Gynaecoserica keithi, 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 : 1551-1553

publication ID	https://doi.org/ 10.1080/00222930902968809
persistent identifier	https://treatment.plazi.org/id/0399C459-DB04-6F69-FDB9-FBA85F280DCC
treatment provided by	Felipe
scientific name	Gynaecoserica keithi
status	sp. nov.

Treatment

Gynaecoserica keithi sp. nov.

( Figures 3G–I View Figure 3 , 8K View Figure 8 , 10A View Figure 10 )

Type material examined

Holotype. Ƌ “NE India Meghalaya 1999 9 km NW of Jowai ; 1400 m; 25°30¢ N 92°10 ¢E 12.v. Dembický & Pacholátko” ( TICB) . Paratypes. 65 ƋƋ same data as holotype ( TICB, CA) .

Description

Length 4.3 mm, length of elytra 2.8 mm, width 2.4 mm. Body oval, dorsal surface reddish brown, with frons, a median spot on pronotum, sutural and lateral intervals of elytra, and ventral surface dark brown, antenna yellowish with dark club, dorsal surface except head dull and sparsely robustly setose.

Labroclypeus subtrapezoidal, widest at base, lateral margins in basal half straight and weakly convergent, anteriorly strongly 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 feebly convex medially and moderately 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 as wide as long; ocular canthus short and moderately broad, finely and sparsely punctate, without terminal seta. Frons shiny, only posteriorly dull, with fine, moderately dense punctures, glabrous except two short setae beside eyes. Eyes small, ratio of diameter: interocular width 0.52. Antenna yellow, with 10 antennomeres; club dark brown, with five antennomeres, club a little longer than the remaining antennomeres combined. Mentum weakly elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins straight and subparallel in basal half, in anterior half weakly curved and convergent anteriorly, anterior angles strongly produced and moderately sharp, posterior angles strongly rounded, anterior margin convexly produced medially, with a distinct fine marginal line, basal margin without marginal line; surface with moderately 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 narrow and short, triangular, with fine, dense punctures, medially smooth, microscopic setae present in the punctures.

Elytra moderately long and egg-shaped, widest shortly behind the middle, striae distinctly impressed and finely and densely punctate, intervals convex, with fine and moderately dense punctures concentrated along the striae, punctures with fine microscopic setae, odd intervals with single coarse puncture bearing strong yellowish setae, which are erect or adjacent, interior apical angle of elytra with a strong seta; epipleural edge fine ending at strongly curved external apical angle of elytra, 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 almost twice 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: 1.82. Pygidium convex at apex, coarsely and densely punctate, without smooth midline, with sparsely scattered long setae.

Legs moderately slender 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: 2.9, dorsally sharply edged, 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 three strong, not equally distant spines, internal face not punctate and smooth, 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 as long as the following two tarsomeres combined and more than twice as long as the upper tibial spur. Protibia moderately long, bidentate, protarsal claws symmetrical.

Aedeagus shown in Figure 3 View Figure 3 (G–I) and female genitalia in Figure 8 View Figure 8 (K).

Variation

Length 4.3–4.4 mm, length of elytra 2.8–2.9 mm, width 2.4 mm. Coloration varies from uniformly reddish brown to dark brown, without any darker portions on elytra or pronotum. Female: antennal club with three antennomeres, distinctly shorter than the remaining antennomeres combined.

Diagnosis

Gynaecoserica keithi sp. nov. is very similar to G. cymosa (Brenske) and G. lobiceps sp. nov. It may be differentiated from both by the shape of the male genitalia only: the fused parameres are narrowed apically, and the lateral apophysis of phallobase is at least twice as wide as long (lateral view) but still convex at apex. Females of the syntopically occurring G. cymosa and G. lobiceps can be distinguished from the new species by the shape of the sclerotized structure of the ductus bursae ( Figure 8K View Figure 8 ), which in G. keithi is medially fused and distinctly narrowed apically but in the two other taxa is medially separate and not narrowed towards the bursae.

Etymology

The new species is named after my dear colleague and friend Denis Keith, Chartres, recognized specialist on Melolonthinae. I am grateful to him for making the interesting sericine beetle material from his collection available to me for study.