Onthophagus (Indonthophagus) turbatus Walker, 1858

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 : 21-25

Onthophagus (Indonthophagus) turbatus Walker, 1858

(Fig. 2, 9–10, 12b,d)

Onthophagus turbatus Walker 1858: 209 ; von Harold 1862: 402 (as junior synonym of O. spinifex ); von Harold 1869: 1036 (as junior synonym of O. spinifex ); Arrow 1907: 429; Boucomont 1914: 222 (as possible junior synonym of O. mopsus ); Boucomont and Gillet 1921: 38; Boucomont and Gillet 1927: 149; Arrow 1931: 329; Paulian 1945: 118 (as “ Onthophagus turbatus Boucomont (nec Walker)”, junior synonym of O. hastifer ); Balthasar 1963: 569; Endrödi 1974: 2; Krajcik 2006: 138; Biswas and Mulay 2001: 140; Rajan 2006: 133; Vinod and Thomas 2006: 5; Jadhav and Sharma 2012: 491; Krajcik 2012: 187; Thakare et al. 2012: 78; Karimbumkara and Rajan 2013: 177; Krajcik 2013: 281; Rani and Sanjayan 2013: 242; Mittal and Jain 2015: 402; Sathiandran et al. 2015: 8256; Latha and Thomas 2018a: 16123; Lau 2019: 95 (as “ Onthophagus turbatus Boucomont & Gillet (nec Walker 1858)”); Latha 2019: 59; Kalawate et al. 2021: 17583; Sathiandran et al. 2021: 741; Asha et al. 2022: 7; Rajagopal et al. 2023: 329.

Onthophagus (Indonthophagus) turbatus, Kabakov 2006: 154 (footnote); Kharel et al. 2020: 371; Schoolmeesters 2023.

Onthophagus (Colobonthophagus) turbatus, Gupta et al. 2022: 425 .

Onthophagus (Onthophagus) turbatus, Sobhana et al. 2013: 95 ; Kalawate et al. 2021: 17583.

Type localities. “ Ceylon ” [ Sri Lanka].

Type material. 2 syntypes, a medium ♂ and a ♀, studied ( NHMUK).

Diagnostic features. Length 7.0 to 8.0 mm. Colour reddish brown or bronzed, with slight metallic lustre, moderately shiny, with distinct isodiametric microreticulation. Elytra dark red, sometimes with lighter red irregular basal and apical spots. Antennal scape, pedicel and funicle reddish yellow, antennal club yellow. Dorsal pubescence whitish yellow.

Head short, distinctly wider than long, with clypeus broadly round, slightly or not at all sinuate anteriorly, sides not sinuate; clypeofrontal carina distinct, bent backward, placed nearly halfway between base of the horn and anterior clypeal margin; occipital carina with a long and slender thread-like horn, flat and clearly moderately enlarged at base ( Fig. 12b ), curving backward, sometimes reaching and also exceeding the pronotal hind margin, in major males, reduced to a short transverse tubercle between the eyes in minor males, and into a straight, sometimes sinuate transverse carina in females ( Fig. 12d ), clearly broader than clypeofrontal one, almost reaching inner margin of eyes; clypeal surface with transversely rugose, setigerous punctures, frontal surface doubly sparsely punctate.

Pronotum convex, declivous anteriorly, with a slight anteromedian depression in major males, front pronotal margin vertical in the middle, the upper edge of the declivity forming a more or less evident anteromedian prominence in minor males and in females, in the latter the prominence being slightly bilobate; medium males, including the syntype, with horn shortened sometime by half, and a deep wide pronotal anteromedian hollow, its surface smooth and scarcely simply punctate; both sexes with a slightly depressed posterolateral area (Fig. 2), duller than pronotal disc, on either side near pronotal posterior angles, anteriorly with a tuft of longer setae; anterior angles distinctly produced, sides not sinuate behind them in dorsal view; dorsal surface setigerously punctate, punctures slightly impressed, sub-regular in distribution, separated by 1 to 3 diameters on disc, smaller than the punctures of elytral striae, bearing pale-yellow setae, shorter on disc, barely longer at sides.

Elytral striae shiny, distinctly impressed, with punctures slightly larger than strial width and barely crenulating interstrial sides; interstriae flat to barely convex, all rather regularly granulate; granules smaller than strial punctures, each granule with a short, pale-yellow, thin seta.

Pygidium with regularly or sub-regularly distributed, setigerous punctures; setae pale-yellow, thin, clearly longer that those of elytra.

