Onthophagus (Indonthophagus) nitidulus Klug, 1845

Ziani, Stefano, 2024, Historical and morphological review of the subgenus Indonthophagus Kabakov, 2006 of Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini), Insecta Mundi 2024 (38), pp. 1-42 : 18-21

Onthophagus (Indonthophagus) nitidulus Klug, 1845

( Fig. 8 )

Onthophagus nitidulus Klug 1845 : [4], pl. xli; Marseul 1866: 52; von Harold 1869: 1033; Gestro 1889: 16; Reitter 1892: 184; d’Orbigny 1898: 203; d’Orbigny 1900: 297; d’Orbigny 1904: 303; d’Orbigny 1913: 381; Boucomont 1927: 188; Boucomont and Gillet 1927: 184; Winkler 1929: 1034; Arrow 1931: 348; Schatzmayr 1946: 47; Scott in Paulian 1948: 151; El-Zoheiry and Mohamed 1949: 58; Balthasar 1956: 435; Frey 1956: 654; Balthasar 1963: 452; Baraud 1968: 920; Ferreira 1972: 697; Alfieri 1976: 205; Paulian 1980: 153; Zunino 1981: 412; Baraud 1985: 287; Carpaneto and Piattella 1990: 271; Gillett 1995: 20; Gillett and Gillett 2005: 355; Van Harten 2005: 21; Krajcik 2006: 120; Krajcik 2012: 183; Krajcik 2013: 185.

Onthophagus (Palaeonthophagus) nitidulus, Janíková 1998: 30 ; Bunalski et al. 2014: 158.

Onthophagus (incertae sedis) nitidulus, Löbl et al. 2006: 175 .

Onthophagus (Indonthophagus) nitidulus, Kabakov 2006: 154 (footnote); Král and Batelka 2017: 131; Ziani and Bezděk 2016: 188; Montreuil 2017: 269; Ziani et al. 2019: 18 ; Schoolmeesters 2023.

Onthophagus nitidulus var. mediofasciatus d’Orbigny 1898: 203 [type locality: “Egypte: Le Caire” (Cairo, Egypt); “ Sind: Kurrachee ( Karachi , Pakistan ”]; d’Orbigny 1913: 380; Boucomont and Gillet 1927: 184; Winkler 1929: 1034 (as aberration of O. nitidulus ); Balthasar 1963: 452 (as aberration of O. nitidulus ); Ferreira 1972: 697; Alfieri 1976: 205; Balthasar 1963: 452 (as aberration of O. nitidulus ); Baraud 1985: 287 (as aberration of O. nitidulus ); Krajcik 2006: 121 (as junior synonym of O. nitidulus ); Löbl et al. 2006: 175 (as junior synonym of O. nitidulus ); Ziani and Bezděk 2016: 188 (as junior synonym of O. nitidulus ); Schoolmeesters 2023 (as junior synonym of O. nitidulus ).

Onthophagus tetraspilus Fairmaire 1887: 114 [type locality: “Somâlis” [ Côte française des Somalis, presently Djibouti]; d’Orbigny 1898: 202 (as junior synonym (= chromatic variety) of O. nitidulus ); d’Orbigny 1900: 297 (as O. nitidulus var. tetraspilus ); d’Orbigny 1904: 303 (as O. nitidulus var. tetraspilus ); d’Orbigny, 1913: 380 (as junior synonym (= chromatic variety) of O. nitidulus ); Boucomont and Gillet 1927: 184 (as junior synonym of O. nitidulus ); Winkler 1929: 1034 (as aberration of O. nitidulus ); Balthasar 1963: 452 (as aberration of O. nitidulus ); Ferreira 1972: 697 (as O. nitidulus var. tetraspilus ); Alfieri 1976: 205 (as O. nitidulus var. tetraspilus ); Baraud 1985: 287 (as aberration of O. nitidulus ); Krajcik 2006: 121 (as junior synonym of O. nitidulus ); Löbl et al. 2006: 175 (as junior synonym of O. nitidulus ); Ziani and Bezděk 2016: 188 (as junior synonym of O. nitidulus ); Schoolmeesters 2023 (as junior synonym of O. nitidulus ).

Type locality. “ Benisuef ” [Beni Suef, Egypt] ; “Syenam” [Aswan, Egypt] ; “Ambukohl” [Ambigol, Sudan] .

Type material.

Onthophagus nitidulus Klug, 1845: 4 syntypes (1 ♂ and 3 ♀♀), examined by photos (ZMB).

Onthophagus tetraspilus Fairmaire, 1887 : presumably, holotype ♀, fixed by monotypy, not traced.

Onthophagus nitidulus var. mediofasciatus d’Orbigny, 1898 : number of type specimens not specified in the original description, but at last two. A syntype, a minor ♂, examined by photos (MNHN).

