Microserica ferestictica Ahrens, Lukic

Ahrens, Dirk, Liu, Wangang, Lukic, Daniel & Bai, Ming, 2023, A taxonomic review of Microserica Brenske, 1894 from continental Asia (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 5241 (1), pp. 1-115 : 44-45

Microserica ferestictica Ahrens, Lukic & Liu, new species

Figs. 15A–D , 28

Type material examined. Holotype Ô “ Yunnan, Lvchun shuiku, 2012-V-13 / LW-1264” ( ZFMK).

Description of holotype. Length: 6.0 mm, length of elytra: 4.4 mm, width: 3.8 mm. Body oval, body including legs and antenna yellow, two spots on pronotum and multiple symmetric smaller spots on elytra, and abdomen including pygidium brown, frons posteriorly slightly darker; dorsal surface dull, brown areas with some greenish shine, surface nearly glabrous.

Labroclypeus trapezoidal, distinctly wider than long, widest at base, lateral margins straight and convergent to bluntly rounded anterior angles; anterior margin weakly emarginate medially, margins weakly reflexed; lateral margins and ocular canthus produce a blunt angle; surface weakly shiny, medially convexly elevated, coarsely, densely punctate, with a few long, erect setae anteriorly in a transversal line; frontoclypeal suture finely incised and curved medially. Frons dull, with sparse, fine punctures and a few setae beside eyes, otherwise glabrous. Smooth area in front of eyes narrow, 1.5 times as wide as long. Ocular canthus wide, short (1/4 of ocular width), sparsely finely punctate, with a terminal seta. Eyes small, ratio of diameter/interocular width: 0.5. Antenna with ten antennomeres; club composed of four antennomeres, straight, 1.1 times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum wide, widest at base, lateral margins evenly moderately convex and convergent to sharp and distinctly produced anterior angles; posterior angles blunt. Anterior margin of pronotum weakly convex, with fine, complete marginal line; basal marginal line absent; surface finely and densely punctate, with minute setae in punctures, anterior and lateral anterior margins sparsely setose. Hypomeron not carinate. Scutellum triangular, evenly finely and densely punctate, impunctate along midline, glabrous.

Elytra elongate, widest at posterior third, striae distinctly impressed, finely and densely punctate, intervals convex, with fine and dense punctures only along striae, with minute setae in punctures, elytra with a single band of transversal and symmetrical dark dots at posterior third on interval 2-6, odd intervals with a few short setae; epipleural edge robust, ending at slightly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without a fringe of short microtrichomes (visible at ca 100x magnification).

Ventral surface dull, finely and densely punctate, metasternum sparsely covered with fine, short, or very minute setae; metacoxa glabrous, with a few single setae laterally. Mesosternum between mesocoxae as wide as mesofemur. Ratio of length of metepisternum/metacoxa: 1/1.58. Abdominal sternites finely punctate, with a transverse row of coarse punctures, each bearing a robust seta. Pygidium weakly convex and dull, with sparse, fine punctures, without smooth midline, with a few short adpressed setae on apical half, otherwise with minute setae in punctures.

Legs moderately wide; femora finely and sparsely punctate, with two longitudinal rows of longer setae. Metafemur moderately shiny, anterior margin acute, without submarginal serrated line; anterior row of seta-bearing punctures present; ventral posterior margin distinctly not serrate but moderately widened, dorsal posterior margin smooth, with short setae. Metatibia moderately long and wide, widest at apical third, ratio width/length:1/3.4; dorsal margin longitudinally convex, with two groups of spines, basal group at one third, apical one at three quarters of metatibial length, in basal third without robust setae; lateral face longitudinally convex, finely and sparsely punctate, glabrous; ventral margin finely serrate, with four robust setae of which the distal one is more distant; medial face smooth, apex interiorly near tarsal articulation sharply truncate. Tarsomeres with fine, sparse setae ventrally, neither laterally nor dorsally carinate, dorsally impunctate; metatarsomeres glabrous, with a strongly serrated ridge ventrally and a parallel subventral smooth carina immediately beside it; first metatarsomere as long as following two tarsomeres combined and little less than twice as long as dorsal tibial spur. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 15A–C . Habitus: Fig. 15D . Female unknown.

Diagnosis. The species differs from all other Microserica species by the lacking carina of the hypomeron, as well as the non carinate dorsal margin of the metatibia; of course, also the male genitalia are different from all other species. The systematic position of this species is based on Eberle et al. (2017) close to the species of the Microserica quadrimaculata group.

Etymology. The name of the new species is derived from the combined Larin prefix “ fere- ” (almost) and the adjective, “ sticticus ” (line, file), with reference to the imperfect stripe-dotted color pattern of the elytra.

Genbank accessions. Table 1 .

Figures

FIGURE 15. A–D: Microserica ferestictica Ahrens, Lukic & Liu, new species (holotype). A: Aedeagus, left side lateral view; C: Aedeagus, right side lateral view; B: Parameres, dorsal view; D: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 28. Distribution of the Microserica avicula group.