Tomarus bidentulus ( Fairmaire, 1892 )

Neita-Moreno, Jhon César, Alexander, Recursos Biológicos, Agustín, San, de, Villa, Leyva, Boyacá, Ratcliffe, Brett C., Collections, Systematics Research, of, University, Museum, Nebraska State, Hall, Nebraska, of, University, Nebraska, Lincoln, Ne & Usa, 2017, The genus Tomarus Erichson (Coleoptera: Scarabaeidae: Dynastinae: Pentodontini) in Argentina, Chile, and Uruguay, Insecta Mundi 2017 (547), pp. 1-36 : 4-5

Tomarus bidentulus ( Fairmaire, 1892)

( Fig. 1a , 2g –h , 3a , 4a , 5a , 6a–b , 7a , 8a , 10a–b , 11a , 12a , 13a , 14a , 15a , 16a )

Ligyrus bidentulus Fairmaire 1892: 245 (original combination).

Redescription. Male. Length 12.2–16.7 mm; width 4.4–8.6 mm. Color light to dark reddish brown. Head: Frons mostly impunctate between eyes and coarsely rugopunctate just behind frontoclypeal carina. Frontoclypeal region with transverse carina slightly separated at middle ( Fig. 4a ). Clypeus strongly rugopunctate to transversely rugose, tapering to slightly emarginate, broad apex with 2 reflexed teeth. Mandibles with 2 teeth, apical tooth acute, subapical notch deep ( Fig. 6a–b ); labium densely setose, paraglossa undeveloped, apex convergent ( Fig. 7a ); maxilla with galea developed, with 5 teeth. Pronotum: Surface crazed, sparsely punctate; punctures moderately large, umbilicate. Anterior margin with small, median tubercle followed by small, shallow fovea ( Fig. 8a ). Elytra: Surface with micropunctures and large punctures mixed (large punctures moderately dense, ocellate) and with 3 distinct pairs of punctures. First broad interval with or without large punctures. Pygidium: Surface sparsely punctate, punctures becoming dense in basal angles; punctures small to moderate in size, weakly ocellate. In lateral view, surface of males regularly convex, surface in females weakly convex. Legs: Protibia tridentate, basal tooth slightly removed. Protarsus in male simple, not enlarged. Mesotibia with 1 basal and 1 medial transverse carina, each with spine-like setae ( Fig. 10a–b ). Metatibia with 1 basal, transverse carina interrupted at middle and with spine-like setae and 1 medial, complete, transverse carina; apex with about 29 spinules ( Fig. 10b ). First metatarsomere triangularly expanded, apex subtruncate. Venter: Prosternal process tall, thick; apex small, suboval, usually with long, slender setae. Mesosternal surface sparsely setose, slightly concave at middle. Metasternal surface densely punctate, punctures ocellate, setose; setae slender, long; lateral edge rugopunctate with long, slender setae. Abdominal ventrite VIII depressed at middle, ( Fig. 1g –h ). Male Genitalia: Parameres ( Fig. 11a , 12a , 13a ) subtriangular, rounded apices curving outwards. Internal sac ( Fig. 15a ) lacking copulatory lamellae.

Female. Length 16.9–19.6 mm; width 8.3–10.6 mm. Similar to male, but disc of pronotum smooth, pygidium slightly concave, and gonocoxite smaller than gonocoxal sternite and lacking a semicircular furrow ( Fig. 14a ).

Distribution. Tomarus bidentulus occurs in Argentina and Uruguay ( Endrödi 1969a –b, 1985; Abadie et al. 2008).

Locality Records ( Fig. 16a ). 711 specimens examined from BCRC, CMNC, IADIZA, MACN, MLPA, URMU.

ARGENTINA (676). BUENOS AIRES (46): Bahía Blanca , Buenos Aires-Capital Federal, Necochea, San Blas, Villa Gessell, Villarica (30 km SW). CATAMARCA (5): Tinogasti-Fiambala. CHACO (1): Resistencia. CHUBUT (2): Dolavon. CHUBUT (2): Estación de Esquel, San Jorge. CÓRDOBA (1): No Data. JUJUY (3): Posta de Lozano, No Data. LA PAMPA (2): Chacharramendi. LA RIOJA (7): Jaguey, Mascasin, Patiquía, Tinogasta, Villa Union. MENDOZA (30): Bardas Blancas, Cerro Quadral, Las Heras, La Valle, Mendoza Capital, Ov. Balleza, Ranquil Norte, El Nihuil-San Rafael. MISIONES (2): Posadas. NEUQUÉN (72): Allere, Anelo, Bajada Marucho, Bajada Agrio, Collon-Curá, Covuco, Coyunca, Huncal, La Negra, La Pintada, Pampa Salado, Picun Leufu, Piedra del Agüila, Pilmatus, Planicie Banderita, Río Salado, Zalapa-Catuto. RÍO NEGRO (469): Allén, Catriel, Cipolletti, Conesal, Fray Luis Beltrán, General Gómez, General Roca, Paso Flores, Piedra Aguila, Río Negro-Capital, San Antonio Oeste, Valcheta, Villa Regina. SALTA (32): Cafayate-Norte 1 km., Los Lajitas, Salta-Capital. SAN LUIS (1): Paso Patria. SANTA CRUZ (1): Santa Cruz-Capital. TUCUMÁN (1): Tafi de Valle. URUGUAY (7). CANELONES (7): Banda Oriental. NO DATA (28).

