name (adjective in the nominative singular) is derived from the combined Greek word pseudo- (false) and Latin word uncinatus, with reference to the uncinated shape of the right paramere.

Holotype: ♂ “Laos, Champassak Prov. Dong Hua Xao NBCA 2 km S of Ban NongLuang, bank of Touay-Guai stream/ 15°4'N, 106°13'E, 800 m, at light, No. 24 1-5.IV.1998, leg. O. Merkl & G. Csorba/ 599 Sericini Asia spec.” (HNHM). Paratypes: 2 ♂♂ “Laos, Champassak Prov. Dong Hua Xao NBCA 2 km S of Ban NongLuang, bank of Touay-Guai stream/ 15°4'N, 106°13'E, 800 m, at light, No. 24 1-5.IV.1998, leg. O. Merkl & G. Csorba” (HNHM, ZFMK), 3 ♂♂ “Laos, Attapeau prov.; Annam Highlands Mts Dong Amphan; NBCA, ca. 1160 m NONG FA (crater lake) env.; 15°05.9'N, 107°25.6'E, St. Jakl lgt, 30.4.-6.5.2010” (NMPC, ZFMK), 1 ♂ “X-DA4499 labcode: VD022 Laos, Attapeu prov. Annam Highlands Mts. Dong Amphan NBCA, ca.1160 m NONG FA (crater lake) env. 15°05.9'N, 107°25.6'E, 30.iv-6.v.2010, Jiři Hájek leg. Tetraserica spLA_Annam1/ X-DA4499/ sp-LA-Annam1” (ZFMK), 1 ♂ “X-DA4498 labcode: VD021 Laos, Attapeu prov. Annam Highlands Mts. Dong Amphan NBCA, ca.1160 m NONG FA (crater lake) env. 15°05.9'N, 107°25.6'E, 30.iv-6.v.2010, Jiři Hájek leg. Tetraserica spLA_Annam1/ X-DA4498” (ZFMK).

Length of body: 11.8 mm; length of elytra: 7.5 mm; maximum width: 7 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.53. Ratio of length of metepisternum/metacoxa: 1/1.58. Metatibia short and wide, ratio width/length: 1/3.21; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 2F–I. Habitus: Fig. 2J.

Female unknown.

Length of body: 11.8–12.5 mm; length of elytra: 7.5–9.2 mm; maximum width: 6.4–7.0 mm.

Tetraserica falciformis sp. n. differs in male genital shape from the similar T. sculptilis by having the posterior margin of metafemur straight rather than being blunt or with a tooth; furthermore, the dorsal lobe of the right paramere is markedly curved and strongly widened at base.

The species name (adjective in the nominative singular) is derived from the combined Latin words falcis- (sickle) and formis (of shape), with reference to the sickle-shaped right paramere.

Vietnam: 1 ♂ “Vietnam: Vinh Phú: Tam Doa W. Edge of the town. 930 m 20–31 May 1996 B. Hubley R. Bain. ROM 961033/ UV light; scrub growth at 1° forest edge 21°27'N, 105°39'E” (HWML), 1 ♂ “Vietnam, Vinh Phú: Tam Dao Hill Stn. Telecommunications tower, Jan-May 1996 per B. Hubley, ROM 961024” (HWML).

Aedeagus: Fig. 2K–M. Habitus: Fig. 2N.

The species was known only from China (Hubei and Yunnan provinces); it is now recorded for first time from northern Vietnam.

Holotype: ♂ “Laos centr. Khammouan prov. NAKAI env. 4-8.5.1998, Route No 8, alt 560±20 m, N17°42.8, E 105°08.9 (GPS) E. Jendek & O. Šausa leg./ Coll. P. Pacholátko/ 167 Sericini Asia spec.” (CPPB).

Length of body: 10.1 mm; length of elytra: 7.5 mm; maximum width: 6.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.57. Ratio of length of metepisternum/metacoxa: 1/1.58. Metatibia short and wide, ratio width/length: 1/2.89; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 3A–C. Habitus: Fig. 3D.

Figure 3. 

A–D Tetraserica pseudoliangheensis sp. n. (holotype) E–H T. liangheensis Liu et al., 2014 (holotype) I–L T. T. doisuthepensis sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Tetraserica pseudoliangheensis sp. n. differs from T. falciformis by the dorsal lobe of right paramere having a sharp hook at its apex (dorsal view). The species is also rather similar to T. liangheensis Liu et al., 2014; however, in the new species the posterior margin of metafemur does not possess a tooth and the dorsal lobe of the right paramere is much wider at the base.

The species name (adjective in the nominative singular) is derived from the combined Latin words pseudo- (nearly) and the species name liangheensis, with reference to the similarity to T. liangheensis Liu et al., 2014.

Laos: 13 ♂♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m, leg. C. Holzschuh ZFMK Ankauf 2012” (ZFMK), 4 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.IV.- 14.V.2008, Vít Kubáň leg.” (ZFMK), 1 ♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, Phu Pane Mt., 1480–1510 m, 17.5.-3.6.2007, Vit Kubáň leg.” (ZFMK), 1 ♂ “Laos -NE: Houa Phan prov. 20°12.138'N, 104°00621'E, PHU PHAN Mt ~1750 m 17.5- 3.6.2007 Vit. Kubáň leg.” (ZFMK), 1 ♂ “Laos, 21°09'N, 101°19'E, Louangnamtha pr. Namtha-Muang Sing, 5-31.v.1997, 900–1200 m Vit. Kubáň leg/ coll. P. Pacholátko” (CPPB), 1 ♂ “X-DA3439a labcode VD006 Laos, Xieng Khouang, Phonsavan (30 km NE), Phou Sane Mt. 1400–1600 m 19°38'20"N, 103°20'20"E, 10-30.5.2009 Vit. Kubáň Tetraserica spLA1/ sp-LA-1” (ZFMK), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5’-104°01'E, Ban Saluei- Phou Pane Mt., 1340–1870 m, 10.v.-16.vi.2009, M. Brancucci & local coll. leg./ NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň” (NHMB), 9 ♂♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20–1'E, 30 km NE Phonsavan Ban Na Lam -> Phou Sane Mt., 1300–1700 m, 10.-30.v.2009, M. Geiser leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (NHMB), 7 ♂♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20–1'E, Phonsavan (30 km NE) Phou Sane Mt., 1400–1700 m, 10.-30.v.2009, D. Hauck leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (NHMB), 7 ♂♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20'E, Phonsavan (30 km NE) Phou Sane Mt., 1420 m, 10-30.v.2009, Z. Kraus leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (NHMB), 5 ♂♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20'E, 30 km NE Phonsavan Ban Na Lam- > Phou Sane Mt., 1300–1500 m, 10.-30.v.2009, M. Brancucci leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (NHMB), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5’-104°01'E, Ban Saluei- Phou Pane Mt., 1340–1870 m, 10.v.-16.vi.2009, M. Brancucci & local coll. leg./ NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň” (NHMB), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5’-104°01'E, Ban Saleui- Phou Pane Mt. 1340–1870 m, 15.iv.-15.v.2008; Lao collectors leg./ 911 Sericini Asia spec.” (NHMB), 1 ♂ “X-DA3439b labcode VD007 Laos, Xieng Khouang, Phonsavan (30 km NE), Phou Sane Mt. 1400–1600 m 19°38'20"N, 103°20'20"E, 10-30.5.2009 Vit. Kubáň Tetraserica spLA1” (ZFMK), 1 ♂ “X-DA2443b labcode VD009 Laos, Xieng Khouang, Phonsavan (30 km NE), Phou Sane Mt. 1400–1600 m 19°38'20"N, 103°20'20"E, 10-30.5.2009 Vit. Kubáň Tetraserica spLA1” (ZFMK), 1 ♂ “X-DA2443a labcode VD008 Laos, Xieng Khouang, Phonsavan (30 km NE), Phou Sane Mt. 1400–1600 m 19°38'20"N, 103°20'20"E, 10-30.5.2009 Vit. Kubáň Tetraserica spLA1” (ZFMK), 1 ♂ “X-DA2409 labcode VD005 Laos, Xieng Khouang, Phonsavan (30 km NE), Phou Sane Mt. 1400–1600 m 19°38'20"N, 103°20'20"E, 10-30.5.2009 Vit. Kubáň Tetraserica spLA1” (ZFMK), 1 ♂ “X-DA4505 labcode VD027 Laos, Chiang Tung (Stupa) GH 5 km SE Muang Sing, 750 m, 26.03.-5.04.10 S. Murzin leg. Tetraserica liangheensis” (ZFMK), 1 ♂ “X-DA4504 labcode VD026 Laos, Chiang Tung (Stupa) GH 5 km SE Muang Sing, 750 m, 26.03.-5.04.10 S. Murzin leg. Tetraserica liangheensis” (ZFMK), 1 ♂ “X-DA4508 labcode VD029 Laos, Chiang Tung (Stupa) GH 5 km SE Muang Sing, 750 m, 26.03.-5.04.10 S. Murzin leg. Tetraserica liangheensis” (ZFMK), 1 ♂ “Haut Mekong Muong Sing 18.IV.1918 R.V. de Salvaza.” (NHMUK), 1 ♂ “X-DA4509 labcode VD030 Laos, Chiang Tung (Stupa) GH 5 km SE Muang Sing, 750 m, 26.03.-5.04.10 S. Murzin leg. Tetraserica liangheensis” (ZFMK), 1 ♂ “X-DA4513 labcode: VD033 LAOS Hua Phan prov.; Ban Saleui, Phou Pan (Mt) 20°12'N, 104°01'E, 3-5.iv.2013 leg. C. Holzschuh Tetraserica spLA_V6/ X-DA4513” (ZFMK), 1 ♂ “X-DA4562 labcode: VD042 LAOS Hua Phan prov.; Ban Saleui, Phou Pan (Mt) 20°12'N, 104°01'E, 3-5.iv.2013 leg. C. Holzschuh – ZFMK Ankauf 2014 Tetraserica liangheensis/ X-DA45623” (ZFMK), 1 ♂ “X-DA4812 labcode VD101 Laos, Stupa GH, 5 km W Muang Sing, 750 m, 21.1482N 101.1711E, M. Murzin O. Shulga leg. Tetraserica spLA_V60” (ZFMK). Thailand: 1 ♂ “Thai N, Nan prov. 19°13'N, 101°7'E, Doi Phukha N.P. Headq. 22-26.iv.1999, ca 1500 m”, D. Hauck leg./ coll. Pacholátko” (CPPB), 1 ♂ “Thai N, Nan prov., Doi Phu Kha N.P Headq., 19°13'N, 101°7'E, 28.iv.-1.v.1999, M. Riha leg/ coll. P. Pacholátko/ 126 Sericini Asia spec.” (CPPB). China: 1 ♂ “China: S-Yunnan (Xishuangbanna) 37km NW Jinghong Guo Men Shan (NNNR)/ N22°17.91 E100°38.85 1080 m 26.V.2008 leg. A. Weigel LF” (NME).

