Onthophagus (Palaeonthophagus) samai, Ziani, Stefano, 2011

Ziani, Stefano, 2011, A new Iranian Onthophagus species belonging to the O. semicornis group (Coleoptera: Scarabaeidae: Onthophagini), Zootaxa 2907, pp. 47-50 : 47-49

Onthophagus (Palaeonthophagus) samai , new species

(Figs. 1–7)

Type locality. Iran, Semnan: 4–9 km NE Abr.

Type series. Holotype 3: Iran, Semnan prov., 4/ 9 km NE Abr, 1600 m / 1800 m, 19/ 23.v.2010, G. Sama leg. Allotype: Iran, Semnan prov., 9 km NE Shahmirzād, 2200 m, 18/ 25.v.2010, G. Sama leg. Paratype 3: Iran, Mazandaran prov., Fūlād Mahalle, 32 km NE Shahmirzād, 18.v.2010, D. Baiocchi leg.

Types depositaries. Holotype in MHNG, allotype and paratype in SZCM.

Type labelling. Holotype bears two labels, as follow. 1) white, printed in black: “ IRAN – Semnan – 4/ 9 km / NE Abr 1600 / 1800 / 19–25 V 2010 leg. G. Sama”; 2) red, printed in black: “ Holotype / Onthophagus (Palaeonthophagus) / samai mihi / S. Ziani, 2011 ”.

Etymology. The new species is dedicated to Gianfranco Sama, a well-known specialist of Palearctic Cerambycidae beetles, who once in a while and much to the benefit of scarabaeology, enjoys collecting scarabs.

Description. Holotype (Fig. 1). Major male, based on the size and the development of cephalic and pronotal outgrowths. Length 6.3 mm, width 3.6 mm. Pronotum shorter than elytra (length ratio = 0.88).

Black, upper side almost dull, with a distinct isodiametric microreticulation; elytra with feeble green reflections; pubescence yellowish white; antennal scape, pedicel and funicle reddish brown; antennal club dark reddish brown.

Head (Figs. 2, 7) short, clearly wider than long (width/length ratio = 1.75). Clypeus broadly round on either side of shallow but distinct median emargination. Clypeofrontal carina moderately elevate but distinct, bent backward, edge in contact with clypeogenal suture. Occipital carina wider at base than clypeofrontal carina but not reaching lateral margins of head. Head with a strong, transverse, terminally narrow lamina, approximately one half longer than wide at base, bearing a pair of erect points distinctly reflexed towards pronotum. Margin between horns, as well as sides of lamina, sinuate in front view. Clypeal and frontal surface with rather coarse, large, setigerous punctures, more widely spaced on frons than on clypeus; setae long, thin, erect, only slightly thicker basally, gradually thinner apically.

Pronotum ( Fig. 7 ) convex, strongly declivous towards anterior edge, with distinct anterolateral tubercle on either side and with an anteromedian round prominence; prominence clearly projecting further forward than the anterolateral tubercles. Anterior angles distinctly produced, sides sinuate behind them; dorsal surface setigerously punctuate; punctures broad, irregular, umbilicate on the anterior half, separated by 1–2 diameters on disc; each puncture bears a small granule at its anterior margin. Bristles whitish yellow, long, thick at their base, gradually thinner apically.

Onthophagus (Paleonthophagus) samai Male, holotype, and female, allotype ( Iran, Semnan Province). 1. Male: habitus; 2. Male: head, frontal view; 3. Female: habitus; 4. Parameres, lateral view; 5. Parameres, dorsal view; 6. Lamella copulatrix, ventral side. Photographs by A. Degiovanni.

Elytral striae shiny, barely impressed, with punctures larger than strial width and crenating interstrial sides. Interstriae flat to barely convex; all, except the sutural interstria, rather regularly biserially granulate; granules smaller than strial punctures, posterior margin of each granule with a small, indistinct, setigerous puncture. Setae whitish yellow, thin, erect.

Pygidium with widely spaced, setigerous punctures; setae dark yellow, long, thin.

Protibial spur bent inward and downward; inner angle of protibial apex with a small denticle curved downward.

Genital armature. Figs. 4, 5. Lamella copulatrix as in Fig. 6.

Allotype (Fig. 3). Length 6.4 mm, width 3.6 mm. External morphology differs from the holotype by the clypeal margin more deeply emarginate medially, the clypeofrontal carina elevated, the pronotal anteromedian prominence less projected forward and slightly sinuate medially, and by the shape and size of the pygidium and sixth abdominal sternite. Elytra without green reflections. Inner angle of protibial apex without denticle.

Variability. The paratype, a major male, is 6.3 mm long and 3.6 mm wide, as is the holotype. The paratype differs from the holotype only by the occipital carina, which is of the same height but slightly broader medially; and by the elytra, without green reflections.

Distribution and ecology. The new species is known from three localities in Semnan and Mazandaran provinces, northeastern Iran. All the specimens in the type series were collected in dung deposited in open areas. However, more observations are necessary to understand whether the habitat of the new species, like that of other species belonging to the O. semicornis group, is associated with rodent burrows.

Remarks. Onthophagus samai belongs to the subgenus Palaeonthophagus Zunino, 1979 , and can be placed in the O. semicornis (Panzer, 1798) lineage of the O. semicornis group as defined by Ziani & Gudenzi (2006, 2007). This group is characterized by relatively small species (length less than 7.5 mm) with distinct pronotal anterolateral gibbosities, elytra with thin setae that are slightly or not at all thicker basally than distally. The new species can be easily distinguished from the other species of the group, particularly O. semicornis (a species with many similar character states), using the key below. Moreover, the shape of the lamella copulatrix, particularly the right branch broader than the left branch in ventral view (Fig. 6), is specific to the new species.

Figures

FIGURES 7 – 10. Onthophagus “ semicornis lineage ”, head and pronotum of male in dorsal view. 7: Onthophagus samai n. sp., holotype; 8: Onthophagus semicornis (Panzer, 1798) (Italy, Abruzzo Province); 9: Onthophagus eulaminicornis Pittino, 2006 (Greece, Thrace); 10: Onthophagus sacharovskii Olsoufieff, 1918 (Turkey, Kayseri Province). Photographs by A. Degiovanni.