Temporal Distribution. January (36), February (29), March (35), April (15), May (4) September (3), October (14), November (42), December (12).

Diagnosis. Tomarus bidentulus is distinctive because the apex of clypeus has the teeth distinctly separated ( Fig. 4a ); the pronotum has a small, subapical tubercle followed by a small fovea; and the surface on the disc is moderately punctate with the sides and anterior angles densely punctate ( Fig. 8a ). Tomarus bidentulus also resembles T. burmeisteri but is easily distinguished by the presence of the pronotal tubercle, which is absent in T. burmeisteri .

Life History. Adults are nocturnal and are attracted to lights. This is an infrequently collected species. Adult emergence is during the summer, which is the rainy season in Argentina and Uruguay.

Figures

Figure 1. Habitus of Tomarus spp. a) Tomarus bidentulus (Fairmaire) dorsal view. b) Tomarus burmeisteri (Steinheil) dorsal view. c) Tomarus gyas Erichson dorsal view. d) Tomarus rosettae (Endrödi) dorsal view. e) Tomarus roigjunenti n. sp. dorsal view, holotype. f) Tomarus roigjunenti n. sp. dorsal view, allotype.

Figure 2. Habitus of Tomarus spp. a) Tomarus rosettae (Endrödi) dorsal view. b) Tomarus spinipenis n. sp. dorsal view, holotype. c) Tomarus spinipenis dorsal view, allotype. d) Tomarus burmeisteri (Steinheil) dorsal view. e) Tomarus villosus (Burmeister) ventral view. f) Tomarus gyas ventral view. g) Tomarus bidentulus (Fairmaire) abdomen segments, ventral view (female). h) Tomarus bidentulus abdomen segments, ventral view (male).

Figure 3. Types of Tomarus spp. a) T. bidentulus female holotype, dorsal view. b) T. burmeisteri male holotype, dorsal view. c) T. burmeisteri male holotype, lateral view. d) T. burmeisteri male holotype parameres, caudal view. e) T. burmeisteri male holotype parameres (lateral view). f) Label for T. burmeisteri holotype. g) T. gyas male holotype, dorsal view and labels and parameres, caudal view). h) T. maimon holotype, dorsal view. i) T. rosettae male holotype, dorsal view. j) T. villosus male holotype, dorsal view. k) T. villosus male holotype, dorsal view of head. l) T. villosus male holotype, parameres, caudal view. m) Label for T. villosus holotype.

Figure 4. Head, dorsal view of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 5. Maxilla, ventral view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 6. Mandibles, ventral view, of Tomarus spp. a–b) T. bidentulus. c–d) T. burmeisteri. e–f) T. gyas. g–h) T. maimon. i–j. T. roigjunenti n. sp. k–l. T. rosettae. m–n. T. spinipenis n. sp. o–p. T. villosus.

Figure 7. Labium, dorsal view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 8. Pronotum, dorsal view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 10. Meso- and metatibia, dorsal view, of Tomarus spp. a–b) T. bidentulus. c–d) T. burmeisteri. e–f) T. gyas. g–h) T. maimon. i–j. T. roigjunenti n. sp. k–l. T. rosettae. m–n. T. spinipenis n. sp. o–p. T. villosus.

Figure 11. Parameres, caudal view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 12. Parameres, lateral view, of: a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 13. Parameres, anterior view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus.

Figure 14. Gonocoxite, ventral view, of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus. Components are: (Gx) gonocoxite), (Gs) gonocoxal sternite.

Figure 15. Internal sac of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. gyas. d) T. maimon. e) T. roigjunenti n. sp. f) T. rosettae. g) T. spinipenis n. sp. h) T. villosus. Components are: (AL) accessory lamella, (CL) copulatory lamella (CL), (Ra) raspula, (Esp) speculum, and (Fg) a complex, spike-like flagellum that varies in length and thickness.

Figure 16. Distribution of Tomarus spp. a) T. bidentulus. b) T. burmeisteri. c) T. maimon. d) T. gyas.