Aedeagus: Fig. 3E–G. Habitus: Fig. 3H.

The species was known only from China (Yunnan province); it is now recorded for first time from Laos and Thailand.

Holotype: ♂ “Thai 24-29-iv.1993 Doi Suthep Pacholátko & Dembický leg./ coll. P. Pacholátko/ 141 Sericini Asia spec.” (CPPB). Paratype: 1 ♂ “Laos, La Oudomxay 16.6.2005, ex coll. Sabatinelli” (ZFMK).

Length of body: 10.4 mm; length of elytra: 7.6 mm; maximum width: 6.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.56. Ratio of length of metepisternum/metacoxa: 1/1.63. Posterior margin of metafemur with sharp hook. Metatibia moderately long and wide, ratio width/length: 1/4.14; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 3I–K. Habitus: Fig. 3L.

Female unknown.

Length of body: 10.1–10.4 mm; length of elytra: 7.4–7.6 mm; maximum width: 5.5–6.6 mm.

Tetraserica doisuthepensis sp. n. differs from T. liangheensis Liu et al., 2014 by the dorsal lobe of right paramere being weakly curved, barely exceeding the ventral lobe of right paramere, and in having no additional hook at the apex. The new species differs from T. sculptilis by the stouter left paramere having a bluntly angulate dorsal margin.

The new species is named after the type locality, Doi Suthep (adjective in the nominative singular).

Holotype: ♂ “Laos, 21°09'N, 101°19'E, Louangnamtha pr. Namtha-MuangSing 5-31.v.1997. 900–1200 m, Vit Kubáň leg/ coll. Pacholátko/ 232 Sericini Asia spec.” (CPPB). Paratypes: 1 ♂ “Laos, 21°09'N, 101°19'E, Louangnamtha pr. Namtha-MuangSing 5-31.v.1997. 900–1200 m, Vit Kubáň leg/ coll. Pacholátko/ 232 Sericini Asia spec.” (CPPB), 1 ♂ “LAOS north, 5-11.v.1997, 20 km NW Louang Namtha, N21°09.2 E 101°18.7, alt. 900±100 m, M. Štrba & R. Hergovits leg./ coll. P. Pacholátko/ 186 Sericini Asia spec.” (ZFMK).

Length of body: 8.3 mm; length of elytra: 5.8 mm; maximum width: 4.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.64. Metatibia moderately long and wide, ratio width/length: 1/3.31; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 4A–C. Habitus: 4D.

Figure 4. 

A–D Tetraserica trilobiforceps sp. n. (holotype) E–H T. phukradungensis sp. n. (holotype) I–M T. cucphongensis sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, L aedeagus, right side lateral view B, F, J parameres, dorsal view K parameres, ventral view D, H, M habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.3–8.9 mm; length of elytra: 5.8–6.2 mm; maximum width: 4.5–5.2 mm.

Tetraserica trilobiforceps sp. n. differs from all other Tetraserica species by the left paramere having a dorsal lobe distant from base.

The species name (noun in apposition) is derived from the combined Latin words tri- (three times), lobatus (lobed), and forceps, with reference to the shape of the left paramere.

Holotype: ♂ „THAI-NE, Loei prov., Phu Kradung N.P., 16°52'N, 101°49‘E, 16-18.v.1999, 1000 m, D. Hauck leg./ coll. P. Pacholátko” (CPPB).

Length of body: 9.1 mm; length of elytra: 6.9 mm; maximum width: 5.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.68. Ratio of length of metepisternum/metacoxa: 1/1.63. Metatibia moderately long and wide, ratio width/length: 1/3.36; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 4E–G. Habitus: Fig. 4H.

Female unknown.

Tetraserica phukradungensis sp. n. differs from T. trilobiforceps sp. n. species by the shorter and stouter left paramere which has a short fine dorsal lobe behind the middle (rather than before the middle as in T. trilobiforceps).

The new species is named after the type locality, Phu Kradung (adjective in the nominative singular).

Holotype: ♂ “N-Vietnam, Cuc Phuong Nat. Park. 21-22.v.1996 Pacholátko & Dembický leg./ coll. P. Pacholátko/ 937 Sericini Asia spec.” (CPPB).

Length of body: 7.3 mm; length of elytra: 5.5 mm; maximum width: 4.9 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.48. Ratio of length of metepisternum/metacoxa: 1/1.67. Metatibia moderately long and wide, ratio width/length: 1/3.33; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 4I–L. Habitus: Fig. 4M.

Female unknown.

This species differs from all other Tetraserica species in having a simple left paramere, by the strongly asymmetric phallobase (dorsal view), the very short median lamina of phallobase, and by having the right paramere more or less straight (ventral view).

The new species is named after the type locality, Cuc Phuong (adjective in the nominative singular).

Holotype: ♂ “Tonkin occ. Rég. de Hoa Binh R.P.A. de Cooman 1918/ 1006 Asia Sericini spec.” (MNHN). Paratypes: 3 ♂♂ “Tonkin occ. Rég. de Hoa Binh R.P.A. de Cooman 1918” (MNHN, ZFMK).

Length of body: 7 mm; length of elytra: 4.9 mm; maximum width: 4.3 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons both glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.46. Ratio of length of metepisternum/metacoxa: 1/1.81. Metatibia short and wide, ratio width/length: 1/3.27; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 5A–C. Habitus: Fig. 5D.

Figure 5. 

A–D Tetraserica geiserae sp. n. (holotype) E–I T. thainguyensis sp. n. (holotype) A, E aedeagus, left side lateral view C, H aedeagus, right side lateral view B, F parameres, dorsal view G parameres distal view D, I habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 7.0–7.1 mm; length of elytra: 4.9–6.2 mm; maximum width: 4.3–5.2 mm.

Tetraserica geiserae sp. n. differs from T. cucphongensis in lacking the dorsal subbasal lobe of the left paramere.

The new species is named in honour of Dr Geiser, Silvia’s oncologist, for all her efforts and care (noun in genitive singular).

Holotype: ♂ “N. Vietnam: 40 km NE Thainguyen, 300 m, 8.V.1963, leg. O. Kabakov/ 1009 Asia Sericini spec.” (ZIN).

Length of body: 7.6 mm; length of elytra: 7.1 mm; maximum width: 6.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.56. Ratio of length of metepisternum/metacoxa: 1/1.74. Metatibia short and wide, ratio width/length: 1/2.32; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 5E–H. Habitus: Fig. 5I.

Female unknown.

Tetraserica thainguyensis sp. n. differs from the similar T. geiserae by having the left paramere very short and split into two lobes.

The new species is named with reference to its occurrence close to Thainguyen (adjective in the nominative singular).

Holotype: ♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20'E, 30km NE Phonsavan Ban Na Lam- > Phou Sane Mt., 1300–1500 m, 10.-30.v.2009, M. Brancucci leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (NHMB). Paratypes: 1 ♂ “LAOS-NE, Xieng Khouang prov., 19°37–8'N, 103°20'E, Phonsavan (30km NE) Phou Sane Mt., 1420 m, 10-30.v.2009, Z. Kraus leg./ NHMB Basel, NMPC Prague, Laos 2009, Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň/ 914 Sericini Asia spec.” (ZFMK).

Length of body: 8.6 mm; length of elytra: 6.5 mm; maximum width: 5.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.68. Ratio of length of metepisternum/metacoxa: 1/1.73. Metatibia moderately long and wide, ratio width/length: 1/3.62; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 6A–C. Habitus: Fig. 6D.

Figure 6. 

A–D Tetraserica xiengkhouangensis sp. n. (holotype) E–H T. doisangensis Kobayashi, 2017 (Thailand: Doi Inthanon) I–M T. curviforceps sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, L aedeagus, right side lateral view B, F, J parameres, dorsal view K parameres, ventral view D, H, M habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.6–8.7 mm; length of elytra: 6.3–6.5 mm; maximum width: 5.2–5.3 mm.

Tetraserica xiengkhouangensis sp. n. differs from the similar T. damaidiensis by having the right paramere distinctly not wider (dorsal view) than the left one, and the left paramere short, one third as long as phallobase.

The new species is named with reference to its occurrence in the Xieng Khouang province (adjective in the nominative singular).

1 ♂ “Ban Angkhai alt. 750 m Samoeng Distr. Chiangmai pref. Thailand 15-20-V-1998 K. Masumoto leg.” (ZFMK), 1 ♂ “X-DA 4639 labcode VD079 THAILAND, Chiang Mai Doi Inthanon NP Vachirathan Fall 700 m Malaise Trap, 18°32.31'N, 98°36.048'E, 9-16.iii.2007, Y. Areeluck leg. T1808, Tetraserica spTH_V39/ X-DA4639/ sp-TH-V39” (QSBG), 1 ♂ “NW Thailand 9-16.V. 1991 MAE HONG SON Ban Huai Po 1600 m leg. P. Pacholátko/ coll. P. Pacholátko/ TS67/ 157 Sericini Asia spec.” (CPPB), 1 ♂ “N THAILAND: Angkhai village, Samoeng Dist., Chiang Mai Prov., 9-11.v.1999 K. Masumoto leg.” (ZFMK), 1 ♂ “X-DA 4640 labcode VD073 THAILAND, Chiang Mai Doi Inthanon NP Vachirathan Fall 700 m Malaise Trap, 18°32.31'N, 98°36.048'E, 9-16.iii.2007, Y. Areeluck leg. T1808, Tetraserica spTH_V39/ X-DA4639” (ZFMK), 1 ♂ “N-Thailand Ban Mai [Huai] Po 9.-16.5.1991 L. Horak lgt./ Coll. Milan Nikodym Praha” (ZFMK), 1 ♂ “Chiang Mai N. Thailand V 1985 N. Koyama leg./ Ex coll. Takeshi Matsumoto (formerly Itoh) via coll. D. Ahrens” (ZFMK), 1 ♂ “NW Thailand, 19.19N, 97.59E, Mae Hong Son, 1991 Ban Huai Po, 1600–2000 m 17.-23.5., L. Dembický leg.” (NHMW).

Aedeagus: Fig. 6E–G. Habitus: Fig. 6H.

