Research Article |
Corresponding author: Milada Bocakova ( milada.bocakova@upol.cz ) Academic editor: Vinicius S. Ferreira
© 2024 Elynton Alves Nascimento, Milada Bocakova.
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:
Nascimento EA, Bocakova M (2024) Phylogenetic analysis reveals a new net-winged beetle genus of Eurrhacini (Coleoptera, Lycidae) from the Pacific slopes of Central America and Ecuador. ZooKeys 1204: 241-259. https://doi.org/10.3897/zookeys.1204.114932
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The first phylogenetic inference of Calopterini and Eurrhacini focused on Calocladon and related taxa was carried out. A data matrix composed of 46 species and 51 morphological characters was assembled and analyzed using parsimony and model-based approaches. Eurrhacini were recovered monophyletic. Furthermore, phylogenetic analyses highly supported the Calocladon clade including also Atlanticolycus, Cladocalon, and Gorhamium gen. nov. as its sister clade. Our trees consistently recovered monophyly of the new genus with two new species: Gorhamium bidentatum sp. nov. (Panama, Baru Volcano) and G. unidentatum sp. nov. from the Pacific slopes of Ecuador. A revised key to the genera of Eurrhacini is given and illustrations of distinguishing characters are provided. Phylogenetic relationships of Eurrhacini and character evolution are discussed.
Lycinae, Neotropical Region, new genus, new species
The Eurrhacini is a Neotropical lineage of Lycidae, which until recently was part of the tribe Calopterini in the broader sense (
The placement of Eurrhacini in the Calopterini was based on their resemblance, as the two groups often have similar coloration. Eurrhacini, however, are characterized by a very long male terminal sternum, which is twice as long as that of the Calopterini, and a distorted phallus and phallobase. When established (
Likewise, species of the recently discovered Cladocalon Nascimento & Bocakova, 2022, Currhaeus Nascimento, Bressan & Bocakova, 2020, and Atlanticolycus Nascimento & Bocakova, 2023 were originally placed in Calocladon, as they are similar to Calocladon and Emplectus (
The morphological matrix is based on that of
Data matrix of 51 morphology-based characters of Calopterini and Eurrhacini used in phylogenetic analyses.
Dictyoptera aurora | 011000000000000000000001000000000000000000-00-0-000 |
Lygistopterus sanguineus | 10-01-00000000000000001100000000-000000010-00-0-000 |
Plateros brasiliensis | 10-100000000001-0-00001100000000-001000000-00-0-0-0 |
Conderis signicollis | 011000000000000000000000000010000000000001000-0-000 |
Lycus palliatus | 10-11-00000000000000000000000100-100000000-00-0-000 |
Haplobothris basipennis | 11101-000100000110??????100000??0101000010-00-0-000 |
Haplobothris scapularis | 11101-000100000110101000100000000100000010-00-0-000 |
Calocladon testaceum | 111100010100200111101100110000000021000001001110000 |
Calocladon oculatum | 111100010100200111101100110000000021000001001110000 |
Calocladon ephippium | 111100010100200111101100110000000021000001001110000 |
Atlanticolycus camposgerais | 111?000101042001?11031??110000000000000001011112000 |
Atlanticolycus japi | 111?000101042001?11031??110000000000000001011112000 |
Cladocalon chiriquense | 111?000101031100111011??100000000000000001001012011 |
Cladocalon histrionicum | 111?000101031100111011??100000000000000001001?12011 |
Gorhamium bidentatum | 1110000101032000211011??100002000000000001001011102 |
Gorhamium unidentatum | 111?00010103200121??????110002000000000001001111102 |
Emplectus bimaculatus | 1110000???????????100111?0????00000??0?00100??????? |
Emplectus apicalis | 11100001010020001-100111100000000000000001000---0-- |
Currhaeus striatus | 111?0001010-001-0-??????100000??1002000001000-0-000 |
Currhaeus championi | 111?0001010-001-0-??????100000??1002000001000-0-000 |
