Gastroserica ivoi 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 : 20-21

Gastroserica ivoi Ahrens, Lukic & Liu, new species

Figs. 6A–D , 24

Type material examined. Holotype: Ô “THAI-N, 1.-19.v.1998 Chiang Mai prov., Ban San Pakia , 1400m, Ivo Martinů leg. / Coll. Dirk Ahrens / 15 Sericini Asia spec.” ( ZFMK) . Paratypes: Thailand: 1 Ô “NW Thailand 9.-16.V. Mae Hong Son 1991 Ban Huai Po 1600m leg. P. Pacholátko / TS 72” ( CP) , 21 ÔÔ “NE Thailand 1.-15.5[?]. 1991 Mae Hong Son Ban Huai Po 800-1600 m S. Bily leg.” ( NHMW, ZFMK) , 25 ÔÔ “NW Thailand, 19.19N, 97.59E Mae Hong Son, 1991 Ban Huai Po 1600-2000 m 17.-23.5., L. Dembicky leg.” ( NHMW, ZFMK) , 4 ÔÔ “NE Thailand 28.4.1991 Mae Hong Son S. Bily leg.” ( NHMW) , 5 ÔÔ, 2 ♀♀ “N. Thailand Ban Huai Po 9.- 16.5. 1991 I. Horák leg. / Coll. Milan Nikodym Praha ” ( ZFMK) , 1 Ô “NW Thailand, Chieng Dao, Ban San Pakia , 5.-10.v.2004, 1200m, Sv. Bily ” ( NME) . China: 1 Ô “China: S-Yunnan (Xishuangbanna) 45 km SW Jinghong vic. Bangzhang vill. / N21°44’37’’, E100°27’02’’, 16-1700m, 03.-05.V.2009 leg. A. Weigel, blüh Cast” ( NME) .

Description of holotype. Length: 5.1 mm, length of elytra: 3.1 mm, width: 2.9 mm. Body oval, body including legs and antenna yellow, two spots on pronotum, margins of elytra and frons blackish, dorsal surface shiny, nearly glabrous.

Labroclypeus narrow and semicircular, as wide as long, widest shortly before base, lateral margins strongly convex and convergent to strongly rounded anterior angles; anterior margin 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 numerous long, erect setae; frontoclypeal suture finely incised and curved medially. Frons shiny, with dense, fine punctures, beside eyes and behind frontoclypeal suture with a few single short setae, otherwise with minute setae in punctures. Smooth area in front of eyes twice as wide as long. Ocular canthus sparsely finely punctate, narrow and moderately long (1/3 of ocular width), terminal seta abraded. Eyes moderately large, ratio of diameter/interocular width: 0.63. Antenna with ten antennomeres; club composed of four antennomeres, strongly reflexed, three times as long as remaining antennomeres combined. Mentum elevated and slightly flattened anteriorly.

Pronotum wide, widest at base, lateral margins evenly convex and convergent to sharp but moderately produced anterior angles, posterior angles blunt and moderately rounded. Anterior margin of pronotum convex, with robust and complete marginal line; basal marginal line absent; surface coarsely and densely punctate, with minute setae in punctures, anterior and lateral anterior margins sparsely setose. Hypomeron carinate, weakly produced ventrally. Scutellum triangular, coarsely and densely punctate, on median base impunctate.

Elytra short, widest at middle, striae finely impressed, finely and densely punctate, intervals convex, with fine and sparse punctures concentrated along striae, with very minute setae in punctures, 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 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 mixed finer and larger punctures, without smooth midline, with numerous short setae and a few longer in the larger 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 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:1/3.33; dorsal margin sharply carinate, with two groups of spines, basal group at middle, apical one at three quarter 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 sparsely finely punctate; 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 twice as long as dorsal tibial spur. Protibia short, bidentate; anterior claws symmetrical, basal tooth of both claws bluntly truncate at apex.

Aedeagus: Fig. 6A–C . Habitus: Fig. 6D .

Diagnosis. Gastroserica ivoi Ahrens, Lukic & Liu, new species is in external appearance and shape of aedeagus rather similar to Gastroserica lucens (Ahrens & Fabrizi, 2009) . Gastroserica ivoi differs by long antennal club in male, the light yellowish body color, and by the shape of aedeagus: the phallobase is distinctly shorter compared to the longer parameres, and strongly curved (lateral view); the basal lobe of the left paramere is distally distinctly produced.

Etymology. The name of the new species is named after one of its collectors Ivo Martinů (noun in singular genitive).

Variation. Length: 5.0– 5.1 mm, length of elytra: 3.0– 3.1 mm, width: 2.8–2.9 mm. Paratypes without brown dots on the pronotum. Female: completely yellow, antennal club short, composed of three antennomeres; pygidium flat.

Figures

FIGURE 6. A–D: Gastroserica ivoi Ahrens, Lukic & Liu, new species (holotype); E–I: G. lucidomarginalis Ahrens, Lukic & Liu, new species (holotype); J–M: M. loei Ahrens, Lukic & Liu, new species. A, E, J: Aedeagus, left side lateral view; C, H, L: Aedeagus, right side lateral view; B, F, G, K: Parameres, dorsal view; D, I, M: Habitus (not to scale). Scale: 0.5 mm.

FIGURE 24. Distribution of the genus Gastroserica (Helioserica Ahrens, Lukic & Liu, new subgenus), part 1.