Gynaecoserica feresimplex Ahrens, 2021

Ahrens, Dirk, 2021, New species of the genus Gynaecoserica Brenske, 1896 from Indochina (Coleoptera: Scarabaeidae: Sericini), Zootaxa 5005 (2), pp. 218-226 : 221-223

Gynaecoserica feresimplex Ahrens , new species

Fig. 1I–M

Type material examined. Holotype ♂ “Thai, 17.-24.V.1991 Chiang Dao 1000m 19°25’N 98°52’E Vít Kubáň leg. / Asia Sericini sp. 18” ( ZFMK) . Paratypes: 2 ♂♂ “NW Thailand 19.19N 97.59E Mae Hong Son, 1991 Ban Huai Po 1600-2000m 17.-23.5., L. Dembický leg.” ( NHMW) , 3 ♂♂ “NW Thailand 19.19N 97.59E Mae Hong Son, 1991 Ban Huai Po 1600-2000m 17.-23.5., L. Dembický leg.” ( NHMB) , 1 ♂ “NW Thailand 9.-16.V. Mae Hong Son 1991 Ban Huai Po 1600m leg. P. Pacholátko / TS137” ( CPPB) , 1 ♂ “ Birmanie S.S.S. Bihtan X-1937 G. Fasoli ” ( MSNM) , 3 ♂♂ “Chieng Mai N. Thailand V.-VI.1983 / Museum Leiden coll. P.J.J.H. Kuijten” ( RMNH) , 1 ♂ “Chieng Mai N. Thailand 31.V.1981 Doi Suthep / Museum Leiden coll. P.J.J.H. Kuijten” ( RMNH) , 2 ♂♂ “NW Thailand, 19.19N, 97.5°E Mae Hong Son, 1991 Ban Si Lang , 1200m 23.-31.5., L. Dembický leg.” ( NHMB) , 1 ♂ “NW Thailand, 19.19N, 97.5E Mae Hong Son, 1991 Ban Huai Po , 1600-2000m 17.-23.5., L. Dembický leg.” ( NHMB) , 1 ♂ “NW Thailand, 8.-17.V.1992 Mae Hong Son, Ban Huai Po 1600m S. Bílý leg. ” ( NHMB) , 10 ♂♂ “NW Thailand, 1.- 15.1991, Mae Hong Son, Ban Huai Po 800-1600m S. Bílý leg.” ( NHMB) .

Description of the holotype, male. Length: 4.4 mm, length of elytra: 2.7 mm, width: 2.4 mm. Body oblong, dorsal surface dark-yellowish brown, frons dark greenish brown, antenna and legs yellow, except shiny head dorsal surface dull, sparsely setose.

Labroclypeus widest shortly before base, semicircular, lateral margins strongly convex, anterior angles obsolete, strongly convex, lateral border and ocular canthus producing a distinct blunt angle; margins weakly reflexed; anterior margin very shallowly sinuate medially; surface flat and shiny, finely and densely punctate, distance between punctures less than their diameter, with a transversal raw of a few coarser punctures behind anterior margin each bearing a long, erect seta; frontoclypeal suture feebly incised and curved; smooth area in front of eye little wider than long; ocular canthus short and slender (length subequal 1/5 of ocular diameter), impunctate, with a short terminal seta. Frons shiny, with fine, dense punctures, glabrous except some short erect setae beside eyes and behind frontoclypeal suture. Eyes small, ratio of diameter/ interocular width: 0.55. Antenna yellow, with ten antennomeres; club dark, with six antennomeres, 1.1 times as long as the remaining antennomeres combined. Mentum weakly elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins subparallel and straight in basal half, in anterior 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 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 shortly at middle, striae weakly impressed, finely and densely punctate; intervals weakly convex, with fine and moderately dense punctures concentrated along striae, punctures with minute white adjacent setae, odd intervals with a few single robust, white, adjacent 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; metacoxa 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/ 1.69. Pygidium weakly convex, coarsely and densely punctate, without smooth midline, completely dull, with 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 not serrate, internally (dorsally) finely serrate, with short setae. Metatibia slender and moderately long, widest at middle of metatibial length, ratio width/ length: 1/ 3.2, dorsally sharply carinate, with two groups of spines, basal one at anterior third, apical one at two thirds of metatibial length, basally nearly glabrous; external face longitudinally convex, with sparse and fine punctures, glabrous; ventral margin carinate and serrate, with three strong spines, of which the two distal are widely separated; internal face very finely and sparsely punctate; apex interiorly near tarsal articulation sharply and deeply truncate. Tarsomeres dorsally glabrous and very sparsely punctate, ventrally with sparse, short setae; metatarsomeres ventrally with a strongly serrate ridge, beside which is a fine longitudinal carina; first metatarsomere little shorter than two following tarsomeres combined and little less than twice as long as dorsal tibial spur. Protibia moderately long, bidentate, protarsal claws symmetrical.

Aedeagus: Fig. 1I–L . Habitus: Fig. 1M .

Female unknown.

Variation. 3.5–4.4 mm, length of elytra: 2.3–2.7 mm, width: 2.2–2.4 mm. Colour may vary from yellowish brown to dark brown.

Diagnosis. Gynaecoserica feresimplex Ahrens , new species differs from Gynaecoserica fallaciosa Ahrens , new species by the slightly smaller eyes and the shape of the parameres: the external tooth of the left paramere is situated more distally, behind the half of the length of the paramere.

Etymology. The name of the new species (adjective in nominative singular case) is derived from the combined Latin words fere (nearly) and simplex (simple), with reference to its similarity with Microserica simplex Arrow, 1946 .

Figures

FIGURE 1. A–C: Gynaecoserica bihtanensis Ahrens, new species (holotype); E–H: G. fallaciosa Ahrens, new species (holotype); I–M: G. feresimplex Ahrens, new species (holotype). A, E, I: aedeagus, left side lateral view; C, G, L: aedeagus, right side lateral view; B, F, J, K: parameres, dorsal view; D, H, M: habitus. Scale: 0.5 mm. Habitus not to scale.