Gynaecoserica maekasana, Ahrens & Fabrizi, 2009

Ahrens, Dirk & Fabrizi, Silvia, 2009, A review of the genus Gynaecoserica Brenske, 1896 (Coleoptera, Scarabaeidae, Sericini), Journal of Natural History 43 (25 - 26), pp. 1505-1584 : 1563-1564

Gynaecoserica maekasana sp. nov.

( Figures 4G–I , 10A )

Type material examined

Holotype. Ƌ “W-Thailand: 750 m., Thung Yai Wildlife Sanctuary 15°25¢N – 98°44¢E./ Kanchanaburi Prov. , Sangkhla Buri Dist., Mae Kasa stream. iv/ v.1988 / M.J.D. Brendell B.M. 1988-183/ 487 Sericini Asia spec.” ( BMNH).

Description

Length 4.1 mm, length of elytra 2.7 mm, width 2.4 mm. Body oval, surface yellowish, frons posteriorly a little darker, dorsal surface except head dull and almost glabrous.

Labroclypeus distinctly wider than long, widest at base, lateral margins weakly convex basally, anteriorly very strongly curved and convergent to strongly rounded anterior angles, 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 few coarse punctures behind anterior margin each bearing a long, erect seta; frontoclypeal suture indistinctly incised and medially weakly curved; smooth area in front of eye approximately as wide as long; ocular canthus short and slender, smooth, only laterally sparsely punctate, with a fine terminal seta. Frons moderately shiny, only posteriorly dull, with fine, moderately dense punctures, glabrous except a few short setae beside eyes and behind frontoclypeal suture. Eyes small, ratio of diameter: interocular width 0.52. Antenna yellow, with 10 antennomeres; club with five antennomeres, club as long as the remaining antennomeres combined, fourth antennomere not transversely lamella-like. Mentum weakly elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins weakly curved and weakly convergent anteriorly, in anterior half more strongly curved and strongly convergent towards the strongly produced and sharp anterior angles, posterior angles blunt, anterior margin moderately convexly produced medially, with a distinct fine marginal line, basal margin without marginal line; surface with dense and fine punctures, with microscopic setae in punctures only; anterior and lateral borders setaceous; hypomeron distinctly margined at base but not ventrally produced. Scutellum short triangular, with fine, dense punctures, medially not smooth, microscopic setae present in the punctures.

Elytra short and oval, widest at middle, striae distinctly impressed, finely and densely punctate, intervals distinctly convex, with sparse, fine punctures concentrated along the striae, punctures glabrous, sutural interval in posterior half with single coarse punctures bearing a short robust yellowish seta, interior apical angle of elytra with a strong seta; epipleural edge fine, ending at strongly curved external apical elytral angle, epipleura densely setaceous, apical border without short microtrichomes.

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, penultimate sternite apically with a shiny smooth sclerotized bor- der, which is one-sixth as long as sternite, last sternite medially a little shorter than the penultimate one. Mesosternum between mesocoxae as wide as mesofemur, with irregularly scattered very strong setae. Ratio of length of metepisternum: metacoxa: 1: 1.72. Pygidium moderately convex medially, coarsely and densely punctate, without smooth midline, with moderately dense, robust light setae.

Legs robust and short; femora dull, with two longitudinal rows of setae, finely and sparsely punctate; metafemur shiny and sparsely punctate, sharply margined anteriorly and without a submarginal serrate line, posterior margin weakly convex and glabrous, only weakly widened externally in apical half and not serrate, internally finely serrate, with short setae. Metatibia broad and short, medially convexly widened, widest at middle, ratio width: length: 1: 2.7, dorsally longitudinally convex, with two groups of spines, basal one at one-third, apical one at two-thirds of metatibial length, basally with a few single, fine spines in the punctures; external face longitudinally convex, with very sparse, fine punctures, glabrous; ventrally edged and serrate, with three strong, equally distant spines, internal face finely punctate, apex interiorly near tarsal articulation sharply and deeply 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 slightly shorter than the following two tarsomeres combined and twice as long as the upper tibial spur. Protibia very short, bidentate, protarsal claws symmetrical.

Aedeagus shown in Figure 4 (G–I).

Female unknown.

Diagnosis

Gynaecoserica maekasana sp. nov. is externally similar to G. nahangensis sp. nov.; it may be differentiated from G. nahangensis by the antennal club having five antennomeres and by the parameres which are distinctly narrowed basally.

Etymology

Named according to the Mae Kasa stream close to the type locality.

Figures

Figure 4. (A–C) Gynaecoserica lubosi sp. nov. (holotype), (D–F) G. luteata sp. nov. (holotype), (G–I) G. maekasana sp. nov. (holotype), (J–L) G. maymyoensis sp. nov. (holotype), (M–O) G. nahangensis sp. nov. (holotype), (P–R) G. namtamaiensis sp. nov. (holotype). (A, D, G, J, M, P) Aedeagus, left side lateral view; (C, F, I, L, O, R) aedeagus, left side lateral view; (B, E, H, K, N, Q) parameres, dorsal view. Scale bars 0.5 mm.

Figure 10. Distribution of Gynaecoserica species (A, upper panel; B, lower panel). “?” indicates the rather imprecise type locality (Tenasserim) of G. jelineki sp. nov. in Myanmar.