Gastroserica rubropicea 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 : 27-28

Gastroserica rubropicea Ahrens, Lukic & Liu, new species

Figs. 7F–I , 25

Type material examined. Holotype Ô “Burma ( Myanmar) SW Shan state Taunggyi J. Rejsek 1.- 18.6.1997 / Coll. Dirk Ahrens ” ( ZFMK).

Description of holotype. Length: 5.4 mm, length of elytra: 3.4 mm, width: 2.9 mm. Body oval, body yellowish brown, pronotum and scutellum reddish brown, frons and elytra dark blue to blackish, elytra iridescent, legs and antennal club brown, antennal funiculus yellow, dorsal surface shiny, nearly glabrous.

Labroclypeus subrectangular, distinctly wider than long, widest at base, lateral margins basally parallel, moderately convex and convergent to strongly rounded anterior angles; anterior margin almost straight, very weakly incised medially, margins weakly reflexed; lateral margins and ocular canthus produce a blunt angle; surface medially weakly convexly elevated, finely and coarsely, densely punctate, with a few long, erect setae; frontoclypeal suture finely incised and curved medially. Frons shiny, with dense, fine punctures, glabrous. Smooth area in front of eyes 1.5 times as wide as long. Ocular canthus sparsely finely punctate, narrow and moderately long (1/3 of ocular width), without terminal seta. Eyes large, ratio of diameter/interocular width: 0.84. Antenna with ten antennomeres; club composed of four antennomeres, weakly reflexed, twice as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum wide, widest at posterior quarter, lateral margins evenly convex and convergent to rectangular and moderately produced anterior angles and to the blunt posterior angles. Anterior margin of pronotum convex, with fine, complete marginal line; basal marginal line absent; surface finely and moderately densely punctate, with minute setae in punctures, anterior and lateral anterior margins sparsely setose. Hypomeron carinate, weakly produced ventrally. Scutellum triangular, evenly finely and densely punctate.

Elytra short, widest at middle, striae finely impressed, finely and densely punctate, intervals weakly convex, with fine and sparse punctures concentrated along striae, with very minute setae in punctures, penultimate lateral 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 shiny, 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: 1/1.5.Abdominal sternites finely punctate, with a transverse row of coarse punctures, each bearing a robust seta. Pygidium strongly convex and shiny, with dense, fine, partly longitudinally rugose punctures, without smooth midline, with a few short setae at apex.

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 finely serrate at apex, only weakly widened in apical half, dorsal posterior margin serrate, with a few short setae basally. Metatibia moderately long and wide, widest at middle, ratio width/ length:1/3.1; dorsal margin sharply carinate, with two groups of spines, basal group at one third, apical one at two thirds of metatibial length, in basal third with a few robust single setae; lateral face longitudinally convex, finely and sparsely punctate, along midline smooth, with minute setae in punctures; ventral edge finely serrate, with three robust equidistant setae; 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 little shorter than following two tarsomeres combined and twice as long as dorsal tibial spur. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 7F–H . Habitus: Fig. 7I . Female unknown.

Diagnosis. Gastroserica rubropicea Ahrens, Lukic & Liu, new species is in shape of aedeagus similar to Gastroserica lucidomarginalis Ahrens, Lukic & Liu, new species and Gastroserica piceocoerulea Ahrens, Lukic & Liu, new species. Gastroserica rubropicea new species differs from both by the characteristic coloration.Furthermore, the ventral lamina of phallobase is entirely lacking in Gastroserica rubropicea Ahrens, Lukic & Liu, new species; the distal margin of the basal lobe of the left paramere is sharply pointed as in Gastroserica lucidomarginalis Ahrens, Lukic & Liu, new species, but the phallobase is not as strongly curved as in the latter.

Etymology. The name of the new species is derived from the combined Latin words rubrus (red) and piceus (black) (adjective in singular nominative), with reference to the red and blackish body surface color.

Figures

FIGURE 7. A–E: Gastroserica piceocoerulea Ahrens, Lukic & Liu, new species (holotype); F–I: G. rubropicea Ahrens, Lukic & Liu, new species (holotype). A, F: Aedeagus, left side lateral view; D, H: Aedeagus, right side lateral view; B, C, G: Parameres, dorsal view; E, I: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 25. Distribution of the genus Gastroserica (Helioserica Ahrens, Lukic & Liu, new subgenus), part 2.