Diagnostic features. Length 3.0 to 6.0 mm. Colour black, with distinct isodiametric microreticulation and slight metallic lustre, elytra yellow ochre, usually with dark brown symmetrical spots arranged in a V-shaped pattern, at third, fifth and seventh interstria, and the first interstria brown along entire length; sometimes spots are joined to each other, sometimes lacking in some interstriae. Antennae and dorsal pubescence yellow.

Head short, slightly wider than long, with clypeus broadly round, slightly sinuate anteriorly, sides not sinuate; clypeofrontal carina distinct, bent backward, placed slightly closer to the base of the horn than to the anterior margin of clypeus in major males; occipital carina with a long slender thread-like horn, thickened and flat at base, arising in correspondence of the anterior margin of eyes, directed backward and tapering gradually to the extremity, in major males, reduced to a short, erected conical tubercle, in minor males, to a sinuate carina, longer than the clypeofrontal one, placed between the eyes or little further back in females; clypeal surface with transversely rugose, setigerous punctures, frontal surface double sparsely punctate.

Pronotum convex, declivous anteriorly, with an almost undistinguishable anteromedian smooth and unpunctured area, in major males, with an anteromedian slightly bilobate prominence, in minor males and females; both sexes with a small unpunctured area, duller than the surrounding surface, on either side near pronotal posterior angles;anterior angles distinctly produced, sides not sinuate behind them in dorsal view; dorsal surface setigerously punctate, punctures broad, sub-regular in distribution, separated by 2 to 3 diameter on disc, bearing pale-yellow setae.

Elytral striae little or not at all shiny, barely impressed, with punctures slightly larger than strial width and crenulating interstrial sides; interstriae barely convex, all rather regularly granulate; granules spread, smaller than strial punctures, each granule with a small, indistinct, setigerous puncture; setae short, pale-yellow, thin.

Pygidium with rather regularly distributed, setigerous punctures; setae pale-yellow, thin, longer than those of elytra.

Males with protibial spur outward and with a strongly curved downward denticle on the inner angle of protibial apex.

Male genital armature. Parameres short, apices slightly bent ventrally, slightly diverging apically, without latero-proximal denticle, round at apex ( Fig. 8b–c ); endophallus with the presence of accessory endophallites, two evident raspulae and a U-shaped lamella copulatrix, with an arm straight, the other broad and clearly divided in two unequal branches ( Fig. 8d ).

Distribution. Egypt, Sudan ( Klug 1845). Eritrea, “Arabia” ( Gestro 1889). Iraq, Djibouti, Somalia, Saudi Arabia, Yemen, Pakistan ( d’Orbigny 1898). Afghanistan ( Balthasar 1956). Rajasthan, India ( Frey 1956). Ethiopia ( Balthasar 1963). Iran ( Baraud 1968). United Arab Emirates, Oman ( Gillett 1995).

Material examined. Egypt: “ Aegypt Ehrenb. / […], “ nitidulus / Klug”, examined by photos (4 syntypes of O. nitidulus , 1 ♂ and 3 ♀♀, ZMB) . Saudi Arabia: Madinah prov., 10 km N Wadi Reem , 200 m. 17°55′28″N ; 42°15′20″E, 30.iii.2017, G. Magnani leg. 1 ex. ( SZCM) . Yemen: Abyan gov., W Lawdar, env. 1150 m, 13°52’36”N 45°48’01”E, 22.x.2005, D. Král leg. 1 ex. ( SZCM) ; Al Hudaydah gov., Al Munirah , 21 m, 15°20′10″N 42°50′12″E, 31.x.2005, D. Král leg. 1 ex. ( SZCM) . Oman: Dhofar gov., Road 47 before Al Mughssyl , 61 m, 16°54’11”N 53°49’20”E, 11.ix.2000, M. Dellacasa leg. 3 exx. ( SZCM) ; Dhofar gov., Khor Rori , 37 m, 17°02’27”N 54°26’16”E, 12.ix.2000, M. Dellacasa leg. 3 exx. ( SZCM) ; Dhofar gov., Salalah - Wadi Darbat , 41 m, 17°04’23”N 54°25’56”E, 10.vii.2018, I. Zappi leg. 1 ex. ( SZCM) ; Dhofar gov., Rakhyut , 27.x.2022, L. Melloni leg. 4 exx. ( SZCM) ; Dhofar gov., 15 km W Salalah , 20 m, 16°56’52”N 53°57’37”E, 4.iv.2023, S. Ziani leg. 8 exx. ( SZCM) ; Dhofar gov., Wadi Ayun 840 m, 17°15’14”N 53°53’33”E, 5.iv.2023, S. Ziani leg. 4 exx. ( SZCM) . Iran: Lorestan prov., Kumas, 2.iv.2015 ( SZCM) ; Hormozgan prov., Ahmadi , 10.iii.2017, 2 exx. ( SZCM) ; Hormozgan prov., Chah Faleh , 19 m, 30.iii.2018, G. Sabatinelli leg. 2 exx. ( SZCM) . Pakistan: “Kurrachee” [ Karachi ], viii-ix, Maindron leg. 1 ♂, examined by photos (syntype ♂ of O. nitidulus var. mediofasciatus, d’Orbigny collection, MNHN) ; Punjab prov., Chakri, motorway for Islamabad , 26.vi.2011 ( SZCM) .

