Onthophagus (Furconthophagus) ganalensis Gestro, 1895

Montanaro, Giulio, 2025, New synonymies between Afrotropical Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae: Onthophagini), Zootaxa 5647 (1), pp. 85-95 : 87-89

Onthophagus (Furconthophagus) ganalensis Gestro, 1895

( Fig. 1 )

Onthophagus ganalensis Gestro, 1895: 320 , 321; d’Orbigny, 1902: 232; d’Orbigny, 1904: 307; d’Orbigny, 1905: 504; d’Orbigny, 1913a: 462, 694, 733; Ferreira, 1972: 634, 1018; Ferreira, 1972 (annex XLIV): 14; Montanaro & Ziani, 2022: 421, 422, 426, 427.

Onthophagus omostigma d’Orbigny, 1902: 226 (new subjective synonymy); d’Orbigny, 1904: 307; d’Orbigny, 1905: 501; d’Orbigny, 1908: 168; d’Orbigny, 1910: 51; d’Orbigny, 1913a: 462, 694, 735; d’Orbigny, 1913b: 113–115; Ferreira, 1972: 701, 565, 1039; Ferreira, 1972 (annex XLIV): 24; Gordon & Barbero, 2008: 143, 155, 159; Montanaro & Ziani, 2022: 421, 422, 426, 427.

Type locality: Onthophagus ganalensis : Arussi Galla, Ganale Guddà [ Ethiopia]; Onthophagus omostigma : Sambara [ Tanzania].

Type material examined. Onthophagus ganalensis . Lectotype, ♂ (present designation): ARUSSI GALLA / GANALE GUDDA’ / III V.93. / V. BOTTEGO [wc, pb] // TYPUs [wc, pr] // ganalensis / Gestro [wc, hb] // Onthophagus / ganalensis / typus! Gestro [wc, hb] // SYNTYPUS / Onthophagus / ganalensis / Gestro, 1895 [rc, first line pb, other lines hb] // vidit d’Orbigny, 1904 [wc, pb] // MUseo Civico / di Genova [wc, pb] // LECTOTYPE (♂) / Onthophagus / ganalensis Gestro / G. Montanaro des. 2025 [rc, hb] . Paralectotypes (2♂♂, 3♀♀): ARUSSI GALLA / GANALE GUDDA’ / III V.93. / V. BOTTEGO [wc, pb] // Museo Civico / di Genova [wc, pb] // SYNTYPUS / Onthophagus / ganalensis / Gestro, 1895 [rc, first line pb, other lines hb] // vidit d’Orbigny, 1904 [wc, pb] // PARALECTOTYPES / OnthophagUs / ganalensis Gestro / G. Montanaro des. 2025 [rc, hb] [1♂ and 1♀ pinned together] ; ARUSSI GALLA / GANALE GUDDA’ / III V.93. / V. BOTTEGO [wc, pb] // Museo Civico / di Genova [wc, pb] // SYNTYPUS / Onthophagus / ganalensis / Gestro, 1895 [rc, first line pb, other lines hb] // vidit d’Orbigny, 1904 [wc, pb] // PARALECTOTYPE / Onthophagus / ganalensis Gestro / G. Montanaro des. 2025 [rc, hb] [1 ♀] ; ARUSSI GALLA / GANALE GUDDA’ / III V.93. / V. BOTTEGO [wc, pb] // non com. / a Orbigny [wc, hb] [“non com[unicato]. a Orbigny” translates to “not dispatched to d’Orbigny”] // SYNTYPUS / Onthophagus / ganalensis / Gestro, 1895 [rc, first line pb, other lines hb] // Museo Civico / di Genova [wc, pb] // // PARALECTOTYPE / OnthophagUs / ganalensis Gestro / G. Montanaro des. 2025 [rc, hb] [1♂, 1♀].

Onthophagus omostigma . Lectotype, ♀ (present designation): Sambara [wc, hb] // Afrique Orient. / Kilima N’djaro / R.P. Leroy / 1890 [wc, pb] // omostigma / n. sp. d’Orb. [wc, hb] // D’Orbigny / Onth.Afr.1902. [wc, pb] // LECTOTYPE / Onthophagus o / omostigma d’Orb ; 1902 / G. MONTANARO des. 2023 [rc, hb] .

