Aphodius (Liothorax) isikdagensis
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 isikdagensis

description: Aphodius (Liothorax) isikdagensis (Balthasar, 1952)
Figs 3 c, d, 6 a, b, 16 e, 18 s, 24 c, 26 c ’
Aphodius (Ataeniomorphus) isikdagensis Balthasar, 1952: 22.
Type material studied.
Holotype (labelled as ♂, undissected), with the locality data as given above and a label “ Aphodius (Ataeniomorphus) isikdagensis n. sp., Dr V. Balthasar ”. At present A. isikdagensis is known only from the type series, the holotype and seven paratypes, one labelled as ♀ allotype, with the locality data Çamlidere, Isik d., Anat. 23. vi. 47. Exp. N. Mus. ČSR. Paratypes: 1 labelled as ♀ allotype and 6 paratypes, noted by Balthasar as 4 ♂♂ and 2 ♀♀. Thus 1 paratype is unaccounted for. Balthasar does not appear to have dissected any of the types (though a male paratype had been dissected) and apparently distinguished the sexes on the degree of clypeal bulging and the degree to which the genae were angled out at their junction with the clypeus. Both these characters are clear in two of the paratypes (Figs 3 c, d, 6 a, b) the largest of the ♂♂ and ♀♀, but not in two other ♀♀ where the reduced clypeal bulging is clear, but not the outward angling of the genae. Assuming 1 ♂ paratype is elsewhere, the 6 paratypes noted by Balthasar comprise 2 ♂♂ and 4 ♀♀. It may be that Balthasar inadvertently switched the numbers of males and females. Balthasar gives the length range as 4.5–5.5 mm. Our measurements are based on stacked images.
Additional material studied.
One male, Turkey, Artvin Çam gec. 2000 m, coll. Ziani, shown by its aedeagus (Fig. 24 k) to belong to the A. niger section, may belong here. Its length is 4.64 mm, width 1.89 mm, so it is within the size range of A. isikdagensis, with which it also agrees in the brown, not blackish, legs, though the maxillary palpi are black. The aedeagus (Fig. 24 k) in lateral view is shown to have the parameres only weakly downturned apically.
Differential diagnosis.
The larger of the two known Turkish species, identified as a member of the A. niger group by the large recurved endophallic teeth (Fig. 24 c). Maxillary palpi mid-brown. Epipharynx (Fig. 8 c, d) with apophobae arranged in narrow bands ca two bristles wide.
Redescription.
General appearance (Fig. 3 c, d). Length 4.6–5.8 mm, width 1.9–2.5 mm. Head black, browner towards the anterior and lateral margins, no tubercle on frontoclypeal suture. Frontoclypeal suture fine and straight-transverse over middle 1 / 3, at either end of this either effaced or angled forward to reach the edge of the head at the junction of the clypeus and genae. Outer margin of genae more or continuous with that of the frons in male, distinctly angled outwards in female (Fig. 6 a, b). Clypeus moderately bulging upwards medially in male, weakly so in the female, anterior margin broadly excised medially, the sides of this excision bluntly rounded. Punctation rather weak, sometimes stronger and tending to be rugose towards the anterior and lateral margins. Epipharynx (Fig. 8 c, d) with the central tylus strongly projecting and the anterior margin of the clithra clearly excised either side. Central darkened sclerotised epitorma broadly triangular, the whole median darkened region appearing widest at base (Fig. 8 c) or narrowed basally (Fig. 8 d). Acropariae virtually absent, chaetopedia strong, six or seven each side. Surface of gymnopedia covered with small tooth-like asperities. Prophobae quite strong, clustered at the edges of the sclerotised mesoepitorma, apophobae fine, arranged in a narrow slightly irregular band ca two bristles wide, outside the chaetopariae. Antennae and palpi mid brown. Pronotum (Fig. 6 a, b) hemicylindrical, highly arched transversely, scarcely at all longitudinally. Entire lateral margins visible from above. Surface with double punctation, male paratype with the larger punctures separated by at least twice their diameter, sparser on disc. The female paratype has the punctation sparser and finer. Posterior margin completely bordered (Figs 6 a, b, 16 e), the border wider medially, narrowed but continuous round the posterior corners.
Scutellum pentagonal, elongate, glossy, sometimes with a few punctures medio-basally. Elytra black, interstices flat, 6–8 × width of the striae, with fine isodiametric reticulation and sparse fine punctures (Fig. 17 k).
Metaventrite (Fig. 21 x, y) moderately punctured, flattened over median diamond-shaped plate, sometimes with an impressed median line. Legs mid brown, basal segment of mesotarsi elongate, either clearly longer than the longer tibial spur, or ca the same length (Fig. 18 s).
Aedeagus (Fig. 24 c): total length ca 1.1 mm, parameres length ca 0.48 mm, basal piece length ca 0.64 mm, length of endophallic tooth-field ca 0.70 mm. Length of longest tooth on endophallus (measured from photograph) ca 60 μm. Parameres with darkened sclerotised strut running from near the outer margin at the base to the inner margin at apex, where the apical sensory pads run round the apex from the tip of the oblique strut to the outer edge, almost to its outer apical angle.
Remarks.
This species is identified as a member of the Aphodius niger group by the large, recurved teeth on its endophallus (Fig. 24 c), and the parameres with the apical sensory pads running round the apex from the tip of the oblique strut to the outer edge. This may be the result of collapse of only weakly downturned apically parameres as a result of drying.
Dellacasa et al. (2001 b) regarded this species as conspecific with A. rutilipennis, at that time known as A. ressli (Petrovitz, 1962). They figure the aedeagus (without the endophallus in its sac), but the parameres do not really match those of the paratype shown in Fig. 24 c. Dellacasa et al. (2007), in their revision of the world species of Liothorax, show the same figure of the aedeagus.
At present A. isikdagensis is known only from the type series, the holotype and seven paratypes, one labelled as ♀ allotype, with the locality data Çamlidere, Isik d., Anat. 23. vi. 47. Exp. N. Mus. ČSR (Fig. 29 b, c). Other Turkish material (Vilayet Rize, Ovitdagi gecidi m 2600, coll. Balerio; Kizildag Gecidi 2290 m, coll. Král; Artvin Çam gec. 2000 m, coll. Ziani) is shown by its parameres to belong to the A. niger species complex, and this is also true of a male from central Armenia, Selim Pass 2350 m, coll. Ziani. See discussion of L. alberti sp. nov.
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