A taxonomic review on the species of Tetraserica Ahrens, 2004, of China (Coleoptera, Scarabaeidae, Sericini)

Abstract A review on the Chinese species of Tetraserica Ahrens, 2004, is presented. The lectotype of Tetraserica tonkinensis (Moser, 1908), comb. n. is designated. Twenty-nine new Tetraserica species are described from China and adjacent regions: Tetraserica anhuaensis sp. n., Tetraserica changjiangensis sp. n., Tetraserica changshouensis sp. n., Tetraserica damaidiensis sp. n., Tetraserica daqingshanica sp. n., Tetraserica fikaceki sp. n., Tetraserica graciliforceps sp. n., Tetraserica jinghongensis sp. n., Tetraserica leishanica sp. n., Tetraserica liangheensis sp. n., Tetraserica linaoshanica sp. n., Tetraserica longipenis sp. n., Tetraserica longzhouensis sp. n., Tetraserica maoershanensis sp. n., Tetraserica mengeana sp. n., Tetraserica menglongensis sp. n., Tetraserica pingjiangensis sp. n., Tetraserica ruiliana sp. n., Tetraserica ruiliensis sp. n., Tetraserica sculptilis sp. n., Tetraserica shangsiensis sp. n., Tetraserica shunbiensis sp. n., Tetraserica sigulianshanica sp. n., Tetraserica tianchiensis sp. n., Tetraserica wandingensis sp. n., Tetraserica wangtongensis sp. n., Tetraserica xichouensis sp. n., Tetraserica yaoanica sp. n., Tetraserica yaoquensis sp. n. A key to the Chinese Tetraserica species is given, species distribution as well as the habitus and male genitalia of all species are illustrated.


Introduction
The genus Tetraserica was established by Ahrens (2004).The genus included so far 8 nominal species from Indian subcontinent and Myanmar.Other species are known or described from India, Indochina, Philippines, Sumatra and Borneo, but they are not yet formally transferred to Tetraserica.Based on the results of this study, the genus is for the first time recorded for China.Recent molecular work confirmed the monophyly of Tetraserica (Ahrens and Vogler 2008;Liu et al., unpublished data).
In this study, we examined the material collected in China mainland and deposited in Chinese institutional collections as well as various European and American collections.We found twenty-nine new taxa, which are described herein.Additionally, non-Chinese records are added to the species recorded from China, while the taxa occurring exclusively out of China are not revised herein.A key to the Chinese Tetraserica species is given, species distribution, as well as habitus and male genitalia, are illustrated.

Material and methods
The terminology and methods used for measurements, specimen dissection and genital preparation follow Ahrens (2004).Data from specimens examined are cited in the text with original label contents given in quotation marks, multiple labels are separated by a "/".Male genitalia were glued to a small pointed card attached to the specimen.Descriptions and illustrations of new taxa are based on the holotype or lectotype specimen, while the variation of other specimens is given separately.All descriptions and measurements were made under an Olympus SZX 12 microscope, and all genital and habitus illustrations were made with a digital camera (AxioCam HRc) attached to a stereo microscope (Zeiss Stereo Discovery V20) and Axio Version 4.8 software.The distribution maps were generated using Q-GIS 2.0.1 and Inscape software.
Type specimens and other examined material are deposited in the following institutions or collections:
Diagnosis.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 10 antennomeres; club composed of 4 antennomeres in male, straight, rarely longer than 1.5 times as the remaining antennomeres combined; club in female composed of 3 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.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.
Aedoeagus.Phallobasis with a more or less long median ventral extension.
Remarks.So far seven species from Himalaya and the type species from Myanmar have been formally assigned to Tetraserica (Ahrens 2004;Ahrens and Fabrizi 2009).Most other oriental species (so far grouped with 'Neoserica') await taxonomic revision.Tetraserica differs from closely related genera Microserica Brenske, 1894, andTrioserica Moser, 1922, by the lacking ventral carina of hypomeron.From Microserica it also differs by the lacking 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.
Distribution.The genus is distributed almost in the entire Oriental region; we know described species so far assigned to "Neoserica" from Philippines, Indochina, Sumatra, and Borneo (Ahrens 2004).Except in Meghalaya and Himalaya, the genus does not occur on Indian subcontinent south of the Ganges.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.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.7.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: 1/3.2; basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica sculptilis sp.n. is in the external shape and morphology of the male genitalia very similar to T. daqingshanica.It differs only in the shape of the parameres: the left paramere is more narrow in T. sculptilis sp.n., its dorsal margin weakly and evenly curved (Fig. 1E).

