Research Article |
Corresponding author: Michael Balke ( balke.m@snsb.de ) Academic editor: Christoph Germann
© 2020 Michael Balke, Yoandri S. Megna, Nilver Zenteno, Luis Figueroa, Lars Hendrich.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Balke M, Megna YS, Zenteno N, Figueroa L, Hendrich L (2020) Two new species of Liodessus Guignot, 1939 diving beetles from Northern Peru (Coleoptera, Dytiscidae, Hydroporinae). Alpine Entomology 4: 173-178. https://doi.org/10.3897/alpento.4.55139
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The diving beetles Liodessus altoperuensis sp. nov. and Liodessus caxamarca sp. nov. (Dytiscidae, Hydroporinae, Bidessini) are described from the high altitudes of the Puna regions of north western Peru. They occur in shallow and exposed mossy peatland puddles. We delineate the two species using structures such as male genitalia, beetle size, shape and colour pattern. Mitochondrial Cox1 data were also generated, and revealed clusters congruent with morphological evidence. Altogether fourteen Liodessus species are now known from the Andean region.
Dytiscidae, Liodessus, new species, Peru
There are 32 species of Liodessus Guignot, 1939 known from the Americas. Twelve of these have been recorded from the Andean region (
The beetles were studied with a Leica M205C stereo microscope at 10–160×. Habitus images were taken with a Canon EOS 5 DS camera fitted with a 10× Mitutoyo ELWD Plan Apo objective attached to a Carl Zeiss Jena Sonnar 3.5 / 135 MC as focus lens. The male genitalia were imaged with a 20× Mitutoyo ELWD Plan Apo. Illumination was with three SN-1 LED segments from Stonemaster. Image stacks were generated using the Stackmaster macro rail (Stonemaster) (10×: 0.007 mm steps; 20×: 0.003 mm steps), and images were then assembled using Helicon Focus 4.77TM. To study the distribution of mtDNA sequence diversity in four populations of L. caxamarca, haplotype networks were constructed using the TCS algorithm (
The following acronyms are used in the text: MUSM (Natural History Museum of San Marcos National University, Lima, Peru) and ZSM (SNSB-Zoologische Staatssammlung, München, Germany). Codes such as PER_YSM_2018_45 are our field locality codes.
Peru, Cajamarca, Encañada District, Conga, -6.934, -78.442.
Male (MUSM): Peru: Cajamarca, Cajamarca, Encañada District, Conga, 4030 m, 7.ix.2018, -6.934, -78.442, Y. S. Megna & N. Zenteno (PER_YSM_2018_46).
254 Paratypes (MUSM, ZSM). 100 exs.: same data as holotype; 30 exs.: Peru: Cajamarca, Cajamarca, Encañada District, Conga, 4013 m, 7.ix.2018, -6.95, -78.354, Y. S. Megna & N. Zenteno (PER_YSM_2018_45); 55 exs.: Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3928 m, 8.ix.2018, -6.887, -78.595, Y. S. Megna & N. Zenteno (PER_YSM_2018_47); 23 exs.: Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3947 m, 8.ix.2018, -6.892, -78.599, Y. S. Megna & N. Zenteno (PER_YSM_2018_48); 23 exs.: Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3961 m, 8.ix.2018, -6.894, -78.6, Y. S. Megna & N. Zenteno (PER_YSM_2018_49); 41 exs.: Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3933 m, 8.ix.2018, -6.902, -78.603, Y. S. Megna & N. Zenteno (PER_YSM_2018_50); 12 exs.: Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3935 m, 8.ix.2018, -6.91, -78.614, Y. S. Megna & N. Zenteno (PER_YSM_2018_51).
Habitus with distinct discontinuity between pronotum and elytra (as in Fig.
Dark brown to blackish dorsally and ventrally (as in Fig.
Head more or less smooth and with few setiferous punctures in front of a faint cervical line, faint microreticulation present along sides of eyes; with distinct distinct microreticulation but without punctures posteriorly of occipital line. Pronotum and elytron shiny; with dense and coarse setiferous punctation.
Antenna stout. Head with faint cervical line that dissolves into serial punctures laterally; with rounded clypeus. Pronotum with distinct lateral bead; with distinct and deep basal striae (as in Fig.
Median lobe of aedeagus curved in lateral view, tip thin and appearing fragile; in ventral view slender and gently narrowed towards tip (Figs
Liodessus spp. males: Liodessus caxamarca sp. nov., holotype, median lobe of aedeagus in ventral view (A), same in lateral view (B), right paramere external surface view (C); Liodessus altoperuensis sp. nov. holotype, median lobe of aedeagus in ventral view (D), same in lateral view (E), right paramere external surface view (F).
