Serica breviantennalis Liu, Ahrens, Li & Su, 2023

Su, Xie, Li, Wei, Liu, Wan-Gang, Ahrens, Dirk, Zheng, Ying-Juan & Liu, Yang, 2023, An update to the taxonomy of Serica MacLeay, 1819 (sensu lato) from China (Coleoptera, Scarabaeidae, Sericinae, Sericini), ZooKeys 1185, pp. 181-198 : 181

Serica breviantennalis Liu, Ahrens, Li & Su sp. nov.

Figs 1A-H , 3

Type materials.

Holotype: ♂ [China] "Black Tiger Mountain, Tianxin Township, Wuding County, Chuxiong, Yunnan Province, 20.V.2022, light trap, leg. Zhao Yuchen, Lu Jinbo" (SENU). Paratypes: 28 ♂♂ [China] "Black Tiger Mountain, Tianxin Township, Wuding County, Chuxiong, Yunnan Province, 20.V.2022, light trap, leg. Zhao Yuchen, Lu Jinbo" (SENU, IZAS, ZFMK), 2 ♂♂ [China] "Gaojianchou village, Yao 'an County, Chuxiong, Yunnan Province, 24.V.2022, light trap, leg.Xu Rentao" (SENU), 2 ♂♂ [China] "Xiaogupu Village, Shangdianliang Road, Wuding County, Chuxiong Autonomous Prefecture, Yunnan Province, 21.V.2022, light trap, 2092.6m, 25.6724°N, 102.2782°E, leg. Lu Jinbo" (SENU), 1 ♂ [China] "Zhangjiacun Mixing Town, Yao 'an County, Chuxiong City, Yunnan Province, 23.V.2022, light trap, 25.4041°N, 101.1683°E " (SENU).

Description of the holotype.

Length 7.9 mm, elytral length 5.6 mm, width 4.1 mm. Body oblong, reddish brown; frons dark reddish brown, dull; legs yellowish brown; antenna yellow, with moderately long setae on head dorsal surface.

Labroclypeus wide, trapezoidal, with lateral margins moderately convex and convergent, producing a blunt angle with ocular canthus; anterior angles strongly convex; anterior margin distinctly emarginate medially; margins moderately reflexed; surface moderately convex, finely and densely punctate, with numerous long and erect setae; frontoclypeal suture distinct, moderately curved; ocular canthus moderately narrow (length slightly>1/3 ocular width), smooth and glabrous, with four terminal setae. Frons with dull toment, with fine, moderately dense punctures, anteriorly and laterally with a few long setae. Antenna with nine antennomeres, club with three antennomeres, 1.5 times as long as remaining antennomeres combined, distinctly reflexed. Eyes small, ratio diameter to interocular width 0.47. Mentum convexly elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins moderately convex and convergent anteriorly; anterior angles acute, moderately produced, posterior angles blunt; anterior margin weakly convex, marginal line fine but complete; basal margin without marginal line; surface with coarse, dense punctures and minute setae, anteriorly and laterally bearing erect long setae. Hypomeron not carinate ventrally. Scutellum narrow, long, triangular, with fine but dense punctation and minute setae in punctures, and basally with a triangular smooth area.

Elytra elongate, narrow, widest in posterior third; striae distinctly impressed, finely punctate; intervals weakly convex, finely and densely punctate, with punctures concentrated along striae; elytra glabrous, lateral intervals with a few moderately long, adpressed or erect setae; epipleural margin robust, ending at strongly rounded external apical angle of elytra; epipleura sparsely setose; apex of elytra with a very fine, membraneous rim of short microtrichomes.

Ventral surface finely and densely punctate, glabrous. Metacoxae laterally with a few longer setae. Mesosternum between mesocoxae slightly wider than mesofemur. Ratio of length of metepisternum to metacoxa 1:1.52. Abdominal sternites finely and moderately densely punctate, each with a row of coarse punctures, each puncture bearing each a robust seta. Pygidium almost flat and finely, densely punctate, with moderately dense, long setae.

Legs long, narrow, shiny; femora finely, sparsely punctate, with two longitudinal rows of setae. Metafemur with anterior margin acute, without adjacent serrate line; posterior ventral margin almost straight, weakly widened in apical half, ventrally and dorsally not serrate, sparsely setose. Metatibia long, narrow, widest at apex, ratio of width to length 1:3.9, sharply carinate dorsally, with three groups of spines, basal one at one-third, middle one at three-fifths, apical one at four-fifths of metatibial length, basally with a number of robust single setae; lateral face longitudinally convex, finely and moderately densely punctate, glabrous; apex shallowly, concavely truncate interiorly near tarsal articulation. Ventral edge finely serrate, with four robust equidistant setae. Tarsomeres finely punctate dorsally, with moderately dense, fine setae ventrally; metatarsomeres ventrally with a strongly serrate carina, subventrally with a second, smooth longitudinal carina; first metatarsomere a little shorter than following two tarsomeres combined, and little shorter than dorsal tibial spur. Protibia long, bidentate; anterior claws symmetrical, interior tarsal claws sharply pointed.

Aedeagus: Fig. 1A-C, E-G . Habitus: Fig. 1D, H . Female unknown.

Diagnosis.

Serica breviantennalis sp. nov. differs from S. lupina Arrow, 1946 and all other species of this species group in the short antenna and the shape of aedeagus; both parameres are long (subequal to half of the length of phallobase), nearly equal in length, parallel, and basally expanded to basal short lobes.

Etymology.

The name of the new species is derived from the combined Latin words brevis (short) and antennalis (antenna), with reference on the short antenna. (An adjective in nominative singular case.)

Variation.

Length 7.5-8.2 mm, elytral length 5.6-6.1 mm, width 4.0-4.3 mm. There is some variation of the parameres and lateral intervals of the elytra. Parameres of some specimens are closed, some are slightly open (Fig. 1A-C ), and in others turned or rotated outside (Fig. 1E-G ). Furthermore, the left paramere is sometimes curved externally (Fig. 1A-C ) or sometimes dorsally (Fig. 1E-G ). Lateral intervals of the elytra have a few moderately or distinctly dense, long, adpressed or erect setae.

Figures

Figure 1. Serica species A-D S. breviantennalis Liu, Ahrens, Li & Su, sp. nov. (holotype) E-H S. breviantennalis (paratype) I-L S. allonanhua Liu, Ahrens, Li & Su, sp. nov. (paratype). A, E, I aedeagus, left side view C, G, K aedeagus, right side view B, F, J aedeagus, dorsal view D, H, L habitus (not to scale). Scale bars: 0.5 mm (A, B, C, E, F, G, I, J, K).

Figure 3. The distribution map of Serica breviantennalis Liu, Ahrens, Li & Su, sp. nov., S. allonanhua Liu, Ahrens, Li & Su, sp. nov., S. fengensis Liu, Ahrens, Li & Su, sp. nov., including updated records of S. nanhua Ahrens, Fabrizi & Liu, 2022 and S. baishuitaiensis Ahrens, Fabrizi & Liu, 2022.