Dichotomius (Dichotomius) Hope, 1838

Dichotomius (Dichotomius) Hope, 1838 View in CoL *

Type species: Scarabeus boreus Olivier,1789 View in CoL , by original designation

Diagnosis: distinguished from other subgenera of Dichotomius by the following combination of characters: Medium to large size individuals (more than 15 mm).Clypeus completely rounded or weakly emarginate, lacking clypeal teeth or inconspicuous ( Fig. 2a, C View Figure 2 ). Head margin at clypeo-genal junction lacking angle or division ( Fig. 2a, c View Figure 2 ). Ventral clypeal process with conical to triangular shape with truncate, bicuspid or acute tip. Metaventrite with long setae on its entire surface, or at least on the metaventrite lateral side. Males with sixth abdominal ventrite with constriction at the medial portion ( Fig. 2b View Figure 2 ). Females sixth abdominal ventrite without constriction and not differentiated by the presence of tubercles, lobe or emarginations ( Fig.2d View Figure 2 ). Male genital organ with symmetrical parameres, with subtriangular to subquadrangular shapes in lateral view, long parameres with different shapes among species groups ( Fig. 2e View Figure 2 ), with or without subgenital plate, and with or without setae in apical region. Endophallus with tubular shape ( Fig.2e View Figure 2 ). Medial area of endophallus with semisclerotized membranes with raspules. Four endophallites: ME large and sclerotized, with variable shapes in the species groups (five different shapes) ( Fig. 2e View Figure 2 ). SRP with “C” shape with different widened and sclerotized in the species groups. FLP with “N” shape ( Fig.2e View Figure 2 ). A+SA complex elongated, curved and with different shapes in the species groups ( Fig. 2e View Figure 2 ). Northeastern United States to central Argentina.