Tobochares Short & Garcia , 2007: 2

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

publication ID	https://dx.doi.org/10.3897/zookeys.1019.59881
publication LSID	lsid:zoobank.org:pub:740EFFB9-3ADA-4B2A-BD23-A839AAE71FB2
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scientific name	Tobochares Short & Garcia , 2007: 2
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Genus Tobochares Short & Garcia, 2007: 2 View in CoL

Type species.

Tobochares sulcatus Short & García, 2007: 4; by original designation.

Differential diagnosis.

Small beetles, total body length 1.5-2.6 mm. Color yellowish brown, orange brown to dark brown. Body shape oval in dorsal view; moderately (Fig. 5B View Figure 5 ) to strongly convex in lateral view (e.g., Fig. 9E View Figure 9 ). Antennae with eight antennomeres (e.g., Kohlenberg and Short 2017: fig. 8). Maxillary palps curved inward, short (e.g., slightly shorter than the width of the head) and slender (Fig. 2A; e View Figure 2 .g., T. goias sp. nov.), to very short (nearly half the width of the head) and stout (Fig. 2G; e View Figure 2 .g., T. pemon sp. nov.). Elytra without sutural striae, but in T. akoerio sp. nov. and T. romanoae sp. nov. stria I more strongly impressed along posterior half of elytra (Fig. 8A and D View Figure 8 , respectively); elytral punctures seemingly arranged in rows, in some species more evidently so (Fig. 8 View Figure 8 ); in some species interserial punctures not longitudinally aligned (Figs 9 View Figure 9 , 10 View Figure 10 ); serial punctures sometimes impressed into distinct grooves (e.g., Kohlenberg and Short 2017: fig. 2). Prosternum flat (e.g., Fig. 5C View Figure 5 ). Posterior elevation of mesoventrite either flat, bulging (Fig. 3E View Figure 3 ) or with a transverse or longitudinal ridge (Fig. 3D View Figure 3 ). Metaventrite densely pubescent, except for a median glabrous patch, which is either ovoid and wide (e.g., Kohlenberg and Short 2017: fig. 10) or longitudinal and narrow (Fig. 3D, E View Figure 3 ). Posterior femora mostly glabrous, with only few scattered setae, sometimes with hydrofuge pubescence along basal half of anterodorsal margin ( Kohlenberg and Short 2017: fig. 22). Fifth abdominal ventrite apically evenly rounded, without stout setae (e.g., Kohlenberg and Short 2017: fig. 13). Aedeagus with basal piece usually very short (nearly one third of the length of parameres; Fig. 11 View Figure 11 ).

Remarks on diagnostic features of Tobochares Short & García, 2007

Body shape and coloration. In lateral view, the degree of convexity of the body can be diagnostic, as only a few species (all in the Tobochares communis species group) are comparatively strongly convex (e.g., T. kolokoe sp. nov., Fig. 9E View Figure 9 ; T. akoerio , Fig. 8E View Figure 8 ). Except for a few cases (e.g., the paler elytral margins of T. luteomargo sp. nov., Fig. 5B View Figure 5 ) the general dorsal coloration of the body in Tobochares is not particularly useful for diagnosis. The coloration of the head is diagnostic for some species of the Tobochares sulcatus species group.

Maxillary palps. In general, the maxillary palps in Tobochares are short (nearly as long as the width of the head; e.g., Fig. 2A, D, F, H, I View Figure 2 ) or very short (nearly half as long as the width of the head; e.g., Fig. 2G View Figure 2 ). The longer palps are slender, as the regular acidocerine maxillary palps (e.g., Crucisternum Girón & Short, 2018), but in the shorter forms, the maxillary palps are also stout: each palpomere is shorter and apically wider (or mesally in the case of maxillary palpomere IV). The coloration of palpomere IV (uniformly yellowish vs. apically darkened) can be diagnostic for some species, especially in the Tobochares sulcatus species group (see Kohlenberg and Short 2017).

Eyes. The direction of the anterior margin of the eye in dorsal view is partly diagnostic at the species-group level. The anterior margin of the eye is oblique and posteriorly directed in the Tobochares sulcatus and Tobochares emarginatus species groups (Fig. 2A-C View Figure 2 ), forming a reduced to well-developed Tobochares canthus , which in lateral view of the head results in a clearly emarginate anterior margin of the eye (Fig. 2B View Figure 2 ); it is oblique and anteriorly directed to perpendicular to the outer margin of the head in the Tobochares luteomargo and Tobochares communis species groups (Fig. 2D-I View Figure 2 ), which in lateral view of the head results in a straight anterior margin of the eye (Fig. 2E View Figure 2 ), only rarely slightly emarginated. The outer margin of the eyes can also be considered diagnostic, being continuous with the outline of the head (eyes not bulging) in the Tobochares sulcatus species group (Fig. 2A View Figure 2 ), or slightly bulging from the outline of the head in the Tobochares luteomargo and Tobochares communis species groups (e.g., Fig. 2D, F View Figure 2 ).

