Archeohomaloplia xiajuan, Introduction, 2023

Introduction, Dirk Ahrens, 2023, Two new species of Archeohomaloplia Nikolajev, 1982 from China (Coleoptera: Scarabaeidae: Sericini), Bonn zoological Bulletin 72 (1), pp. 55-61 : 56

Archeohomaloplia xiajuan sp. nov.

urn:lsid:zoobank.org:act:F493B503-84CF-45CE-9400-6E4384BEE573

Fig. 1

Type material examined. Holotype: ♂ “ Yunnan 70km NNW Xiajuan 24.V.2002 Volkovitch / Asia Sericini sp 1158” ( ZIN).

Description. Length: 4.9 mm, length of elytra: 3.1 mm, width: 2.5 mm. Body oblong, black, antenna black, dorsal surface shiny, with sparse and evenly spaced long, erect setae.

Labroclypeus trapezoidal, widest at base and strongly convergent apically, lateral margins weakly convex; anterior angles almost blunt, only weakly rounded; lateral border and ocular canthus producing an indistinct blunt angle; margins moderately reflexed, anterior margin moderately emarginate medially; surface medially convex and shiny, finely and densely punctate, distance between punctures less than their diameter, with a few robust punctures behind anterior margin bearing each a long, erect seta; frontoclypeal suture feebly incised, distinctly elevated and moderately curved; smooth area in front of eye approximately 1.2 × as wide as long; ocular canthus short and wide, subtriangular, rounded at apex, finely and densely punctate, with one terminal seta. Frons shiny, with fine, dense punctures; with numerous erect setae behind the frontoclypeal suture and beside eyes. Eyes very small, ratio of diameter/interocular width: 0.39. Antenna brown, with ten antennomeres; club dark brown, with three antennomeres, little shorter than remaining antennomeres combined. Mentum weakly elevated and flattened anteriorly.

Pronotum moderately wide, widest at middle, lateral margins strongly curved and slightly convergent basally, but stronger convergent anteriorly; anterior angles strongly produced and sharp, posterior angles strongly rounded and almost obsolete; anterior margin convexly produced medially, with a broad marginal line; basal margin with fine and complete marginal line; surface with dense and fine punctures, with a few long yellow, semierect setae on disc; anterior and lateral borders densely setose; hypomeron simple, not carinate at base and consequently not ventrally produced. Scutellum triangular and dull, slightly longer than wide, with fine and dense punctures, with minute setae in punctures.

Elytra oblong, widest in apical third, striae weakly impressed, finely and densely punctate, intervals weakly convex, with fine, moderately dense punctures often concentrated along the striae, odd intervals with single, fine, long, yellow setae (setae longer than interval width); interior apical angle of elytra with a short seta; epipleural edge fine ending at the strongly curved external apical angle of elytra, epipleura densely setose; apical border of elytra with a narrow membraneous rim of short microtrichomes.

Ventral surface shiny, with fine and moderately dense punctures, finely densely setose; metacoxa glabrous with a few fine, long, adjacent setae laterally only; abdominal sternites micro-reticulate, with an indistinct, transverse row of coarse punctures bearing a moderately long seta between fine, dense punctation, a few fine punctures bear a short seta; penultimate sternite apically with a smooth, sclerotized border which is one fifth as long as the sternite, last sternite medially 0.75 × as long as penultimate one. Mesosternum between mesocoxae as wide as mesofemur, with fine, long setae. Ratio of length of metepisternum/metacoxa: 1/1.48. Pygidium strongly convex at apex, finely and densely punctate, without smooth midline; surface shiny, sparsely covered with short and longer setae.

Legs slender and moderately long; femora shiny, with two longitudinal rows of setae, coarsely but sparsely punctate; metafemur sharply carinate anteriorly and without a submarginal serrate line, posterior margin weakly convex and with a few short setae basally, its ventral part only weakly widened in apical half and not serrate, dorsal posterior margin not serrate, with dense, long setae. Metatibia slender and moderately long, evenly widened towards apex, ratio width/length: 1/3.2; dorsally longitudinally convex, apically also weakly carinate, with two groups of spines, basal group at first quarter, apical group at two thirds of metatibial length, basally with a few single, fine setae; external face longitudinally convex, with fine punctures laterally, glabrous; ventrally with a sharp, finely serrate margin, with four robust setae; internal face laterally with a few punctures bearing each a fine seta; apex interiorly deeply excavate at middle and not truncate near tarsal articulation. Meso- and metatarsomeres dorsally glabrous and finely densely punctate, ventrally with sparse, short setae; metatarsomeres ventrally with a finely serrate ridge, beside it with a robust longitudinal carina; metatarsomere 1 as long as following tarsomere and slightly longer than dorsal tibial spur. Protibia moderately long, bidentate, protarsal claws symmetric.

Aedeagus: Fig. 1A–D . Habitus: 1E. Female unknown.

Diagnosis. Archeohomaloplia xiajuan sp. nov. is in external appearance rather similar to A. hebashana Ahrens, 2011 . The new species differs by the shape of the dorsal apophysis of the phallobase which is apically more strongly widened and truncate at apex; the parameres are narrower and weakly curved.

Etymology. The species is named according to its occurrence near Xiajuan (noun in apposition).

Figures

Fig 1. A–E. Archeohomaloplia xiajuan sp. nov. (holotype). F–I. Archeohomaloplia volkovitchi sp. nov., holotype. A, F. Aedeagus, left side lateral view. D, H. Aedeagus, right side lateral view.B, G.Aedeagus, dorsal view.C. Parameres, ventral view.E, I. Habitus (not to scale). Scale: 0.5 mm.