Types repositories: MSNG (types of O. ganalensis ); MNHN (types of O. omostigma ).

Diagnosis. This species belongs to d’Orbigny’s Onthophagus species-group n. 31 ( d’Orbigny 1913a) and falls within the dichotomy 46(53), together with O. aethiopicus d’Orbigny, 1902 , O. taboranus d’Orbigny, 1902 and —outside of the Afrotropical region— O. shaykh Montanaro & Ziani, 2022 ( Montanaro & Ziani 2022). Large and medium males can be easily set apart from any other member of the group due to the shape of the vertex carina, which is high medially and bears two long horns laterally, and is associated with an anterior transverse tubercle even in major males. See also Montanaro & Ziani (2022) and d’Orbigny (1913a) for further comparisons with similar species. Additionally, male genitalia ( Fig. 1e–h ) allow an easy identification even in presence of poorly developed males.

Comments. I examined six syntypes of O. ganalensis , all from Ethiopia (Ganale Guddà), while I have not seen the specimens from Somalia (Bardera) mentioned in the original description. For this reason, I prefer to designate a lectotype, a well-developed male bearing an old “Typus” label, most likely by Gestro’s own hands ( Fig. 1a–b, 1e–h ). In the material of O. omostigma present at MNHN, two specimens bearing labels with the localities indicated by d’Orbigny (1902) in the original description are present—one from southern Kenya, one from northern Tanzania (“Sambara”). I here designate the one from Tanzania as the lectotype ( Fig. 1i–k ).

Gestro (1985) described O. ganalensis based on several specimens, both males and females, while d’Orbigny (1902) described O. omostigma based on two females. The French author could not see Gestro’s material until 1904, when he noticed the similarity between O. ganalensis and other species, including O. omostigma . However, he still separated O. ganalensis from its allies by the anterior third of pronotum bearing granulose punctures instead of simple granules ( d’Orbigny 1904). One year later, he described the males of O. omostigma and discussed the great similarity of the species with O. sugillatus ( d’Orbigny, 1905) . Lastly, in the Synopsis des Onthophagides d’Afrique ( d’Orbigny 1913a), he placed O. omostigma and O. ganalensis in the same terminal dichotomy, distinguishing them again by slight differences in pronotal punctuation and other details.

I examined female paralectotypes of O. ganalensis ( Fig. 1c–d ) and compared them to the lectotype of O. omostigma ( Fig. 1i–k ). I could not find any character justifying the status of the latter as a separate species. Specimens are extremely similar both in external and genital morphology ( Fig. 1 ). Furthermore, I studied several other specimens identified as O. omostigma by d’Orbigny himself, including major males, which are with little or no doubt conspecific with Gestro’s types. The differential features mentioned by d’Orbigny to separate the two taxa seem to fall within the intraspecific variation of O. ganalensis . One of the most variable features is indeed pronotal granulation, which can be more or less coarse, with posterior ocellate punctures more or less conspicuous.

Subgeneric placement. As already mentioned by Montanaro & Ziani (2022), the species belongs to the subgenus Furconthophagus Zunino, 1979 , as it possesses all the defining features of the group—arched threebranched lamella copulatrix, anterior hypomeral carina reaching straightly the anterolateral hypomeral angle, general habitus, etc. ( Ziani 2020).

Etymology. The adjective ganalensis refers to the type locality, Ganale Guddà. The adjective omostigma , literally “with equal markings”, may refer to the relatively homogeneous, conspicuous pronotal punctures.

Distribution. Ethiopia, Kenya, Somalia, Tanzania ( d’Orbigny 1913a).

Figures

FIGURE 1. Type specimens of Onthophagus ganalensis Gestro, 1895 (a–h) and O. omostigma d’Orbigny, 1902 (i–k). Onthophagus ganalensis, lectotype: habitus (a); labels (b); aedeagus in lateral (e), frontal (f) and dorsal (g) views; lamella copulatrix (h). Onthophagus ganalensis, female paralectotype: habitus (c); genitalia (d). Onthophagus omostigma, lectotype: habitus (i); genitalia (j); labels (k). Images are not to scale.