Aegidinus Arrowı 1904

Frolov, Andrey V., Akhmetova, Lilia A. & Vaz-de-Mello, Fernando Z., 2019, Contribution to the knowledge of Aegidinus Arrow (Coleoptera: Scarabaeidae: Orphninae): new species and comments on the classification and nomenclature, JOURNAL OF NATURAL HISTORY 53 (11), pp. 725-747 : 726-727

Genus Aegidinus Arrowı 1904

Type species

Aegidium guianensis Westwoodı designated by Paulian (1984).

Diagnosis

Body small to mid-sized (length 6 to 12 mm)ı reddish brown to dark brown. Mandibles subsymmetricalı with long processes on the outer sides. Clypeus with tubercle or horn on anterior margin medially in malesı without horn in females. Pronotum variably excavated medially in malesı convex to depressed medially in females; anterior margin of pronotum in males with a tubercle or horn medially. Propleura with carinae separating anterolateral areas from basal area. Scutellum narrowly rounded apicallyı about 1/15 length of elytra. Elytra convexı with marked humeral umbones and striae marked with elongated punctures. Wings fully developed. Metepisternon trianguları its posterior angle rounded to triangular and situated in distinct concavity of epipleuron. Protibiae with three strong outer teeth in both sexes and with a smaller medial tooth in majority of males. Each procoxa with two cavities. Phallobase tube shaped with strongly sclerotised ventral side but without differentiation of ventral and dorsal sclerites. Parameres relatively shortı with complex shapeı apices without setae. Gonocoxites separated into two more or less distinct parts.

Aegidinus is distinct among the orphnines in having the following unique characters: mandibles with processes on the outer sides; shape of the gonocoxites is diverse and species specific at least in majority of species; procoxae with two cavities each; parameres are asymmetric in two species; phallobase with protruding ventroapical plate in some species. From other Aegidiiniı Aegidinus also differs in the absence of a hole connecting mesocoxal cavitiesı and in having more or less distinct transverse carina on metatibiae.

Diagnostic characters of species

Most Aegidinus species are similar externally andı despite some interspecific variation of the body sculpture and head and protoracic armature in some speciesı reliable identification is only possible by examining the shape of the male genitalia. External female genitalia (gonocoxites) are also highly specificı although their usefulness in distinguishing closely related species requires further evaluation (see Discussion below).

Species composition and distribution

Aegidinus comprises 14 species including two newly described in this work. Members of the genus occur in South Americaı mostly in the Amazon and Guianan moist forest regions to Yungas in the westı and on the island of Trinidad ( Figure 7 ).

Figures

Figure 7. Aegidinus spp. Locality records map.