Males with protibial spur outward. Terminal margin of male protibiae at right angle to the inner margin, with a tuft of short pale-yellow bristles, and with a small denticle curved downward on the inner angle of protibial apex.

Male genital armature. Parameres short, apices bent ventrally and rhombus-shape, diverging apically, without basolateral plate denticle ( Fig. 10b–c ); endophallus with the presence of accessory endophallites, two evident and large raspulae of different sizes and a U-shaped lamella copulatrix, with one arm bifurcate apically, the other with a spinelike process, more or less long but never reaching the apex that appears clearly lobate ( Fig. 10d ).

Distribution. Sri Lanka ( Walker 1858). India ( Boucomont 1914). First records for Pakistan, Nepal and Bhutan.

Material examined. Pakistan: Islamabad Capital Territory, Marghalla hills, 1000 m, 15.viii.2010, G. Sabatinelli leg. 3 ♂♂ and 2 ♀♀ ( SZCM) ; Islamabad Capital Territory, Islamabad , sect. E 7, 600 m, 1.ix.2012, G. Sabatinelli leg. 2 ♂♂ at light ( SZCM) ; Khyber Pakhtunkhwa, Jaba Dara ( Manshera ), 28.iv.2011, S. Ziani leg. 3 ♂♂ and 1 ♀ ( SZCM) . India: Kerala state, Cardamon H., Periyar, env. Aranya Nivas , 950 m, 4.xi.1972, C. Besuchet, I. Löbl, R. Mussard leg. 1 ♀ ( MHNG) ; Karnataka state, Bangalore University Campus, Bangalore , 6.vii.2004, R. Ramalingam leg. 3 major ♂♂ and 1 medium ♂, examined by photos ( AIMB) ; West Bengal state, Siliguri distr., Sevoke , 200 m. 7.vi.2008, V. Patrikeev leg. 1 minor ♂ ( STCH) ; Arunachal Pradesh state, West Kameng, Bhalukpong , 150 m, 27°00′48″N 92°39′08″E, 1/ 8.v.2012. L. Dembický leg. 1 major ♂ ( SZCM) ; Kerala state, Nelliyampathy / Palakkad , 97 m, 23.iii.2022, K. A. Sobhana leg. 1 medium ♂, examined by photos ( ZSIK) ; Kerala state, Meppadi / Wayanad , 987 m, 29.xi.2022, J. Subha Babu leg. 2medium ♂♂, examined by photos ( ZSIK) . Sri Lanka: “ Typus ”, “Ceylon”, “ Onth. turbatus / Walker / (type)”, “ turbatus ” (syntype ♂ of O. turbatus, NHMUK ) ; “ Ceylon ”, “ Onth. turbatus / Walker / (type)” (syntype ♀ of O. turbatus, NHMUK ) ; Central Province, Kandy , 1892, E. Simon leg. 1 ♂ and 1 ♀ (Balthasar collection, NMPC) ; Uva prov., Inginiyagala , 12.ii.1970, Mussard, Besuchet, Löbl leg. 1 ♂ ( NMPC) ; Sabaragamuwa prov., Pinnawala – Rambukkana , 2.ii.2024, M. Rivalta and P. Subini leg. 1 ♀ ( SZCM) . Nepal: Central region, Annapurna - Himalaya / near Tatopani , 1300 m, 3.vi.1996, L. Nádai leg. 1 ♂ ( SZCM) . Bhutan: Punakha, Sobsokha , 1200 m, 13.vii.2016, S. Ziani leg. 2 ♀♀ ( SZCM) .

Historical review. Onthophagus turbatus was described on one male and one female at least, since Walker (1858) has featured both sexes. The “types” present in NHMUK, with Walker’s handwritten labels, are therefore to be considered syntypes.

The taxon did not appear to be born under a lucky star: only four years after its description, O. turbatus was synonymized by von Harold (1862). He affirmed that Walker described the species on a female of O. spinifex ( Fabricius, 1781) , and later confirmed such synonymy (von Harold 1869).

On the contrary, Arrow (1907), claiming to have examined the type material of both species, stated that O. turbatus and O. spinifex were absolutely not conspecific.