Historical review. The specimens (syntypes) examined and used by Klug (1845) for describing Onthophagus nitidulus came from three localities, “Benisuef ” [Beni Suef], “Syenam” [Aswan] and “Ambukohl” [Ambigol], respectively in northern Egypt, in southern Egypt, and in northern Sudan. The type locality of the taxon encompasses all these three localities (Article 73.2.3 of the Code, ICZN 1999).

Kolenati (1846) and von Harold (1867, 1869) mentioned Onthophagus sexstriatus Waltl [“ 6-striatus Waltl.”] and Onthophagus niloticus Reiche , presumably as junior synonyms of O. nitidulus . As specified by von Harold (1867), in the first half of the nineteenth century, specimens of this last species were often found in entomological collections under the names “ niloticus ” and “ 6-striatus ”. It does not appear that Joseph Waltl and Louis Jérome Reiche published papers where, respectively, Onthophagus sexstriatus and Onthophagus niloticus have been described. Therefore, as specified by von Harold (1869), it can be reasonably presumed that these names are “ nomina nuda ”, hence not available. It should be noted that, later on, Montrouzier (1855) and von Harold (1879) described, respectively, Onthophagus sexstriatus from “Woodlark” [ Papua New Guinea] and Onthophagus niloticus from “Kordofan, Nilus coeruleus” [ Sudan], valid names of taxa that, obviously, have nothing to do with Onthophagus sexstriatus Waltl , nomen nudum, with Onthophagus niloticus Reiche , nomen nudum, and with Onthophagus nitidulus Klug.

Ten years after having described Onthophagus nitidulus, Klug (1855) described “another” Onthophagus nitidulus – clearly different from Onthophagus nitidulus Klug, 1845 – from Sena, Mozambique, description confirmed a few years later ( Klug 1862) with, in addition, the statement “ nova spec. ” after the name of the species, as if the 1855 paper had never been published. Whatever happened, Klug most likely forgot his 1845 paper and his “first” Onthophagus nitidulus . Aware of this clear primary homonymy ( Onthophagus nitidulus Klug, 1845 and Onthophagus nitidulus Klug, 1855 ), von Harold (1867) replaced the junior homonym with the new name virescens.

Onthophagus tetraspilus Fairmaire, 1887 was described from the then “ Côte française des Somalis ”, presently Djibouti, and considered close to the female of O. nitidulus . Later d’Orbigny (1898) deemed O. tetraspilus as a simple chromatic variation of O. nitidulus , with elytral spot only on the 3 rd and 7 th interstriae or even just on 7 th.

In 1898 d’Orbigny described the variety mediofasciatus of O. nitidulus , from Cairo, Egypt, and from Karachi, Pakistan, with elytral spots joint to form a transversal V-shaped band, sometimes interrupted on the 6 th interstria. Since d’Orbigny’s taxon was published before 1961, it must be considered of subspecific rank according the Article 45.6.4 of the Code ( ICZN 1999). From Winkler (1929), mediofasciatus was deemed to be an aberration of O. nitidulus , hence its junior synonym.

Janíková (1998) and Bunalski (2014) inserted O. nitidulus in the subgenus Palaeonthophagus Zunino, 1979 without any explanation. No subsequent authors followed this systematic concept.

Remarks. The current systematic literature ( Balthasar 1963; Krajcik 2006; Löbl et al. 2006; Ziani and Bezděk 2016; Schoolmeesters 2023) considers O. tetraspilus and O. nitidulus ssp. mediofasciatus junior synonyms of O. nitidulus . This paper follows such direction.

According to Zunino (1981), O. nitidulus has phylogenetic affinities with Onthophagus sellatus Klug, 1845 (tentatively inserted in the subgenus Furconthophagus Zunino, 1979 by Ziani 2020b), and Onthophagus margaritifer d’Orbigny, 1898 (inserted in Onthophagus sensu lato, without a subgeneric placement, by Ziani and Bezděk 2016). After studying the external morphology and the structures of the endophallus of the last two species, I prefer not to insert them in Indonthophagus .

Figures

Figure 8. Onthophagus (Indonthophagus) nitidulus Klug, 1845 [major ♂: Yemen, Abyan gov.]. 8a) Dorsal habitus. 8b) Parameres, lateral view. 8c) Parameres, dorsal view. 8d) Endophallus. AcS: accessory endophallites. LC: lamella copulatrix. Rs: raspulae. Photos by A. Degiovanni, edited by G. Fiumi.