Currhaeus paranaensis | 111?0001010-001-0-??????100000??1002000001000-0-000 |
Eurrhacus tristis | 11110001210-201-0-??????100000??0001100001000---0-- |
Eurrhacus pectinicornis | 11110001210-201-0-100111100000000001100001000---0-- |
Eurrhacus kaboureki | 111?0001210-201-0-??????100000??0001100001000---0-- |
Neolinoptes imbrex | 111100002100100011100101100000001001000001000-0-000 |
Neolinoptes rubidus | 111100000100200011??????100000??1001000001000-0-000 |
Lycoplateros mimicus | 10-1000???????????100100?0????00-00?011001100-0-000 |
Lycoplateros diversipes | 10-10001010020001110010000000000-001011001100-0-000 |
Cyrtopteron muhlenbecki | 11011-001000010110100000000000101000000001100-0-000 |
Mesopteron riveti | 10-11-001000010110??????001000??-000000011100-0-000 |
Falsocaenia meridanum | 11011-101000010110112000000000101000000011100-0-000 |
Lycinella opaca | 10-?01001001000100??????010000??-000000020-00-0-000 |
Lycinella parvula | 10-?01001001000100??????010000??-000000020-00-0-000 |
Ceratopriomorphus humeralis | 111?01000001010110??????010100???000000011100-0-000 |
Ceratopriomorphus piceus | 111?01000001010110??????010100???000000011100-0-000 |
Acroleptus chevrolati | 111?01010001010110??????010000??0000000010-00-0-000 |
Metapteron suturalis | 11111-000012010110111000000000000000000001000-0-000 |
Calopteron apicale | 10-11-00001001011010200000000001-100000001000-0-000 |
Cartagonum bernardi | 10-11-100010010110??????000000??-000000021000-0-000 |
Leptoceletes basalis | 10-11-01001001011010200000000000-010000001000-0-000 |
Caenia dimidiata | 10-10001101000011010200000000000-010000001000-0-000 |
Idiopteron flavocinctum | 10-11-11101001001010200000000000-010000021100-0-000 |
Xenomorphon baranowskii | 10-?---01000010110??????010000??--00000121100-0-000 |
Lycomorphon elongaticolle | 10-?1-101000010110??????010000??-000000001000-0-000 |
Lycomorphon bolivianum | 110?1-101000010110??????010000??1000000001000-0-000 |
Lycomorphon angusticolle | 10-?1-101000010110??????010000??-000000001000-0-000 |
Phylogenetic analyses were conducted using maximum parsimony (MP), Bayesian (BA), and maximum likelihood (ML) criteria. MP analyses were performed in TNT 1.5 (
Maximum likelihood (ML) searches were applied under IQ-Tree 2 software (
Approximately 100 Eurrhacini specimens were examined using an Olympus SZX 12, or Zeiss Stereo Discovery V8 stereoscopic microscopes. Eyes are differentiated into small, medium-sized, and large. In medium-sized eyes, the eye diameter is equal to the interocular distance; in small eyes the eye diameter is less than the interocular distance; in large eyes the eye diameter is greater than the interocular distance. Nine longitudinal elytral costae are distinguished in four strong primary costae and five less elevated alternate secondary costae. Costae and intercostal intervals are numbered from the suture as in other Coleoptera. Dissection of genitalia was made after boiling in 10% KOH solution and followed previous studies (
The syntypes of Calocladon chiriquense Gorham, 1884 were borrowed from The Natural History Museum (
Different analytical approaches resulted in congruent patterns of major lineages. Our ML tree (Fig.
Bayesian analyses of the dataset resulted in trees with low posterior probabilities for Eurrhacini (PP = 0.51), while Calopterini were unsupported (PP = 0.29, Suppl. material
Initial unweighted MP analyses resulted in 23 shortest trees (TL = 131, CI = 49.62, RI = 80.7), the strict consensus of which recovered monophyly of Eurrhacini (Suppl. materials
Phylogenetic relationships within the tribe Eurrhacini revealed the genus Haplobothris as the most basal branch in all analyses. The remaining Eurrhacini was strongly supported (UFBoot = 98, PP = 0.98, BrS = 4). MP trees further indicated a bifurcation of Calocladon and Eurrhacus clades (Suppl. materials
Gorhamium bidentatum sp. nov. (by present designation).
