Ligyrus (Ligyrus) bidentulus Fairmaire, 1892

López-García, Margarita M. & Deloya, Cuauhtémoc, 2022, Cladistic analysis reveals polyphyly of Tomarus (Coleoptera: Scarabaeidae: Dynastinae): new classification and taxonomic revision, Zootaxa 5211 (1), pp. 1-119 : 39

Ligyrus (Ligyrus) bidentulus Fairmaire, 1892

( Figs. 1G , 13F , 15J , 18B , 25G ; 35 )

Ligyrus bidentulus Fairmaire, 1892: 244 .

Male neotype designated by López-García & Deloya (2019: 128) (USNM) “ La Rioja / Tinogasta / v.965 Kohler // ARGENTINA / 1968 Colln. / J. Daguerre // Ligyrus bidentulus / Fairmaire, 1892 / NEOTYPE ”. Type locality: La Rioja, Argentina.

Description. Habitus as in Fig. 25G . Length 12.1–19.3 mm; humeral width 5.8–10.7 mm. Color dark reddish brown. Head: Frons deeply rugopunctate, with large and sparse punctures, nearly smooth on vertex and with only sparse, small punctures. Frontoclypeal region with a carina, narrowly interrupted at middle ( Fig. 1G ). Ocular canthus acute; with 8 ventral setae. Clypeal surface rugopunctate to transversely rugose, striae denser than those on frons. Clypeus triangular, base 3.5 times wider than apex ( Fig. 1G ). Clypeal teeth triangular, slightly separated ( Fig. 1G ). Mandible with 2 apical and 1 lateral, rounded tooth, tooth 1 longer and narrower than tooth 2. Maxilla subrectangular; galea with 3 dorsal and 2 ventral teeth. Apex of labrum straight to rounded. Interocular distance equal to 3.5 times an eye width. Antennal club very long. Pronotum: Surface with large, sparse punctures. Apex with small tubercle and shallow fovea. Elytra: First interval punctate, punctures similar to the other intervals. Inner surface of apex with small, transverse tubercles forming about 115 parallel lines. Abdomen: Apex of tergite IV with a diagonal line of 10 transverse, parallel, short carinae. Pygidium: Surface with small to large punctures, denser on base and anterior corners. Strongly (male) to slightly (female) convex in lateral view. Legs: Protibia tridentate; basal tooth slightly distant from others. Protarsus of male simple, inner claw simple. Metatibia triangular. Apex of metatibia entire, with 25–29 spinules. Female genitalia: Subcoxite subrectangular (2 times wider than long). Coxite subquadrate (as long as wide); surface flat. Subcoxite wider and subequal in length to coxite ( Fig. 13F ). Male genitalia: Spiculum gastrale thin, apex truncate. Parameres with apical 4th narrowed, without minute spines; lateral ventral teeth short, triangular ( Figs. 15J , 18B ).

Diagnosis. Ligyrus bidentulus can be recognized by the very long antennal club (2 times longer than antennomeres 2–7); clypeus long, strongly contracted towards apex ( Fig. 1G ); clypeal teeth triangular, long, and not separated; frontal carinae narrowly interrupted at middle ( Fig. 1G ); pronotum with small tubercle and narrow fovea ( Fig. 25G ); parameres with apical 4th narrowed, without minute spines; lateral teeth of parameres short, triangular ( Figs. 15J , 18B ).

Distribution. Argentina ( Endrödi 1985) and Uruguay ( Neita-Moreno & Ratcliffe 2017).