Total length: 2.5–2.8 mm; length without head: 2.2–2.5 mm; maximum width: 1.1–1.4 mm. The elytral stria can be short yet well visible to very faint to absent. The color is rather variable, from comparably lightly colored (Fig.
Dorsal surface dull due to presence of well impressed microreticulation between surface punctation (Figs
We provided 27 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.
Named after the Caxamarca pre Inca culture that inhabited the area between 200–1,300 AD, and also gave the name to the Department Cajamarca. The name is a noun in the nominative standing in apposition.
The species is well characterized by its size, discontinuous habitus, shape of male genitalia (Figs
Only known from the high Andes in north western Peru (Fig.
Peru, San Pablo, Tumbaden District, Alto Peru, -6.902, -78.603.
Male (MUSM): Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3933 m, 8.ix.2018, -6.902, -78.603, Y. S. Megna & N. Zenteno (PER_YSM_2018_50).
(MUSM, ZSM). 28 exs., same data as holotype. 1 ex. Peru: Cajamarca, Cajamarca, Encañada District, Conga, 4030 m, 7.ix.2018, -6.934, -78.442, Y. S. Megna & N. Zenteno (PER_YSM_2018_46); 1 ex. Peru: Cajamarca, San Pablo, Tumbaden District, Alto Peru, 3928 m, 8.ix.2018, -6.887, -78.595, Y. S. Megna & N. Zenteno (PER_YSM_2018_47).
Habitus with little discontinuity between pronotum and elytra, therefore appearing more parallel sided (Fig.
Blackish dorsally and ventrally (as in Fig.
Head with faint microreticulation, frons and clypeus more or less smooth and with few setiferous punctures; with distinct microreticulation but without punctures posteriorly of a faint cervical line. Pronotum and elytron shiny; with dense and coarse setiferous punctation; pronotum with faint microreticulation along anterior margin and towards pronotal disc.
Antenna stout. Head with faint cervical line that dissolves into serial punctures laterally; with rounded clypeus. Pronotum with distinct lateral bead; with distinct and deep basal striae (as in Fig.
Median lobe of aedeagus with inner side comparably straight in lateral view, tip slightly bent and comparably robust; in ventral view slender and gently narrowed towards tip (Figs
Total length: 1.9–2.2 mm; length without head: 1.7–1.8 mm; maximum width: 0.9–1.0 mm. The elytral stria can be short yet well visible to very faint to absent. We assessed the length of the metathoracic wings in 10 specimens, which all had the same wing length. This does not rule out the possibility that a certain number of specimens can be fully winged.
Dorsal surface as in male, shiny (Fig.
We provided 10 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.
Named after the type area. The name is an adjective in the nominative singular.
The species is well characterized by its smaller size, almost entirely black coloration, elytral plica very short or absent, shape of male genitalia and cox1 signature.
Only known from the high Andes in north western Peru (Fig.
Shallow and exposed peatland puddles, collected with strainer out of mats of vegetation including mosses (Fig.
As mentioned above, we established a DNA sequence based platform for the study of the Andean Liodessus species, using the Barcode of Life Data System (BOLD). Our project on the BOLD platform is “COLLI”, being an acronym for “Colombian and Andean Liodessus”. We use the standard genetic marker for molecular biodiversity assessment, the 5’ end of the mitochondrial cytochrome c oxidase 1 gene (cox1 or CO1), also referred to as the “DNA barcode” (
This work was supported by the Alexander von Humboldt Foundation through a HERMES fellowship to Y. S. Megna. We thank Juliane Diller, Gerardo Lamas and Pavel Matos for their help with planning our work in Peru. We thank SERFOR (Servicio Nacional Forestal y de Fauna Silvestre del Ministerio de Agricultura y Riego) for authorizing this research, which was conducted in cooperation with the Natural History Museum of San Marcos National University, Lima, Peru (MUSM) (Permit number 419-2017-SERFOR/DGGSPFFS).
We are grateful for the generous support from the SNSB-Innovative scheme, funded by the Bayerisches Staatsministerium für Wissenschaft und Kunst (Project: “Geographische Isolation, Endemismus und Artbildungsprozesse bei Insekten in der hochmontanen Páramo Kolumbiens (und darüber hinaus)”).
Michael Balke acknowledges support from the EU SYNTHESYS program, projects FR-TAF-6972 and GB-TAF-6776, which supported this research during visits to NHM and MNHN in 2017.
Consortium of European Taxonomic Facilities (CETAF) data use statement: “Data on genetic material contained in this taxonomic article are published for non-commercial use only. Utilization by third parties for purposes other than non-commercial scientific research may infringe the conditions under which the genetic resources were originally accessed, and should not be undertaken without obtaining consent from the original provider of the genetic material.”