Belladessus soqtapata Miller, new species

Zoobank.org/ urn:lsid:zoobank.org:act: A08412EA-13C8-4245-ACAB-5A334C740BA9

(Figs. 1–5, 8–13)

Type locality. Peru, Cusco Prov, Soqtapata Conservation Reserve, 13.345235°S 70.849646°W, 988 m elev, pools in small stream (Figs. 8, 9).

Diagnosis. This species shares the following character states with other Belladessus within Bidessini: 1) Absence of an occipital line (Fig. 1); 2) presence of a basal pronotal stria (Fig. 1); 3) presence of a basal elytral stria (Fig. 1); 4) absence of a sutural elytral stria (Fig. 1); 5) absence of a transverse carina on the elytral epipleuron at the humeral angle; and 6) presence of a distinct marginal bead on the anterior clypeal margin (Fig. 1). From other Belladessus, this species differs in having males. Males have a distinctive median lobe that is exceptionally broad in lateral aspect (Fig. 3) and apically bifid in ventral aspect (Fig. 4). Also, the complex dorsal color pattern with maculae and fasciae is distinctive (Fig. 1). The pronotum is entirely pale orange in other species of Belladessus (Figs. 6, 7), but in B. soqtapata there is a conspicuous posteromedial marginal dark, well-defined border (Fig. 1). Finally, the anterior clypeal margin is distinctly and strongly beaded as in B. puella, but unlike B. femineus, which has this bead present but less distinctly impressed.

Description. Measurements: TL = 1.9–2.1 mm, GW = 1.1–1.2 mm, PW = 0.8–1.0 mm, HW = 0.6–0.7 mm, EW = 0.4–0.5 mm, TL/GW = 1.7–1.8, HW/EW = 1.6–1.7, FL/RL = 1.7–1.8. Body shape oval, lateral outline slightly discontinuous between pronotum and elytron, posterior apex pointed (Fig. 1). Coloration: Head yellow-orange, slightly darker anteriorly. Pronotum yellow, narrowly dark along posterior margin laterally. Elytron maculate, dark brown and yellow, with large brown regions anteromedially, lateromedially, medially, and in longitudinal vittae subapically on each elytron as well as in other small areas (Fig. 1). Sculpture and structure: Head shiny and smooth with small micropunctures; anterior clypeal margin produced, distinctly and broadly beaded; eyes moderately large (HW/EW = 1.6–1.7). Pronotum smooth and shiny, with few micropunctures; pronotal plica strongly impressed, curved, extending about onehalf distance across pronotum; lateral pronotal margin distinctly, narrowly beaded. Elytron with lateral margin broadly rounded; surface shiny with dispersed micropunctures; elytral stria elongate, distinctly longer than length of pronotal stria. Prosternum medially short, carinate, prosternal process broad, deeply longitudinally grooved. Metaventrite and metaventrital wings smooth and shiny with few micropunctures. Metacoxa smooth and shiny, with few micropunctures; metacoxal lines distinct, region between metacoxal lines moderately broad; metatrochanter large relative to metafemur (RL/FL = 1.7–1.8; Fig. 2). Male genitalia: Median lobe in lateral aspect extremely broad, broadly and evenly curved along ventral margin, dorsal margin slightly curved, apex pointed (Fig. 3); in ventral aspect slender, apically bifid, sides subparallel, slightly convergent (Fig. 4); lateral lobe in lateral aspect robust, apical segment with apex rounded, with distinct apical tooth-shaped lobe (Fig. 5).

Sexual Dimorphism. Males have the pro- and mesotarsomeres I–III somewhat but distinctly broader than in females.

Variation. There is some minor variation in extent of coloration of the dorsal surface but otherwise specimens are similar.

Etymology. This species is named soqtapata, the Quechua word for “six floors,” and the name of the Soqtapata Conservation Reserve, the type locality of the species.

Distribution. Belladessus soqtapata is only known from the type locality (Figs. 8, 9). However, this habitat type extends north and south along the base of the Andes Mountains for many miles, suggesting the species may be considerably more widespread.

Habitat. Soqtapata is a conservation reserve at the base of a steep area of the east slope of the Andes Mountains. The type locality is at 988 m elevation in dense tropical forest (Figs. 10–13). The specimens were found in small rock pools in a trickling spring in the heavily shaded forest adjacent to the larger stream in a former channel of the stream (Figs. 10–13). Specimens were not found in the larger stream or side pools, only in the rock pool habitat of the small trickling spring. The pools had extensive leaf-pack and areas with denser algae. Specimens were uncommon despite extensive search. The only other diving beetles found in this habitat were members of a rarely collected species of Laccophilus Leach (not identified to species).

Discussion. This species includes specimens with the same diagnostic features of Belladessus, but clearly there are male specimens involved, which are not known from the other two species of Belladessus . The relationship of this species to the other two species in the genus is not perfectly clear, but specimens are similar in general appearance and diagnostic combination within Bidessini. All share a somewhat similar habitus and dorsally complex coloration (Figs. 1, 6, 7) (Miller and Short 2015).

Type Material. Holotype in MUSM, male, labeled “ PERU Cusco Dist, Soqtapata Cons Res, 988m 13.345235°S 70.849646°W pools in small stream, 5 Jun 2019 / HOLOTYPE Belladessus soqtapata Miller, 2020 [red label with double black line border].” 2 paratypes labeled same as holotype, except “…/ PARATYPE Belladessus soqtapata Miller, 2020 [blue label with black line border].” 1 paratype, labeled “ PERU: Cusco Dept. Conc. Soqtapata, 3Aug2018 13.34714°S 70.84400°W Pools in stream KBM03081801 KBMiller/ PARATYPE Belladessus soqtapata Miller, 2020 [blue label with black line border].”