Tomarus gyas Erichson, 1848

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 : 6-7

publication ID	https://doi.org/10.5281/zenodo.5172580
publication LSID	lsid:zoobank.org:pub:F8317A32-DFD7-42EA-8BC6-DCB5A3659F6C
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treatment provided by	Felipe (2021-08-06 17:25:18, last updated by Plazi 2023-11-03 19:10:00)
scientific name	Tomarus gyas Erichson, 1848
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( Fig. 1c View Figure 1 , 2f View Figure 2 , 3g View Figure 3 , 4c View Figure 4 , 5c View Figure 5 , 6e–f View Figure 6 , 7c View Figure 7 , 8c View Figure 8 , 9a View Figure 9 , 10e–f View Figure 10 , 11c View Figure 11 , 12c View Figure 12 , 13c View Figure 13 , 14c View Figure 14 , 15c View Figure 15 , 16d View Figure 16 )

Tomarus gyas Erichson 1848: 561 (original combination).

Ligyrus amazonicus Arrow 1914: 273 (synonym).

Redescription. Male. Length 21.3–28.8 mm; width 10.4–13.3. Color dark reddish brown to black. Head: Frons and clypeus coarsely rugose. Frontoclypeal region with 2 distinctly transverse tubercles; tubercles narrowly separated, usually about 2.5 tubercle diameters apart ( Fig. 4c View Figure 4 ). Clypeus strongly rugopunctate to transversely rugose, tapering to slightly emarginate, broad apex with 2 reflexed teeth. Mandibles with 2 teeth, apical tooth subacute, subapical notch moderately deep and narrow ( Fig. 6e–f View Figure 6 ); labium on lateral edge densely setose, paraglossa developed, apex slightly concave at center ( Fig. 7c View Figure 7 ); maxilla with galea developed and with 6 teeth ( Fig. 5c View Figure 5 ). Pronotum: Surface with disc moderately punctate, sides and anterior angles densely punctate to rugopunctate; punctures moderate in size on disc, becoming large laterally; fovea rugose within. Anterior margin with strong, median tubercle; fovea small, subequal to width between eyes ( Fig. 8c View Figure 8 ). Elytra: Surface densely punctate; punctures mostly moderately in size with sparser, minute punctures between larger punctures; larger punctures usually ocellate and with 3 pairs of double rows. Pygidium: Surface densely punctate, punctures becoming denser in basal and lateral angles; punctures small to moderate in size, weakly ocellate. In lateral view, male with surface convex, females with weakly convex surface. Legs: Protibia tridentate and with weak basal convexity suggestive of 4 th tooth, teeth subequally spaced from each other ( Fig. 9a View Figure 9 ). Protarsus in males simple, not enlarged. Mesotibia on transverse carinae with long, slender spinules ( Fig. 10e–f View Figure 10 ). Metatibia with 1 basal, transverse carina interrupted at middle (carina with spine-like setae) and 1 medial, transverse carina, metatibial apex with about 22 spinules ( Fig. 10f View Figure 10 ). Venter: Prosternal process long, thick, apex longitudinally oval. Mesosternal surface glabrous, slightly concave at middle. Metasternal surface with sparse, ocellate punctures ( Fig. 2f View Figure 2 ). Male Genitalia: Parameres ( Fig. 11c View Figure 11 , 12c View Figure 12 and 13c View Figure 13 ) subtriangular, rounded apices only weakly curving outwards. Internal sac with 5 copulatory lamellae ( Fig. 15c View Figure 15 ).

Female. Length 22.6–25.3 mm; width 11.5–12.8 mm. Similar to male, but pronotal surface with punctures slightly less dense than those of males. Gonocoxite larger than gonocoxal sternite, with a semicircular furrow ( Fig. 14c View Figure 14 ).

Distribution. Tomarus gyas occurs from southern Mexico to Argentina ( Endrödi 1969a, 1985; Ratcliffe 2003). It is widely distributed in the lowlands in tropical rain forest in South America.

Locality Records ( Fig. 16d View Figure 16 ). 173 specimens examined from CMNC, FSCA, IADIZA, MACN, MLPA. USNM.

ARGENTINA (118). BUENOS AIRES (1): Quilmes. CATAMARCA (1): Catamarca-Capital. CHACO (6): Resistencia. CORRIENTES (10): Bella Vista, Corrientes-Capital, Goya. ENTRE RÍOS (5): Concordia, Paraná. FORMOSA (1): Pilcomato. JUJUY (11): Jujuy-Capital,Parque Nacionla Calilegua. LA RIOJA (1): La Rioja. RIÓ NEGRO (1): General Roca. SALTA (52): Campinchuelo, General Güemes, Hypolito Irigoyen, Parque Nacional El Rey, Pocitos, Rosario de Lerma, Salta-Capital, Vespucio. SANTA FÉ (13): Santa fé-Capital, San Tomé. SANTIAGO DEL ESTERO (4): Amigo, Santiago del Estero-Capital, No Data. TUCUMÁN (7): Tucumán-Capital. NO DATA: (5). URUGUAY (55). COLONIA (8): La Floresta- Canelones, Colonia. MALDONADO (40): Maldonado-Capital, Punta Bellena. MONTEVIDEO (7): Banda Oriental, Colón, Montevideo.

Temporal Distribution. January (20), February (50), September (1), October (5), November (45), December (10).

Diagnosis. Tomarus gyas is externally similar to T. roigjunenti . The labial apex in T. gyas is narrowly notched at its center ( Fig. 7c View Figure 7 ), but in T. roigjunenti the apex is subtruncate and slightly concave ( Fig. 7e View Figure 7 ). The tubercles on the head of T. gyas are rounded and widely separated from each other ( Fig. 4c View Figure 4 ), whereas the tubercles of T. roigjunenti are distinctly transverse and less separated from one another ( Fig. 4e View Figure 4 ). In addition, the fovea of the pronotum in T. gyas is larger (usually as wide as the distance between the eyes, rarely less) than that of T. roigjunenti , which is only slightly indicated. The parameres are different between both species, and this is especially notable at the base on the ventral side (compare Fig. 11c View Figure 11 , 12c View Figure 12 , 13c View Figure 13 and 11e View Figure 11 , 12e View Figure 12 , 13e View Figure 13 ). The internal sac of T. gyas has five copulatory lamellae ( Fig. 15c View Figure 15 ), but in T. roigjunenti there are three copulatory lamellae ( Fig. 15e View Figure 15 ).

Life History. Adults are attracted to lights at night.

References

Arrow, G. J. 1914. Some further notes on lamellicorn beetles of the subfamily Dynastinae. Annals and Magazine of Natural History 8: 257 - 277.

Endrodi, S. 1969 a. Monographie der Dynastinae, 4. Tribus: Pentodontini (Coleoptera, Lamellicornia). Entomologische Abhandlungen 37: 1 - 145.

Endrodi, S. 1985. The Dynastinae of the World. Dr. W. Junk; Dordrecht, The Netherlands. 800 p.

Erichson, W. F. 1848. Die Insekten, p. 533 - 617. In: R. Schomburgk. Reisen in Britisch-Guiana in den Jahren 1840 - 1844, Volume 3. J. J. Weber; Leipzig, Germany.

Ratcliffe, B. C. 2003. The dynastinae scarab beetles of Costa Rica and Panama. Bulletin of the University of Nebraska State Museum 16: 1 - 506.

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 9. Protibia, dorsal view, of Tomarus spp. a) T. gyas and b) T. maimon.

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.