Pseudorphnus Benderitter, 1913

Frolov, Andrey V., Montreuil, Olivier & Akhmetova, Lilia A., 2016, Review of the Madagascan Orphninae (Coleoptera: Scarabaeidae) with a revision of the genus Triodontus Westwood, Zootaxa 4207 (1), pp. 1-93 : 12-13

Genus Pseudorphnus Benderitter, 1913

Pseudorphnus Benderitter, 1913: 83 .

Type species. Orphnus coquerelii Fairmaire, 1868 , by monotypy.

Diagnosis. Body length 6.5–13 mm, brown to dark brown. Mandibles subsymmetrical. Frontoclypeus with rounded anterior margin, with tubercle or longitudinal ridge in males; females have frontoclypeus without tubercles or ridges. Pronotum with deep excavation in the middle and with 2 horn or ridge-shaped lateral processes bordering excavation near anterior margin in males; females with pronotum convex or slightly impressed anteromedially. The shape of the head and prothoracic armature in males is subject to moderate allometric variability: they vary from fully developed as described above to only a small tubercle on the frontoclypeus and a shallow fossa on the disc of the pronotum anteriorly. Propleurae smoothly convex, without carinae separating anterolateral areas from basal area. Scutellum triangular, narrowly rounded apically, about 1/10 length of elytra. Elytra convex, with feebly marked humeral humps. Sculpture of elytron varies. Wings fully developed. Metepisternum triangular, tapering caudally, with slightly widened anterodorsal angle slightly overlapping epipleuron. Protibiae with 2 strong outer teeth and 1 small tooth located basally. Phallobase strongly sclerotized dorsally and with a thin membrane ventrally. Parameres relatively long apices tapering or curved downwards, without setae. Internal sac of aedeagus with species-specific armature.

Diagnostic characters. The most reliable characters to differentiate Pseudorphnus species are the shape of the parameres and the shape of the frontoclypeal and prothoracic armature (especially when fully developed). Body size also varies among the species.

Species composition, distribution, and habitat. Pseudorphnus is endemic to Madagascar. Four species of the genus are known so far. The species are distributed chiefly along the eastern slopes of the Central Escarpment corresponding to the distribution of the Malagasy tropical wet forests. All species are apparently forest litter dwellers feeding on different rotten substances. One species, P. coquerelii , is quite common in the collections, which may indicate a secondary adaptation to the developing in the crop fields (similar to Triodontus nitidulus , see below). Nesting behavior and preimaginal stages are unknown.