Pachyserica jianfengensis Zhao & Ahrens, 2023

Zhao, Ming-Zhi & Ahrens, Dirk, 2023, New species of the tribe Sericini Kirby, 1837 from China, with further updates on their taxonomy and distribution (Coleoptera: Scarabaeidae: Sericinae), Zootaxa 5361 (2), pp. 181-220 : 189-191

Pachyserica jianfengensis Zhao & Ahrens , new species

( Figs 3E , 4E )

Type material examined. Holotype. ♂ ( SCAU), “ CHINA: Hainan, Ledong, Jianfengling (main peak), 1412 m, 18.V–17.VI.2022, local collector leg.”

Description of the holotype. General. Body shape ovoid, strongly convex, color dark reddish brown, frons, pronotum, scutellum and impunctate portions on elytra with rather strong greenish sheen, abdomen strongly iridescent; clypeus and legs reddish brown (excluding metacoxa), palpi and antennae yellowish brown, shiny, tibiae and tarsi iridescent. Setae yellow.

Head. Labroclypeus nearly rectangular, ratio of maximum length/ width: 1/ 1.63; lateral margins almost straight and subparallel, anterior angle generally right-angled, anterior margin straight; margins strongly reflexed; surface flat, with dense and large punctures each bearing an short erect seta; frontoclypeal suture finely incised, curved medially; smooth area anterior to eye large and flat, as wide as long; ocular canthus moderately long and slender (slightly shorter than 1/3 of ocular diameter), with a short terminal seta. Frons flat, with scattered and small punctures, lateral portions each bearing some oblong setae, mixed with some short erect setae. Eyes large, ratio diameter/ interocular width: 0.60. Antenna with ten antennomeres; antennomeres 7 transverse and short; club straight, with three antennomeres, 1.3 times as long as remaining antennomeres combined. Mentum strongly and transversely elevated anteriorly. Labrum transverse, strongly produced anteriorly, deeply emarginate.

Pronotum subtrapezoidal, widest at base, lateral margins evenly curved and strongly convergent anteriad; anterior angle almost obsolete, posterior angle almost right-angled; hypomeron carinate at base and strongly produced ventrally; anterior margin without marginal line; surface with moderately dense and large punctures, midline impunctate in posterior half, rather sparsely punctate beside it, punctures each bearing an elliptical seta, aggregated near anterior and lateral margins, here also with rows of short erect setae.

Scutellum elongated triangular, apex somewhat rounded; basomedial and apical portions impunctate, other portions with dense and small punctures, each bearing an elliptical seta, setae minute near lateral margins.

Elytra oval, widest shortly after middle. Striae finely impressed, strial punctures moderately dense and large; intervals weakly convex, with scattered and small punctures, most of the punctures each bearing an elliptical seta, interrupted by some impunctate sections (including humeral umbone), each elytron with several areas covering slightly larger and more aggregated scale-like setae, each area including an upright and rather large scale-like setae, some irregular and large areas upon elytra impunctate, a single semi-erect long setae situated near base. Epipleura abruptly ending before strongly curved external apical angle of elytron, with a row of dense and short semi-erect setae; elytral apex with two short spiniform setae, posterior margin with a fine membranous rim composed of microtrichomes.

Ventral thoracic surface. Hypomeron with scattered and short setae, a small area bearing oblong setae; ventral mesothoracic surface densely punctate and setose; ventral metathoracic surface as well as metacoxae with moderately dense and small punctures, more densely punctate laterally, setae on the medial and anterior portions semi-erect dense, other portions with dense and oblong setae. Mesosternum between mesocoxae slightly wider than width of the mesofemur. Ratio of length of metepisternum/ metacoxa: 1/ 1.48.

Abdomen. Abdominal ventrites with moderately dense and small punctures, punctures denser medially, each bearing a short semi-erect seta, lateral portions with elliptical seta, each ventrite with a sparse and transverse row of short spiniform setae, devoid on ultimate ventrite, replaced with scattered and long setae. Antepenultimate ventrite strongly rimmed at posterior margin, ultimate ventrite at middle almost as long as penultimate one. Pygidium moderately convex, with longitudinal and impunctate midline, posterior margin weakly reflexed; surface with moderately dense and large punctures each bearing a large, oblong or elliptical seta, interspersed some moderately long setae at sides, which are somewhat aggregated near apex.

Femora. Profemur dull at dorsal third, with a row of moderately long setae near dorsal margin. Mesofemur dull, two longitudinal rows of moderately dense punctures each bearing a short seta. Metafemur with moderately dense punctures each bearing a recumbent short seta, or a few ones oblong setae; anterior margin moderately sharp, ventral posterior margin serrate at apical third, dorsal posterior mrgin completely serrate, several minute to short setae situates between the latter two margins.

Tibiae. Protibia moderately long, bidentate, tibial teeth acute, mesial lateral margin weakly convex. Metatibia widest shortly before apex, ratio of width/length: 1/4; dorsal margin sharply carinate; lateral face sparsely and finely punctate, dorsally with two groups of spiniform setae not touching the dorsal carina, basal group at two fifths, distal group at three quarters of metatibial length, basal half with several minute setae; ventral margin serrate except for base, with three spiniform setae of which distal two are more distant, base with several minute setae; medial face glabrous; apex interiorly serrate, near tarsal articulation shallowly concave.

Tarsi. Protarsomeres short, pro- and mesotarsomeres with sparse and minute setae ventrally. Mesotarsomeres finely serrate ventrally. All metatarsomeres serrate ventrally, first metatarsomere carinate laterally, as long as following two tarsomeres combined and twice as long as dorsal tibial spur. Protarsal claws symmetric, basal tooth similar to the distal one but rounded at apex and shorter. Basal teeth of meso- and metatarsal claws more acute at apex.

Male genitalia. Fig. 4E .

Female. Unknown.

Measurements. Length: 8.1 mm; length of elytra: 5.7 mm; width: 4.4 mm.

Diagnosis. Pachyserica jianfengensis Zhao & Ahrens , new species appears most similar to P. rubrobasalis Brenske, 1897 among Pachyserica species which lack the anterior pronotal marginal line. The new species is much smaller in size, both parameres possess a large mesially directed basal lobe, and the mesial margin of right paramere has a large denticle at middle.

Etymology. The species name derives from its type locality, Jianfengling.

Figures

FIGURE 3. Habitus in dorsal view. A, Pachyserica albosignata (Moser, 1915), male (Guangdong); B, P. dongnanensis Zhao & Ahrens, new species, holotype; C, P. dongnanensis, male paratype (Guangdong); D, P. dongnanensis, female paratype (Fujian); E, P. jianfengensis Zhao & Ahrens, new species, holotype. Scale bar = 5 mm.

FIGURE 4. Aedeagus. A, Pachyserica dongnanensis Zhao & Ahrens, new species, holotype; B, P. dongnanensis, paratype (Guangxi); C, P. dongnanensis, paratype (Guangdong); D, P. albosignata (Moser, 1915), male (Guangdong); E, P. jianfengensis Zhao & Ahrens, new species, holotype. a, aedeagus in left lateral view; b, parameres in dorsal view; c, aedeagus in right lateral view. Scale bar = 1 mm.