Gorhamium gen. nov. can be distinguished from other Eurrhacini by the combination of the following characters: a) elytra (Fig.
Body length: 5.5–6.4 mm, width across the humeri: 1.2 mm. Head partly covered by pronotum from above. Labrum small, mandibles slender, arcuate (Fig.
Male. Eyes medium-sized to large, eye diameter 1.3–1.7× longer than interocular distance. Antennae reaching beyond elytral midlength, antennomeres 3–10 flabellate, antennal branches flattened, antennomere 1 (=A1) stout, A2 small, transverse, A3 slightly (1.15–1.3×) shorter than A4, A4–A10 subequal in length. Lamellae arise basally, lamella of A3 slightly longer than antennomere body, remaining lamellae considerably longer. Abdominal sternum VIII widely emarginated distally (Fig.
Terminal abdominal segments A–D Gorhamium bidentatum sp. nov. E–H Gorhamium unidentatum sp. nov., male G Cladocalon chiriquense (Gorham, 1884) A, B, E, G male terminalia (sternum IX and tergum IX–X), A – ventral view; B, E, G – dorsal view C Male sternum and tergum VIII, ventral view D female terminal sternum, ventral view. F, Male sternum VIII, ventral view H Male tergum VIII, dorsal view.
A–G, Male genitalia A, B Cladocalon chiriquense (Gorham, 1884) C–E Gorhamium bidentatum sp. nov. F–H Gorhamium unidentatum sp. nov. H female genitalia of Gorhamium bidentatum sp. nov., ventral view. A, C, F ventral view B, D, G lateral view E ventrolateral view. Abbreviations: a1 – pointed anchor-shaped base of phallus, a2 – flat anchor-shaped base of phallus, b – phallic ventral opening, c – dorsal dent, d1 – arcuate ventrobasal parameral process, d2 – flattened ventrobasal parameral process, d3 – a ring-like ventral bridge (ventrobasal processes medially fused), e – internal sac.
Female. Eyes small, interocular distance 1.3× longer than eye diameter, antennae serrate (Fig.
The genus is named in honor of H. S. Gorham, the author of chapters on Malacodermata in Biologia-Centrali Americana (
Panama, Ecuador.
Holotype • male, “Panama, V. de Chiriqui, 25–4000 ft. Champion”, secondary labels - B.C.A. Col. III. (2). Calocladon chiriquense, SYNTYPE - blue-edged circle (BMNH). [Volcan de Chiriqui is now referred to as Volcán Barú].
Paratypes • Panama, same data as for holotype, 1 male, 3 females (BMNH); • “PANAMA, V. de Chiriqui, 2-3000 ft. Champion”, secondary labels - same data as for holotype, SYNTYPE - blue-edged circle, 1 female (BMNH); • “Panama, V. de Chiriqui, 4000–6000 ft. Champion, secondary labels - same data as for holotype, SYNTYPE - blue-edged circle, 3 males (BMNH).
Pronotum and elytra largely yellow, only median longitudinal stripe on pronotum, basal half of elytral suture, and elytral apex black. Phallus rod-like apically, ventromedial opening oval, widest medially. Parameres shorter than half of phallus, their ventrobasal projects separated (d1, Fig.
Body length: 5.1–6 mm, width across the humeri: 1.1–1.2 mm. Body dark brown, only anterior pronotal margin, broad sides of pronotum, trochanters, bases of femora, scutellum, and most of elytra yellow (Fig.
Male. Eyes large, hemispherically prominent, eye diameter 1.5–1.7× longer than interocular distance. Antennae with antennomere 3 (=A3) 1.15× shorter than A4, A4–A10 subequal in length; antennal branches flattened, lamella of A3 1.7× longer than antennomere length, remaining lamellae considerably longer, ~ 2.4× longer than antennomere length (Fig.
Female. Eyes small, eye diameter 1.3× shorter than interocular distance. Antennae serrate (Fig.
Named after the shape of apical portion of parameres.
Panama.