Boucomont (1914), in a footnote at p. 222, asserted that “Ce nom [ O. turbatus ] est probablement synonyme de mopsus F., (…), malheureusement le type de Fabricius est perdu et la description est insuffisante” [This name [ O. turbatus ] is probably a synonym of mopsus F., (…), unfortunately Fabricius’ type has been lost and the description is insufficient]. Later, Boucomont, with Gillet, accepted the validity of the species, first in “Faune entomologique de l’Indochine française” ( Boucomont and Gillet 1921), then in “Coleopterorum Catalogus” ( Boucomont and Gillet 1927). It is worth noting that Boucomont and Gillet (1921) recorded this species from Vietnam (“ Tonkin: Quang Yen; Annam: Quang-tri), whereas Arrow (1931) specified that these records were wrong.

Paulian (1945) hypothesized that O. turbatus sensu Boucomont [and Gillet] (1921), which is the species recorded from Vietnam by Boucomont and Gillet (1921) – and from Myanmar, China and Taiwan by himself – was not conspecific with O. turbatus Walker. This last taxon, always according to Paulian (1945), is distributed in Sri Lanka and south India, whereas in north-western India “l’espèce est représentée par le vicariant O. mopsus Fabricius ” [the species is represented by the vicariant O. mopsus Fabricius ]. O. turbatus sensu Boucomont [and Gillet] 1921, always according to Paulian (1945), is a junior synonym of O. hastifer .

Lau (2019) quoted, in the “Checklist of Insects of Hong Kong ”, “ Onthophagus turbatus Boucomont and Gillet (nec Walker, 1858)”, but as bona species.

Kharel et al. (2020) recorded the species, cited as O. turbatus Walker , also from Thailand. Regarding its subgeneric placement, the taxon was mentioned twice by Kalawate et al. (2021), either belonging to the subgenus Onthophagus and as “ species incertae sedis ”.

Remarks. After the study of type material of O. turbatus and O. hastifer , as well as other specimens belonging to both taxa, I fully agree with Paulian (1945) in considering O. turbatus sensu Boucomont [and Gillet] 1921 not conspecific with O. turbatus Walker , and a junior synonym of O. hastifer . Consequently, the distribution of O. turbatus Walker does not include localities eastward of Bhutan. Most probably O. turbatus and O. hastifer are sister species and, for what I know, their distributional areas are not overlapping.

All the morphological descriptions of O. turbatus published in the literature ( Boucomont 1914; Boucomont and Gillet 1921; Arrow 1931; Balthasar 1963), including the original description ( Walker 1858), report as the main distinctive characters of males, the cephalic horn, short and far from reaching the pronotal hind margin, and the pronotal deep and wide antero-median depression. The authors who pointed out such features had clearly described the syntype male or had reported a previous description of the syntype male, without noticing, or stressing at least, that the specimen was not a major male, but a so-called “medium” male, with all the characteristics of moderately developed males, such as shorter cephalic horn and evident pronotal antero-median depression ( Fig. 10a ). Actually, major males of O. turbatus have the cephalic horn reaching and sometimes exceeding the pronotal hind margin, and a very shallow anteromedian hollow, if any ( Fig. 11 ). The morphology of lamella copulatrix leaves no doubts about the conspecificity of major and medium specimens. For these reasons, in the dichotomous key to the Indonthophagus species provided below, also other characters for discriminating O. turbatus from other species, particularly O. hastifer , the taxon in the same couplet, are used.

Figures

Figure 10. Onthophagus (Indonthophagus) turbatus Walker, 1858 [major ♂: Pakistan, Mansehra prov.]. Dorsal habitus. Photos by A. Degiovanni, edited by G. Fiumi.

Figure 11. Onthophagus (incertae sedis) spinifex (Fabricius, 1781) [major ♂: Pakistan, Capital Territory].11a) Dorsal habitus. 11b) Parameres, lateral view.11c) Parameres, dorsal view.11d) Endophallus. AcS: accessory endophallites. LC: lamella copulatrix. Photos by A. Degiovanni, edited by G. Fiumi.

Figure 12. Head from above:12a) Onthophagus (Indonthophagus) hastifer von Lansberge, 1914 [major ♂: Taiwan, Pingtung]. 12b) Onthophagus (Indonthophagus) turbatus Walker, 1858 [major ♂: India, Arunachal Pradesh st.]. 12c) Onthophagus (Indonthophagus) hastifer von Lansberge, 1914 [♀: Taiwan, Pingtung]. 12d) Onthophagus (Indonthophagus) turbatus Walker, 1858 [♀: Pakistan, Islamabad Capital Territory]. Photos by A. Degiovanni, edited by G. Fiumi.