Holotype: ♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.iv.- 14.v.2008, Vít Kubán leg./ sp51” (ZFMK). Paratypes: 6 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.iv.- 14.v.2008, Vít Kubáň leg.” (ZFMK), 4 ♂♂, 3 ♀♀ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.IV.- 14.V.2008, Vít Kubáň leg.” (ZFMK), 7 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pane Mt., 22.4.- 14.5.2008, Vít Kubáň leg.” (ZFMK), 1 ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m, leg. C. Holzschuh ZFMK Ankauf 2012/13” (ZFMK), 1 ♂ “X-DA4511 labcode: VD031 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 3-5.v.2013, leg. C. Holzschuh Tetraserica spLA_V17/ X-DA4511” (ZFMK), 1 ♂ “X-DA4566 labcode: VD044 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 15-30.iv.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4566” (ZFMK), 1 ♂ “X-DA4570 labcode: VD045 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 15-30.iv.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4570/ sp-LA-V17” (ZFMK), 1 ♂ “X-DA4577 labcode: VD047 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 15-30.iv.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4577/ sp-LA-V17” (ZFMK), 1 ♂ “X-DA4583 labcode: VD050 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 15-30.iv.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4583” (ZFMK), 1 ♂ “X-DA4588 labcode: VD052 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 1.-2.v.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4588” (ZFMK), 1 ♂ “X-DA4593 labcode: VD055 LAOS: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 6-14.iv.2014, leg. C. Holzschuh - ZFMK Ankauf 2014 Tetraserica spLA_V17/ X-DA4570/ sp-LA-V17” (ZFMK), 5 ♂♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5’-104°01'E, Ban Saleui-> Phou Pane Mt. 1340–1870 m, 15.iv.-15.v.2008; Lao collectors leg.” (NHMB), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5'–104°01'E, Ban Saluei- Phou Pane Mt., 1340–1870 m, 10.v.-16.vi.2009, M. Brancucci & local coll. leg./ NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubáň” (NHMB).

Length of body: 6.5 mm; length of elytra: 5.4 mm; maximum width: 4.4 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.56. Ratio of length of metepisternum/metacoxa: 1/1.52. Metatibia moderately long and wide, ratio width/length: 1/3.45; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 6I–L. Habitus: Fig. 6M.

Female unknown.

Length of body: 6.5–7.8 mm; length of elytra: 5.4–6.0 mm; maximum width: 4.4–4.8 mm.

Tetraserica curviforceps sp. n. differs from T. sigulianshanica Liu et al., 2014 by the distinctly finer and longer parameres. From T. doisangensis Kobayashi, 2017 it differs by the narrow median phallobasal apophysis and the strongly curved dorsal lobe of the right paramere.

The species name (noun in apposition) is derived from the combined Latin words curvus (curved) and forceps, with reference to the shape of the curved right paramere.

Lectotype (here designated): ♂ “Pegu India/ Neoserica miniatula Type ♂ Moser” (ZMHB). Paralectotype: 1 ♀ “Pegu India/ Neoserica miniatula Type ♀ Moser” (ZMHB).

Redescription. Length of body: 8.0 mm; length of elytra: 5.8 mm; maximum width: 4.8 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes large, ratio of diameter/interocular width: 0.72. Ratio of length of metepisternum/metacoxa: 1/1.62. Metatibia moderately long and wide, ratio width/length: 1/3.07; basal group of dorsal spines of metatibia at first third of metatibial length.

Female: Antennal club with three antennomeres, as long as remaining antennomeres combined. Eyes smaller than in male, ratio of diameter/interocular width: 0.64. Pygidium flat.

Aedeagus: Fig. 7A–C. Habitus: Fig. 7D.

Figure 7. 

A–D Tetraserica miniatula (Moser, 1915) (syntype) E–H T. univestris Ahrens & Fabrizi, 2016 sp. n. (holotype) I–L T. jinghongensis Liu et al., 2014 (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

1 ♂ “INDIA: Kolasib, Mizoram; 24°13'N, 92°40'E, K. Sreedevi

25.iv.2014” (NBAIR).

The species was described from Assam (India). This is the first record from Mizoram state (India).

Aedeagus: Fig. 7E–G. Habitus: Fig. 7H.

4 ex. “China: S-Yunnan (Xishuangbanna) 37 km NW Jinghong Guo Men Shan (NNNR)/ N22°17.91 E100°38.85 1080 m 26.V.2008 leg. A. Weigel LF” (NME).

Aedeagus: Fig. 7I–K. Habitus: Fig. 7L.

This species has been recorded only from China (Yunnan Province) and Thailand (Kobayashi 2017).

Holotype: ♂ “X-DA4699 labcode: VD088, VIETNAM Tua Thien Hue Prov. Bach Ma Nat. Park, surr. Hotel Morin (1350–1400 m), 23-28.V.2014, legit L. Bartolozzi, G. Chelazzi, A. Bandinelli, S. Banbi, F. Fabiano, (n° Magazz. 2978) Tetraserica sp VI_V49/ sp VI-V49/ 935 Sericini Asia spec.” (VNMN).

Length of body: 10.1 mm; length of elytra: 7.6 mm; maximum width: 6.9 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons both glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.56. Ratio of length of metepisternum/metacoxa: 1/1.56. Metatibia short and wide, ratio width/length: 1/2.68; basal group of dorsal spines of metatibia at first third of metatibial length. Ventral metatibial spine extremely elongated, distinctly exceeding first metatarsomere.

Aedeagus: Fig. 8A–C. Habitus: Fig. 8D.

Figure 8. 

A–D Tetraserica bachmaensis sp. n. (holotype) E–H T. pluriuncinata sp. n. (holotype) I–L T. chiangdaoensis Kobayashi, 2017 (Thailand, Chiang Dao) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Tetraserica bachmaensis sp. n. differs from the similar T. sigulianshanica Liu et al., 2014 and T. curviforceps sp. n. by its shorter median phallobasal lamina.

The new species is named after the type locality, Bach Ma National Park (adjective in the nominative singular).

Holotype: ♂ “NE Thailand 1-15.[v.]1991. Mae Hong Son, Ban Huai Po, 800–1600 m, S. Bily leg.” (ZFMK). Paratypes: 1 ♂ “NW Thailand, Mae Hong Son, 9-16.V.1991 Ban Huai Po 1600 m leg. P. Pacholátko/ coll. P. Pacholátko/ TS135/ 146 Sericini Asia spec.” (CPPB), 7 ♂♂ “NW Thailand, 19.19N, 97.59E, Mae Hong Son, 1991 Ban Huai Po, 1600–2000 m 17.-23.5., L. Dembický leg.” (NHMW, ZFMK).

Length of body: 7.6 mm; length of elytra: 5.9 mm; maximum width: 5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.77. Ratio of length of metepisternum/metacoxa: 1/1.52. Metatibia moderately long and wide, ratio width/length: 1/3.38; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 8E–G. Habitus: Fig. 8H.

Female unknown.

Length of body: 7.6 mm; length of elytra: 5.8–5.9 mm; maximum width: 4.8–5 mm.

Tetraserica pluriuncinata sp. n. differs from T. bachmaensis by the left paramere being split into two long branches (or lobes) and by having much longer median phallobasal apophysis.

The species name (adjective in the nominative singular) is derived from the combined Greek word pluris (higher) and Latin word uncinatus (hooked), with reference to the pluri-hooked shape of the right paramere.

1 ♂ “X-DA4842 labcode VD102 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 1-5.vi.2009, S. Murzin leg. Tetraserica spTH_V53/ X-DA 4842/ 925 Sericini Asia spec.” (ZFMK), 1 ♂ “DA2072/ 835092/ 835092 X-DA2072 Thailand Chiang Mai Pr. 114 km N Chiang Mai Highway station, 700 m, 5-7.vi.2008 leg. S. Murzin” (ZFMK), 1 ♂ “X-DA4543 labcode VD041 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 28-31.v.2009, S. Murzin leg., Tetraserica spTH_V15/ X-DA4543” (ZFMK), 1 ♂ “X-DA4741 labcode VD093 Thailand, Chiang Dao Hill Resort 600 m, 19.55779N 99.0766E, 28.iv.-5.v.2011, M. Murzin, O. Shulga leg., Tetraserica spTH_V53/ X-DA4714” (ZFMK), 1 ♂ “X-DA4770 labcode: VD097, LAOS, Stupa GH, 5km W Muang Sing, 750 m, 21.1482N 101.1711E, 9.v-2.vi.2011, M. Murzin, O. Shulga leg. Tetraserica spLA_V56” (ZFMK), 1 ♂ “X-DA4846 labcode VD103 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 1-5.vi.2009, S. Murzin leg. Tetraserica spTH_V53/ X-DA 4846” (ZFMK), 1 ♂ “X-DA4863 labcode VD104 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 1-5.vi.2009, S. Murzin leg. Tetraserica spTH_V53/ X-DA 4863” (ZFMK), 1 ♂ “X-DA4864 labcode VD105 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 1-5.vi.2009, S. Murzin leg. Tetraserica spTH_V53/ X-DA 4864” (ZFMK), 1 ♂ “X-DA4884 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4887 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4916 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4919 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4930 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4959 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4936 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “X-DA4937 Thailand N: Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m 28.v.-8.vi. 2009 S. Murzin leg.” (ZFMK), 1 ♂ “THAI-NE, Loei prov., Phu Kradung N.P., 16°52'N, 101°49'E, 16-18.v.1999, 1000m, D. Hauck leg./ coll. P. Pacholátko/ 128 Sericini Asia spec.” (CPPB), 1 ♂ “Thailand, Nam Nao, Phetchabua; 16°5'N, 101°40'E; 19.V.1999; leg. K. Masumoto” (ZFMK).

Aedeagus: Fig. 8I–K. Habitus: Fig. 8L.

Holotype: ♂ “Vietnam bor. Pr. Hoang lien son SA PA V.1990, J Picka lgt./ 908 Sericini Asia spec.” (NHMB).

Length of body: 8.8 mm; length of elytra: 7.1 mm; maximum width: 5.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.6. Ratio of length of metepisternum/metacoxa: 1/1.31. Metatibia moderately long and wide, ratio width/length: 1/4.91; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 9A–D. Habitus: 9E.

Figure 9. A–E 

Tetraserica sapana sp. n. (holotype) F–I T. setuliforceps sp. n. (holotype) J–M T. parasetuliforceps sp. n. (holotype) A, F, J aedeagus, left side lateral view D, H, L aedeagus, right side lateral view B, G, K parameres, dorsal view C parameres, distal view E, I, M habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Tetraserica sapana sp. n. is similar to T. pluriuncinata sp. n. in shape of male genitalia but differs from the latter by the shorter and simpler left paramere and the presence of trichome-like spines on the dorsal lobe of the right paramere.

The new species is named after the type locality, Sa Pa (adjective in the nominative singular).

Holotype: ♂ “NW Thailand, 19.19N, 97.59E, Mae Hong Son, 1991 Ban Huai Po, 1600–2000 m 9–16.5., L. Dembický leg./ 130 Sericini Asia spec.” (NHMW). Paratypes: 1 ♂ “NW Thailand, 19.19N, 97.59E, Mae Hong Son, 1991 Ban Huai Po, 1600–2000 m 17.-23.5., L. Dembický leg.” (NHMW), 1 ♂ “NW Thailand: 7-12.V., Mae Hong Son distr. 1996 Soppong-pai; 19°27’, 98°20’, J. Horák lgt.; 1500 m leg./ coll. Pacholátko” (CPPB), 1 ♂ “NW Thailand 9.-16.V. Mae Hong Son 1991, Ban Huai Po, 1600 m, leg. P. Pacholátko/ coll. P. Pacholátko” (CPPB), 1 ♂ “NW THAI 7-14.V. DOI SUTHEP PUI 1300–1500 m 1992 leg. P. Pacholátko/ coll. P. Pacholátko” (CPPB), 1 ♂ “THAI 24-29.lV.1993, DOI SUTHEP Pacholátko & Dembicky leg/ coll. P. Pacholátko” (ZFMK).

