Scatonomus barbatus Erichson 1835
Creators: name: Valois, Marcely C.
name: Vaz-de-Mello, Fernando Z.
name: Silva, Fernando A. B.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Scatonomus
Scatonomus barbatus

description: Scatonomus barbatus Erichson, 1835, 258.   
 Diagnosis   
 Scatonomus barbatus and S. fasciculatus are closely related species. Both species have body longer than 9 mm; dorsal surface shiny, almost smooth; genal edge not distinctly angulate laterally (Figure 3 (a, d)); and clypeal edge bidentate, with deep lateral emarginations filled with a tuft of long setae (Figure 3 (a, d)). However, S. barbatus may be distinguished from S. fasciculatus by the following combination of characters: median clypeal teeth shorter than the lateral tuft of setae (Figure 3 (a)); anterior edge of gena rounded (Figure 3 (a)); and dorsum with green reflections (Figure 1 (a)).   
 Redescription   
 Male: length: 9–11 mm. Dorsum black with green reflections (Figure 1 (a)). Head: densely punctate, slightly wrinkled medially (Figure 3 (a)). Anterior and posterior edges narrowly margined. Clypeo-genal and fronto-clypeal sutures arched, moderately impressed, not carinate. Clypeal median teeth upturned, separated by a deep U-shaped emargination (Figure 3 (a)). Anterior portion of clypeus strongly concave medially, surface of concavity less punctate than remaining portions of head. Edges of clypeus and gena densely coated with rows of long erect setae. Antennal club globose, densely coated with long setae. Thorax: pronotum shiny, sparsely punctate, mid-longitudinal sulcus feebly impressed on disc. Lateral edge of hypomera with a row of indistinct setose punctures, setae short. Transverse carina of hypomera almost complete, not reaching lateral edge. Surface of mesepimeron and mesanepisternum with green reflections, finely striate. Anterior and lateral lobes of metaventrite with inconspicuous microgranulation; lateral lobes also with shallow punctures. Metaventral disc densely puncticulate. Elytra: striae thin, shallow, indistinctly punctate; striae on disc 7 times narrower than third interstria. Seventh stria not reaching the basal and apical portions of elytra. Eighth stria weakly impressed, visible at the apical half. Ninth stria weakly impressed near elytral base. Interstriae flat, surface shiny and sparsely punctate. Legs [ventral surface]: profemora densely punctate, surface between punctures smooth. Mesofemur and metafemur sparsely punctate. External edge of protibia with 3 distinct teeth separated by U-shaped emarginations. Outer edge of mesotibia and metatibia with a row of sparse setae and small teeth throughout their length. Abdomen: ventrite VI 1.5 times as long as ventrite V. Pygidium: 1/3 wider than long. Disc punctate, punctures spaced by 3 times their diameter. Genital capsule: paramera apex divided into apical and lateral lobes by a deep L-shaped emargination. Apical and lateral lobes slightly acute (Figure 5 (a)). Female: differs from male by the abdominal ventrite VI twice as long as V. Disc of pygidium with punctures spaced by 2 times their diameter; apical edge of pygidium slightly angulate.
description: Published as part of Valois, Marcely C., Vaz-de-Mello, Fernando Z. & Silva, Fernando A. B., 2020, A taxonomic revision of the Neotropical genus Scatonomus Erichson, 1835 (Coleoptera: Scarabaeidae: Scarabaeinae), pp. 1081-1114 in Journal of Natural History 54 (17 - 18) on pages 1091-1092, DOI: 10.1080/00222933.2020.1781947, http://zenodo.org/record/5020903