Masculine.

Aulonochares tubulus Girón & Short, 2019: 120; by original designation.

Medium sized beetles, total body length 5.8–7.5 mm. Body shape elongated oval in dorsal view; weakly convex in lateral view (Fig. 21). Color orange brown to dark brown; ventral surface covered with rather long golden setae, especially on abdominal ventrites, and more densely so (with shorter setae) on surface of femora. Head subquadrate in dorsal view, seemingly constricted at anterior margin of eyes (Fig. 11J). Eyes relatively small, separated by distance nearly 6.5 × the maximum width of an eye (Fig. 11J). Clypeus with lateral margins nearly parallel, slightly convex, with anterior margin only slightly narrower than posterior margin (Fig. 11J). Labrum fully exposed. Mentum and submentum roughly punctate (Fig. 21C). Antennae with nine antennomeres, with cupule slightly asymmetrical and round in outline. Maxillary palps long, nearly 1.5 × longer than maximum width of head, with inner and outer margins of maxillary palpomere 2 evenly curved (Fig. 21A). Pronotum with ground punctation shallow and uniformly sparse. Elytra without sutural striae, with outer margins slightly flared; serial punctures, ground punctures and systematic punctures similar in size, shallowly impressed. Surface of prosternum flat (slightly carinate only along midline of antero-mesal projection of anterior margin). Posterior elevation of mesoventrite simple, without carinae or ridges; anapleural sutures concave, anteriorly converging, anteriorly separated by distance nearly 0.3 × as wide as anterior margin of mesepisternum. Metaventrite densely and uniformly pubescent. Protibiae with spines of anterior row very small and appressed (Fig. 21C); apical spurs of protibiae very short (not exceeding the length of the first tarsomere) and stout. Hydrofuge pubescence covering most surface of metafemora (Fig. 21C). Ventral face of tarsomeres 1–4 densely covered by stiff setae. Apex of fifth abdominal ventrite strongly emarginate; emargination fringed by stout setae. Aedeagus tubular (Fig. 22A–C), somewhat cylindrical, with parameres forming a 5–7 × longer than wide tube; basal piece very short and strongly concave; gonopore reduced, located at apex of median lobe.

Aulonochares can be easily mistaken with Novochares in the New World, and the two genera can be collected together. The subquadrate shape of the head (Fig. 11J; as opposed to trapezoid as in Fig. 11G), the roughly punctate mentum, the long setae composing the ventral pubescence of the abdominal ventrites, ventrally densely setose tarsomeres, along with the tubular shape of the aedeagus (Fig. 22A–C) are very distinctive and uniquely combined in Aulonochares among Neotropical acidocerines.

Neotropical: Brazil (Amazonas, Roraima), French Guiana, Guyana, Suriname, Venezuela; Fig. 4.

Specimens of Aulonochares have been collected in densely forested sandy streams and detrital pools in forests along creeks. They seem to prefer habitats with abundant detritus or decaying organic matter. Females of A. tubulus and A. ligulatus have been observed carrying their egg cases underneath their abdomen (Girón and Short 2019; pers. obs.).

Immature stages are not known for the genus.

Recently described by Girón and Short (2019).

Only three species are known for the genus (Girón and Short 2019).

Aulonochares lingulatus Girón & Short, A. novoairensis Girón & Short, A. tubulus Girón & Short. Holotypes and paratypes of all three species were available for this study. We have not seen any specimens of the genus from outside the Guiana Shield region of South America.

Girón and Short 2019: original description of the genus and all its currently known species; Short et al. 2021: phylogenetic placement.