Length of body: 7.5 mm; length of elytra: 5.9 mm; maximum width: 4.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.59. Ratio of length of metepisternum/metacoxa: 1/1.68. Metatibia moderately long and wide, ratio width/length: 1/3.33; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 9F–H. Habitus: Fig. 9I.

Female unknown.

Length of body: 6.7–8.5 mm; length of elytra: 4.9–6.0 mm; maximum width: 4.5–5.0 mm.

Tetraserica setuliforceps sp. n. resembles T. changjiangensis Liu et al., 2014 in the shape of aedeagus but it differs by the distinctly longer dorsal lobe of right paramere, which also bears trichome-like spines, and by the nearly straight left paramere.

The species name (noun in apposition) is derived from the combined Latin words setulus (with small setae) and forceps, with reference to the setae present on the right paramere.

Holotype: ♂ “THAILAND, Prov. Tak, Doi Mussoi, 800 m a.V. 2010, leg. T. Ihle 16°45, 309'N, 98°55, 404'E/ 901 Sericini Asia spec.” (NME).

Length of body: 7.6 mm; length of elytra: 6 mm; maximum width: 4.9 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.73. Metatibia short and wide, ratio width/length: 1/3; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 9J–L. Habitus: Fig. 9M.

Female unknown.

Tetraserica parasetuliforceps sp. n. differs from T. setuliforceps sp. n. by the longer parameres, with the left paramere being as long as phallobase.

The species name (noun in apposition) is derived from the combined Greek prefix para- (near) and the species name setuliforceps, with reference to the similarity to the previous species.

Holotype: ♂ “INDIA: Kolasib, Mizoram; 24°13'N, 92°40'E; K. Sreedevi 25.iv.2014/ 942 Sericini Asia spec.” (NBAIR). Paratype: 1 ♂ “INDIA: Kolasib, Mizoram; 24°13'N, 92°40'E; K. Sreedevi 25.iv.2014” (ZFMK).

Length of body: 7.5 mm; length of elytra: 5.6 mm; maximum width: 4.8 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.67. Ratio of length of metepisternum/metacoxa: 1/1.48. Metatibia short and wide, ratio width/length: 1/3.21; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 10A–D. Habitus: Fig. 10E.

Figure 10. A–E 

Tetraserica kollae sp. n. (holotype) F–I T. jakli sp. n. (holotype) A, F aedeagus, left side lateral view D, H aedeagus, right side lateral view B, G parameres, dorsal view C parameres, ventral view E, I habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 7.5–7.8 mm; length of elytra: 5.6–5.8 mm; maximum width: 4.8–4.9 mm.

Tetraserica kollae sp. n. is very similar to T. brahmaputrae Ahrens, 2004 in the shape of the genitalia; it differs from it by having a wider dorsal lobe of the right paramere, which is inserted more laterally on the right side, as well as the more strongly curved distal lobe of the right paramere.

The new species is named after Dr Kolla Sreedevi, collector of the new species (noun in the genitive singular).

Holotype: ♂ “Laos, Attapeau prov.; Annam Highlands Mts Dong Amphan; NBCA, ca. 1160 m NONG FA (crater lake) env.; 15°05.9'N, 107°25.6'E; St. Jakl lgt, 30.4.-6.5.2010/ 1012 Asia Sericini sp. “ (ZFMK).

Length of body: 7.3 mm; length of elytra: 5.6 mm; maximum width: 4.8 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.5. Ratio of length of metepisternum/metacoxa: 1/1.78. Metatibia short and wide, ratio width/length: 1/2.86; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 10F–H. Habitus: Fig. 10I.

Female unknown.

The shape of aedeagus of T. jakli sp. n. is somewhat similar to that of T. ferrugata (Blanchard, 1850) from the Himalayas; the left paramere of the new species is, however, distinctly longer and distinctly split into two short filiform branches at apex.

The new species is named after its collector, St. Jakl (noun in genitive singular).

Holotype: ♂ “X-DA4795 labcode: VD100, LAOS, Stupa GH, 5 km W Muang Sing, 750 m, 21.1482N 101.1711E, 9.v-2.vi.2011, M. Murzin, O. Shulga leg. Tetraserica spLA_V59/ sp-LA-v59/ X-DA4795” (ZFMK). Paratype: 1 ♂ “Laos, 21°09'N, 101°19'E, Louangnamtha pr. Namtha->Muang Sing, 5-31.v.1997, 900-Vit. Kubáň leg. -1200 m/ Coll. P. Pacholátko/ LS57” (CPPB).

Length of body: 8.8 mm; length of elytra: 6.5 mm; maximum width: 5.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.65. Ratio of length of metepisternum/metacoxa: 1/1.52. Metatibia short and wide, ratio width/length: 1/3.21; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 11A–D. Habitus: Fig. 11E.

Figure 11. A–E 

Tetraserica appendiculata sp. n. (holotype) F–I T. allomengeana sp. n. (holotype) J–M T. quadrifurcata sp. n. (holotype) A, F, J aedeagus, left side lateral view D, H, L aedeagus, right side lateral view B, G, K parameres, dorsal view C parameres, ventral view E, I, M habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 7.8–8.8 mm; length of elytra: 5.9–6.5 mm; maximum width: 5.0–5.3 mm.

The shape of aedeagus of T. appendiculata sp. n. is very similar to that of T. mengeana Liu et al., 2014; the new species differs in having one filiform sub-branch of the left paramere reduced, being much shorter than the width of principal branch at apical third.

The species name (adjective in the nominative singular) is derived from the Latin word appendiculus (small appendage), with reference to the small appendix of the paramere.

Holotype: ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m leg. C. Holzschuh - ZFMK Ankauf 2012/ sp 34 Silvia” (ZFMK). Paratypes: 4 ♂♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m leg. C. Holzschuh - ZFMK Ankauf 2012” (ZFMK), 1 ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m, leg. C. Holzschuh ZFMK Ankauf 2012/13” (ZFMK), 1 ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.) 20°12'N, 104°01'E, 11.iv.-15.v.2012, 1300–1900 m, leg. C. Holzschuh - ZFMK Ankauf 2012/2013/ sp 88 Silvia” (ZFMK), 6 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, 1480–1510 m, Phou Pan (Mt.) 22.IV.- 14.V. 2008, Vit Kubáň leg.” (ZFMK), 2 ♂♂ “NE-Laos: Houa Phan prov., 20°13'09–19"N, 103°59'54"–104°00'03"E, Phu Pane Mt., 1480–1510 m, 22.4.- 14.5.2008, Vit Kubáň leg.” (ZFMK), 1 ♂ “Laos-NE, Houa Phan prov., 20°12–13.5'N, 103°59.5'–104°01'E, Ban Saleui- Phou Pane Mt. 1340–1870 m, 15.iv.-15.v.2008; Lao collectors leg./ 911 Sericini Asia spec. “ (NHMB), 1 ♂ “Laos, 24-30.iv.1999, Louangphrabang pr., 20°33–4'N, 102°14'E, Ban Song Cha (5km W), 1200m, Vít Kubáň leg./ 202 Sericini Asia spec.” (CPPB), 1 ♂ “Laos-NE, Houa Phan prov., 20°13'09–19"N, 103°59'54’’ – 104°00'03"E, 1480–1550 m, Phou Pane Mt., 1.-16.vi.2009, Zdeněk Kraus leg./ NHMB Basel, NMPC Prague Laos 2009 Expedition: M. Brancucci, M. Geiser, Z. Kraus, D. Hauck, V. Kubán” (NHMB).

Length of body: 8.9 mm; length of elytra: 6.6 mm; maximum width: 5.0 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes large, ratio of diameter/interocular width: 0.7. Ratio of length of metepisternum/metacoxa: 1/1.65. Metatibia moderately long and wide, ratio width/length: 1/3.36; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 11F–H. Habitus: Fig. 11I.

Female unknown.

Length of body: 8.1–9.1 mm; length of elytra: 5.6–6.9 mm; maximum width: 4.8–5.3 mm.

The shape of aedeagus of T. allomengeana sp. n. is very similar to that of T. mengeana Liu et al., 2014; the new species differs by the filiform branches of left paramere being approximately two thirds of the paramere length, and by having the median phallobasal lamina evenly narrowed towards apex, rather than being narrow for most of its distal part as in T. mengeana.

The species name (adjective in the nominative singular) is derived from the combined Greek word allo- (other) and the species name mengeana, with reference to the similarity to T. mengeana.

Holotype: ♂ “Cambodia: Kirirom Nat. Park, h = 650 m, 11°18'6"N, 104°5'40"E, 9-16.XII.1999 leg. M. & S. Murzin/ coll. D. Ahrens/ 117 Sericini Asia spec.” (ZFMK). Paratype: 1 ♂, 1 ♀ “Thailand, Khao Yai; at light, 15.VII.1991; leg. M. Tanida” (ZFMK).

Length of body: 8.9 mm; length of elytra: 6.8 mm; maximum width: 5.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.62. Ratio of length of metepisternum/metacoxa: 1/1.67. Metatibia moderately long and wide, ratio width/length: 1/3.33; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 11J–L. Habitus: 11M.

Length of body: 8.9–9.8 mm; length of elytra: 6.8–7.0 mm; maximum width: 5.5–5.6 mm. Female: Eyes as large as in male; antennal club composed of four antennomeres, basal joint of club one quarter as long as club.

Tetraserica quadrifurcata sp. n. differs from all other Tetraserica species by its long median phallobasal apophysis having the median phallobasal lamina bifurcate at apex.

The species name (adjective in the nominative singular) is derived from the combined Latin prefix quadri (four) and furcata (forked), with reference to the shape of doubly bifurcate parameres.

Lectotype (here designated): ♂ “Fort de Kock (Sumatra) 920 m Januari 1922 leg. E. Jacobson/ Neoserica siantarensis Mos. [handwritten by Moser] det. J. Moser 1926 [handwritten by curator?]” (ZMAN). Paralectotype: 1 ♀ “Fort de Kock (Sumatra) 920 m Januari 1922 leg. E. Jacobson/ Neoserica siantarensis Mos.[handwritten by Moser]/ det. J. Moser 1926 [handwritten by curator?]” (ZMAN).