Holotype
• male, “Ecuador, 50 km SW Quito, San Francisco de las Pampas, Otonga res., 1500 m, 0°25'S, 79°00'W, 5–6.Dec 2010, Bolm lgt.“ (
Pronotum black. Elytra bicolor orange-black with suture, longitudinal median oval spot, and triangular apical spot black. Phallus ball-shaped apically, ventromedial opening widest in basal third. Apex of each paramere fitted with a sharp laterally projected tooth, internal sac with a series of diminutive teeth (e, Fig.
Body length: 6.4 mm, width across the humeri: 1.2 mm. Body black, only elytral sidebars orange (with whole suture, longitudinal median oval spot and triangular spot in apical quarter black, remaining sidebars orange (Fig.
Male. Eyes medium-sized, interocular distance 1.3× longer than eye diameter (Fig.
Female. Unknown.
The specific name refers to the single sharp tooth at the apex of each paramere.
Ecuador.
1 | Each elytron with only 4 longitudinal costae, secondary costae absent | Haplobothris Bourgeois, 1879 |
– | Each elytron with 9 longitudinal costae, alternate costae strong, more elevated | 2 |
2 | Pronotum with a median longitudinal carina, areola absent, or at most slot-like | 3 |
– | Pronotum with longitudinal carinae forming median longitudinal areola | 4 |
3 | Median longitudinal areola on pronotum absent, posterior pronotal margin with prominent medioposterior protrusion covering whole scutellum, male antennae flabellate | Lycoplateros Pic, 1922 |
– | Median longitudinal areola on pronotum slot-like, basal margin of pronotum almost straight in median portion, scutellum visible, male antennae serrate | Neolinoptes Nascimento & Bocakova, 2017 |
4 | Aedeagus trilobate, parameres often shortened, but separate from the phallus, basal portion of each paramere with an arcuate ventral protrusion, usually joining medially in a ring-like bridge (character 45, state 1) | 7 |
– | Aedeagus unilobed, parameres either absent, or strongly shortened and coalescent with phallus, sometimes with remnants of sutures dorsally | 5 |
5 | Male genitalia with phallobase not fused to phallus and parameres, terminal maxillary palpomere enlarged, 1.8× longer than palpomere 2 (P2); parameres entirely integrated into the widened basal 1/10–1/3 of tubular phallus, posterior trochanters spinose | Eurrhacus Waterhouse, 1879 |
– | Male genitalia with phallobase fused to phallus and parameres (if present), terminal maxillary palpomere small, 1.3–1.6× shorter than P2 | 6 |
6 | Phallus and phallobase ventrally coalescent to parameres, basal 3/5 of phallus with integrated parameres conical, parameres dorsally visible, slightly folded. Terminal maxillary palpomere 1.3× shorter than P2, posterior trochanters triangular | Emplectus Erichson, 1847 |
– | Parameres absent, phallus S-shaped, basally fused to median portion of phallobase, terminal maxillary palpomere 1.6× shorter than P2 | Currhaeus Nascimento, Bressan & Bocakova, 2020 |
7 | Pronotum ~ 1.3× longer than wide; apical half of phallus strongly curved ventrally, parameres short, as long as 1/3 of phallus; base of phallus sharply triangular (character 47, state 1), integrated to dorsobasal portion of parameres; phallobase elongate, as long as 2/3 of phallus | Calocladon Gorham, 1881 |
– | Pronotum wider than long, base of phallus anchor-shaped (inverted mushroom-shaped) (Fig. |
8 |
8 | Primary costa 3 usually joined to primary costa 2 in distal 1/3–1/4 of elytra. Parameres almost as long as phallus, laterally compressed, connected basally by a strong annular ventral bridge, apex rounded | Atlanticolycus Nascimento & Bocakova, 2023 |
– | Primary costa 3 almost fully developed, not joining to primary costa 2. Parameres shorter than the phallus by at least a quarter of the length, distal half flattened, with ventrobasal projects either strongly flattened (Fig. |
9 |
9 | Parameres flattened, ribbon-like, L-shaped in lateral view, apex with basally-oriented hooks, ventrobasal parameral projects flattened, sometimes constituting a ventral bridge, base of phallus more or less flat anchor-shaped (inverted mushroom-shaped) | Cladocalon Nascimento & Bocakova, 2022 |