Mesoventrite. The posterior elevation of the mesoventrite exhibits high variation within Tobochares . It usually bears a low, transverse medial ridge, but it can also be flat, or with a weakly elevated bulge (Fig. 3E View Figure 3 ), or a broad and low longitudinal ridge (Fig. 3D View Figure 3 ). Not necessarily a diagnostic feature at the species-group level.

Metaventrite. The surface of the metaventrite is overall densely covered by hydrofuge pubescence, with a posteromedial glabrous patch. The shape of the glabrous patch is diagnostic at the species-group level: members of the Tobochares sulcatus species group have a broad, ovoid to diamond-shaped glabrous patch ( Kohlenberg and Short 2017: fig. 10), whereas in the Tobochares luteomargo and Tobochares communis species groups, the glabrous patch is shaped like a narrow longitudinal bar (Fig. 3D, E View Figure 3 ).

Elytral punctation. The distribution and characteristics of the elytral punctation are highly variable in Tobochares . The disposition and degree of impression of the elytral punctation (i.e., serial punctures, ground punctures and systematic punctures) are useful for species recognition. The elytral punctures are generally aligned in rows, but this is not so evident in some species (e.g., T. luteomargo (Fig. 5A View Figure 5 ), T. communis (Figs 3A View Figure 3 , 6A View Figure 6 ), T. microps sp. nov. (Fig. 6D View Figure 6 ), T. fusus sp. nov. (Fig. 5D View Figure 5 )), where the punctures seem to be evenly distributed rather than longitudinally aligned. In species of the Tobochares luteomargo and Tobochares emarginatus species groups, and some species in the Tobochares communis species group all the elytral punctures are similar in size and degree of impression. Most members of the Tobochares sulcatus species group have well developed, impressed, elytral striae (see Kohlenberg and Short 2017). The sutural striae are always absent in Tobochares , but in T. akoerio (Fig. 8A View Figure 8 ) and T. romanoae (Fig. 8D View Figure 8 ) the impressed stria I on each elytron is more strongly impressed along the posterior half of the elytra, which might resemble a well-developed sutural stria. In some species the elytral striae are only impressed along the posterior half or third of the elytra (e.g., T. kasikasima Short, 2013, Kohlenberg and Short 2017: fig. 3C; T. romanoae (Fig. 8D View Figure 8 ) and T. akoerio (Fig. 8A View Figure 8 )).

In some species in the Tobochares communis species group, the serial punctures can be recognized by their higher density in comparison with interserial punctures (Figs 3H, I View Figure 3 , 10A, D View Figure 10 ), whereas in others the serial punctures are larger and less dense than the interserial punctures ( T. atures sp. nov., Figs 3B, G View Figure 3 , 7D View Figure 7 ). Seta bearing systematic punctures are distributed in irregular rows in the Tobochares sulcatus species group, whereas in the Tobochares luteomargo and Tobochares communis species groups, seta bearing systematic punctures are rather scarce, sometimes only evident along the sides and posterior third of elytra (e.g., Fig. 3A-C View Figure 3 ). Some details of the elytral punctation require high magnification to be properly observed.

Hind wings. Most species of Tobochares have well-developed hind wings (Fig. 3J View Figure 3 ), with the notable exception of T. microps , which is polymorphic, with individuals exhibiting either full size or brachypterous wing forms (e.g., Fig. 3K View Figure 3 ).

Metafemora . For the most part, the anterior surface of the metafemora is glabrous, smooth and shiny, with only few scattered setae and very shallow reticulations ( Kohlenberg and Short 2017: fig. 12). Sometimes there is a narrow strip of hydrofuge pubescence along the basal half of the anterodorsal margin. Not necessarily a diagnostic feature at the species-group level.

Abdomen. All the abdominal ventrites are uniformly covered by fine pubescence, which varies in density: in T. canthus Kohlenberg & Short, 2017, T. emarginatus Kohlenberg & Short, 2017, and T. luteomargo the pubescence is rather scanty, whereas in the remainder species of the genus the pubescence is very dense ( Kohlenberg and Short 2017: fig. 13). The posterior margin of the fifth ventrite is evenly rounded and lacks thick, flat spine-like setae ( Kohlenberg and Short 2017: fig. 13).

Aedeagus. As is usual in acidocerines, the configuration of the aedeagus is diagnostic at the species and species-group level, although, it can be considered highly variable within the genus, which is unusual in the subfamily. The basal piece is usually short (between 0.3 and 0.6 × the length of the parameres), except in T. luteomargo , in which the basal piece is slightly longer than the parameres (Fig. 11D View Figure 11 ). The median lobe varies from roughly triangular and apically rounded (as in most species of the Tobochares sulcatus species group, Kohlenberg and Short 2017: fig. 14) to rather sagittate, either narrowing along its apical third (e.g., Fig. 11G-I View Figure 11 ), or apically pinched (e.g., Fig. 11K-M View Figure 11 ). The apex of the median lobe is rarely emarginate at apex (e.g., Fig. 11D, E View Figure 11 ). The parameres range in length from shorter to nearly as long as the median lobe, with outer margins straight, broadly curved or sinuate. The overall shape and proportions of the aedeagus, particularly the median lobe, are variable in Tobochares .