Tetraserica wangtongensis
Description.Body length: 9.1 mm, length of elytra: 6.9 mm, 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: 0.6.Antennal club 1.3 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.7.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight, without blunt tooth.Metatibia short and wide, ratio width/length: 1/3.2; basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica wangtongensis sp.n. is in the external shape and morphology of the male genitalia similar to T. daqingshanica and T. sculptilis.It differs by the lacking tooth at the posterior margin of metafemur and in the shape of the parameres: the right paramere is straight (in dorsal view) and not curved as in T. daqingshanica and T. sculptilis (Fig. 1J).
Etymology.Tetraserica wangtongensis sp.n. is named after its type locality, Wang Tong.
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: 1/2.84;basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica maoershanensis sp.n. is in the external shape and morphology of the male genitalia similar to T. daqingshanica and T. sculptilis.It differs by the shape of the parameres: the dorsal lobe of the right paramere is short and does not exceed the length of the ventral lobe (Fig. 2C).
Etymology.The new species is named after its type locality, Maoershan.Diagnosis.Tetraserica fikaceki sp.n. is in the external shape and morphology of the male genitalia similar to T. wangtongensis.It differs by the shape of the parameres: the dorsal lobe of the right paramere (in lateral view) is curved ventrally (while being straight in T. wangtongensis) (Fig. 2I), the left paramere is reduced in size (Fig. 2E).
Etymology.The new species is named after one of the collectors of the type series, Martin Fikáček (Prague).Description.Body length: 8.4 mm, length of elytra: 6.5 mm, 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: 0.63.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.67.

Tetraserica changjiangensis
Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight, without blunt tooth.Metatibia short and wide, ratio width/length: 1/2.74;basal group of dorsal spines of metatibia at first third of metatibial length.lateral view) is long, filiform, and strongly curved (Fig. 3A), the left paramere is much longer than that of T. fikaceki sp.n. (Fig. 2K, L).
Etymology.The new species is named after its type locality, Sigulian Shan.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.Antennal club 1.3 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.5.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight, without blunt tooth.Metatibia short and wide, ratio width/length: 1/3.21; basal group of dorsal spines of metatibia at first third of metatibial length.
Variation.Body length: 6.9-7.6 mm, length of elytra: 5.1-5.8mm, width: 4.0-4.6 mm.Female has the antennal club composed of three lamellae, short, as long as the remaining antennomeres combined; eyes as large as those in male.
Diagnosis.The new species differs from the other known Tetraserica species by having both parameres simple, not being divided in two lobes.
Etymology.The new species is named after its type locality, Damaidi.
Diagnosis.The new species differs from T. damaidiensis in the shape of the parameres: the left paramere is straight instead of being curved dorsally (Fig. 3I), the right paramere is slender in dorsal view, lacking the basal dorsal tooth (Fig. 3J) which is present in T. damaidiensis.
Etymology.The new species is named after its type locality, Shunbi.
Aedeagus.Fig. 4A-C.Habitus: Fig. 4D.Female unknown.Diagnosis.Tetraserica longzhouensis sp.n. differs from all other species with straight or slightly convex posterior margin of metafemur by the small eyes, short ventral process of phallobasis being at maximum subequeal to half of the length of the phallobasis, strongly asymmetric phallobasis (dorsal view), right paramere being simple, and left paramere having the ventral lobe shorter than the dorsal one.
Etymology.The new species is named after its type locality, Longzhou.
Diagnosis.Tetraserica yaoquensis sp.n. differs from all other species with straight posterior margin of metafemur by the short ventral process of the phallobasis being subequal to half of the length of phallobasis, right paramere being simple and basiventrally strongly widened towards apex, and left paramere having two lobes.
Etymology.The new species is named after its type locality, Yaoqu.Etymology.The species name is derived from the combined Latin words, longuslong and penis -male copulation organ, with reference to the long parameres of the species.Description.Body length: 7.6 mm, length of elytra: 5.8 mm, 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: 0.63.Antenna missing in holotype.Ratio of length of metepisternum/metacoxa: 1/1.69.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setaebearing punctures absent; posterior margin straight, without blunt tooth.Metatibia short and wide, ratio width/length: 1/3.36; basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica jinghongensis sp.n. differs from all other species with long ventral phallobasal process by the simple left paramere being not separated into lobes, right paramere having no brush of spines and being composed of two lobes: its dorsal lobe is narrow, evenly curved and sharply pointed.
Etymology.The species name is named after its type locality, Jinghong Na Ban village.Description.Body length: 7.6 mm, length of elytra: 5.8 mm, width: 4.3 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: 0.59.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.64.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight, without blunt tooth.Metatibia short and wide, ratio width/length: 1/3.23; basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica menglongensis sp.n. differs from T. jinghongensis by the slightly lighter colour, bilobate left paramere, as well as the right paramere having the dorsal lobe shorter than the ventral one (Fig. 5E).
Etymology.The new species is named after its type locality, Menglong.
Diagnosis.Tetraserica tianchiensis sp.n. differs from T. jinghongensis by dorsal lobe of the right paramere being wide, with a sickle-shaped, large apical hook (Fig. 5J).
Etymology.The new species is named after its type locality, Tianchi.
Diagnosis.Tetraserica liangheensis sp.n. differs from all other known Tetraserica species by the large and sharp hook at the posterior margin of metafemur.
Etymology.The new species is named after its type locality, Lianghe.Description.Body length: 8.9 mm, length of elytra: 7.2 mm, width: 5.7 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: 0.5.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.6.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin with a large sharp hook.Metatibia short and wide, ratio width/length: 1/3.2; basal group of dorsal spines of metatibia at first third of metatibial length.Variation.Body length: 8.8-9.3 mm, length of elytra: 6.9-7.1 mm, width: 5.4-5.6 mm.
Diagnosis.Tetraserica wandingensis sp.n. differs from T. liangheensis by the larger eyes (ratio diameter/interocular distance: 0.72 vs. 0.59) and dorsal lobe of the right paramere being very small and bent basally.
Etymology.The new species is named after the type locality, Wanding.
Redescription.Body length: 9.0 mm, length of elytra: 7.0 mm, width: 5.9 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: 0.66.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/ metacoxa: 1/1.45.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin with a large sharp hook.Metatibia short and wide, ratio width/length: 1/3.25; basal group of dorsal spines of metatibia at first third of metatibial length.
Remarks.The species is recorded for the first time for China.Aedeagus.Fig. 8E-G.Habitus: Fig. 8H.Female unknown.
Diagnosis.Tetraserica changshouensis sp.n. differs from all other species with a brush of robust trichome-like spines at the base of the right paramere by the left paramere being composed of two lobes and the ventral lobe of the right paramere being abruptly and strongly widened at apex.
Etymology.The new species is named after its type locality, Changshou.Description.Body length: 8.1 mm, length of elytra: 5.8 mm, 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: 0.63.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.74.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight.Metatibia moderately long and wide, ratio width/length: 1/3.54; basal group of dorsal spines of metatibia at first third of metatibial length.
Diagnosis.Tetraserica ruiliensis sp.n. differs from all species with straight posterior margin of metafemur, long ventral phallobasis process, and right paramere without brush of spines by the right paramere being simple, not composed of two lobes.
Etymology.The new species is named after its type locality, Ruili.
Description.Body length: 7.2 mm, length of elytra: 5.2 mm, width: 4.2 mm.Labroclypeus surface with a few erect setae.Disc of frons with a few single setae.Smooth area in front of eye approximately 4 times as wide as long.Eyes large; ratio of diameter/interocular width: 0.82.Antennal club 1.4 times as long as remaining antennomeres combined.
Ratio of length of metepisternum/metacoxa: 1/1.5.Metafemur with a serrated continuous line beside anterior margin, with fine sparse punctures behind line each bearing a short seta.
Metatibia moderately long, ratio width/length: 1/3.25; basal group of dorsal spines of metatibia behind middle; beside dorsal margin in basal half with a blunt carina being partly finely serrate.
Diagnosis.T. anhuaensis sp.n. differs in a number of characters from all so far known Tetraserica species: metafemur possessing a serrated continuous line beside anterior margin and fine sparse punctures with short setae behind line; the labroclypeus and frons having a few erect setae on disc; basal group of dorsal spines situated behind the middle of metatibia; metatibia beside dorsal margin in basal half with a blunt carina being partly finely serrate.