2 ♂♂, 1 ♀ “Malaysia W, Kelantan 40 km N of Gua Musang Gunung Berangkat Kampong Riek; 1100 m, 15.v.-8.vi.2017 Petr Cechovsky lgt.” (NME), 1 ♂, 1 ♀ “W-Sumatra Payakumbuh Sarilamak env. 15.-16.2.91 Jezevec lgt.” (ZFMK), 1 ♂ “Indonesia W, Sumatra, Harau Valley, Payakumbuh near Bukit Tinggi, XI.1993-IV.1994, Sarimudanas leg.” (ZFMK), 1 ♂, 1 ♀ “Indonesia Sumatra Utara Sungei Kopas II, ca 60 km E Pematangsiantar ca. 300 m, Sekundärwald 25.03.1997, leg.C U. P. Zorn” (ZFMK), 1 ♂ “I-W. Sumatra 600 m Paykumbuh 6-10.1. Harau vill. env. St. Jakl lgt.1991” (ZFMK), 1 ♂, 1 ♀ “Sumatra Utara Aek Bum b. Rantanprabat 11/12.2.96 lg. Zorn” (ZFMK), 2 ♂♂ “Malaysia 10-16.iv.1999 Kelantan prov. Kampong Raja env. Lgt. Mir. Janalik” (ZFMK), 1 ♂ “Indonesien Sumatra Aceh-Prov. Umg. Kotacane Ketambe 15.-22. Januar 2016 leg. Horst Rudolph” (Coll. H. Rudolph), 1 ♂ “Indonesien/Sumatra Sindar Raya LF Simaraopa 350 m NN 24. Februar 1993 leg. Horst Rudolph” (Coll. H. Rudolph).

Body length: 8.8 mm, length of elytra: 7.2 mm, width: 6.0 mm.

Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye three times as wide as long. Antennal club 1.1 times as long as remaining antennomeres combined. Eyes moderately large; ratio of diameter/interocular width: 0.69. Ratio of length of metepisternum/metacoxa: 1/1.59. Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin with a blunt tooth. Metatibia short and wide, ratio width/length: 1/2.7; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 12A–C. Habitus: Fig. 12D.

Figure 12. 

A–D Tetraserica siantarensis (Moser, 1922) (lectotype) E–H Tetraserica feresiantarensis sp. n. (holotype) I–L T. rubrithorax sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Holotype: ♂ “Malaysia: Hulu Perak, Bangunan Camp c/o Kampung Semelor (E shore Lake Tasek-Temengor), 230 m a.s.l., 10-19/VII/2007 L. Bartolozzi legit/ Museo Zoologico “La Specola” num. Mag. 2814/ 916 Sericini Asia spec.” (MZUF). Paratypes: 2 ♂♂ “Malaysia: Hulu Perak, Bangunan Camp c/o Kampung Semelor (E shore Lake Tasek-Temengor), 230 m a.s.l., 10-19/VII/2007 L. Bartolozzi legit/ Museo Zoologico “La Specola” num. Mag. 2814” (MZUF, ZFMK), 1 ♂ “Malaysia: Hulu Perak, Bangunan Camp c/o Kampung Semelor (E schore Lake Tasek-Temengor), 101°26'16"E, 5°30'18"N, 230 m 29.VI-4.VII.2008/ L. Bartolozzi, G. Mazza, F. Cianferoni, F. Fabiano (num. Mag. 2847)” (MZUF), 1 ♂ “S Thailand: Betong Gunung Cang dun vill. Yala dist., J. Horák leg./ 159 Sericini Asia spec.” (CPPB), 1 ♂ “S. Thailand 25.4.1992 Betong S. Bily leg.” (NHMB).

Length of body: 8.9 mm; length of elytra: 6.3 mm; maximum width: 5.9 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.71. Metatibia short and wide, ratio width/length: 1/2.68; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 12E–G. Habitus: Fig. 12H.

Female unknown.

Length of body: 8.9–9.5 mm; length of elytra: 6.3–7.2 mm; maximum width: 5.8–5.9 mm.

Tetraserica feresiantarensis sp. n. differs from the very similar T. siantarensis Moser, 1915 by the median lamina of phallobase having no dorsal preapical tooth and the dorsal lobe of left parameres and median lamina of phallobase being as long as phallobase, rather than being distinctly longer as in T. siantarensis.

The species name (adjective in the nominative singular) is derived from the combined Latin words fere- (nearly) and the species name siantarensis, with reference to the similarity to T. siantarensis (Moser).

Holotype: ♂ “Myanmar N (Burma), H-550 m, 21 km E Putao, Nan Sa Bon vill., leg S. Murzin & V. Sinaev 1-5.5.98/ coll D. Ahrens/ 427 Sericini Asia spec.” (ZFMK).

Length of body: 6.9 mm; length of elytra: 5 mm; maximum width: 3.9 mm. Body blackish brown, pronotum reddish. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.43. Ratio of length of metepisternum/metacoxa: 1/1.42. Metatibia short and wide, ratio width/length: 1/3.08; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 12I–K. Habitus: Fig. 12L.

Female unknown.

Tetraserica rubrithorax sp. n. differs from all other known Tetraserica species by having the body blackish brown and pronotum reddish.

The species name (noun in apposition) is derived from the combined Latin words rubus (red) and thorax, with reference to the red pronotum of the species.

Holotype: ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v. 2012, 1300–1900 m leg. C. Holzschuh - ZFMK Ankauf 2012/ sp 37 Silvia Indochina” (ZFMK). Paratypes: 2 ♂♂, 2 ♀♀ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 11.iv.-15.v. 2012, 1300–1900 m leg. C. Holzschuh - ZFMK Ankauf 2012 “ (ZFMK), 1 ♂ “NE-Laos: Houa Phan prov.; Ban Saleui, Phou Pan (Mt.)- 20°12'N, 104°01'E, 1300–1900 m 01.-31.5.2011, leg. C. Holzschuh - ZFMK Ankauf 2012” (ZFMK), 4 ♂♂ “C. Vietnam: Thanhhoa prov., Langchan, 300 m, 17.-18.IV.1963, leg. O. Kabakov” (ZIN, ZFMK), 1 ♂ “N Vietnam 1986 prov. Ha son binh Hoa Binh 5.-7.7. V. Shliva lgt.” (NHMB).

Length of body: 6.9 mm; length of elytra: 5.1 mm; maximum width: 4.5 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.44. Ratio of length of metepisternum/metacoxa: 1/1.44. Metatibia moderately long and wide, ratio width/length: 1/3.8; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 13A–C. Habitus: Fig. 13D.

Figure 13. 

A–D Tetraserica falciforceps sp. n. (holotype) E–H T. olegi sp. n. (holotype) A, E aedeagus, left side lateral view C, G aedeagus, right side lateral view B, F parameres, dorsal view D, H habitus. Scale bars: 0.5 mm. Habitus not to scale.

Length of body: 6.9–7.5 mm; length of elytra: 5.1–5.9 mm; maximum width: 4.5–5.2 mm. Female: Eyes as large as in male; antennal club composed of three joints, short, as long as remaining antennomeres combined.

Tetraserica falciforceps sp. n. is rather similar to T. sigulianshanica Liu et al., 2014 in shape of the aedeagus; the new species differs by the straight left paramere not being widened at apex and by the longer and widely arched dorsal lobe of the right paramere.

The species name (noun in apposition) is derived from the combined Latin words falcis (sickle) and forceps, with reference to setae present to the sickle-shaped right paramere.

Holotype: ♂ “N. Vietnam: 40 km NE Thainguyen, 300 m, 14.V.1963, leg. O Kabakov” (ZIN).

Length of body: 6.8 mm; length of elytra: 5.6 mm; maximum width: 0.1 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.42. Ratio of length of metepisternum/metacoxa: 1/1.56. Metatibia short and wide, ratio width/length: 1/3.14; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 13E–G. Habitus: Fig. 13H.

Female unknown.

The new species is very similar to the Chinese species T. longzhouensis Liu et al., 2014, but differs by the wider apical lobe of its left paramere.

The new species is named after Oleg N Kabakov (1928–2009).

Holotype: ♂ “Coll. I. R. Sc. N. B., Cambodia, Pursat prov., Phnom Samkos W.S. forest edge, light trap 14.iv.2005 Leg. K. Smets & I. Var” (ISNB). Paratypes: 2 ♂♂ “Coll. I. R. Sc. N. B. Cambodia (Pursat Prov.) Phnom Samkos wild life Sanctuary, light trap Forest Edge & Primary 14-IV-2005 Leg. K. Smets & I. Var” (ISNB), 7 ♂♂ “Coll. I. R. Sc. N. B. Cambodia, Pursat prov. Phnom Samkos W.S. Pramaoy Forest Edge 15-IV-2005, Light Trap Leg. K. Smets & I. Var” (ISNB, ZFMK).

Length of body: 9.4 mm; length of elytra: 6.9 mm; maximum width: 5.8 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.65. Ratio of length of metepisternum/metacoxa: 1/1.79. Metatibia short and wide, ratio width/length: 1/2.78; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 14A–C. Habitus: Fig. 14D.

Figure 14. 

A–D Tetraserica smetsi sp. n. (holotype) E–H T. shangsiensis Liu et al., 2014 (Vietnam: Tay Yen Tu Nat. Res.) I–L T. namnaoensis sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 9.3–9.4 mm; length of elytra: 6.6–6.9 mm; maximum width: 5.7–5.8 mm.

Tetraserica smetsi sp. n. is very similar to T. shangsiensis Liu et al., 2014 in shape of the aedeagus. The new species differs from the latter by the median lamina of phallobase being approximately as long as left paramere and slightly bifurcate at apex, as well as the preapical tooth of the left paramere being dorsally positioned and duplicate. In T. shangsiensis the median lamina of phallobase is distinctly shorter than left paramere, simply pointed, and slightly rounded at apex.

The new species is named after one of its collectors, K Smets (noun in genitive singular).

Vietnam: 1 ♂ “N-Vietnam Tam Dao Vinh Phu Prov. 21°27'18"N, 105°38'58"E, 1050–1200 m 2.-6.VI.1999 leg. Fabrizi, Jäger, Ahrens/ coll. D. Ahrens” (ZFMK), 1 ♂ “N-Vietnam, Thal Nguyen Prov., vic. Ngoc Thanh, Me Linh (IEBR station), 12.V.2012, 21°23'3"N, 105°42'44"E, 60–80 m, leg. A. Skale” (CASH), 2 ♂♂ “N-Vietnam, Bac Giang Prov., Tay Yen Tu Nat. Res., Thanh So’n, N21°12.812’ E106°45.846’, 86 m 18.5-21.5.2016 leg. A. Skale” (CASH, ZFMK), 1 ♂ “C-Vietnam: Kon Tum Province, surroundings Kon Plong, 1120 m 14°37, 350'N, 108° 17, 651E/ leg. L. Bartolozzi, S. Bambi, A. Badinelli, V. Sbordoni- at light 4-7.V.2016 (Mag. 3078)” (MZUF), 2 ♂”C Vietnam: Thua Thien-Hue Prov., A Luoi District, Sao La Nature Reserve (600–650 m) 16.077°N 107.488°E/ 20-27.V.2017 L. Bartolozzi, E. Orbach, V. Sbordoni, S. Banbi, A. Bandinelli leg. at light (numero Mag. 3089)” (MZUF, ZFMK), 4 ♂♂ “Vietnam, N, Ninh Binh Pr., 90 km SW Hanoi Cuc Phuong NP, primat rescue centre, 25.IV./ 2012, 190 m, 20°14'24"N, 105°42'53"E, leg. A. Weigel, light trap/ collection NATURKUNDE MUSEUM ERFURT” (NME), 1 ♂ “N-Vietnam, Tonkin /Tam Dao/ Vinh Phu Prov. 2-11.6.1985, Vít Kubáň leg./ Coll. P. Pacholátko/ VS38” (CPPB). Laos: 1 ♂ “Laos centr., Khammouan prov. NAKAI env., 4-8.5.1998, Route No 8, alt. 560±20 m N17°42.8, E 105°08.9 (GPS), E. Jendek & O. Šausa leg.” (CPPB), 3 ♂♂ “Laos, Sekong prov., ca. 12 km S. Sekong TAD FAEK waterfalls (at light) 15°14.7'N, 106°45.1'E, 118 m, Jiři Hájek leg. 8+12.v.2010” (NMPC), 1 ♂ “Khouang 1944/ Indo Chine Coll. Dussault” (NHMB).

