Liodessus meridensis, Balke & Bilton & García & Viloria & Villastrigo & Hendrich, 2022

Balke, Michael, Bilton, David T., Garcia, Mauricio, Viloria, Angel L., Villastrigo, Adrian & Hendrich, Lars, 2022, Two new high Andean species of Liodessus diving beetles from Venezuela (Coleoptera, Dytiscidae, Bidessini), Alpine Entomology 6, pp. 7-12 : 7

Liodessus meridensis sp. nov.

Figs 1A , 2A, B , 3A , 4

Type locality.

Laguna de Mucabají, Mérida, Venezuela.

Type material.

Holotype: Male: Venezuela; Mérida, Laguna de Mucabají, 3,500 m, i.2004, 8.7964, -70.8255, García & Balke ( MIZA). Paratypes: 13 exs same label data as holotype ( MIZA, ZSM); 47 exs Venezuela: Mérida, ca. 5 km E Gavidia, 3,600 m, 23.I.2012, 8.6895, -70.8817, Short, Arias & Gustafson, lagoon margin, VZ12-0123-03A ( MIZA, SEMC).

Description.

Habitus with only slight discontinuity between pronotum and elytron (Fig. 1A ), pronotum widest before base and more parallel sided laterally (Fig. 1A ). Total length (TL) 2.1 mm; length without head (TL-h) 1.9 mm; maximum width (MW) 0.9 mm.

Color. Very dark brown to blackish dorsally and ventrally, basal antennomeres, base of meso- and metatibia contrastingly of lighter color (Figs 1A , 2A, B ).

Surface sculpture. Head with few larger and smaller setiferous punctures; with distinct microreticulation except on middle of head between the eyes (Figs 1A , 2A, B ). Pronotum and elytron shiny; with moderately dense and coarse setiferous punctation (Fig. 1A ).

Structures. Antenna stout. Head without occipital line; with rounded clypeus. Pronotum with distinct lateral beads; with distinct long and deep basal striae (Fig. 1A ). Elytron with short basal stria; without sutural line; without basal epipleural transverse carina. Metathoracic wings not examined in holotype (in paratype: short, about half the length of elytron).

Genitalia. Median lobe of aedeagus of long, simple curvature in lateral view, more or less gradually narrowing towards tip; also gradually narrowing towards a narrow tip in ventral view; parameres of simple " Bidessini " type, two-segmented (Fig. 3A ).

Female. Pronotum and elytra microreticulate, dull (specimens from Gavidia); shiny in the ones from Laguna de Mucabají.

Variation. Size variation of the paratypes is TL 2.1-2.3 mm; TL-h 1.8-2.0 mm; MW 0.9-1.1 mm. The elytral striae are hardly noticeable in a few paratypes.

Etymology.

Named after the state of Mérida, in which the collecting localities are situated. The name is an adjective in the nominative singular.

Comparative notes.

Distinguished from the other species of Liodessus by the diagnostic combination of the following features: Species from Venezuela; beetle smaller (TL 2.1-2.3 mm); very dark brown to blackish; head without occipital line; pronotal and elytral striae present; wings reduced considerably; shape of median lobe (narrow and “pointed” in lateral and ventral view, with its particular shape).

BOLD platform.

We provided 1 entry to our BOLD Liodessus project. The species is well delineated from all other Liodessus , with an uncorrected p-distance of around 9% or more.

Distribution.

Known from around Mérida, Venezuela.

Habitat.

Collected from shallow water at the edge of high-altitude ponds (Fig. 4 ).

Figures

Figure 1. Dorsal habitus of Liodessus spp. nov. L. meridensis (A); L. venezuelanus (B). Scale bar: 2 mm.

Figure 2. Liodessus spp. nov. Detail of head in dorsal view. L. meridensis (A, B); L. venezuelanus (C, D).

Figure 3. Liodessus spp. nov. Median lobe ventral and lateral views; parameres outer and inner surfaces, L. meridensis (A); L. venezuelanus (B). Scale bar: 0.5 mm.

Figure 4. Habitat of Liodessus spp. nov. near Gavidia, Venenzuela, where both new species were collected (collecting event VZ 10 - 0123 - 03 A). Overview (A); detail of shallow water at the edge (B).