Meligethes polyedricus, Lin & Chen & Huang & Yang, 2015

Lin, Xiao-Li, Chen, Ying, Huang, Min & Yang, Xing-Ke, 2015, A new species of the genus Meligethes Stephens (Coleoptera: Nitidulidae: Meligethinae) from China, Zoological Systematics 40 (3), pp. 268-289 : 269

Meligethes polyedricus sp. nov. ( Figs 1–2 , 45–49 )

Diagnosis. The species is characterized by the uniqueness of male genitalia, tegmen pentangular with a small V-shaped excision and median lobe trapezoidal.

Description. Length 1.7 mm, breadth 1.1 mm, height 0.7 mm.

Body colour brown and rather shining with clear blue lustre; pronotum with narrow transparent lateral margins; head and pronotum with fine and significant yellow pubescence longer than distances among their insertions ( Figs 1–2 ).

Body moderately convex and oval. Head with punctures equal to eye facets in diameter, interspaces among them broader than or equal to a puncture diameter and smoothly microreticulated. Pronotum with finer punctures, interspaces on disk almost smooth. Scutellum semicircular and rugose with very fine punctuations close to each other. Elytra with punctures similar to pronotum, interspaces smooth and among them markedly broader than a puncture diameter. Prosternal process with dense punctures slightly smaller than eye facets in diameter. Metaventrite and abdominal sternite 1 with more or less distinct punctures markedly smaller than eye facets in diameter, and with interspaces completely smooth and among them larger than a puncture diameter.

Head subflattened and about as long as the distance between moderately large eyes (consisting of rather fine facets), clypeus anterior edge slightly bordered, transverse and with lateral angles rounded ( Fig. 45 ). Antennal grooves subparallel. Antennal club composing about 3/10 of total length, about 3/2 long as wide. Pronotum with anterior edge rather arcuated than trapezoidally excised, its posterior edge sinuated. Elytra longer than their combined width, both sides of elytra curved, sharply narrowing distad to round apices. Pygidium slightly convex, apically rounded at apex.

Last labial palpomere about 2.1 long as wide, clearly narrowed apically. Mentum subpentangular, 3 times wider than long, with sides subparallel. Prosternum gently convex along the middle, with distinctly prosternal grooves; prosternal process elongated and gradually widened with apex broadly rounded, its broadened part stretching up to widest point of prosternum and distinctly broader than antennal club ( Fig. 47 ). Distance between metacoxae about 2 times as great as that between mesocoxa, about 3 times as great as that between procoxae. Metaventrite convex with a weak median depression.

Femora almost 1.5 times as wide as corresponding tibiae, tarsi moderately short, about 1/2 as long as corresponding tibiae. Protibia moderately crenulated along outer edge, but with three larger teeth in distal position, obviously wider than antennal club ( Fig. 46 ). Mesotibiae and metatibiae with a single row of long and thinpegs along outer edge. Protarsus about 4/5 as wide as protibia. Claws without dentation at base.

Tegmen and median lobe (penis trunk) slightly sclerotised, tegmen pentangular with a small V-shaped excision, median lobe trapezoidal and ossiform at apex of median lobe ( Figs 48–49 ).

Material examined. Holotype ♂, China, Shaanxi, Canyon of Qinling Botanical Garden (33.92ºN, 108.35ºE; elev. 925 m), 5 July 2012, leg. Ying Chen. Paratype ♂, same data as holotype .

Distribution. China (Shaanxi)

Etymology. The species epithet is derived from the Latin word " polyedricus ", to indicate the shape of polygonal male aedeagus.

Remarks. This new species is very distinct due to the male aedeagus being polygonal, tegmen pentangular with a small V-shaped excision and median lobe trapezoidal. Body shape and colour similar with M. shirakii Hisamatsu, 1956 , but the latter with dentations at base of claws.

Figures

Figs 1–8. Habitus, ♂. 1–2. Meligethes polyedricus sp. nov. 3–4. M. alani Kirejtshuk, 1988. 5–6. M. dilutipes Easton, 1956. 7–8. M. flavimanus Stephens. Scale bars=0.5mm.

Figs 45–49. Meligethes polyedricus sp. nov., ♂. 45. Head. 46. Front tibia. 47. Prosternal process. 48. Tegmen, ventral view. 49. Medial lobe of aedeagus, ventral. Scale bar=0.2 mm.