Serica (Taiwanoserica) yexiaohani Ahrens, Zhao, Pham & Liu, 2024

Ahrens, Dirk, Zhao, Ming-Zhi, Pham, Phu Van & Liu, Wan-Gang, 2024, Taxonomic updates on Pachyserica Brenske, 1898 and Serica MacLeay, 1819 reveal 38 new species and new challenges of Sericini systematics regarding DNA barcodes and genus-level diagnostic key characters (Coleoptera: Scarabaeidae: Sericinae), Zootaxa 5491 (1), pp. 1-89 : 34-35

Serica (Taiwanoserica) yexiaohani Ahrens, Zhao, Pham & Liu , new species

Fig. 13 G–K

Type material examined. Holotype ♂ “ CHINA: Zhejiang, Lishui, Mt. Fengyangshan , 1500 m 27.89589364°N, 119.16751297°E 2023.VII.26, at light, Xiao-Han Ye & Jia-Jia Liu leg. / Se-FY-1” ( SCAU) . Paratype: 1 ♂ “ CHINA: Zhejiang, Lishui, Mt. Fengyangshan , 1500 m 27.89589364°N, 119.16751297°E 2023.VII.26, at light, Xiao-Han Ye & Jia-Jia Liu leg.” ( CZMZ) .

Description of holotype. Length: 7.5 mm, length of elytra: 5.2 mm, width: 4.0 mm. Body oval, including legs dark reddish brown, femora and antennae more yellowish, head and pronotum darker, elytra with irregular and sparse dark spots, frons with green toment, pronotum and elytra iridescent; with white, scale-like setae on pronotum and elytra.

Labroclypeus subtrapezoidal, about twice as wide as long, widest at base, lateral margins straight, convergent anteriorly to broadly rounded anterior angles, anterior margin deeply and narrowly emarginated medially, moderately reflexed, lateral margins strongly reflexed; surface flat and shiny, coarsely and densely punctate, with a few long, erect setae situated behind anterior margin; frontoclypeal suture indistinctly incised, weakly elevated and moderately convex; smooth area anterior to eye moderately large and flat, approximately twice as wide as long; ocular canthus long and slender (1/3 of ocular diameter), smooth, with one minute terminal seta. Frons flat, entirely with dull toment; surface with large and moderately dense punctures each bearing a long and erect seta. Eyes small, ratio diameter/interocular width: 0.57. Antenna with ten antennomeres; antennomere three slightly longer than wide, antennomere seven transverse and short; club with three antennomeres, 0.75 times as long as remaining antennomeres combined and straight. Mentum strongly elevated, anteriorly flattened. Labrum transverse, strongly produced along middle, narrowly and deeply emarginate medially.

Pronotum transverse, twice as wide as long, widest at base, lateral margins evenly convex and convergent anteriorly; anterior angles weakly produced, sharp; posterior angles moderately rounded; anterior margin straight, marginal line distinct but medially widely incomplete; surface with dense and coarse punctures each bearing a minute seta, with a few white, adpressed and scale-like short setae at disc; anterior and lateral margins with rather long and sparse setae; hypomeron strongly carinate at base, weakly produced ventrally. Scutellum triangular, apex rounded, densely and coarsely punctate, each puncture with a minute seta, interspaced with a few short, adpressed setae.

Elytra oblong, widest at apical third, striae moderately impressed, strial punctures dense and large, intervals slightly convex, with dense punctures, dark spots completely impunctate; intervals with sparse, long, scale-like setae, other punctures each bearing a minute seta, fine long setae absent; epipleural edge fine, ending shortly after moderately curved external apical angle of elytra, epipleura moderately densely setose, apical border with a fine rim composed of microtrichomes (magnification 100x).

Ventral surface dull, densely and coarsely punctate, moderately densely setose, metacoxa glabrous, with a few short setae only laterally; abdominal sternites finely and densely punctate, each with a transverse row of long setae, iridescent laterally. Mesosternum between mesocoxae approximately half as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.55. Pygidium weakly convex and iridescent, with dense, large punctures and moderately dense, erect, long setae, midline slightly elevated and impunctate.

Legs slender; femora with two longitudinal rows of setae, with coarse and moderately dense punctures between the rows; metafemur shiny, anterior margin moderately acute, without a continuously serrated line behind anterior margin; ventral posterior margin serrated and weakly widened in apical third, dorsal posterior margin completely serrated, in basal half with a few long setae which are half as long as metafemur width. Metatibia slender and long, widest at apex, ratio of width/length: 1/4.5; dorsal margin moderately carinate, with two groups of spines, basal group at two fifths, apical group at two thirds of metatibial length, basally with a few single, robust setae; lateral face longitudinally concave and wrinkled, with fine and sparse punctures; ventral margin serrated at apical two thirds, with two widely separated robust setae; medial face with a shallow longitudinal groove medially, finely and sparsely punctate and glabrous; apex interiorly near tarsal articulation distinctly but bluntly truncate, serrated. Tarsomeres ventrally with dense, short setae, meso- and metatarsomeres with a strongly serrated ridge ventrally, metatarsomeres laterally and dorsally weakly carinate, ventrally glabrous; first metatarsomere little shorter than following two tarsomeres combined, distinctly longer than dorsal tibial spur. Protibia short, bidentate, external margin widely and weakly convex in base half; anterior claws symmetrical, basal tooth normal.

Aedeagus: Fig. 13I–K . Habitus: Fig. 13G, H . Female unknown.

Diagnosis. Serica (Taiwanoserica) yexiaohani new species is the second species without bifid parameres among subgenus Taiwanoserica . It can be easily characterized by the long and upcurved left paramere as well as right paramere with a robust spine basally.

Etymology. This species (noun in genitive case singular) is named after one of its collectors, Mr. Xiao-Han Ye (Henan University of Science and Technology, China).

Genbank accession numbers: Holotype (voucher: Se-FY-1; Cox 1: PP977018); additional male specimen (see Remarks) (voucher: Se-FY-2; Cox 1: PP977017).

Variation. Length: 7.5–7.7 mm, length of elytra: 5.2–5.5 mm, width: 4.0– 4.1 mm.

Remarks. Apart from the two type specimens, we examined one additional male with same collecting data (voucher number: Se-FY-2). It differs from the new species by the more medially positioned and smaller spine of right paramere. Due to identical COI barcoding sequences of the both forms ( Fig. 22 ), we would like to attend more specimens to confirm this second form (Se-FY-2) as a distinct species.

Figures

FIGURE 13. A–F: Serica nhiae new species (holotype); G–K: S. (T.) yexiaohani new species (holotype); A, I: aedeagus, left side lateral view; D, K: aedeagus, right side lateral view; B, J: parameres, dorsal view; C: aedeagus, dorsal view; E, G: habitus, dorsal view; F, H: habitus, lateral view. Scale bar: 0.5 mm. Habitus images not to scale.

FIGURE 22. Maximum likelihood tree depicting available COI barcode data of some of the newly described species (ultrafast bootstrap values are denoted on the nodes).