Serica (s. l.) caiyiyiae 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 : 194-195

Serica (s. l.) caiyiyiae Zhao & Ahrens , new species

( Figs 5A–B , 7A )

Type material examined. Holotype. ♂ ( SCAU), “ CHINA: Guizhou, Libo County, Maolan, Wuyanqiao , 507 m, N 25°17′16″, E 108°4′18″, 2020.V.23, at light, Bao-Xiang Zhan leg.” . Paratypes. 1♀ ( CZBX), same data as holotype; 2♂♂ , 1♀ ( CZBX, CZMZ), “ CHINA: Guizhou, Libo County, Maolan, Wuyanqiao , 507 m, N 25°17′16″, E 108°4′18″, 2020.V.22, at light, Bao-Xiang Zhan leg.”

Description of the holotype. General. Body shape ovoid, strongly convex, dark brown, body including mesofemur and metacoxa with greenish toment; anterior two third of labroclypeus and legs reddish brown, palpi and antennae yellowish brown, shiny. Setae yellow.

Head. Labroclypeus subtrapezoidal, widest at base, ratio of maximum length/ width: 1/ 1.6; lateral margins almost straight and subparallel, anterior angle reduced into a weak curve, anterior margin deeply emarginate and abruptly angled medially; margins strongly reflexed, anterior margin medially weakly produced; surface flat, with sparse and coarse punctures, each puncture bearing a short erect seta, posterior third tomentum, sparsely and finely punctate, each puncture bearing a small and obovate seta; frontoclypeal suture finely incised, curved medially; smooth area anterior to eye large and flat, approximately 1.6 times as wide as long; ocular canthus moderately long and slender (1/3 of ocular diameter), with a short terminal seta. Frons flat, with moderately dense and fine punctures each bearing an obovate seta, mixed with some moderately long erect setae. Eyes large, ratio diameter/ interocular width: 0.57. Antenna with ten antennomeres; antennomeres 5 equally as wide as long, antennomere 7 transverse and short; club with three antennomeres, 1.5 times as long as remaining antennomeres combined and straight. Mentum strongly and transversely elevated anteriorly. Labrum weakly produced and widely concave medially.

Pronotum subtrapezoidal, widest at base; lateral margins evenly curved and strongly convergent anteriad; anterior angle moderately produced, both anterior and posterior angles rounded at tip; hypomeron carinate at base but not produced ventrally; anterior margin with a fine marginal line, indistinct medially; surface with moderately dense and small punctures, each puncture bearing an oblong seta, setae obovate near sides, with a wide and impunctate midline at posterior two third, also a smaller, rounded and impunctate area at each side; anterior and lateral margins with sparse and short erect setae.

Scutellum triangular, apex somewhat rounded; basomedially and apically impunctate, otherwise with sparse, fine punctures each bearing a small and spatulate seta.

Elytra oval, widest shortly after middle. Striae indistinctly impressed, strial punctures dense and fine; intervals weakly convex, with moderately dense and small punctures each bearing an oblong seta, some setae randomly larger, setose sections randomly interrupted by some large and impunctate ones, including humeral and apical umbones, a single, semi-erect long seta near base. Epipleura ending at moderately curved external apical angle of elytron, with a row of moderately dense and short semi-erect setae, posterior margin with a very fine membranous rim composed of microtrichomes.

Ventral thoracic surface. Ventral thoracic surface and metacoxae with sparse, fine punctures, most punctures each bearing a short seta, setae being shorter medially, ventral metathoracic surface and metacoxae with some oblong setae laterally. Mesosternum between mesocoxae slightly narrower than width of mesofemur. Ratio of length of metepisternum/ metacoxa: 1/ 1.51.

Abdomen. Abdominal ventrites with moderately dense and small punctures, each puncture bearing an oblong or lanceolate seta, some of them obovate laterally, each ventrite with a transverse row of semi-erect short setae, penultimate ventrite with several moderately long setae medially; ultimate ventrite with a tuft of moderately long setae medially and a transverse row of minute setae near posterior margin, medially twice as long as penultimate one. Pygidium strongly convex, with impunctate midline, posterior margin moderately reflexed; surface with sparse and small punctures each bearing an obovate seta, some moderately to long setae presented laterally and somewhat aggregated preapically.

Femora. Profemur dull at dorsal third, with a row of moderately long setae near dorsal margin. Meso- and metafemur dull, two longitudinal rows of moderately dense punctures each bearing a short seta. Anterior margin of metafemur moderately sharp, ventral posterior margin sharp only at apical third, dorsal posterior margin entirely sharp, both not serrate, a few minute to short setae between latter two margins.

Tibiae. Protibia moderately long, bidentate, mesial lateral margin weakly convex. Metatibia widest shortly before apex, ratio of width/ length: 1/ 3; dorsal margin sharply carinate; lateral face with sparse and small punctures, longitudinally wrinkled, dorsally with two groups of short and spiniform setae not touching the dorsal carina, basal group at middle, distal group at three quarters of metatibial length, basally with several short setae; ventral margin serrate except for basal quarter, with two widely distant spiniform setae, basally with several smaller setae; medial face impunctate; apex interiorly serrate, near tarsal articulation shallowly concave.

Tarsi. Protarsomeres short, pro- and mesotarsomeres with moderately dense and minute setae ventrally. Meso- and metatarsomeres serrate ventrally. Metatarsomeres carinate dorsally and laterally, with another weaker carina between dorsal and lateral carina, first metatarsomere as long as following two tarsomeres combined and twice as long as dorsal tibial spur. Protarsal claws asymmetric, the basal tooth of inner claw lobiform and oriented distally, the basal tooth of outer claw normally developed.

Male genitalia. Fig. 7A .

Variation. Female. Antennal club slightly shorter than remaining antennomeres combined; pygidium less convex; eyes smaller than in male, ratio diameter/ interocular width: 0.48; protarsal claws symmetric, similar to outer protarsal claw of male.

Measurements. Length: 8.2–8.6 mm in males (holotype 8.6 mm), 8.0–9.0 mm in females; length of elytra: 5.9–6.1 mm in males (holotype 6.1 mm), 5.7–6.6 mm in females; width: 4.5–4.7 mm in males (holotype 4.7 mm), 4.5–5.0 mm in females.

Diagnosis. Serica caiyiyiae Zhao & Ahrens , new species is most similar to S. jindrai Ahrens, 2007 . The new species can be distinguished by the medial lobe of left paramere which is expanded proximally and acute at apex, but simply rounded in S. jindrai ( Fig. 7B ).

Etymology. The species is dedicated to Ms. Yi-Yi Cai, the mother of Mr. Bao-Xiang Zhan, who greatly supported his field survey.

Figures

FIGURE 5. Habitus in dorsal view. A, Serica (s.l.) caiyiyiae Zhao & Ahrens, new species, holotype; B, S. (s. l.) caiyiyiae, female paratype; C, S. (s. l.) jindrai Ahrens, 2007, male (Guizhou); D, S. (s. l.) babaoshanensis Zhao & Ahrens, new species, holotype; E, S. (s. l.) babaoshanensis, female paratype (Guangdong). Scale bar = 5 mm.

FIGURE 7. Aedeagus. A, Serica (s. l.) caiyiyiae Zhao & Ahrens, new species, holotype; B, S. (s. l.) jindrai Ahrens, 2007, male (Guizhou); C, S. (s. l.) babaoshanensis Zhao & Ahrens, new species, holotype; D, S. (s. l.) zhangyaonani Zhao & Ahrens, new species, holotype; E, S. (s. l.) jicaiyanae 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.