Aphodius (Liothorax) niger Illiger 1798
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 niger

description: Aphodius (Liothorax) niger Illiger, 1798
Figs 4 a, 6 e, 9 a – c, 15 a, b, 17 l, m, 18 i, 19 a, 21 a – c, 23 a – f, 24 a, 25 a, 26 t, 31 a, b, d, e, 34 a – d
Aphodius niger Illiger, 1798: 24. Conserved as valid name: International Commission for Zoological Nomenclature Opinion 2009 (2005: 45).
Type material examined.
Lectotype, unsexed, “ Suec ”, designated by Krell et al. (2003) (ZMB).
Additional material examined.
SV: Sodermanland, Holo, Tulgarn, Nasuden. 58.95 ° N, 17.62 ° E. Trampled bare organic mud. 15. v. 2011. Hans-Erik & Livia Wanntorp. 4 ♂♂, chromosome preps 2: 24. v. 2001, 1: 25. v. 2011, 2: 25. v. 2011, 1: 31. v. 2011, R. B. Angus; 7 ♀♀, chromosome preps 3: 24. v. 2011, 4: 24. v. 2011, 9: 25. v. 2011, 2: 31. v. 2011, 3: 31. v. 2011, 4: 31. v. 2015, 5: 31. v. 2011, R. B. Angus (NHMUK); 1 ♂ same data, chromosome prep. 2: 24. v. 2011 (NMP).
GB: Hampshire, New Forest. Long Slade Bottom. 50.801 ° N, 1.619 ° W. Temporary pool after heavy rain. 30. v. 2002, R. B. Angus. 4 ♂♂, 4 ♀♀, 5 unsexed. Chromosome preps 1–3: 31. v., 2: 1. vi, 4: 1. vi. 2011, R. B. Angus (NHMUK); 1 ♂, same data. (NMP); New Forest, White Moor Pond. 50.820 ° N, 1.607 ° W. 2. x. 2015, 2. v. 2016, R. B. Angus. 8 ♂♂, 7 ♀♀, 3 unsexed. Chromosome preps: 3: x. 2015, 5: v. 2016. New Forest, Balmer Lawn. 50.828 ° N, 1.567 ° W. At edges of pond and ditch. V. 2002. R. B. Angus (NHMUK). Inkpen Common, Berkshire 51.375 ° N, 1.453 ° W (fide Mann and Garvey (2014), not examined) 1 unsexed (OUM).
RU: Yaroslavl oblast’, Berditsino, 57.454 ° N, 40.1108 ° E. leg. Yakovlev. 1 ♂ (NMW).
Differential diagnosis.
Aphodius niger is immediately distinguished from all other Liothorax species (and all Aphodiinae whose chromosomes are known) by its long, almost entirely euchromatic, Y chromosome (Fig. 31 a, b, d, e). The basal segment of the mesotarsus is always clearly longer than the longer mesotibial spur (Fig. 18 i). Elytra glossy black, though interstices have fine reticulation. Central part of metaventrite without reticulation (Fig. 21 a – d). Endophallic teeth clearly longer than high. Length of longest endophallic teeth at least 40 μm.
Redescription.
General appearance (Fig. 4 a). Length 4.2–4.5 mm (♂), 4.1–5 mm (♀), width 1.8–2 mm (♂), 1.8–2.2 mm (♀) (Swedish material), 4.4–4.8 mm (♂), 4.4–5.1 mm (♀), width 2.0– 2.2 mm (♂ and ♀) (English Material).
Head black, without obvious brownish margin. Anterior margin of clypeus excised over middle 1 / 3, the lateral edges of this excision bluntly rounded. Frontoclypeal suture very fine, without any trace of a tubercle, straight-transverse over middle 1 / 2, angled forward to run to the clypeo-genal junction laterally. The lateral parts of the suture may be almost completely effaced. Clypeus raised in a rounded bulge medially. Surface moderately strongly punctate with double punctation. Larger punctures separated by ca their own diameter over most of the head, but sparser on clypeal bulge. Antennae and palpi blackish brown. Epipharynx (Fig. 9 a – c) with the anterior margin of the clithra strongly excised either side of the median tylus and with a few fine acropariae. Chaetopedia stout, 3–6 each side. Chaetopariae ca as stout as chaetopedia, forming a close-set line each side. Apophobae very fine, arranged in a line outside that of the chaetopariae; prophobae vine, quite long, arranged against the sides of the mesoepitorma. Pronotum (Fig. 6 e) hemicylindrical, black, highly arched transversely, weakly so longitudinally, lateral parts of surface bulging outwards so that the lateral margins are often not visible from above in their basal 1 / 3. Surface glossy black, with double punctation, the larger punctures separated by 1–2 × their diameter, sparser medially and sometimes petering out in anterior 1 / 8 where only the fine punctures are present. Scutellum elongate, pentagonal, glossy black with a few sparse punctures. Elytra black, interstices flat, 6–8 × the width of the striae, finely reticulate and with sparse fine punctures (Fig. 17 l, m), the reticulation stronger towards the apex (Fig. 19 a). Striae glossy, without reticulation, with a single row of punctures separated by ca 2 × their diameter and excising the strial margins. Metaventrite moderately punctate, the median plate not reticulate, sometimes distinctly concave in males Fig. 21 a but sometimes almost flat with a median impressed line, as in females (Fig. 21 b, c). Legs blackish brown, mesotarsi always with basal segment longer than longer mesotibial spur (Fig. 18 i).
Aedeagus (Figs 23 a – f, 24 a) length ca 1.2 mm, paramere length ca 0.48 mm, basal piece length ca 0.69 mm, tooth-field length ca 0.67 mm (measurements from the cleared preparation; Fig. 24 a). Length of longest teeth on endophallus 54–65 μm. Parameres with the sclerotised strut running from the base just mediad of the outer lateral margin to the inner apical angle. Apical soft pad of parameres rounded apically, not widened.
Remarks.
Chromosomally verified material is from the New Forest, England and Södermannland, Sweden. Material from Berditsino, Russia (NMW) is taken to belong to this species. In the New Forest A. niger is typically taken at the edges of pools and ditches in April-May, but when large numbers are taken it is almost always due to inwash from the surrounding grassland after heavy rain (Fig. 27 a). In Britain, outside of the New Forest, A. niger has recently been found at Inkpen Common near Hungerford in Berkshire (Mann and Garvey 2014). In the Swedish locality the beetles were burrowing in trampled organic mud (H. - E. Wanntorp, pers. comm., April 2011) (Fig. 27 c). Very occasionally A. niger is taken in dung, as by J. Bergsten in the New Forest in 1999, and sometimes in dry areas of the Swedish island of Öland (H. Lundqvist, pers. comm., April 2011). These are rare, random occurrences and may sometimes result from the beetle taking shelter from drought. One further feature of the occurrence of A. niger is worthy of comment – it shows dramatic fluctuations in abundance. Thus, in 2002 it was very abundant in its New Forest localities whereas more recently RBA has taken it only in low numbers. Similarly, H. - E. Wanntorp describes the species as being in very high numbers in the locality where he usually only took a few specimens (Fig. 29 a).
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