Aphodius (Liothorax) krelli Angus, Maté, Angus & Král, 2024, sp. nov.
Creators: name: Angus, Robert B.
name: Maté, Jason F.
name: Angus, Elizabeth M.
name: Král, David
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Aphodius
Aphodius krelli

description: Aphodius (Liothorax) krelli sp. nov.
Figs 4 e, 6 h, 8 j, 16 b, 17 y, 18 m, n, 23 m, o, 26 y, 33 e – l, 34 i, j
Type material examined.
Holotype ♂: Sardinia, Nuoro Province, Badde Salighes 3. iv. 2012. R. B. & E. M. Angus. L 5.0 mm, b 2.1 mm. Chromosome prep. 2, 5. iv. 2012 (NHMUK). Paratypes: 4 ♂♂, 4 ♀♀, data as holotype, but 1 ♂ taken on 1. iv. 2012. ♂ paratypes with chromosome preparation data prep. 5: 5. iv. 2012 and prep. 1: 10. iv. 2012, ♀ paratypes with data preps 3, 4, 6–8: 5. iv. 2012 (NHMUK); 1 ♀, data as holotype (NMP) 1 ♀, data as holotype (JFMC); 1 ♂, chromosome prep 5, 5. iv. 2012, data as holotype (DMNS); 1 ♀, Sardinia, Sassari, Ciaccia, 17. VII. 2008, old sheep dung, R. B. Angus (JFMC); 2 unsexed, ITALY, Sardegna, Nuoro, Altopiano della Campeda, 40 ° 21.245 ' N, 8 ° 47.044 ' E, 580 m, 18. 5. 2005 leg. Starke (ABC); 1 unsexed, [ITALY], Badde Salighes Sardegna [Nuoro Pr], Aphodius (Nialus) niger Carpaneto det. 1982 (MNHG).
Differential diagnosis.
Sardinian A. krelli differs from Corsican A. bameuli in being less parallel-sided (Fig. 4 e, d) and with the pronotum more heavily punctate (Fig. 6 h, g). The karyotypes of the two are very similar in the sizes and shapes of their chromosomes (Fig. 33 e – l) but the long arm of autosome 7 in A. krelli is heterochromatic and is polymorphic for a deletion – it may be present (Fig. 33 f, i – l) or absent (Fig. 33 g, h).
Description.
General appearance (Fig. 4 e). Length: 4.4–5.0 mm, width: 2.0– 2.1 mm (♂), 4.1–4.5 mm, width 1.7–2.0 mm (♀). Head: glossy black with no trace of reticulation, anterior margin vaguely browner. Sculpture of double punctation, the fine punctures separated by ca 2 × their width, the coarser punctures ca 3 × the diameter of the fine ones, distributed over the anterior and lateral parts of the head and on the frons. Frons elevated in a vague hump on disc. Frontoclypeal suture very fine but distinct and complete. Anterior margin of clypeus emarginated medially, the margin rounded either side of this emargination. Anterior and lateral margins of head bordered, the border extending from the back of the genae. Genae distinct, fairly abruptly divergent anteriorly from anterior margin of the eyes, widest point behind middle of genae, in front of which the genal margins curve more gently to the clypeus, which they meet at a slight angle. Epipharynx (Fig. 8 j) with anterior margin of clithra strongly emarginate each side of the median tylus, and with a few fine acropariae. Chaetopedia stout and long, four or five each side; chaetopariae closely set, fairly stout, forming a line each side. Prophobae very fine, clustered along the edges of the mesoepitorma; apophobae fine and long, arranged in a line outside the chaetopariae. Antennae and palpi blackish brown. Head and pronotum as in Fig. 6 h. Pronotum: hemicylindrical, highly arched transversely but very weakly so longitudinally in the mid-line. Lateral margins entirely visible from above. Lateral margin bordered, basal margin with very fine border, this sometimes complete but usually absent from the median 1 / 2 to 1 / 3 of the margin. Surface glossy black with no hint of reticulation but with double punctation. Fine punctures dot-like, extending over the whole surface, coarser punctures ca 4–8 × the diameter of the dots, sparser and tending to be smaller on the disc. Fine punctures separated by ca 4–6 × their diameter, coarse ones by 1.5–2.5 × their diameter.
Scutellum: narrow, pentagonal, sides parallel in basal 1 / 2 then convergent to a blunt point apically. Surface glossy black with a few punctures in basal 1 / 2.
Elytra: elongate, not quite parallel-sided, widest just behind middle, then tapered to bluntly rounded apex. Ground colour of interstices silky black with very fine faint isodiametric reticulation (Fig. 17 y). Striae glossy black. Interstices flat, ca 10 × the width of the striae, with scattered fine punctures separated by ca 4–5 × their width. Sutural interstices weakly raised longitudinally from their external margins to ca 1 / 3 of the way to the suture, then depressed to the suture. Striae narrow, with vertical sides, with a single row of punctures separated by ca 3 × their diameter, the sides of these punctures encroaching into the strial margins. Metaventrite with median diamond-shaped area fairly strongly punctate, the punctures larger than in A. bameuli, in males concave to median impressed furrow, in females often flatter.
Legs: dark brown, longer spur of mid tibiae clearly longer than basal segment of tarsus, although sometimes only slightly so (Fig. 18 m, n). Post tibiae with apical fringe of spines short and of even-length ventrally, longer, sparser and of uneven lengths dorsally.
Aedeagus: Fig. 23 m – o. Length ca 1.1 mm, length of parameres ca 0.5 mm, of basal piece ca 0.6 mm, of endophallic tooth-field ca 0.6 mm. Length of longest endophallic teeth 56–58 μm.
Etymology.
This species is named after Dr F. - T. Krell of the Museum of Nature and Science, Denver, Colorado.
Remarks.
Aphodius krelli sp. nov. is endemic to Sardinia (Fig. 29 a). Pittino (2010) lists various Sardinian localities, including Badde Salighes, but all the analysed material is from Badde Salighes (Fig. 27 d). Aphodius krelli sp. nov. is described as a new species despite the fact that its karyotype is similar to that of A. bameuli sp. nov. from Corsica. In spite of the karyological similarities, it is genetically divergent from A. bameuli, from which it differs by 4.7 %, and instead clusters with A. bellumgerens sp. nov., forming a strongly supported clade. In addition the morphometric study clusters A. krelli sp. nov. between the niger - crown group and the 3 B group, from which it differs in being significantly more convex. Morphologically it differs from A. bameuli sp. nov. in being generally more heavily sculptured and more rounded. Its habitat is also different – whereas A. bameuli sp. nov. is a dung-inhabiting species, A. krelli sp. nov., like most Liothorax, is found at the edge of water. The type material, brought home alive for laboratory studies, was divided into two lots. One was given organic detritus from where it was collected while the other was given damp fibrous cow-dung of the sort eaten by A. bameuli sp. nov. The beetles given detritus continued feeding on the journey home but those given dung did not feed at all.
description: Published as part of Angus, Robert B., Maté, Jason F., Angus, Elizabeth M. & Král, David, 2024, Towards a revision of the Palaearctic species of Aphodius Hellwig, 1798, subgenus Liothorax Motschulsky, 1860 (Coleoptera, Scarabaeidae, Aphodiinae), pp. 205-299 in ZooKeys 1207 on pages 205-299, DOI: 10.3897/zookeys.1207.117225