Tobochares fusus, Girón & Short, 2021

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

Tobochares fusus sp. nov. Figs 2C , 5D-F , 11C , 14F , 17

Type material examined.

Holotype (male): "Brazil: Amapá: Oiapoque/ 3.85039, -51.81683; 17 m/ Oiapoque (ca. 1 km E); 18.vii.2018/leg. Short; Flotation of detritus/ex forest seep; BR18-0718-03C" (INPA). Paratypes (58 exs.): Brazil: Amapá: Same data as holotype (45, INPA, MNHN, SCC, SEMC including DNA voucher SLE1564); Oiapoque (4 km NE), 3.87234, -51.80315, 14 m, 18.vii.2018, leg. Short, root mats on rock at margin seep, BR18-0718-02A (10, INPA, SEMC); Oiapoque (ca. 5.5 km NE), Balneario, 18.vii.2018, leg. Short, margin of larger stream, BR18-0718-01C (1, SEMC). French Guiana: Savane Roche Virginie, near RN 2, 4.1883, -52.13982, 64 m, 10.iii.2020, leg. Short and Neff, rotting Clusia fruits, FG20-0310-01D (3, SEMC including DNA Voucher SLE2171).

Differential diagnosis.

Tobochares fusus is externally indistinguishable from T. emarginatus , given that both species share the same disposition and degree of impression of the elytral punctures, and a low transverse ridge on the posterior elevation of the metaventrite. However, they can be clearly differentiated by the general shape of the aedeagus, which is rather slender and nearly parallel sided in T. emarginatus ( Kohlenberg and Short 2017: fig. 14I), whereas T. fusus has a fusiform aedeagus (see Fig. 11C ).

Description.

Size and form: Body length 1.7-2.0 mm. Body elongate oval, moderately convex (Fig. 5D, E ). Color and punctation: Dorsal surfaces of body dark brown, with slightly paler pronotum (Fig. 5D ); antennae, mouthparts, and legs yellowish brown, with orange tibiae; ventral surfaces of meso-, metathorax and abdomen dark brown (Fig. 5F ). Ground punctation on head, pronotum and elytra moderately marked. Head: Eyes in dorsal view with anterior margin oblique, posteriorly directed; Tobochares canthus emarginating eye to about a quarter of its dorsal width in lateral view (Fig. 2C ). Maxillary palps 0.7 × width of head. Thorax: Elytra with all kinds of punctures similar in size and degree of impression, seemingly evenly distributed, not forming grooves (Fig. 5D ). Elevation of mesoventrite forming a low transverse ridge (Fig. 5F ). Metaventrite with distinct median, broad, diamond-shaped glabrous area extending along posterior two thirds (Fig. 5F ). Abdomen: Abdominal ventrites uniformly and densely pubescent (Fig. 5F ). Aedeagus (Fig. 11C ). Basal piece nearly 0.4 × length of a paramere; greatest width of a paramere nearly 0.7 × greatest width of median lobe; outer margins of parameres diverging along basal half, then broadly bending inward and tapering along apical fifth; apex of paramere oblique, pointing towards longitudinal midline of aedeagus; median lobe roughly triangular, apically rounded; gonopore situated at apex of median lobe.

Etymology.

Named with the Latin word Tobochares fusus , meaning fusiform, in reference to the shape of the aedeagus of this species.

Distribution.

This species is known from two closely situated localities on either side of the Oiapoque River, the boundary between French Guiana and the Brazilian state of Amapá. See Fig. 13 .

Life history.

The series from Brazil were taken from a seepage habitat in a forested riparian corridor (Fig. 14F ). A thin layer of saturated dead leaves was laying over granite, over which a thin film of water was seeping into an adjacent stream. The short series from French Guiana was collected from the rotting fruits of a Clusia on an otherwise dry forest floor and not adjacent to any aquatic habitat (Fig. 17C ).

Figures

Figure 2. Heads of Tobochares spp. A, B T. goias, black mark pointing to Tobochares canthus emarginating the eye A dorsal view B anterolateral view C T. fusus D, E T. luteomargo, black mark pointing to straight anterior margin of the eye D dorsal view E anterolateral view F T. romanoae G T. pemon H T. communis I T. microps.

Figure 5. Habitus of Tobochares spp. in the Tobochares luteomargo and Tobochares emarginatus species group A-C T. luteomargo A dorsal view B lateral view C ventral view. D-F T. fusus D dorsal view E lateral view F ventral view. Scale bars: 1 mm.

Figure 11. Aedeagi of Tobochares spp. A T. benettii B T. goias C T. fusus D T. luteomargo E T. pemon F T. anthonyae G T. atures H T. communis I T. microps J T. romanoae K T. akoerio L T. kappel M T. arawak N T. canaima. Scale bars: 0.5 mm (A-D); 0.1 mm (E-N).

Figure 13. Distribution of Tobochares spp.

Figure 14. Tobochares habitat in Brazil A, B type locality and habitat for T. benettii, seepage near Rio Preto de Eva (collecting event BR 17 - 0610 - 01 A) C type locality and habitat for T. goias, margin of Balneario Lejas (collecting event BR 18 - 0304 - 02 B) D habitat of T. kusad and T. sipaliwini, State of Roraima, near Usina de Jatapu reservoir (collecting Event BR 18 - 0117 - 01 A) E habitat and type locality of T. romanoae, and habitat of T. sipaliwini, State of Roraima, Serra do Tepequem, Igarape Preto Negro, Cachoeira Leje Preta (collecting event BR 18 - 0114 - 04 B) F type locality and habitat of T. fusus, State of Amapa, Calcoene (collecting event BR 18 - 0721 - 02 B).

Figure 17. Habitat of Tobochares fusus. A Brazil, Amapa, near Oiapoque (collecting event BR 18 - 0718 - 02 A), red arrow indicates root mat under which specimens were found B Brazil, Amapa, near Oiapoque (collecting event BR 18 - 0718 - 03 C) C French Guiana, near Savane Roche Virginie, rotting Clusia fruits (collecting event FG 20 - 0310 - 01 D).