Dichotomius (Dichotomius) boreus ( Olivier, 1789 )

2. Dichotomius (Dichotomius) boreus ( Olivier, 1789) View in CoL species group

Diagnosis: The species of the D. boreus species group are recognized by the following combination of characters: (1) Medium-sized to large-sized individuals (16.6–27.1 mm). (2) Head oval and twice as wide as it is long ( Fig. 7a, b View Figure 7 ). (3) Clypeus with two inconspicuous clypeal teeth, sometimes imperceptible ( Fig. 7a, b View Figure 7 ). (4) Ventral clypeal process with invagination and then a conical process obtuse or acute tip ( Fig. 7c View Figure 7 ). (5) Both sexes with two cephalic process, the first one located in the clypeal region and the second one in the fronto-clypeal region ( Fig. 7a, b View Figure 7 ). (6) Protibial spur not angled or slightly angled near the apex ( Fig. 7d View Figure 7 ). (7) Pronotum with an excavation in the anterior area that can go from 1/3 to half of it and laterally to more than 2/3 of the pronotum ( Fig. 7a, b View Figure 7 ). (8) Pronotum with central process with different shapes according to the species. (9) Pronotal process with two humps with spine shape above the lateral foveae. (10) Posterior margin of pronotum with ocellate punctures, sometimes denser in the posteromedial area ( Figs.2a, b View Figure 2 , 7a, b View Figure 7 ). (11) Elytral striae bicarinate, shallow to distinctly impressed and with punctate interestriae. (12) Pygidium with complete apical margin and evident punctures ( Fig. 7e View Figure 7 ) (13). Aedeagus lacking subgenital plate ( Fig. 7h View Figure 7 ). (14) Parameres subtriangular in lateral view ( Fig. 7f View Figure 7 ), without setae in the apical area ( Fig. 7 View Figure 7 f-h). (15) ME well sclerotized, large, and asymmetrical ( Fig. 7l View Figure 7 ).

Composition: Six valid species: Dichotomius boreus ( Olivier, 1789) , D. carinatus ( Luederwaldt, 1925) , D.podalirius ( Felsche, 1901) , D. prietoi Martínez & Martínez, 1982 , D. pelamon ( Harold, 1869) , D.quadrilobatus Chamorro et al., 2021 , and two undescribed species.

Geographic distribution: Pacific dominion (Sabana province), Boreal brazilian dominion (all provinces), South Brazilian dominion (all provinces), Chacoan subregion Southeastern Amazonian dominion (Xingu-Tapajós province), and South American Transition zones (Páramo province) ( Fig. 6b View Figure 6 ).