menglongensis sp. n. - Dorsal lobe of right paramere convexly widened and elongate ...T. ruiliana sp. n. Tetraserica daqingshanica sp. n.
The new species differs from all other so far known Tetraserica species by the blunt tooth at the posterior margin of the metafemur.Etymology.The new species is named after the type locality, Mt.Daqingshan.
Body length: 9.7 mm, length of elytra: 7 mm, width: 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: 0.6.Antennal club 1.2 times as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.8.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight, without 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.
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.Antennal club as long as remaining antennomeres combined.Ratio of length of metepisternum/metacoxa: 1/1.57.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight.Metatibia short and wide, ratio width/length: 1/3.35; basal group of dorsal spines of metatibia at first third of metatibial length.

Tetraserica shangsiensis sp. n.
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: 0.76.Antennal club as long as remaining antennomeres combined.Ratio of length of metepisternum/ metacoxa: 1/1.61.Metafemur dull, anterior margin acute, without submarginal serrated line; anterior row of setae-bearing punctures absent; posterior margin straight.Metatibia short and wide, ratio width/length: 1/3.13; basal group of dorsal spines of metatibia at first third of metatibial length.Aedeagus.Fig.8I-K.Habitus: Fig.8L.The new species differs from the similar T. xichouensis sp.n. by the left paramere being evenly curved without being clearly bent, and having a tiny lateral tooth before apex which is absent in T. xichouensis.Etymology.The new species is named after its type locality in Shangsi prefecture (Guangxi province).