Plagiogonus hielkemai, Bellmann, 2023

Bellmann, Axel, 2023, Plagiogonus hielkemai nov. sp., a new Afrotropical Plagiogonus MULSANT, 1842 (Coleoptera, Scarabaeidae, Aphodiinae), Linzer biologische Beiträge 55 (1), pp. 3-7 : 3-4

Plagiogonus hielkemai nov.sp. ( Figs 1-4 )

M a t e r i a l e x a m i n e d: Holotype ♀: Namibia / Karas, 4 km E of Bethanie 26°29’S 17°12’E, 21-2-2017 1010 m M.A. Hielkema / In/under horse-dung / Plagiogonus hielkemai sp.n. HOLOTYPE A. Bellmann det. 2023 (CAB).

E t y m o l o g y: Thenew species is dedicated to my dear friend and colleague M.A. Hielkema († Gauda , Netherlands), specialized in the Scarabaeoidea and collector of the Holotype.

D e s c r i p t i o n: 4.4 mm. Body elongate, convex. Dorsal surface with microreticulation, moderately shiny. Elytra completely with very fine and short setae. Head and pronotum smooth and shinier than elytra. Colour of body brown to light brown, pronotum with lateral and basal pale areas. Elytra yellow with suture darkend; first interval, lateral and apical margins of elytra weakly darkened. Femora yellow, tibiae darkened to nearly piceous, tarsi yellow.

F e m a l e: ( Figs 1-4 ) Head large, without tubercles; clypeal margin widely rounded at sides and weakly sinuate in the middle; Clypeal border feebly upturned and rather long and densely bristled with hairs as long as first protarsomere. Genae weakly angulate and long ciliate with about 10 closely hairs as long as last protarsomere, eyes feebly protruding. Frontal suture finely impressed. Epistoma nearly flat with punctation simple and fine, with regularly distributed punctures, interstices 4-6 times as wide as diameter of punctures. Punctation on front courser and denser with irregularly distributed punctures, interstices 2-4 times as wide as diameter of punctures.

Pronotum transverse, anterior angles rounded and feebly protruding. Sides nearly straight in the middle, widest before posterior angles, latter truncate and feebly sinuate. Basal margin protruding posteriorly, weakly sinuate on either side. Lateral margins thickly bordered, basal margin thin to the fifth elytral striae, without border across the middle. Anterior margin not bordered. Lateral margins very long ciliate with hairs as long as width of first interval. Punctation double with regularly distributed small punctures and scattered bigger punctures on sides, interstices 2-4 times as wide as diameter of punctures; on disc more scattered without bigger punctures, interstices 4-6 times as wide as diameter of punctures.

Scutellum narrow triangular, without punctures.

Elytron suboval, widest at middle. Humerus without denticle. Striae narrow, weakly impressed and crenulate. Punctation of intervals only near striae and slightly finer than of head and pronotum; intervals feebly convex, nearly punctures entirely with very short setae, latter as long as diameter of punctures on first strie. Epipleuron entirely long ciliate with hairs as long as scutellum.

Protibiae of normal shape, externally with three triangular teeth and 4-5 small denticles, apical spur robust and rounded at tip, slightly curved downwards, as long as first tarsomere. First metatarsomere as long as the following three combined, as long as apical superior spur.

Metasternal plate feebly concave, very finely microreticulate, shiny, with some irregular punctures, marginal punctures with erect setae, disc with distinctly impressed midline.

M a l e: unknown.

D i a g n o s i s: Plagiogonus hielkemai nov.sp. is most similar to P. separatus (PETROVITZ, 1962) and P. tertius (BORDAT, 1992) . It differs from both in having setose elytra, head and pronotum paler in colour and the shape of the head more widely rounded.

C o l l e c t i n g c i r c u m s t a n c e s: In/under horse dung on a unpaved road together with Pharaphodius rubricosus (BOHEMAN, 1857) (M.A. Hielkema in lit.).

D i s c u s s i o n: The distinct differences between this and the other Afrotropical species of the genus Plagiogonus allows a description of this species based on a single female.

Figures

Figs 1-4: Plagiogonus hielkemai nov.sp. (1-4), (1) facies (female, dorsal); (2) facies (female, ventral); (3) facies (female, lateral); (4) epipharynx.