Gynaecoserica ottoi Ahrens, 2021

Ahrens, Dirk, 2021, New species of the genus Gynaecoserica Brenske, 1896 from Indochina (Coleoptera: Scarabaeidae: Sericini), Zootaxa 5005 (2), pp. 218-226 : 224-226

Gynaecoserica ottoi Ahrens , new species

Fig. 2E–H

Type material examined. Holotype ♂ “ Laos: Champassak Prov. Dong Hua Xao NBCA, 2 km S of Ban Nong Lu- ang, bank of Tuoay-Guai stream, / 15°4’N, 106°13’E 800 m, swept, No. 23.1- 5.IV.1998 leg. O. Merkl & G. Csorba / Asia Sericini sp. 50” ( NHNM) . Paratypes: 1 ♂ “S. Laos, Attapu, Nong Lom (lake), 18-30.iv.1999 800 m, 15°02’N, 106°35’E E. Jendek & O. Šauša leg.” ( CPPB), 2 ♀♀ “ Laos: Attapeau prov. : Annam Highlands Mts. Dong Amphan; NBCA ca. 1160m Nong Fa (crater lake) env.; 15°05.9’N, 107°25.6’E St. Jaki [sic!] lgt. 30.4.- 6.5.2010 ” ( NMPC) .

Description of the holotype, male. Length: 5.0 mm, length of elytra: 3.2 mm, width: 2.9 mm. Body oblong, yellow, dorsal surface bicolored, widely yellowish brown, pronotum with two large brown spots on disc, elytra with smaller brown spots formed to two transversal fasciae, humerus region brown, antenna and legs yellow, except shiny labroclypeus dorsal surface dull (with slight iridescent shine), sparsely setose.

Labroclypeus widest at base, lateral margins strongly convex, anterior angles strongly convex, lateral border and ocular canthus producing a distinct blunt angle; margins weakly reflexed; anterior margin shallowly sinuate medially; surface weakly convex and shiny, with fine and coarse punctures, distance between punctures partly larger their diameter, coarser punctures each bearing a long, erect seta; frontoclypeal suture feebly incised and curved; smooth area in front of eye 1.5 times as wide as long; ocular canthus short and slender (length subequal 1/4 of ocular diameter), impunctate, without terminal seta. Frons dull, with fine, dense punctures, with minute setae in punctures and some erect setae beside eyes. Eyes small, ratio of diameter/ interocular width: 0.58. Antenna yellow, with ten antennomeres; club yellow, with four antennomeres, straight, 1.2 times as long as the remaining antennomeres combined. Mentum weakly elevated and flattened anteriorly.

Pronotum transversal, widest at base, lateral margins half weakly curved and convergent anteriorly, anterior angles moderately produced and sharp, posterior angles blunt; anterior margin convexly produced medially, with a distinct fine marginal line, basal margin without marginal line; anterior and lateral margins nearly glabrous; surface with moderately dense and fine punctures, with microscopic white setae in punctures, otherwise glabrous; hypomeron distinctly carinate at base but not ventrally produced. Scutellum narrow and short, triangular, with sparse, fine punctures, punctures with microscopic setae.

Elytra moderately long, widest at middle, striae distinctly impressed, finely and densely punctate; intervals strongly convex, with fine and sparse punctures concentrated along striae, punctures with minute white adjacent setae, odd intervals with a few single, fine, pale setae; interior apical angle of elytra with a strong seta; epipleural edge fine ending at strongly curved external apical angle of elytra; epipleura sparsely setose, apical border without short microtrichomes (at magnification 100x).

Ventral surface dull, with fine and moderately dense punctures, sparsely setose, but minute setae in punctures; metacoxa large, with minute setae in punctures, only laterally with a few strong adjacent setae. Each abdominal sternite with indistinct transverse row of coarse punctures bearing short setae between fine, dense punctation. Mesosternum between mesocoxae as wide as mesofemur, with irregularly scattered very strong setae. Ratio of length of metepisternum/ metacoxa: 1/ 1.93. Pygidium weakly convex, coarsely and densely punctate, without smooth midline, completely dull, with a few long setae on disc and beside apical margin.

Legs moderately slender and long; femora dull, with two longitudinal rows of setae, finely and sparsely punctate; metafemur shiny, sharply margined anteriorly and without a submarginal serrate line, posterior margin weakly convex and glabrous, its external (ventral) part only weakly widened in apical half and finely serrate, internally (dorsally) finely serrate, with short setae. Metatibia moderately slender and short, widest at middle of metatibial length, ratio width/ length: 1/ 2.8, dorsally sharply carinate, with two groups of spines, basal one shortly before middle, apical one at three quarters of metatibial length, basally nearly with two single fine setae; external face longitudinally convex, with moderately dense and fine punctures, along the middle impunctate and smooth, with minutely setose in punctures; ventral margin carinate and serrate, with three strong and long spines, of which the two distal are widely separated; internal face very finely and sparsely punctate; apex interiorly near tarsal articulation bluntly and shallowly truncate. Tarsomeres dorsally glabrous and impunctate, ventrally with sparse, short setae; metatarsomeres ventrally with a strongly serrate ridge, beside which is a fine longitudinal carina; first metatarsomere as long as two following tarsomeres combined and twice as long as dorsal tibial spur. Protibia moderately long, bidentate, protarsal claws symmetrical.

Aedeagus: Fig. 2E–G . Habitus: Fig. 2H .

Variation. Length: 5.0– 5.9 mm, length of elytra: 3.2–4.1 mm, width: 2.9–3.5 mm. In the paratype, the dark spots of dorsal surface are less extended. Female: Eyes slightly smaller, ratio of diameter/ interocular width: 0.55; antennal club short, little shorter than remaining antennomeres combined, composed of three antennomeres.

Diagnosis. Gynaecoserica ottoi Ahrens , new species differs from all other Gynaecoserica species by the more transverse pronotum, the apex of metatibia which is interiorly near tarsal articulation only shallowly truncate, and the distinct patches on the elytra, resembling this way somewhat to Aserica avicula Arrow, 1946 . With the ventrally fused parameres, however, the new species shows a clear synapomorphy of Gynaecoserica , reason why the species is placed in this genus.

Etymology. The new species is named after one of its collectors, Ottó Merkl, curator of the NHNM Budapest, who died much too early this year (genitive singular case).

Figures

FIGURE 2. A–C: Gynaecoserica pseudocymosa Ahrens, new species (holotype); E–H: G. ottoi Ahrens, new species (holotype). A, E: aedeagus, left side lateral view; C, G: aedeagus, right side lateral view; B, F: parameres, dorsal view; D, H: habitus. Scale: 0.5 mm. Habitus not to scale.