– | Parameres basally semicircular in cross-section, apex of parameres with 1 or 2 laterodistal teeth. Ventrobasal parameral projects, or ventral bridge very slender, base of phallus pointed anchor-shaped, or inverted mushroom-shaped (character 47, state 1) | Gorhamium gen. nov. |
Support for a monophyletic origin of Calopterini and the subtribe Calopterina has been confirmed by previous (
Support for major Calopterini and Eurrhacini lineages (
Tree search procedures | ML | BA | MP | MP | MP | MP |
---|---|---|---|---|---|---|
NW | NW | NW | IW | |||
UFBoot | PP | MRCT | BS | SR | MRCT | |
Calopterini + Eurrhacini | 65 | 38 | 100 | 22 | 24 | 100 |
Calopterini | 51 | 29 | 91 | 6 | 10 | P |
Calopterina | 77 | 52 | P | 10 | 16 | 100 |
Acroleptina | P | P | 100 | P | P | 100 |
Eurrhacini | 78 | 51 | 100 | 1 | 2 | 100 |
Calocladon clade | 88 | 93 | 100 | 49 | 55 | 100 |
Eurrhacus clade | P | P | 100 | P | P | 100 |
Consistent with our results, previous analyses supported the Eurrhacini and showed Haplobothris as the deepest branch. The initial trees (
Our updated dataset is the first to include the recently described Atlanticolycus (Brazil), Cladocalon (Mexico, Guatemala, and Panama), and Gorhamium gen. nov. (Panama, Ecuador) proposed here. The analyses show Calocladon and the three closely related genera constitute a highly supported clade (UFBoot = 88, pp = 0.93).
Members of the Calocladon clade share two unambiguous synapomorphies (Suppl. materials
We would like to thank M. Geiser (The Natural History Museum, London) who has kindly searched and loaned us H. S. Gorham‘s syntypes. We are also indebted to V. S. Ferreira for sending preliminary photographs of syntypes from the
The authors have declared that no competing interests exist.
No ethical statement was reported.
This study was supported by a GFD_PdF_2023_06 grant from Palacky University Olomouc (Czech Republic).
Both authors contributed to this work.
Elynton Alves Nascimento https://orcid.org/0000-0002-9071-2823
Milada Bocakova https://orcid.org/0000-0002-2507-0887
All of the data that support the findings of this study are available in the main text or Supplementary Information.
List of morphological characters
Data type: docx
Explanation note: List of morphological characters (adapted from
Bayesian phylogeny of Calopterini and Eurrhacini
Data type: tif
Explanation note: Bayesian phylogeny of Calopterini and Eurrhacini inferred from morphological data, node labels represent posterior probabilities.
Strict consensus of 23 parsimony trees of Calopterini and Eurrhacini using equal weights
Data type: tif
Explanation note: Unambiguous character changes mapped on branches in WinClada, black circles represent nonhomoplasious changes, white circles homoplasious changes. Circles are labelled with small character numbers above and character states below.
Strict consensus of 23 unweighted parsimony trees, fast optimization using ACCTRAN
Data type: tif
Explanation note: Fast optimization using accelerated (ACCTRAN) transformations mapped on branches in WinClada, black circles represent non-homoplasious changes, white circles homoplasious changes. Circles are labelled with small character numbers above and character states below.
Strict consensus of 23 unweighted parsimony trees, fast optimization using DELTRAN
Data type: tif
Explanation note: Slow optimization using delayed (DELTRAN) transformations mapped on branches in WinClada, black circles represent nonhomoplasious changes, white circles homoplasious changes. Circles are labelled with small character numbers above and character states below.
The majority-rule consensus of the 23 MP trees from the initial equal weights parsimony analysis of Calopterini and Eurrhacini
Data type: tif
Bremer support values mapped on the strict consensus of 23 parsimony unweighted trees of Calopterini and Eurrhacini
Data type: tif
Branch support using standard bootstrapping applied on the unweighted Calopterini-Eurrhacini dataset
Data type: tif
Branch support using symmetric resampling applied on the unweighted Calopterini-Eurrhacini dataset
Data type: tif
The single implied weighted parsimony tree using TNT and the concavity constant in the range k = 3–25
Data type: tif