Neoserica (s. l.) tonkinea, Ahrens, Dirk, Liu, Wan-Gang, Fabrizi, Silvia, Bai, Ming & Yang, Xing-Ke, 2014

Ahrens, Dirk, Liu, Wan-Gang, Fabrizi, Silvia, Bai, Ming & Yang, Xing-Ke, 2014, A taxonomic review of the Neoserica (sensu lato) abnormis group (Coleoptera, Scarabaeidae, Sericini), ZooKeys 439, pp. 27-82 : 32

Taxon classification Animalia Coleoptera Scarabaeidae

Neoserica (s. l.) tonkinea sp. n. Figs 2 A–E, 8

Type material examined.

Holotype: ♂ "N Vietnam (Tonkin) pr. Vinh Phu 1990 Tam Dao 6.-9.v. P. Pacholátko leg./ Coll. P. Pacholátko Invt. No./ VS74" (CPPB). Paratypes: 3 ♂♂ "Vietnam N (Sa Pa) Lao Cai Prov., 250km from Hanoi bearing 31°, Sa Pa vill. Env. Hoang Lien Son Nat. Res. 27.5.-3.6.1998 1250m leg. A. Napolov" (CNAR, ZFMK), 1 ♂ "Vietnam N (Sa Pa) Lao Cai Prov., 250km from Hanoi bearing 31°, Sa Pa vill. Env. Hoang Lien Son Nat. Res. 21.-23.6.1998 1250m leg. A. Napolov" (CNAR).

Description.

Body length: 13.0 mm, length of elytra: 9.8 mm, width: 7.8 mm. Body oblong, dark brown, antennal club yellowish brown, anterior labroclypeus shiny, dorsal surface dull, opaque toment on elytra and pronotum less thick, with a light trace of shine, sparsely setose.

Labroclypeus slightly subtrapezoidal, distinctly wider than long, widest at base, lateral margins moderately convex and convergent anteriorly, anterior angles strongly rounded, anterior margin weakly sinuate medially, margins moderately reflexed; surface slightly convex and shiny, basis with dull toment, punctation dense, anteriorly more sparse, behind the anterior margin with coarse punctures each bearing a long erect seta; frontoclypeal suture distinctly incised, flat and distinctly curved medially; smooth area anterior to eye approximately 1.5 times as wide as long; ocular canthus moderately wide and moderately long (length = 1/3 of ocular diameter), glabrous, with a fine terminal seta. Frons dull, with fine and dense punctures, beside the eyes and the frontoclypeal suture with a few erect setae. Eyes small, ratio diameter/interocular width: 0.48. Antenna with ten antennomeres, club with six antennomeres, straight, 1.2 times as long as remaining antennomeres combined; antennomere 5 subequal to length of club, antennomere 4 slightly transverse, antennomere 3 half as long as pedicellus. Mentum elevated and slightly flattened anteriorly. Labrum distinctly produced medially, with a moderate median sinuation.

Pronotum moderately transverse, subtrapezoidal, widest at base, lateral margins evenly convex and convergent anteriorly, anterior angles sharp and distinctly produced, posterior angles blunt, strongly rounded at the tip; anterior margin nearly straight, with a fine and complete marginal line; surface densely and finely punctate with minute setae in punctures; setae of lateral border sparse; hypomeron basally distinctly carinate, but carina only weakly produced. Scutellum long, triangular with nearly straight sides, apex slightly rounded, with fine, dense punctures, basally impunctate at middle, with only minute setae.

Elytra oblong, widest shortly behind the middle, striae weakly impressed, finely and moderately densely punctate, odd intervals narrower and distinctly convex with punctures concentrated along the striae, others evenly punctate and nearly flat, odd intervals with white scale-like, adpressed setae, otherwise only with very minute setae in punctures; epipleural edge fine, very narrow behind the middle, ending at the moderately rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, with only a very fine fringe of microtrichomes (visible at 100 × magnification).

Ventral surface dull, coarsely and densely punctate, metasternum sparsely covered with setae on the disc, glabrous on sides; metacoxa glabrous, with a few short setae laterally, posterior margin weakly convex; abdominal sternites finely and unevenly densely punctuate, nearly glabrous, with a transverse row of coarse punctures, each bearing a robust short seta. Mesosternum between mesocoxae half as wide as slender mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.77. Pygidium moderately convex and dull, densely punctate, fine punctures mixed with coarser ones, without smooth midline, with a few setae beside the margin.

Legs slender; femora with two longitudinal rows of setae, finely and sparsely punctate between the rows; metafemur dull, anterior margin acute, behind anterior edge without serrated line, setae of anterior longitudinal row nearly completely lacking, posterior margin in apical half ventrally smooth and slightly widened, posterior margin dorsally distinctly serrated, on its basal portion with a few short setae. Metatibia slender and long, widest at apex, ratio of width/length: 1/3.7, sharply carinate dorsally, with two groups of spines, basal group just before the middle, apical group at three quarters of metatibial length, basally with a few robust but single setae; lateral face longitudinally convex, very finely, superficially and sparsely punctate, subdorsal longitudinal carina on lateral face present on about two third of metatibial length; ventral edge finely serrated, with four robust equidistant setae; medial face smooth, apex moderately concavely sinuate interiorly near tarsal articulation. Tarsomeres ventrally with sparse, short setae, laterally not carinate, protarsomeres smooth, mesotarsomeres with a few very fine punctures; metatarsomeres lacking in holotype. Protibia long, bidentate; anterior claws symmetrical, basal tooth of inner claw sharply truncate at apex.

Aedeagus: Fig. 2 A–D. Female unknown.

Diagnosis.

Neoserica tonkinea sp. n. is very similar to Neoserica allolaotica and Neoserica taunggyiana externally and in the general shape of male genitalia. It differs principally by the shape of the parameres: the dorsal lobe of left paramere is narrower than in Neoserica allolaotica and the ventral lobe is not extended basally as in Neoserica taunggyiana ; the right paramere is much longer and less widened apically than in either of the species (in lateral view), the basal lobe is directed basally as well but much longer being more than half as long as the distal portion of the right paramere.

Variation.

Body length: 12.5-13.0 mm, length of elytra: 9.4-9.8 mm, width: 7.2-7.8 mm.

Etymology.

The new species is named according to its occurrence in northern Vietnam, formerly during colonial times, called Tonkin.