Tobochares canaliculatus, Kohlenberg, Alex T. & Short, Andrew Edward Z., 2017

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 : 115-117

Tobochares canaliculatus sp. n. Figs 3A, 4 A–B, 8D, 9B, 10B, 11E, 12E, 14G, 15, 18 A–B

Type material.

Holotype (male): "VENEZULEA: Amazonas State/ 5°23.207'N, 67°36.922'W, 125m/ Tobogan de la Selva; 8.viii.2008/ leg. A. Short, M. García, L. Joly/ AS-08-080b; old “tobogancito” / on seepage area w/ detritus", "[barcode]/ SEMC0877724/ KUNHM-ENT" (MIZA). Paratypes (23): VENEZUELA: Amazonas: same data as type (10 exs., SEMC, MALUZ; includes 1 female mounted on SEM stub); same locality but 14.i.2009, leg. Short & Miller, "partly shaded wet rock w/ algae", VZ09-0114-01G (9 exs., SEMC); same locality but 14.i.2009, leg. Short, "clumps of wet leaves on rock", VZ09-0114-01D (3 exs., SEMC); same locality but 23.ii.1986, P.J. Spangler, sandy margin, Colln. #10 (1 ex., USNM).

Differential diagnosis.

The combination of the pale dorsal coloration and deeply sulcate elytra along their entire length (Fig. 3A) will easily separate Tobochares canaliculatus from its congeners. The genitalia is also distinctive in having very narrow parameres which are longer than the median lobe (Fig. 14G). Only T. pallidus is paler in coloration, but that species lacks deeply grooved elytra. Other species with deeply sulcate elytra (e.g. T. sulcatus , T. striatus , T. kusad ) are all very dark brown in color, and also have the tips of their parameres distinctly expanded.

Description.

Size and form: Body length 1.6-2.0 mm. Body elongate oval, moderately dorsoventrally compressed. Color and punctation. Dorsum of head brown to dark brown, anterolateral margins of clypeus with prominent pale preocular patches (Fig. 4 A–B); maxillary palps distinctly pale. Pronotum light brown with the lateral margins slightly paler; elytra light brown to brown, slightly paler at lateral margins and posteriorly (Fig. 3A). Meso- and metathoracic ventrites dark brown, 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 half to slightly more than a third of the width. Thorax. Elytra with ten rows of serial punctures which are depressed into deep, smooth grooves running the full length of the elytra (Fig. 11E). Metafemora mostly glabrous on ventral face, with narrow band of pubescence along proximal third of anterior margin (Fig. 12E). Elevation of mesoventrite forming a low transverse carina, not quite elevated to the same plane as the ventral surface of the mesocoxae (Fig. 9B). 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. 10B). Abdomen. Abdominal ventrites uniformly and very densely pubescent, with small spicules interspersed amongst the setae (e.g. Fig. 13A). Aedeagus (Fig. 14G) with parameres relatively narrow, nearly half as narrow as the median lobe; parallel sided in apical half and slightly convex in basal half; apex of parameres very slightly outwardly curved and about equal to the length of the median lobe; gonopore situated at the tip of the median lobe.

Etymology.

Dimunuative of canalis, referring to the elytral grooves.

Distribution.

Known only from the type locality in Venezuela (Fig. 15).

Biology.

This species has been collected on several occasions on rock seepages along the margin of the Rio Coromoto (Fig. 18A).