Gynaecoserica maymyoensis, 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 : 1565-1566

Gynaecoserica maymyoensis sp. nov.

( Figures 4J–L , 9B )

Type material examined

Holotype. Ƌ “ Maymyo , Burma, H.L. Andrewes. / Maymyo, VI.10 H.L. Andrewes. / Andrewes Bequest. B.M. 1922-221.” ( BMNH) . Paratypes. 12 ƋƋ, 8 ♀♀ same data as holotype ( BMNH, CA) .

Description

Length 3.8 mm, length of elytra 2.7 mm, width 2.4 mm. Body oval, dorsal surface yellowish brown, with head, two symmetrical spots on pronotum, sutural and lateral intervals of elytra, and ventral surface dark, partly with greenish shine, antenna yellowish, dorsal surface except head dull or iridescent shiny and almost glabrous.

Labroclypeus subtrapezoidal, only slightly wider than long, widest at base, lateral margins strongly curved and strongly convergent to moderately rounded anterior angles, lateral border and ocular canthus producing a distinct blunt angle, margins weakly reflexed, anterior margin very shallowly sinuate medially; surface feebly convex medially and shiny, finely and very 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 feebly incised and medially weakly curved; smooth area in front of eye approximately 1.5 times as wide as long; ocular canthus short and slender, smooth, with a fine terminal seta. Frons shiny, only posteriorly dull, with fine, moderately dense punctures, glabrous except three short setae beside eyes. Eyes small, ratio of diameter: interocular width 0.5. Antenna yellow, with 10 antennomeres; club apically a little darker, with five antennomeres, club a little longer than the remaining antennomeres combined, fifth antennomere transversely lamella-like produced. Mentum weakly elevated and flattened anteriorly.

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

Elytra short and oval, widest at middle, striae feebly impressed, finely and densely punctate, intervals flat, with fine and very sparse punctures concentrated along the striae, punctures with fine microscopic setae only, odd intervals 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 border, which is one-sixth as long as sternite, last sternite medially as long as penultimate one. Mesosternum between mesocoxae as wide as mesofemur, with irregularly scattered very strong setae. Ratio of length of metepisternum: metacoxa 1: 1.86. Pygidium moderately convex at apex, finely and moderately 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, sharply margined anteriorly and without a submarginal serrate line, posterior margin weakly convex and glabrous, ventrally only weakly widened in apical half and not serrate, dorsally finely serrate, with short setae. Metatibia slender and short, medially convexly widened, widest at middle, ratio width: length: 1: 2.75, dorsally very weakly edged, almost 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 sparse, fine punctures, glabrous; ventrally edged and serrate, with four strong, equally distant spines, internal face not punctate and smooth, apex interiorly near tarsal articulation concavely 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 slightly less than twice as long as the upper tibial spur. Protibia very short, bidentate, protarsal claws symmetrical.

Aedeagus shown in Figure 4 (J–L).

Variation

Length 3.8–4.0 mm, length of elytra 2.7–2.8 mm, width 2.4–2.5 mm. Coloration often completely yellowish with only frons dark. Female: antennal club with three antennomeres, distinctly shorter than the remaining antennomeres combined, pygidium less convex.

Diagnosis

Gynaecoserica maymyoensis sp. nov. somewhat resembles G. marginipes (Brenske) , but the parameres do not have a basal apophysis and the antennal club in the male has only five antennomeres. It is very similar in the shape of the male genitalia to G. luteata sp. nov. but the parameres are widest at the base, distinctly narrowed behind the basis and strongly concavely sinuate in the middle of left side.

Etymology

Named according 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 9. Distribution of Gynaecoserica species (A, upper panel; B, lower panel). “?” in (B) indicates the not precisely localized collecting locality of G. gisionensis sp. nov. in Vientiane province in Laos.