Aedeagus: Fig. 14E–H. Habitus: Fig. 14H.

The species was recorded from China only, and it is here reported from Vietnam and Laos.

Holotype: ♂ “Thailand, Nam Nao, Phetchabua; 16°5'N, 101°40'E; 19.V.1999; leg. K. Masumoto” (ZFMK). Paratypes: 1 ♂ “Thailand, Nam Nao, Phetchabua; 16°5'N, 101°40'E; 19.V.1999; leg. K. Masumoto” (ZFMK), 1 ♂ “Laos Bolikhamxai pr., 18°16'N, 103°11'E, 70 km NEE Vientiane, 27-30.iv.1997, 150 m, Vít Kubáň leg./ Coll. P. Pacholátko/ LS52/ 190 Sericini Asia spec.” (CPPB), 1 ♂ “X-DA4881 labcode VD107 Thailand, Chiang Dao Hill Resort (100 km N of Chiang Mai) 600 m, 28.v- 8.vi.2009, S. Murzin leg, / Tetraserica spTH_63/ sp THV63” (ZFMK), 4 ♂♂, 1 ♀ “Laos P.D.R.: Xieng Khowang 14-20.May. 1994, K. Miura leg./ coll D. Ahrens” (ZFMK), 1 ♂ “Thai 17-24/5.91 Chiang Dao mts. 19.25'N, 98.52E lgt. D. Kral 1000 m” (NMPC), 1 ♂ “Laos. Xieng Khouang 29.IV.1919. R.V. de Salvazza” (NHMUK).

Length of body: 9.3 mm; length of elytra: 7.3 mm; maximum width: 5.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.77. Ratio of length of metepisternum/metacoxa: 1/1.83. Metatibia moderately long and wide, ratio width/length: 1/3.67; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 14I–K. Habitus: Fig. 14L.

Length of body: 9.3–11.0 mm; length of elytra: 7.3–8.2 mm; maximum width: 5.5–6.8 mm. Female: Eyes as large as in male; antennal club composed of three joints, short, as long as remaining antennomeres combined.

Tetraserica namnaoensis sp. n. is very similar to T. shangsiensis Liu et al., 2014 and T. smetsi sp. n. in shape of the aedeagus. The new species differs from these two species by the median lamina of its phallobase being distinctly curved and evenly narrowed from the base to apex, rather than being straight and strongly narrowed after the basal third.

The new species is named after the type locality, Nam Nao (adjective in the nominative singular).

Holotype: ♂ “C-Vietnam Gia Lai Province, Kon Chu Rang Nature Reserve, surroundings HQ, about 900 m 14°28, 450'N, 108°32, 401'E/ leg. L. Bartolozzi, S. Bambi, A. Badinelli, V. Sbordoni- at light 8-12.V.2016 (n° Mag. 3078)/ 238 Sericini Asia spec.” (VNMN). Paratypes: 5 ♂♂ “C-Vietnam Gia Lai Province, Kon Chu Rang Nature Reserve, surroundings HQ, about 900 m 14°28, 450'N, 108°32, 401'E/ leg. L. Bartolozzi, S. Bambi, A. Badinelli, V. Sbordoni- at light 8-12.V.2016 (n° Mag. 3078) (MZUF, ZFMK), 1 ♂ “S-Vietnam, 14.10N 108.30E 40 Km NW of An Khe Buon Luoi, 620–750 m 28.3-12.4.1995 Pacholátko & Dembický leg./ (coll.Pacholátko)” (CPPB)

Length of body: 9.8 mm; length of elytra: 7.5 mm; maximum width: 6.1 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.66. Ratio of length of metepisternum/metacoxa: 1/1.78. Metatibia short and wide, ratio width/length: 1/3.18; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 15A–C. Habitus: Fig. 15D.

Figure 15. 

A–D Tetraserica konchurangensis sp. n. (holotype) E–H T. angkorwatensis sp. n. (holotype) I–L T. koi sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.6–9.8 mm; length of elytra: 6.5–7.5 mm; maximum width: 5.5–6.1 mm.

Tetraserica konchurangensis sp. n. is very similar to T. shangsiensis Liu et al., 2014, T. namnaoensis sp. n., and T. smetsi sp. n. in shape of the aedeagus. Tetraserica konchurangensis sp. n. differs from all three by the left paramere lacking a tiny tooth before the apex.

The new species is named with reference to its occurrence in the Kon Chu Rang Nature Reserve (adjective in the nominative singular).

Holotype: ♂ “Coll. I. R. Sc. N. B. Cambodia: Siem Reap prov. Forest S of Angkor Wat 26-IV-2005, Light Trap, Leg K. Smets & I. Var/ 904 Sericini Asia spec.” (ISNB). Paratypes: 4 ♂♂ “Coll. I. R. Sc. N. B. Cambodia: Siem Reap prov. Forest S of Angkor Wat 26-IV-2005, Light Trap, Leg K. Smets & I. Var” (ISNB, ZFMK).

Length of body: 7.5 mm; length of elytra: 5.9 mm; maximum width: 4.9 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.68. Ratio of length of metepisternum/metacoxa: 1/1.79. Metatibia short and wide, ratio width/length: 1/3.07; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 15E–G. Habitus: Fig. 15H.

Female unknown.

Length of body: 7.5–7.8 mm; length of elytra: 5.8–5.9 mm; maximum width: 4.9–5.0 mm.

Tetraserica angkorwatensis sp. n. is rather similar to T. gestroi (Brenske, 1898) in shape of aedeagus; the new species differs by having the median lamina of the phallobase curved at its apex dorsally, while the base of the left paramere is not extended ventrally.

The new species is named after the type locality, Angkor Wat (adjective in the nominative singular).

Holotype: ♂ “Thailand (S) Prov. Chumphon, ca 5 km S von Phato 06.VII.2008 leg. M Langer/ 1000 Asia Sericini spec.” (ZFMK). Paratypes: 1 ♂, 1 ♀ “Thailand (S) Prov. Chumphon, ca 5 km S von Phato 06.VII.2008 leg. M Langer” (ZFMK).

Length of body: 7 mm; length of elytra: 5.4 mm; maximum width: 4.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.48. Ratio of length of metepisternum/metacoxa: 1/1.39. Metatibia short and wide, ratio width/length: 1/3.25; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 15I–K. Habitus: Fig. 15L.

Length of body: 7.0–8.4 mm; length of elytra: 5.4–6.1 mm; maximum width: 4.5–4.8 mm. Female: Eyes as large as in male; antennal club composed of three antennomeres, as long as remaining antennomeres combined.

Tetraserica koi sp. n. differs from all other species with the left paramere composed of two lobes at its base, by the right paramere being half as long as phallobase, and the left paramere longer than phallobase.

The new species is named in honour of Prof Dr Ko, Silvia’s oncologist and director of the Johanniter Hospital in Bonn, for all his efforts and care (noun in genitive singular).

Holotype: ♂ “Thailand. Nakhon ratchasima: Khao Yai NP. 700–800 m; 21 Apr 1990 U.V. light EF♀90020E E. Fuller/ 1014 Asia Sericini spec.” (UMIC). Paratypes: 1 ♂ “Thailand. Nakhon ratchasima: Khao Yai NP. 700–800 m; 21 Apr 1990; UV light EF♀90020E E. Fuller” (ZFMK), 3 ♂♂ “Thailand: Nahon Nayok Khao Yai N.P. Lum Ta Kong 14°25.565'N, 101°23.442'E, 726 m; malaise; 19-26.iv.07 Wirat Sukho leg. T2127” (QSBG), 2 ♂♂, 1 ♀ “Thailand: Nahon Nayok Khao Yai N.P. Lum Ta Kong View Point 14°25.565'N, 101°23.442'E, 726 m; Malaise trap; 12-19.iv.07; Wirat Sukho leg. T2124” (QSBG).

Length of body: 9.1 mm; length of elytra: 7.1 mm; maximum width: 5.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.53. Ratio of length of metepisternum/metacoxa: 1/1.73. Metatibia short and wide, ratio width/length: 1/3.25; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 16A–D. Habitus: Fig. 16E.

Figure 16. A–E 

Tetraserica fulleri sp. n. (holotype) F–I T. tonkinensis (Moser) (lectotype) J–N T. paratonkinensis sp. n. (holotype) A, F, J aedeagus, left side lateral view D, H, M aedeagus, right side lateral view B, G, K parameres, dorsal view C, L parameres, ventral view E, I, N habitus. Scale bars: 0.5 mm. Habitus not to scale.

Length of body: 8.4–9.8 mm; length of elytra: 6.5–7.3 mm; maximum width: 5.2–5.8 mm. Female: Eyes as large as in male; antennal club composed of three antennomeres, as long as remaining antennomeres combined.

Tetraserica fulleri sp. n. differs from all other Tetraserica species in having long parameres and a long median phallobasal lamina, and by the simple left paramere being wide for its entire length (at middle nearly as wide as apex of phallobase; lateral view).

The new species is named after its collector, E Fuller (noun in genitive singular).

Holotype: ♂ “Coll. I. R. Sc. N. B. Vietnam, Hoang Lien N.P. 22°21'00"N, 103°46'20"E, 1-5.vii.2013 night collecting Leg. J. Constant & J. Bresseel, I.G.: 32.454/ 234 Sericini Asia spec.” (ISNB). Paratype: 1 ♂ “N Vietnam, (Tonkin) pr. Vinh Phu 1990 Tam Dao, 6-9.v. P. Pacholátko leg./ coll. P. Pacholátko/ VS80” (CPPB), 1 ♂ “Vietnam N (Sa Pa) Lao Cai Prov., 250 km from Hanoi bearin 31°, Sa Pa vill. Env. Hoang Lien Son Nat. Res., 27.5.-3.6.1998 1250 m leg. A. Naplolov” (CNAR).

Length of body: 9.5 mm; length of elytra: 7.4 mm; maximum width: 6.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.47. Metatibia moderately long and wide, ratio width/length: 1/3.69; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 16J–M. Habitus: Fig. 16N.

