Ganelius oberndorferi

Ganelius oberndorferi (Nonfried)

Nigidius oberndorferi Nonfried 1892: 118 (original combination)

Nigidius passaliformis Benesh, 1943: 44 (original combination), new synonymy

Type material. Neotype male of Nigidius oberndorferi Nonfried (Fig. 5), MNHN, here designated, labeled (Fig. 7): a) “ Madagascar / en|au Nossi Bé / Dr. Sicard”; b) on red paper “ Nigidius / oberndorferi ♂ / Nonfried, 1892 / NEOTYPE / des. M.J. Paulsen 2017”; b) “ Ganelius / oberndorferi / (Nonfried, 1892) / det. M.J. Paulsen 2017”.

Holotype female of Nigidius passaliformis Benesh, Museum of Comparative Zoology, labeled: a) handwritten, “West Africa / coll. Harvard”; b) handwritten, “ Eudora / passaliformis / (Benesh) ”; c) on red paper, “HoloTYPE / B. Benesh ”; d) on red paper, “M.C.Z. / Type / 25913”; e) handwritten, “ Nigidius / passaliformis / Benesh”; f) on orange paper, “Allotype” (sic); g) “ H. Bomans det. 196 [72] / [= ♀ Ganelius / madagascariensis / Cast.]”; h) handwritten, “Origin certainly / inaccurate – / This insect seen only in Madagascar / !!”. Images studied (Perkins 2010).

Non-type material (Fig. 34). MADAGASCAR: ANTSIRANANA: Ambanja (2♂, 1♀; MNHN); Ambilobe (1♂, MNHN); “Ambodinadiro” (Fort Ambodimadiro, Passandava Bay) (1♂, 1♀; MHNG); Ankarana (1♂; MNHN); Nosy Be (1♂, 3♀; MNHN). MAHAJANGA: Forêt d’Anobohazo (1♂ MJPC). TOAMASINA: Maroantsetra (1♂, 2♀; IRSNB).

Diagnosis. In males of G. oberndorferi the dorso-basal tooth on the vertical ramus is weakly produced and obtuse and much lower than the interior median denticle of the ramus; in G. madagascariensis the external dorso-basal tooth is strongly produced and near to the interior median denticle of the ramus (see Fig. 26–27). In females of G. oberndorferi the canthus is sloping and concave (Fig. 29), not straight or almost rounded as with female G. madagascariensis. In addition, the tubercle above the antennal insertion is usually much more elevated in females of G. oberndorferi (Fig. 6). The flagellum of the male genitalia (Fig. 8) is somewhat shorter than in G. madagascariensis.

Remarks. The number of specimens examined by Nonfried (1892) is not stated, but may have consisted of only a single specimen. The following information was contributed by S. Boucher, MNHN, concerning the whereabouts of Nonfried’s type (pers. comm.). No probable type specimens of G. oberndorferi Nonfried have been located in MNHN, where Nonfried specimens received a special label printed by Oberthür and thus are readily identifiable. This part of Nonfried’s collection arrived in Paris from Oberthür in 1952, but another large part of Nonfried’s scarabaeoids were deposited at ZMHB, Berlin. All Ganelius material from Berlin was examined and does not appear to have originated with Nonfried. Therefore a neotype specimen is chosen from the original locality to stabilize the nomenclature and tie the name to the appropriate species. The identity of G. oberndorferi was confused with A. nageli by Benesh (1955b), in part. His second figure of G. oberndorferi (Benesh’s fig. 15) is a specimen of A. nageli from ‘Sandramora’ forest, near Vohilava in eastern Madagascar. Because Benesh (1955b) mixed two different species under the name, and Didier (1928) erroneously considered the species to belong to the genus Figulus MacLeay, a neotype is clearly necessary to resolve the identity of G. oberndorferi.

Nonfried (1891) clearly described the mandibles and ocular canthus of this species. The mandibles are described as long, bent nearly vertically and reinforced at the bottom of the base with a large tooth, while the tip is made of two bifurcated small teeth. This description confuses the actual apex with the dorsal ramus, but it nevertheless clearly refers to a male Ganelius. In the original description, Nonfried (1892) noted that it differed by its slimmer construction and differences in pronotal shape and mandibular form. The first two characters are variable based on body size. However, based on the male mandibles of material examined from the type locality as described in the diagnosis, this species is distinct from G. madagascariensis. Based on the relatively few specimens available for study, the species may be restricted to extreme northern Madagascar near the type locality (Fig. 34). A series of specimens from the Lemoult collection in IRSNB are labeled as being from Maroantsetra. If correct these specimens are geographically separated from all others and possibly sympatric with G. madagascariensis, which seems unlikely. However, I do not have any information about whether these might be mislabeled with the locality actually referring to the port from which they were shipped, or if this is a common distributional pattern.

Benesh (1943) described G. passaliformis from ‘West Africa’, which Bartolozzi and Werner (2004) proposed might be referring to Madagascar since the genus is not known from mainland Africa. Benesh discusses the specimen as male, however it is a female, which he confirmed with a subsequent dissection (Benesh 1955a). The holotype is entirely consistent with females of G. oberndorferi. Specimens of that species on hand are indistinguishable from images of Benesh’s type, especially in the concave, sloping anterior margin of the head, elevated suprantennal tubercles, and vaulted appearance of the pronotum anteriorly in lateral view. Thus a name based on a single, abraded female specimen rather unsurprisingly is reduced here to synonymy.