Holotype (♂): “SURINAME: Sipaliwini District; 2°00.342'N, 55°58.149'W; 337 m; Sipaliwini Savanna nature Res., 4-Brothers Mts.; clearwater stream, sandy with emergent vegetation; at night; 31.iii.2017; leg. A. Short; SR17-0331-01F” (NZCS). Paratypes (156): BRAZIL: Roraima: “00°46'35.1"N, 60°19'58.7"W; 97 m; Rorainópolis, Recanto da Cachoeira, vicinal 12; creek flowing through gallery forest; 10.1.2018; leg. A. Short; BR18-0110-04A” (SEMC, 3); “00°54.786'N, 59°34.397'W; 150 m; Caroebe, Rio Caroebe, ca. 13 Km NE of Caroebe; margins of sandy river; 17.i.2018; leg. A. Short & Benetti; BR18-0117-04A” (SEMC, 1). GUYANA: Region 9: “2°05.095'N, 59°14.174'W; 250 m; Parabara, trail to mines; detrital pools in forest; 2.xi.2013; leg. Short, Isaacs, Salisbury; GY13-1102-01A” (CBDG, SEMC, 8); same, except “2°06.492'N, 59°13.653'W;274 m; Parabara, N side of river; small flowing forested creek, detritus margins & leaf packs; 3.xi.2013; GY13-1103-02A” (SEMC, 2). Region 8: “5°07.539'N, 59°06.732'W; 80 m; Konawaruk River, basecamp 2 (NARIL basecamp); unnamed clearwater creek, slow flowing, shallow; 15.ix.2014; leg. Salisbury & La Cruz; GY14-0915-02” (SEMC, 6). Region 6: “4°09.143'N, 58°11.207'W; 105 m; Upper Berbice, c. 1 Km W Basecamp 1; small sandy stream; 21.ix.2014; leg. A. Short; GY14-0921-03A” (SEMC, 2); same, except “margins of creek; 22.iv.2014; leg. Short, Salisbury, La Cruz; GY14-0921-03H” (SEMC, 4); same, except “4°09.136'N, 58°11.365'W; 106 m; Upper Berbice, ca. 1.1 Km W of basecamp 1; stream detrital pool; 23.ix.2014; GY14-0923-02A” (SEMC, 1); same, except “4°09.289'N, 58°10.717'W; 95 m; Upper Berbice, Basecamp 1; margins of basecamp creek; 24.ix.2014; GY14-0924-01A” (SEMC, 1); same, except “4°09.241'N, 58°10.627'W; 109 m; puddles along road; GY14-0924-02A” (SEMC, 4); same, except “margins of creek with leaf packs and mud; 25.ix.2014; leg. Short & La Cruz; GY14-0925-01B” (SEMC, 1); same, except “detritus pools in dry creekbed; leg. Short, Salisbury, La Cruz; GY14-0925-01D” (SEMC, 1); same, except “5°03.892'N, 58°03.303'W; 71 m; Upper Berbice, Logging Road Km 1; marsh and creek; 29.ix.2014; GY14-0929-01B” (CBDG, SEMC, 12). SURINAME: Sipaliwini District: “2°10.521'N, 56°47.244'W; 228 m, Camp 1, on Kutari River; forest swamp; 22.viii.2010; leg. Short & Kadosoe; SR10-0822-02A; 2010 CI-RAP Survey” (SEMC, 2); same, except “2°21.776'N, 56°41.861'W; 237 m; Camp 3, Wehepai; sandy forest creek; 4–6.ix.2010; SR10-0904-01A” (SEMC, 7); “2.97731N, 55.38500W; 200 m; Camp 4 (low), Kasikasima; sandy stream on trail to METS camp; 20.iii.2012; leg. A. Short; SR12-0320-02A; 2010 CI-RAP Survey” (SEMC, 2); same, except “detrital pools along trail to METS camp; 20–25.iii.2012; SR12-0320-03A” (SEMC, 3); same, except “sandy creek, trail to Kasikasima; flotation; 22.iii.2012; SR12-0322-02A” (SEMC, 7); “04°40.910'N, 56°11.138'W; 78 m; Raleighvallen Nature Reserve, Voltzberg Station; stream margins; 29.vii.2012; leg. Short, Maier, McIntosh, Kadosoe; SR12-0729-02A” (SEMC, 1); same, except “detrital side pool; leg. Short & McIntosh; SR12-0729-02B” (SEMC, 1); same, except “margin of stream; 30.vii.2012; leg. Maier & Kadosoe; SR12-0730-01A” (SEMC, 1); same, except “detrital pools along stream; leg. Short & McIntosh; SR12-0730-01B” (NZCS, SEMC, 10); “4°42.48'N, 56°13.15908'W; 24 m; Raleighvallen Nature Reserve, Lolopaise area; side pool of creek; 14.iii.2016; leg. Short et al.; SR16-0314-02D” (SEMC, 1); “4°40.432'N, 56°11.079'W; 86 m; Raleighvallen Nature Reserve, base of Voltzberg; pooled up stream; 16.iii.2016; SR16-0316-01B” (SEMC, 1); “Raleighvallen Nature Reserve, trail from plateau to Voltzberg stream with roots, mud; 17.iii.2016; leg. J. Girón; SR16-0317-04A” (SEMC, 4); “4°42.48'N, 56°13.15908'W; 24 m; Raleighvallen Nature Reserve, Lolopaise area; intermittent stream margins; flotation; 18.iii.2016; leg. Short et al.; SR16-0318-01D” (SEMC, 2); same, except “intermittent stream pools; pan/screen method; 18.iii.2016; leg. Toussaint et al.; SR16-0318-01E” (SEMC, 1); “Raleighvallen Nature Reserve, Copename River, Voltzberg trail; detrital pools in stream bed; 17.iii.2016; leg. A. Short; SR16-0319-01A” (SEMC, 1); “4°42.48'N, 56°13.15908'W; 24 m; Raleighvallen Nature Reserve, Lolopaise area; intermittent stream pools; 19.iii.2016; leg. Toussaint et al.; SR16-0319-02C” (SEMC, 2); “2°00.397'N, 55°58.371'W; 306 m; Sipaliwini Savanna nature Res., palm swamp nr. 4-Brothers Mts.; mud/detritus; 30.iii.2017; leg. Short & Baca; SR17-0330-03A” (SEMC, 1); same, except “2°00.342'N, 55°58.149'W; 337 m; 4-Brothers Mts.; clearwater stream, sandy with emergent vegetation; 31.iii.2017; SR17-0331-01C” (SEMC, 23); same, except “sandy pools in creek; leg. S. Baca; SR17-0331-01E” (SEMC, 10); same data as holotype (NZCS, SEMC, 23). VENEZUELA: Amazonas: “0°50'N, 66°10'W; 140 m; Cerro de la Neblina, 1 Km S Basecamp; along small whitewater stream; pools of dead leaves and sticks; 17.ii.1985; leg. P.J. & P.M. Spangler, R. Faitoute, W. Steiner” (USNM, 2); “Puerto Ayacucho; in small ponds full of dead leaves; 22.i.1985; leg. G.E. Ball” (SEMC, USNM, 5).

Aulonocharestubulus can be distinguished by its dark brown general coloration (Fig. 1A–C), and the shape of the aedeagus, which is parallel sided along its basal 2/3, with cylindrical median lobe (Fig. 2E).

Body length 5.8–7.5 mm, width 3.1–4.0 mm. General coloration

dark brown (Fig. 1A–C). Aedeagus (Fig. 2E) with outer margins of parameres subparallel along basal 2/3, slightly concave along apical third; median lobe cylindrical, rounded at apex.

Named with the Latin word tubulus meaning pipe, after the shape of the median lobe of the aedeagus in this species.

Broadly distributed in the Guiana Shield region, from the Orinoco River to central Suriname (Fig. 3).

The majority of collecting events of this species are from forested streams, including those actively flowing as well as pooled up, or from isolated marginal pools in the stream bed (Fig. 4B). A few collections were made in forested detrital pools, although most if not all of these were near or associated with riparian corridors. They are usually found in habitats with abundant detritus or decaying organic matter. Females have been observed on numerous occasions to carry their egg case beneath their abdomen.