Female unknown.

Length of body: 9.5–10.2 mm; length of elytra: 7.1–7.4 mm; maximum width: 5.8–6.3 mm.

Tetraserica paratonkinensis sp. n. is very similar to T. xichouensis Liu et al., 2014 in shape of aedeagus, but differs by the left paramere being nearly uniformly curved and the median lamina of phallobase that is not narrowed in its apical half.

The species name (adjective in the nominative singular) is derived from the combined Greek word para- (close to) and the species name tonkinensis, with reference to the similarity with T. tonkinensis (Moser).

3 ♂♂ “Tonkin Montes Mauson April, Mai 2-3000’ H. Frustorfer” (MNHN), 2 ♂♂ “Tonkin Montes Mauson April, Mai 2-3000’ H Frustorfer” (CF, ZMHB).

The species was revised and redescribed in Liu et al. (2014).

Aedeagus: Fig. 16F–H. Habitus: Fig. 16I.

Holotype: ♂ “Vietnam N 1989 Tam Dao 12-24.5. Vinh Phu prov. Stranad Jan leg.” (ZFMK). Paratypes: 1 ♂ “Coll. I. R. Sc. N. B. C Vietnam, Tam Dao N.P. 21°31'N 105°33'E, 25-30.vii.2011, Malaise trap, Leg. J: Costant & J. Bresseel, I.G.: 31.933, GTI project” (ISNB), 1 ♂ “N-Vietnam (Tonkin) pr. Vinh Phu, Tam Dao. 6-9.V.1990 Vít. Kubáň leg.”/ Coll. Milan Nikodým, Praha/ 726 Sericini Asia spec.” (ZFMK), 1 ♂ “N. Vietnam, 900 m Tam Dao 13-24.5 1989 A. Olexa/ Fereiwilliger Museumsverain (Basel) 1989” (NHMB), 1 ♂ “N-Vietnam, (Tonkin) Tamdao 12-24.5.1989 PACHOLÁTKO leg./ coll. P. Pacholátko/ VS21/ 242 Sericini Asia spec.” (CPPB), 1 ♂ “Vietnam, Tam dao 27.5.-2.6.1986 Vinh phu prov. Jan Horák lgt.” (NHMB), 2 ♂♂ “N-Vietnam 5-10.VI.1989 Tam Dao Brantlová lgt.” (NHMB), 1 ♂ “N. Vietnam: Vinh Phu prov., Tam Dao 900 m, 14.V.1962 leg. O. Kabakov” (ZIN).

Length of body: 9.9 mm; length of elytra: 7 mm; maximum width: 6.1 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.65. Ratio of length of metepisternum/metacoxa: 1/1.26. Metatibia short and wide, ratio width/length: 1/2.6; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 17A–D. Habitus: Fig. 17E.

Figure 17. A–E 

Tetraserica quadriforceps sp. n. (holotype) F–I T. allochangshouensis sp. n. (holotype) J–M T. changshouensis Liu et al., 2014 (holotype) A, F, J aedeagus, left side lateral view D, H, L aedeagus, right side lateral view B, G, K parameres, dorsal view C parameres, ventral view E, I, M habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.0–9.9 mm; length of elytra: 6.2–7.0 mm; maximum width: 5.0–6.1 mm.

Tetraserica quadriforceps sp. n. differs from all other Tetraserica species with a median lamina of the phallobase that is longer than the half-length of phallobase (but not exceeding the length of it), and by the right paramere having a comb of short spines at base. The shape of aedeagus resembles that of T. changshouensis Liu et al., 2014, but the medial phallobasal lamina is much shorter and the apex of the right paramere less strongly widened.

The species name (noun in apposition) is derived from the combined Latin prefix quadri (four) and forceps, with reference to the four branches of the parameres.

Holotype: ♂ “Tonkin Montes Mauson April, Mai 2-3000’ H. Frustorfer/ 1005 Asia Sericini spec.” (MNHN). Paratype: 1 ♂ “Tonkin Montes Mauson April, Mai 2-3000’ H. Frustorfer” (ZFMK).

Length of body: 8.8 mm; length of elytra: 6.6 mm; maximum width: 5.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.56. Ratio of length of metepisternum/metacoxa: 1/1.5. Metatibia short and wide, ratio width/length: 1/3.27; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 17F–H. Habitus: Fig. 17I.

Female unknown.

The new species is close to the Chinese species T. changshouensis Liu et al., 2014, but differs by the narrower ventroapical lobe of right paramere and the longer ventral lobe of left paramere.

Length of body: 8.2–8.8 mm; length of elytra: 6.5–6.6 mm; maximum width: 5.0–5.6 mm.

The species name (adjective in the nominative singular) is derived from the combined Greek prefix allo- (other) and the species name changshouensis, with reference to the similarity to T. changshouensis.

1 ♂ “China, S- Guizhou, 30.V.-11.VI. Yaorenshan For. Park 25°55'N, 107°58'E, 1100 m Jaroslav Turna leg., 2001” (ZFMK).

Aedeagus: Fig. 17J–L. Habitus: Fig. 17M.

Holotype: ♂ “Museum Leiden Viet Nam (Dong Nai Prov.) Cát Tiên N.P.: along Dong trail, 9.iv-19.v.2007. Leg. C. van Achterberg, R. de Vries, E. Gassó, Miracle & Nguyen Than Mahn/ humid lowland forest; in malaise traps; 250 m. 11°26'20.6"N, 107°25'42"E/ 960 Sericini Asia spec.” (RMNH). Paratypes: 4 ♂♂ “Museum Leiden Viet Nam (Dong Nai Prov.) Cát Tiên N.P.: along Dong trail, 9.iv-19.v.2007. Leg. C. van Achterberg, R. de Vries, E. Gassó, Miracle & Nguyen Than Mahn/ humid lowland forest; in malaise traps; 250 m. 11°26'20.6"N, 107°25'42"E” (RMNH, ZFMK), 2 ♂♂ “Museum Leiden Viet Nam (Dong Nai Prov.) Cát Tiên N.P.: along Dong trail, 1.iv-13.v.2007. Leg. May Phu Quy, Nguyen Than Mahn/ humid lowland forest; in malaise traps; 250 m, 11°26'20.6"N, 107°25'42"E” (RMNH).

Length of body: 10 mm; length of elytra: 7.5 mm; maximum width: 6.4 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.62. Ratio of length of metepisternum/metacoxa: 1/1.61. Metatibia short and wide, ratio width/length: 1/2.36; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 18A–C Habitus: Fig. 18D.

Figure 18. 

A–D Tetraserica dongnaiensis sp. n. (holotype) E–H T. phatoensis sp. n. (holotype) A, E aedeagus, left side lateral view C, G aedeagus, right side lateral view B, F parameres, dorsal view D, H habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 9.1–10.5 mm; length of elytra: 6.9–7.9 mm; maximum width: 5.8–6.8 mm.

Tetraserica dongnaiensis sp. n. differs from all other Tetraserica species that have long median phallobasal lamina with simple left and simple right parameres at base (without brush of spines), by the left paramere being split behind basal third into two filiform branches, and the right paramere being short and curved.

The new species is named with reference to its occurrence in the Dong Nai province (adjective in the nominative singular).

Holotype: ♂ “Thailand, Chumphon prov., 27.iii-14.iv.1996 Pha To env. 9°48’ 98”47, P. Průdek leg./ coll. P. Pacholátko/ 150 Sericini Asia spec.” (CPPB).

Length of body: 8.3 mm; length of elytra: 6.1 mm; maximum width: 5.3 mm. Dorsal surface blackish, ventral surface reddish brown. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes small, ratio of diameter/interocular width: 0.43. Ratio of length of metepisternum/metacoxa: 1/0.04. Metatibia short and wide, ratio width/length: 1/3.07; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 18E–G. Habitus: Fig. 18H.

Female unknown.

Tetraserica phatoensis sp. n. differs from all other Tetraserica species with very short median lamina of the phallobase (one quarter of phallobase length) and a long and narrow, more or less straight, left paramere, and by the right paramere having divergent spines at the base and a separate lobe distally.

The new species is named after the type locality, Pha To (adjective in the nominative singular).

1 ♂ “NW Thailand, 19.19N, 97.59E, Mae Hong Son, 1991 Ban Huai Po, 1600–2000 m, 17-23.5., L. Dembický leg./ 600 Sericini Asia spec.” (NHMW), 1 ♂ “N-Thailand Ban Mai [Huai] Po 9.-16.5.1991 L. Horak lgt./ Coll. Milan Nikodym Praha” (ZFMK), 1 ♂ “Thailand 9.-16.5.1991 Mae Hong Son Ban Huai Po 1600–2000 m J. Horak lgt./ coll. Milan Nikodym, Praha” (ZFMK).

Redescription. Length of body: 8.5 mm; length of elytra: 6 mm; maximum width: 5.3 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.56. Posterior margin of metafemur with sharp hook. Metatibia short and wide, ratio width/length: 1/3.29; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 19A–C. Habitus: Fig. 19D.

Figure 19. 

A–D Tetraserica masumotoi Kobayashi, 2017 (Thailand, Mae Hong Son) E–H T. wiangpapaoana Kobayashi, 2017 (Thailand, Doi Inthanon) I–L T. spinotibialis sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

1 ♂ “X-DA2306 labcode: VD002 Thailand N.: Doi Inthanon Nat. Res., 1250m 22-31.v.2008, S. Murzin leg. Tetraserica spTHAIx1/ X-DA2306/ sp-THAIx1V” (ZFMK), 1 ♂ “Thai 24-29.IV.1993, DOI SUTHEP Pacholátko & Dembický leg.”/ coll. P. Pacholátko/ 142 Sericini Asia spec.” (CPPB), 1 ♂ “NW Thai, 7-14.V.1992, DOI SUTHEP PUI 1300–1500 m leg. P. Pacholátko/ coll. P. Pacholátko/ 137 Sericini Asia spec.” (CPPB), 1 ♂ “Thailand: 29.5.-5.6.1989 Dai [Doi] Inthanon, Lichtfalle, Bang Khun Klang 1200 m 98°32'E, 18°32'N, Chantaramongkol & Malicky leg.” (ZSM), 3 ♂♂ “N-Thailand V.1990 Doi Inthanon lg. Malicky” (ZSM), 1 ♂ “836048 Thailand N. Thailand: Doi Inthanon Nat. Res., 1250 m, 22-31.v.2008, S. Murzin leg. Tetraserica spTHAIx1” (ZFMK), 1 ♂ “836046 Thailand N. Thailand: Doi Inthanon Nat. Res., 1250m 22-31.v.2008, S. Murzin leg. Tetraserica spTHAIx1” (ZFMK).

Redescription. Length of body: 9.5 mm; length of elytra: 7.6 mm; maximum width: 5.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.67. Ratio of length of metepisternum/metacoxa: 1/1.42. Posterior margin of metafemur with sharp hook. Metatibia moderately long and wide, ratio width/length: 1/4.23; basal group of dorsal spines at first third of metatibial length.

