Aphodius (Liothorax) discoides A. Schmidt 1916, stat. rest.
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 discoides

description: Aphodius (Liothorax) discoides A. Schmidt, 1916, stat. rest.
Figs 2 j, k, 5 e – h, 7 h, 14 a, 17 g – i, 18 e, 20 k, l, 22 d – g, e ’, n’, o’, 25 n, 26 h, i
Aphodius (Nialus) plagiatus var. discus Reitter 1892: 204.
Aphodius (Nialus) plagiatus var. discoides Schmidt, 1916: 96 (new name for Aphodius discus Reitter 1892, not Aphodius discus Wiedemann, 1823).
Aphodius (Nialus) bytinskisalzi Petrovitz, 1971: 219.
Note.
Reitter described Aphodius plagiatus “ var. discus m ” as having the elytra yellow with only the wide margins black, and gave the locality “ Araxes, Syria ” (now Aras). Schmidt (1916) proposed the replacement name A. discoides as Reitter’s Aphodius discus is a junior homonym of Aphodius discus Wiedemann, 1823. Dellacasa et al. (2007) dismiss these names as unavailable as they refer to colour variants, but this is incorrect, as it would be the case only if the name was “ infrasubspecific ”. For names published before 1961, the International Code of Zoological Nomenclature (1999, 4 th edition) states that a name “ is subspecific if first published before 1961 and the author expressly used one of the terms “ variety ” or “ form ” (including the use of the terms “ var. ”, “ forma ”, “ v ” and “ f ”), unless the author also expressly gave it infrasubspecific rank, or the content of the work unambiguously reveals that the name was published for an infrasubspecific entity ”. Reitter clearly stated that his name referred to a variety from a known locality, meaning that the taxon concerned was subspecific rather than infra-subspecific. This name is therefore available and, in the form of Schmidt’s replacement name (discoides) is the oldest known name for this species. We have been unable to locate any type material of Reitter’s A. discus and therefore here designate a neotype. The specimen chosen is the holotype of A. bytinskisalzi, a male whose aedeagus has the endophallus extruded, from the same general area as Reitter’s material.
Type material examined.
Holotype. Aphodius bytinskisalzi ♂ Israel, Kuneitra. 6. iv. 1968. Leg Bytinski-Salz Tel-Aviv. This specimen is here designated as the neotype of L. discoides Schmidt. 33.12657 ° N, 35.8586 ° E (IL-SMNH.)
Additional material examined.
TR: 1 ♂, “ Turkei leg Schönmann et Schilhammer ” “ Prov. Diyarbakir Karacadag 28. 5. 1987. “ Aphodius (Liothorax) plagiatus det Pittino 1989 ” (NMW); 1 ♂, Turkey Karacadag In coll. D. Král (NMP); 1 ♀, Turkey, 24. vi. 1993, Kizildag env. Klíma leg. In coll. D. Král (NMP); 1 unsexed, Turkey, 1. v. 1998, Erzincan 8 km Askale. Leg Sama (SZ); 1 ♀, Turkey, 17. v. 2011, Muş 1400 m Buģlan geçidi G. Sama leg. (SZ); 1 black ♂, Turkey or. Karakurt env. In coll. D. Kràl (NMP).
Differential diagnosis.
This species agrees with A. plagiatus in the general form of the aedeagus, and in particular the absence of any bristles on the endophallus, which distinguishes it from all other known species. The lightly punctate central area of the metaventrite gives a clear separation from A. plagiatus. Most of the studied material has the elytra largely yellow, unique among the known Palaearctic Liothorax, but recognition of black specimens requires study of the aedeagus.
Redescription.
General appearance (Fig. 2 j, k). Length: 3.8–4.8 mm (♂), 3.4–4.5 mm (♀), width 1.65–2.1 mm (♂), 1.5–2.0 mm (♀).
Head black, finely and sparsely double punctate, with small punctures and minute dots, the punctures separated by ca 2 × the diameter of the larger punctures, punctation slightly rugose towards the anterior margin, especially either side of the median emargination of the clypeus. Sides of clypeal emargination rounded. Frontal suture almost invisible, but median transverse portion present, with a small vague elevation medially, just behind median bulge of clypeus, in males, and weakly raised at ends, just mediad of inner margins of eyes, where it would be expected to angle forwards to anterior margin of genae. However, this part of the suture is effaced. Centre of clypeus raised. Maxillary palpi blackish brown, antennae mid brown, clubs darker. Epipharynx (Fig. 7 h) with the anterior margin of the clithra only weakly emarginated either side of the tylus, and the apophobae rather stout and the prophobae restricted to areas close to the edges of the basal 1 / 2 of the mesoepitorma.
Pronotum black with anterior and lateral margins vaguely browned. Hemicylindrical, strongly arched transversely, scarcely at all longitudinally. Punctation double, sparse, stronger than on head, punctures separated by at least 2 × the diameter of the larger punctures. The larger punctures more developed posteriorly and laterally, almost absent from the anterior-median 1 / 3. Pronotal surface with a fine weak isodiametric reticulation (viewed at × 80). Sides of pronotum almost straight, parallel, incurved anteriorly. Pronotal surface bulges out laterally in basal 1 / 4, but the basal 1 / 4 of the lateral margins is still just visible from above. Head and pronotum (Fig. 5 e – h): basal margin of pronotum unbordered in middle 1 / 3 (Fig. 14 a).
Scutellum elongate, glossy dark brown, pentagonal, sides parallel in basal 1 / 2, then convergent to bluntly pointed tip.
Central area of elytra typically dull yellowish brown, semi-transparent so that the folded wings are visible, suggesting a vague darker pattern over this part of the elytra. Sutural interstice darker, as are the outer interstices (interstice 7 to the edge), with the darkening of interstice 7 sometimes confined to the outer edge just behind the humeral callus, then expanding over the entire interstice to the apex. Interstice 6 may be darkened in apical 1 / 2, and the apical 1 / 3 of the elytra is darkened throughout. Striae narrow, shallow, strial punctures scarcely encroaching on the strial edges. Interstices flat, sparsely and very finely punctate, ground with a fine isodiametric reticulation giving a silky sheen, though the strength of the reticulation varies (Fig. 17 g – i). In the black male listed above the elytra and scutellum are entirely black. This specimen agrees with A. discus in the shape and sculpture of the head and pronotum and in the endophallus with scales only, lacking any hairs or bristles.
Median diamond-shaped plate of metaventrite (Fig. 20 k, l) weakly depressed to mid-line, finely punctate, the surface with fine isodiametric reticulation.
Legs: dark brown, tarsi a little paler. Longer spur of mid tibiae clearly longer than basal segment of tarsus, extending to ca the middle of segment 2 (Fig. 18 e).
Aedeagus (Fig. 22 d – g) similar to that of A. plagiatus, but smaller, length ca 0.85 mm. Endophallus with short fine scales and with a field of densely packed columnar bristles at its apex (Fig. 22 e ’). The scales of the basal section of the aedeagus are the same size and shape in the black specimen as in the ones with paler elytra (Fig. 22 n ’, o’).
Remarks.
Aphodius discoides appears to have a rather restricted distribution in Anatolia, Syria and Israel (Fig. 29 b). It appears to be a rather rare species. We have no habitat information.
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