Locality records ( Fig. 35 ). 58 examined specimens from MERKB, MNHM, MNHN, USNM, ZMUB. Some records from Neita-Moreno & Ratcliffe (2017). ARGENTINA (101). Buenos Aires (9): Bahía Blanca ; Buenos Aires ; Carmen de Patagones ; Necochea ; Olavarria ; San Blas ; Villa Gesell. Catamarca (3): Ancafri ; Sinquil. Chaco (1): Resistencia. Chubut (6): Dolavon ; Estación de Esquel ; Golfo de San Jorge ; Península Valdés. Entre Ríos (3): Gualeguaychu. Jujuy (1): Posta de Lozano. La Pampa (1): Chacharramendi. La Rioja (9): Jaguel ; La Unión ; Mascasin ; Patquía ; Tinogasta ; Villa Unión. Mendoza (19): Bardas Blancas ; Cerro Guadal ; Mendoza ; El Nihuil (60 km S) ; Las Heras ; La Valle. Misiones (1): Posadas. Neuquén (14): Añelo ; Bajada del Marucho ; Bajada del Agrio ; Collón-Curá ; Covunco ; Huncal ; La Negra ; La Pintada ; Picún Leufú ; Piedra del Águila ; Pilmatué ; Planicie Banderita ; Río Salado ; Zalapa-Catuto. Río Negro (15): Allen ; Catriel ; Cipolletti ; Conesa ; El Bolsón ; Fray Luís Beltrán ; General Gómez ; General Roca ; Paso Flores ; Piedra del Águila ; Río Negro ; San Antonio ; Valcheta ; Villa Regina. Salta (14): Cafayate (desierto) ; Coronel Olleros ; Las Lajitas ; Salta. San Luís (1): Paso Patria. Tucumán (1): Tafi de Valle. No data (3). URUGUAY (1). Canelones (1): Banda Oriental .

Natural history. Adults are attracted to lights at night. Most records are from arid and desert areas.

Figures

FIGURE 1. Head. A) Euligyrus ebenus, B) Proculigyrus cicatricosus, C) Ligyrus (Ligyrodes) peruvianus, D) L. (Anagrylius) moroni, E) L. (Ligyrus) ruginasus, F) L. (Ligyrus) nasutus, G) L. (Ligyrus) bidentulus, H) Tomarus adoceteus, I) T. maimon, J) T. pullus, K) T. pumilus.

FIGURE 13. Female genital plates. A) Euligyrus ebenus, B) Proculigyrus cicatricosus, C) Ligyrus (Anagrylius) moroni, D) L. (Ligyrodes) sallaei, E) L. (Ligyrus) allonasutus, F) L. (Ligyrus) bidentulus, G) L. (Ligyrus) neglectus, H) Tomarus laticaudus, I) T. maternus, J) T. rostratus, K) T. subtropicus. Abbreviations: SCx: Subcoxite, Cx: Coxite.

FIGURE 15. Parameres in frontal view. A) Euligyrus ebenus, B) E. similis, C) Proculigyrus cicatricosus, D) Ligyrus (Anagrylius) cuniculus, E) L. (Anagrylius) moroni, F) L. (Ligyrodes) peruvianus, G) L. (Ligyrodes) relictus, H) L. (Ligyrodes) sallaei, I) L. (Ligyrus) allonasutus, J) L. (Ligyrus) bidentulus, K) L. (Ligyrus) burmeisteri, L) Ligyrus (Ligyrus) fossor, M) L. (Ligyrus) gibbosus, N) L. (Ligyrus) nasutus, O) L. (Ligyrus) neglectus, P) L. (Ligyrus) paranaensis, Q) L. (Ligyrus) peninsularis, R) L. (Ligyrus) rubripes, S) L. (Ligyrus) ruginasus, T) L. (Ligyrus) villosus.

FIGURE 18. Parameres in lateral view.A) L. (Ligyrus.) allonasutus, B) L. (Ligyrus) bidentulus, C) L. (Ligyrus) burmeisteri, D) Ligyrus (Ligyrus) fossor, E) L. (Ligyrus) gibbosus, F) L. (Ligyrus) nasutus, G) L. (Ligyrus) neglectus, H) L. (Ligyrus) paranaensis, I) L. (Ligyrus) peninsularis, J) L. (Ligyrus) rubripes, K) L. (Ligyrus) ruginasus, L) L. (Ligyrus) villosus.

FIGURE 25. Habitus of the species of Ligyrus. Subgenus Anagrylius: A) Ligyrus cuniculus, B) L. moroni. Subgenus Ligyrodes: C) L. peruvianus, D) L. relictus, E) L. sallaei. Subgenus Ligyrus: F) L. allonasutus, G) L. bidentulus, H) L. burmeisteri. Scale bar: 5 mm.

FIGURE 35. Distributional records of Ligyrus (Ligyrus) villosus, L. bidentulus, and L. rubripes.