Onthophagus (sensu lato) guttatus Boheman, 1860

Montanaro, Giulio, 2025, New synonymies between Afrotropical Onthophagus Latreille, 1802 (Coleoptera: Scarabaeidae: Onthophagini), Zootaxa 5647 (1), pp. 85-95 : 89-91

Onthophagus (sensu lato) guttatus Boheman, 1860 valid species

( Fig. 2 )

Onthophagus guttatus Boheman, 1860: 114 ; Péringuey, 1901: 226; d’Orbigny, 1913a: 606; Ferreira, 1972: 641; Davis et al., 2020: 693.

Type locality: “juxta lacum N’Gami” [near lake Ngami , Botswana] .

Type material examined. Syntype, ♀: N’Gami / Africae [wc, pb] // J. Wahlb [wc, pb] // Type [wc, pb] // guttatus Bhm [wc, hb] // Typus [rc, pb] // 55 / 71 [rc, first line pb, second line handwritten in blue] // 9046 / E92 + [light blue cardboard, pb] // NHRS-JLKB / 000073786 [wc, pb] .

Type repository: NHRS .

Diagnosis. The species belongs to d’Orbigny’s (1913a) species-group 2, and keys out within the section 78(83) together with at least O. quadrimaculatus Raffray, 1877 , O. quadrinotatus d’Orbigny, 1905 , O. crucenotatus d’Orbigny, 1905 , and O. witteianus Krell, 2009 ( d’Orbigny 1913a; Frey 1958; Krell 2009). It appears most closely related to O. quadrinotatus due to the transverse tubercles on the vertex, but further comparisons are difficult without a thorough revision of the group ( Davis et al. 2020).

Comments. Onthophagus guttatus was described by Boheman (1860) from the surroundings of Lake Ngami ( Botswana), most likely based on a single female judging from the single body size measurement and the lack of described variation provided by Boheman, as well as the absence of additional specimens in NHRS. However, the existence of other specimens cannot be ruled out with certainty, so the one studied here should be considered a syntype rather than a holotype (ICZN §73.2, see Rossini & Forshage (2023)).

Péringuey (1901) listed O. guttatus as a synonym of O. talpa Fåhraeus in Boheman, 1857 and redescribed it. The synonymy was not considered by d’Orbigny (1913a), who could not see the type of neither O. guttatus nor O. talpa . The taxonomy of the two species were never discussed by any subsequent author.

After examining the syntype of O. guttatus , I can definitely rule out the possibility of a synonymy with O. talpa . Due to its simple (instead of raspish or granulose) pronotal punctuation, straight (instead of sinuous) elytral stria VII, incomplete (instead of complete) sulcus along the posterior pronotal margin, head tubercles placed between (instead of behind) the eyes, anterolateral pronotal angles rounded and directed forward (instead or sharp and curved laterally), O. guttatus does not belong to d’Orbigny’s (1913a) group n. 31. Instead, it finds its closest relatives in species-group 2, section 78(83) (see above).

It is also worth to notice that Péringuey (1901) largely mixed up O. talpa and O. guttatus , probably because he did not examine their types de visu. His redescription of “ O. talpa ” (pp. 226–227) is a mixture of characters belonging to both species and even contradicting each other. For example: “there is no frontal carina” versus “on the vertex are two tuberculiform horns nearly equidistant from the frontal carina and from the apex” (p. 226, lines 30–33), while a frontal carina is present in both species; “on the vertex are two tuberculiform horns” (p. 226, line 32), which is a feature of O. guttatus but not of O. talpa ; “in the large development the anterior part [of pronotum] is slightly bi-sinuate at apex” (p. 226, lines 37–38), feature of O. talpa but not of O. guttatus .

Subgeneric placement. Onthophagus guttatus , similarly to Furconthophagus species, has the anterior hypomeral carina reaching straightly the anterior pronotal angle. This character, albeit relatively uncommon in Onthophagini, is present in several other (sub)genera, for example Onthophagus (Indachorius) Balthasar, 1941 , Onthophagus (Micronthophagus) Balthasar, 1963 ( Ziani 2020), Onthophagus (Pseudophanaeomorphus) Ochi, 2007 ( Ochi 2007), Digitonthophagus Balthasar, 1959 (Génier & Moretto 2015), etc. However, other features set this species apart from Furconthophagus , for example the entirely simple pronotal punctuation, the shape of the elytral carina VII, the shape of the anterolateral pronotal angles, as well as the very different female genitalia (see Fig. 2 ) ( Ziani 2020; Zunino 1979). O. guttatus probably belongs to an unnamed lineage within Onthophagus , together with other members of d’Orbigny’s (1913a) group 2. A systematic revision of the species-group, currently the most diverse in the Afrotropical fauna, is highly needed.

Etymology. The Latin adjective guttatus means “spotted”, likely referring to the orange spots presents on the beetle’s elytra.

Distribution. Angola ( Ferreira 1972; source of record unclear), Botswana ( Boheman 1860).

Figures

FIGURE 2. Syntype of Onthophagus guttatus Boheman, 1860: habitus (a); labels (b); habitus in lateral view (c); view of hypomeron (d); forebody in dorsal view (e); genitalia (f). Images are not to scale.