Aedeagus: Fig. 19E–G. Habitus: Fig. 19H.

Holotype: ♂ “NW Thailand, 9-16.V. MAE HONG SON. 1991 Ban Huai Po 1600 m leg. P. Pacholátko/ coll. P. Pacholátko/ 918 Sericini Asia spec.” (CPPB). Paratypes: 1 ♂ “NW Thailand, 1-8.V. MAE HONG SON 1992 BAN SI LANG 1200 m J. HORAK LEG./ coll. P. Pacholátko” (ZFMK), 4 ♂♂ “NW Thailand, 19.19N, 97.59E Mae Hong Song, 1991 Ban Huai Po, 1600–2000 m 17.-23.5., L. Dembicky leg.” (NHMW, ZFMK), 2 ♂♂ “NW Thailand, 19.19N, 97.59E Mae Hong Song, 1991 Ban Si Lang, 1200 m 23.-31.5., L. Dembicky leg.” (NHMW), 1 ♂ “N-Thailand Ban Mai [Huai] Po 9.-16.5.1991 L. Horak lgt./ Coll. Milan Nikodym Praha” (ZFMK), 3 ♂♂, 1 ♀ “Birmania Lashio VI-53 Bentoglio” (MSNM).

Length of body: 9 mm; length of elytra: 5.8 mm; maximum width: 5.8 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.71. Ratio of length of metepisternum/metacoxa: 1/1.72. Metatibia short and wide, ratio width/length: 1/2.05; basal group of dorsal spines of metatibia at first third of metatibial length. Ventral terminal spine of metatibia distinctly longer than first metatarsomere.

Aedeagus: Fig. 19I–K. Habitus: Fig. 19L.

Length of body: 9.0–9.9 mm; length of elytra: 5.8–7.0 mm; maximum width: 5.5–5.8 mm. Female: Eyes as large as in male; antennal club composed of three antennomeres, as long as remaining antennomeres combined.

Aedeagus of Tetraserica spinotibialis sp. n. resembles that of T. ruiliensis Liu et al., 2014 in shape. The new species differs by the ventral terminal spine of metatibia being distinctly longer than first metatarsomere, as well as by the right paramere being more strongly bent in the middle in lateral view.

The species name (adjective in the nominative singular) is derived from the combined Latin words spina and tibialis, with reference to the strongly developed spine of the mesotibia.

Holotype: ♂ “Coll. I. R. Sc. N. B. Cambodia, Pursat Prov., Phnom Samkos W.S., forest edge, light trap 14.iv.2005 Leg. K. Smets & I. Var” (ISNB). Paratypes: 1 ♂ “Coll. I. R. Sc. N. B., Cambodia, Pursat Prov., Phnom Samkos, W.S. Pramaoy, edge forest, Light trapping/ 16-XI-2005 Leg. K. Smets & I. Var” (ISNB), 1 ♂ “Coll. I. R. Sc. N. B. Cambodia Kirirom N. P. Light Trap Pine forest, 21 IV 2005 Leg. Smets & I. Var” (ISNB), 2 ♂♂ “Coll. I. R. Sc. N. B., Cambodia, Pursat Prov., Phnom Samkos Wildlife Pramaoy 16.XI.2005 forest edge, Light trapping, Leg. K. Smets & I. Var” (ISNB), 3 ♂♂ “Coll. I. R. Sc. N. B., Cambodia, Pursat prov. Phnom Samkos W.S., forest edge, light trap 14.iv.2005 Leg. K. Smets & I. Var” (ISNB, ZFMK), 1 ♂ “Coll. I. R. Sc. N. B. Cambodia (Pursat Prov.) Phnom Samkos wild life Sanctuary, light trap Forest Edge & Primary 14-IV-2005 Leg. K. Smets & I. Var” (ZFMK), 1 ♂ “Coll. I. R. Sc. N. B. Cambodia, Pursat Prov Phnom Samkos W.S., Pramaoy Forest Edge 15-IV-2005, Light Trap Leg. K. Smets & I. Var” (ISNB), 1 ♂ “E Thailand, 5-13.5. Chanthaburi Dist. Khao Soi Dao, 1998, M. Knížek lgt./ coll. P. Pacholátko” (CPPB), 1 ♂ “Cambodia, Cardamom Mts., near Pramuoy village, 12°16'N, 103°01'E, 270 m, Dry Dipterocarp and Gallery Forest, 24-25.ii.2000, leg. M. Nuss/ Staatl. Museum für Tierkunde Dresden/ 118 Sericini Asia spec.” (SMTD).

Length of body: 10.4 mm; length of elytra: 8 mm; maximum width: 6.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.66. Ratio of length of metepisternum/metacoxa: 1/1.69. Metatibia short and wide, ratio width/length: 1/2.62; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 20A–C. Habitus: Fig. 20D.

Figure 20. 

A–D Tetraserica vari sp. n. (holotype) E–H T. constanti sp. n. (holotype) I–L T. vientianeensis sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 10.4–11.2 mm; length of elytra: 8.0–8.1 mm; maximum width: 6.6–6.9 mm.

Tetraserica vari sp. n. differs from all other Tetraserica species in having a long median phallobasal lamina, a basally bent left paramere, and the median phallobasal lamina widened and sharply truncated at its apex.

The new species is named after one of its collectors, I Var (noun in genitive singular).

Holotype: ♂ “Coll. I. R. Sc. N. B. Cambodia - 8 km north of Sre Noi (road to Along Vaeng)/ Light trap 29.V.2003 Leg. J. Constant & K. Smets/ 926 Sericini Asia spec.” (ISNB). Paratype: 1 ♂ “Coll. I. R. Sc. N. B. Cambodia (Siem Road prov) Kbal Spean, Light Trap 28 V 2005 Leg Var & Grootaert” (ZFMK).

Length of body: 9.8 mm; length of elytra: 7.5 mm; maximum width: 6.5 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.63. Ratio of length of metepisternum/metacoxa: 1/1.79. Metatibia short and wide, ratio width/length: 1/2.57; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 20E–G. Habitus: Fig. 20H.

Female unknown.

Length of body: 9.8–10.2 mm; length of elytra: 7.3–7.5 mm; maximum width: 6.2–6.5 mm.

Tetraserica constanti sp. n. is very similar to T. vari sp. n. in the shape of aedeagus but differs by the distinctly shorter median phallobasal lamina and parameres.

The new species is named after one of its collectors, J Constant (noun in genitive singular).

Holotype: ♂ “Laos Bolikhamxai pr., 18°16'N, 103°11'E, 70 km NEE Vientiane 27-30.iv.1997, 150 m, Vít Kubáň leg./ coll. P. Pacholátko/ 197 Sericini Asia spec.” (CPPB).

Length of body: 8.3 mm; length of elytra: 6 mm; maximum width: 4.9 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.64. Ratio of length of metepisternum/metacoxa: 1/1.65. Metatibia short and wide, ratio width/length: 1/2.93; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 20I–K. Habitus: Fig. 20L.

Female unknown.

Tetraserica vientianeensis sp. n. differs from the similar T. constanti sp. n. by the basally straight and unbent left paramere, and by the median lamina of phallophase which is not widened at apex.

The new species is named with reference to its close occurrence to the city of Vientiane (adjective in the nominative singular).

Holotype: ♂ “Laos, Sekong Prov. ca. 12 km S Sekong TAD FAEK Waterfalls (at light) 15°14, 7'N, 106° 45, 1'E, 118m, Jiři Hájek leg., 8+12.v.2010/ 207 Sericini Asia spec.” (NMPC). Paratype: 1 ♂ “Laos centr., Khammouan prov. NAKAI env. 4-8.5.1998, Route No 8, alt. 560 ± 20 m, N17°42.8, E 105°08.9 (GPS), E Jendek & O Šauša leg./ coll. P Pacholátko” (CPPB), 1 ♂ “Laos, Sekong Prov. ca. 12 km S Sekong TAD FAEK Waterfalls (at light) 15°14, 7'N, 106° 45, 1'E, 118 m, Jiři Hájek leg. 8+12.v.2010/ 207 Sericini Asia spec.” (ZFMK).

Length of body: 8 mm; length of elytra: 6 mm; maximum width: 5.6 mm. Surface of labroclypeus and disc of frons glabrous. Smooth area anterior to eye twice as wide as long. Eyes moderately large, ratio of diameter/interocular width: 0.74. Ratio of length of metepisternum/metacoxa: 1/2.08. Metatibia short and wide, ratio width/length: 1/2.44; basal group of dorsal spines of metatibia at first third of metatibial length.

Aedeagus: Fig. 21A–C. Habitus: Fig. 21D.

Figure 21. 

A–D Tetraserica breviforceps sp. n. (holotype) E–H T. nahaeoensis sp. n. (holotype) I–L T. champassakana sp. n. (holotype) A, E, I aedeagus, left side lateral view C, G, K aedeagus, right side lateral view B, F, J parameres, dorsal view D, H, L habitus. Scale bars: 0.5 mm. Habitus not to scale.

Female unknown.

Length of body: 8.0–9.2 mm; length of elytra: 6.0–6.5 mm; maximum width: 5.5–5.6 mm.

Tetraserica breviforceps sp. n. differs from all other Tetraserica species with its short parameres and very short median phallobasal lamina, and by the left paramere having a robust (nearly half as long as paramere), subsphaerical, and apically convex dorsal lobe at its base.

The name of the new species (noun in apposition) is derived from the combined Latin words brevis (short) and forceps, with reference to the short parameres.

Holotype: ♂ “Coll. I. R. Sc. N. B. THAILAND (loei), Na-Haeo (field res stat) 15-19.V.2003 Light trap Leg. J. Constant, K. Smets & P. Grootaert/ 143 Sericini Asia spec.” (ISNB). Paratypes: 1 ♂ “Coll. I. R. Sc. N. B. THAILAND (loei), Na-Haeo (field res stat) 15-19.V.2003 Light trap Leg. J. Constant, K. Smets & P. Grootaert” (ISNB), 1 ♂ “Coll. I. R. Sc. N. B. THAILAND (Loei Prov.) Na-Haeo (Field Res. St.) 15-19.V.2003 Light trap Leg Constant & K. Smets” (ZFMK), 1 ♂ “Coll. I. R. Sc. N. B. THAILAND (Loei) Na-Haeo (edge pond) Light trap 17.V.2003 Leg. J. Constant, K. Smets” (ISNB), 1 ♂ “Coll. I. R. Sc. N. B. Thailand, Loei Na Haeo 22/V/2000 Station Leg. P. Grootaert” (ZFMK), 1 ♂ “Coll. I. R. Sc. N. B. Thailand (Loei) Na Haeo 23/05/1998 Leg. P. Grootaert” (ISNB), 1 ♂ “Thai 21-26.V.1993, Namuang Pacholátko & Dembicky leg./ coll. P. Pacholátko/ TS92” (CPPB).