Tobochares arawak, Girón & Short, 2021

Giron, Jennifer C. & Short, Andrew Edward Z., 2021, Review of the Neotropical water scavenger beetle genus Tobochares Short & Garcia, 2007 (Coleoptera, Hydrophilidae, Acidocerinae): new lineages, new species, and new records, ZooKeys 1019, pp. 93-140 : 93

Tobochares arawak sp. nov. Figs 3C, E , 10A-C , 11M , 13 , 15A, B

Type material examined.

Holotype (male): "Guyana: Region VIII: 5°0.730'N, 59°38.965'W; 585 m; Upper Potaro Camp I; ca. 7 Km NW of Chenapau; top of falls on Potaro River; seeps with roots and algae; 12.iii.2014; leg. Short, Salisbury, La Cruz; GY14-0312-01B" (CBDG). Paratypes (127 exs.): Guyana: Region VIII: Same data as holotype (127, CBDG, SEMC).

Differential diagnosis.

Tobochares arawak can be recognized by its strongly convex body in lateral view (Fig. 10B ), accompanied by elytral punctation uniform in size and degree of impression, with serial punctures seemingly aligned in rows, not impressed to form grooves (Fig. 10A ); the interserial punctures are somewhat irregularly distributed in two or three rows (Fig. 10A ). The general habitus and punctation of T. arawak are similar to those of T. canaima , T. kappel , and T. kolokoe . In T. kappel and T. kolokoe the interserial punctures form only one or two irregular rows (Fig. 3H ). In T. canaima (Fig. 10D ) the pronotal and elytral punctations are sharper than in T. arawak and the apodemes of the median lobe are one fourth the length of the median lobe in T. canaima (Fig. 11N ), as opposed to half as long in T. arawak (Fig. 11M ).

Description.

Size and form: Body length 1.6-1.8 mm. Body elongate oval, strongly convex (Fig. 10A, B ). Color and punctation: Dorsal and ventral surfaces of body dark brown, with lateral margins of prothorax and elytra only slightly paler (Fig. 10A, B ); mouthparts yellow, with slightly darker apical third of maxillary palpomere IV; antennae brown; legs reddish to dark brown with paler tarsi (Fig. 10C ). Ground punctation on head, pronotum and elytra moderately marked (Fig. 10A, B ). Head: Eyes in dorsal view with anterior margin oblique (anteriorly directed), and outer margins slightly bulging from outline of head; in lateral view, eyes not emarginate (see Fig. 2E ). Thorax: Elytra with slightly defined rows of shallow serial punctures, not forming grooves (Fig. 10A ); interserial punctures somewhat irregularly distributed in two or three rows (Fig. 3I ). Elevation of mesoventrite forming a very low transverse carina (Fig. 10C ). Metaventrite with distinct median, longitudinal, narrow glabrous area extending along posterior half (Fig. 10C ). Abdomen: Abdominal ventrites uniformly and densely pubescent. Aedeagus (Fig. 11M ). Basal piece 0.4 × the length of a paramere; parameres nearly 1/3 as narrow as greatest width of median lobe, with outer margins widely and uniformly convex, and rounded apex; median lobe roughly triangular, rounded and slightly pinched at apex; gonopore situated nearly at midlength of median lobe.

Etymology.

Noun in apposition. Named after the Arawak, an indigenous tribe of northern South America.

Distribution.

Tobochares arawak is only known from the Upper Potaro region in Guyana. See Fig. 13 .

Life history.

This species was collected in a wet seepage area along rocks at the margin of the Upper Potaro River. Specimens were collected by pulling back root mats and moss that were growing over the wet rock areas. See Fig. 15A, B .

Figures

Figure 2. Heads of Tobochares spp. A, B T. goias, black mark pointing to Tobochares canthus emarginating the eye A dorsal view B anterolateral view C T. fusus D, E T. luteomargo, black mark pointing to straight anterior margin of the eye D dorsal view E anterolateral view F T. romanoae G T. pemon H T. communis I T. microps.

Figure 3. Characters of elytra and wings of Tobochares spp. A-E Scanning Electron Micrographs A-C elytra: white arrows point to serial punctures; black arrows point to interserial punctures A T. communis B T. atures C T. arawak D, E ventral view of mesoventrite: D T. communis: top white arrow points to posterior elevation of mesoventrite with low longitudinal elevation; bottom white arrow points to narrow longitudinal glabrous patch of the metaventrite E T. arawak: top white arrow points to posterior elevation of mesoventrite with weakly elevated bulge; bottom white arrow points to narrow longitudinal glabrous patch of the metaventrite. F-I detail of elytral punctation; black marks at top of each circle indicates serial punctures F T. pemon (all punctures relatively large; serial punctures longitudinally aligned; interserial punctures in irregular single row) G T. atures (all punctures longitudinally aligned; serial punctures larger than interserial punctures; interserial punctures more densely distributed) H T. kolokoe (serial punctures longitudinally aligned; interserial punctures forming one or two irregular rows) I T. canaima (serial punctures longitudinally aligned; interserial punctures forming two or three irregular rows) J, K hindwings J T. sipaliwini K T. microps.

Figure 10. Habitus of Tobochares spp. in the Tobochares communis species group A-C T. arawak A dorsal view B lateral view C ventral view D-F T. canaima D dorsal view E lateral view F ventral view. Scale bars: 1 mm.

Figure 11. Aedeagi of Tobochares spp. A T. benettii B T. goias C T. fusus D T. luteomargo E T. pemon F T. anthonyae G T. atures H T. communis I T. microps J T. romanoae K T. akoerio L T. kappel M T. arawak N T. canaima. Scale bars: 0.5 mm (A-D); 0.1 mm (E-N).

Figure 13. Distribution of Tobochares spp.

Figure 15. Tobochares habitat in Guyana and Venezuela A, B habitat for T. arawak, Guyana, upper Potaro River (collecting event GY 14 - 0312 - 01 B) C, D habitat for T. luteomargo, Venezuela, rock outcrop by Rio Cuchivero, (collecting event VZ 10 - 0710 - 01 A) E habitat for T. luteomargo, Venezuela Campamento Rio Aro (collecting event VZ 10 - 0711 - 01 B) F type locality and habitat for T. atures, Venezuela, Tobogan de la Selva (collecting event VZ 09 - 0114 - 01 F).