Tobochares sipaliwini Short & Kadosoe, 2011

Kohlenberg, Alex T. & Short, Andrew Edward Z., 2017, Revision of the Neotropical water scavenger beetle genus Tobochares Short & Garcia, 2007 (Coleoptera, Hydrophilidae, Acidocerinae), ZooKeys 669, pp. 113-146 : 128-131

Tobochares sipaliwini Short & Kadosoe, 2011 Figs 2C, 4 C–D, 7A, 9E, 10E, 11A, 12B, 14C, 15, 16 A–B, E–F

Tobochares sipaliwini Short & Kadosoe, 2011: 85.

Type material examined.

Holotype (male): "SURINAME: Sipaliwini District/ 2°10.973'N, 56°47.235'W, 210 m/ Camp 2, on Sipaliwini River/ leg. Short & Kadosoe; Inselberg/ 29-30. viii.2010; SR10-0829-01A/ 2010 CI-RAP Survey" (NZCS). Paratypes (4): SURINAME: Sipaliwini District: Same data as type (3 exs., SEMC, USNM, NZCS). Same camp but 31.viii.2010, sandy forest creek, SR10-0831-01B (1 ex., SEMC).

Additional material examined

(120). SURINAME: Sipaliwini: Same data as type except 1.ix.2010, seep on inselberg, SR10-0901-01A (1 ex., SEMC; DNA voucher SLE1023); Raleighvallen Nature Reserve, plateau below Voltzberg, 28.vii.2012, leg. Short, Maier, & McIntosh, seep/wet rocks in shaded part of trail, SR12-0728-01J (1 ex., SEMC); same data but rock pool, SR12-0728-01F (1 ex., SEMC); Raleighvallen Nature Reserve, Voltzberg trail, 30.vii.2012, leg. Short & McIntosh, detrital pools along stream, SR12-0730-01B (6 exs., SEMC); same data but leg. Maier & Kadosoe, margin of stream, SR12-0730-01A (3 exs., SEMC; includes one specimen on SEM stub); Raleighvallen Nature Reserve, base of Voltzberg, 16.iii.2016, leg. A. Short, seepage on top of rock, SR16-0316-01C (38 exs., SEMC); same data but seepage spot on side of rock, SR16-0316-01A (45 exs., SEMC); same locality but 17.iii.2016, leg. Short & Girón, flotation of roots and debris from seepage, SR16-0317-01C (5 exs., SEMC); Camp 4 (high), Kasikasima, 24.iii.2012, leg. A. Short, main seepage area, SR12-0324-01C (9 exs., SEMC; includes DNA voucher SLE422); same data but "white rock seepage area on trail", SR12-0324-01B (2 exs., SEMC; DNA vouchers SLE478 and SLE497). GUYANA: Region IX: Kusad Mts., large seepage near basecamp, 24.x.2013, leg. Short & Washington, on wet rocks, GY13-1024-03C (6 exs., SEMC; includes DNA voucher SLE1020); Kusad Mts., nr. Basecamp, 24.x.2013, leg. Salisbury, small rock pool with detritus, GY13-1024-03A (3 exs., SEMC).

Differential diagnosis.

This species can be distinguished from most other Tobochares by the elytral striae being impressed only on the posterior half (Fig. 11A), and its dark brown coloration (Fig. 2C). It is most similar to T. kasikasima from which it may be distinguished by the more extensive elytral striae (only in posterior third in T. kasikasima ), the uniformly pale maxillary palps (Fig. 7A), and its differently shaped aedeagus (Fig. 14C).

Description.

Size and form: Body length 1.7-2.1 mm. Body elongate oval, moderately dorsoventrally compressed. Color and punctation. Dorsum of head very dark brown to black, anterolateral margins of clypeus with paler preocular patches (Fig. 4 C–D); maxillary palps distinctly pale (Fig. 7A). Pronotum very dark brown with the lateral margins paler; elytra very dark brown, slightly paler at lateral margins and posteriorly (Fig. 2C). Meso- and metathoracic ventrites and abdominal ventrites very dark brown (nearly black), with prosternum slightly paler; epipleura, legs, labial palps, and antennae distinctly paler, with antennal club slightly darker than proximal antennal segments. Ground punctation on head, pronotum and elytra moderately fine. Head. Eyes measuring ~100µm anteroposteriorly, continuous with outline of head, emarginate at lateral margin, narrowing to about half to slightly greater than half the width. Thorax. Elytra with ten rows of serial punctures which are depressed into shallow grooves in the posterior half, with depth of the grooves greatest near the elytral suture (Fig. 11A). Metafemora mostly glabrous on ventral face, with narrow band of pubescence along proximal third of anterior margin (Fig. 12B). Elevation of mesoventrite forming a low transverse carina with an acute “tooth,” elevated to the same plane as the ventral surface of the mesocoxae (Fig. 9E). Metaventrite with distinct median ovoid glabrous area that is more than half of the total metaventrite length, and about half as wide as it is long (Fig. 10E). Abdomen. Abdominal ventrites uniformly and very densely pubescent, with small spicules interspersed amongst the setae (e.g. Fig. 13A). Aedeagus (Fig. 14C) with parameres slightly wider than median lobe; parallel sided in basal half, then slightly narrowing in apical half to third; apex of parameres very slightly expanded and bluntly rounded. Median lobe gradually tapering to a bluntly rounded apex, which slightly extends beyond the apex of the parameres; gonopore situated distinctly below the apex of the median lobe.

Distribution.

Originally described from an inselberg on the Suriname-Guyana boarder, this species has now been found at other localities in both countries (Fig. 15).

Biology.

The most frequently encountered species of the genus thus far in the eastern Guianas, T. sipaliwini has been found in a variety of seepage habitats, though most have been associated with more permanent flowing water (Fig. 16 A–B, E–F). A few specimens have been taken along the margins of streams that were fed by or adjacent to rock seepages.