Liodessus alpinus, Balke & Megna & Zenteno & Figueroa & Hendrich, 2020

Balke, Michael, Megna, Yoandri S., Zenteno, Nilver, Figueroa, Luis & Hendrich, Lars, 2020, New Liodessus species from the high Andes of Peru (Coleoptera: Dytiscidae Bidessini), Zootaxa 4852 (2), pp. 151-165 : 155

publication ID	https://doi.org/ 10.11646/zootaxa.4852.2.1
publication LSID	lsid:zoobank.org:pub:2A612C28-2E39-4729-9DDD-27EE6ED90F4E
DOI	https://doi.org/10.5281/zenodo.4519031
persistent identifier	https://treatment.plazi.org/id/03EDDF2B-FFC2-F219-FF0C-FEBE19F8F8D7
treatment provided by	Plazi
scientific name	Liodessus alpinus
status	sp. nov.

Treatment

Liodessus alpinus View in CoL sp. nov.

( Figs 2A, B View FIGURE 2 , 4C View FIGURE 4 , 5C, E View FIGURE 5 , 7 View FIGURE 7 )

Type locality. Peru: Junín, Junín, Lagoon Estancia Azulmito , 4,452 m , -11.303° -75.989°.

Type material. Holotype: Male ( MUSM): “ Peru: Junín, Junín, Lagoon Estancia Azulmito, 4452 m, 14.viii.2018, -11.303° -75.989°, Y. S. Megna & N. Zenteno ( PER _YSM_2018_14)”; “ Holotype Liodessus alpinus sp. nov. Balke, Megna, Hendrich des. 2020” [red printed label].

85 Paratypes ( MUSM, ZSM) : 5 exs.: same data as holotype ; 55 exs.: “ Peru: Junín, Junín, Shalacancha , 4600 m, 11.viii.2018, -11.09° -75.879°, Y. S. Megna & N. Zenteno ( PER _YSM_2018_09)” ; 2 exs.: “ Peru: Junín, Junín, Shalacancha , 4320 m, 11.viii.2018, -11.075° -75.863°, Y. S. Megna & N. Zenteno ( PER _YSM_2018_10)” ; 15 exs.: “ Peru: Junín, Junín, Junín, 4099 m, 12.viii.2018, -11.164° -76.008°, Y. S. Megna & N. Zenteno ( PER _YSM_ 2018_11)” ; 18 exs.: “ Peru: Junín, Junín, Shoqui , 4324 m, 15.viii.2018, -11.046° -75.897°, Y. S. Megna & N. Zenteno ( PER _YSM_2018_18)” ; 7 exs.: “ Peru: Cusco, Canchis, Checacupe, Cayena , 4906 m, 25.viii.2018, -14.009° -71.067°, Y. S. Megna & N. Zenteno ( PER _YSM_2018_28)”. All paratypes are provided with our red printed paratype labels .

Description of holotype. Habitus with distinct discontinuity between pronotum and elytra; broadest at about 1/3 of elytral length and body therefore appearing slightly pear shaped (as in Figs 2A, B View FIGURE 2 ). TL: 2.0 mm; TL-H: 1.7 mm; TW: 0.9 mm.

Colouration. Mostly blackish dorsally and ventrally (as in Figs 2A, B View FIGURE 2 ).

Surface sculpture. Head with faint microreticulation at base and along hind angles of eyes, frons and clypeus more or less smooth and with few fine setiferous punctures; pronotum shiny with with sparser and fine setiferous punctation; elytra shiny with dense and coarser setiferous punctation.

Structures. Antenna stout. Head without cervical line but few serial punctures instead. Pronotum on each lateral side (or margin) with distinct bead and with distinct and deep basal plicae. Elytron with short and faint basal plicae only visible using diffuse lateral lighting. Metathoracic wings short, about half the length of elytron.

Genitalia. Median lobe of aedeagus thick, bulky in lateral view, tip with short nose which is also prominent in ventral view, dorsally on both sides at about mid-length with shallow lateral keels; lateral lobes (parameres) with distal part longish ( Fig. 4C View FIGURE 4 ).

Variation. TL: 2.0– 2.2 mm; TL-H: 1.7–1.8 mm; TW: 0.9–1.0 mm. Few specimens show an extremely faint, interrupted cervical line. We assessed the length of the metathoracic wings in 10 specimens, which all had the same short wing length. While these specimens are certainly not able to fly actively, there might be few fully winged individuals that are capable of flight.

Female. Dorsal surface as in male, few specimens with more or less extensive microreticulation on clypeus and along eyes, pronotal disc and laterally as well as on elytron apically only or from about basal 1/3 up to apex (dullest form depicted in Fig. 2B View FIGURE 2 ).

BOLD platform. We provided 17 entries in the “COLLI” project, all retrieved in one cluster. Assignment to that cluster was unambiguous, meaning all specimens were correctly assigned to this morphologically delineated species.

Etymology. The specific name is the Latin adjective alpinus (of high mountains).

Distribution. High Andes of central and southeastern Peru ( Fig. 7 View FIGURE 7 ), ca. 4,300 –4,900 m.

Habitat. Shallow and exposed puddles, collected with strainer out of mats of vegetation ( Fig.5C, E View FIGURE 5 ). Other Dytiscidae associated with this species were species of Rhantus Dejean, 1833 and Lancetes Sharp, 1882 , as well as Liodessus acollensis .