Toward a revised checklist of the Western Palearctic butterflies, hyperlinked to the original descriptions at species, genus and family level (Lepidoptera, Papilionoidea)
Part IV: Rationale and framework for the Riodinidae and Lycaenidae (part I)
Submitted: 11.iii.2026 | Accepted: 25.iii.2026 | Published online: 30.iii.2026.
DOI: 10.5281/zenodo.18985843

Michel Taymans¹ | Sylvain Cuvelier²
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¹ Clos du Moulin Royal 2 bte 02, B-6900 Marche-en-Famenne, Belgium. michel.taymans@hotmail.com
² Diamantstraat 4, B-8900 Ieper, Belgium. sylvain.cuvelier@telenet.be

Abstract
Taxonomic and nomenclatural issues concerning the butterfly families Riodinidae and Lycaenidae (partim) are reviewed in light of the rules of the International Code of Zoological Nomenclature (ICZN), historical classifications, recent phylogenetic studies and current usage. Particular attention is given to the classification of subfamilies and tribes, where older names and synonymies have sometimes conflicted with prevailing usage, requiring rigorous evaluation under the Code.
The classification all species of the genera and subgenera of the tribe Lycaenini is debated and justified, particularly for the species alciphron, hippothoe, and candens. The status of the species Lycaena dimorphus (Staudinger, 1881) are clarified. Lycaena japhetica Nekrutenko & Effendi, 1983 is added to the checklist.

Key words
Taxonomy — Checklist — Papilionoidea — Lycaenidae — Riodinidae — Lycaeninae — Theclinae — Aphnaeinae — Lycaenini — Lycaena  — Cigaritis  — Thecla  — Favonius  — Laeosopis  — Deudorix — Tomares  — Callophrys  — Neolycaena  — Satyrium — Lycaena dimorphus — Lycaena japhetica  — Western Palearctic.

Introduction
The present article seeks to clarify the classification adopted in the checklist for the family Riodinidae and for the subfamilies of the family Lycaenidae, with the exception of Polyommatinae, which will be addressed in a subsequent paper. Despite extensive research, the internal classification of this family remains partly unresolved. In particular, the rank and delimitation of the principal groups traditionally regarded as subfamilies have been interpreted in different ways by different authors, depending on the morphological or molecular evidence on which their conclusions are based.
Over the past decades, several phylogenetic studies have proposed different hypotheses regarding the relationships among these groups. Analyses based on morphological characters or molecular data have produced alternative arrangements of the principal clades and have sometimes attributed to them different taxonomic ranks, treating them either as subfamilies or as tribes within broader assemblages. Consequently, no single classification has yet achieved general consensus, and the placement and relationships of some groups remain uncertain.
Furthermore, some recent phylogenetic studies have delimited genera primarily on the basis of genetic data, sometimes without considering other criteria, which may lead to a certain degree of nomenclatural instability.

1. Classification of families and subfamilies

1.1. Riodinidae
The Riodinids, long treated as a subfamily of the Lycaenidae, are here regarded as a distinct family, following Espeland et al. (2015). This study places the genus Hamearis (the only West Palaearctic genus of this family) within the tribe Nemeobiini of the subfamily Nemeobiinae.
The present checklist therefore follows Espeland et al. (2015) for the classification of the Riodinidae.

1.2. Lycaenidae
Among the Lycaenids, only the subfamilies Lycaeninae, Aphnaeinae and Theclinae are analysed in the present article. The subfamily Polyommatinae, which comprises a large number of tribes, genera and species, will be treated in a subsequent paper.
The classification adopted in the checklist follows the results of recent publications on classification and phylogeny produced over the last fifty years. Over time, the validity of the subfamilies and their relationships have been the subject of several hypotheses that differ markedly from one another. A representative sample is given below:
- Eliot, 1973: (Lipteninae + Poritiinae) + (Liphyrinae + Miletinae) + Curetinae + (Theclinae + Lycaeninae + Polyommatinae).
- Pierce et al., 2002: Riodininae + (Poritiinae + Miletinae + Curetinae + Lycaeninae*) *including Theclini + Aphnaeini + Lycaenini + Polyommatini.
- Heikkilä et al., 2012: Curetinae + (Lycaeninae** + (Aphnaeinae + Miletinae + Poritiinae)) **including Theclini + Lycaenini + Polyommatini.
- Liu et al., 2020: Curetinae + ((Aphnaeinae + Miletinae) + (Lycaeninae + (Polyommatinae + Theclinae))).
- Wiemers et al., 2020 (Europe only): (Aphnaeinae + Lycaeninae) + (Theclinae + Polyommatinae).
- Kawahara et al., 2023: Curetinae + (Miletinae + ((Aphnaeinae + Poritiinae) + (Lycaeninae + (Theclinae + Polyommatinae)))).
- Zhang et al., 2023: ((Liphyrinae + Miletinae) + (Poritiinae + Aphnaeinae)) + (Lycaeninae + (Theclinae + Polyommatinae)).
Recent phylogenetic studies of the Lycaenidae (Liu et al., 2020; Wiemers et al., 2020; Kawahara et al., 2023) yield somewhat different results regarding the relationships among the subfamilies. However, the subfamilies considered valid are the same, namely, for the West Palaearctic fauna: Aphnaeinae, Lycaeninae, Theclinae and Polyommatinae.
These four subfamilies have therefore been retained in the checklist. In the most recent studies, the position of the subfamily Aphnaeinae remains somewhat uncertain. It is therefore likely that the arrangement of the subfamilies will need to be revised in a future update of the checklist, based on further studies.

1.3. References
Eliot J.1973. The higher classification of the Lycaenidae (Lepidoptera): a tentative arrangement. — Bulletin of the British Museum (Natural History) Entomology 28(6): 371-505, fig. (url)

Espeland M., Hall J., De Vries P., Lees D., Cornwall M., Hsu Y-F., Wu L-W., Campbell D., Talavera G., Vila R., Salzman S., Ruehr S., Lohman  D.. & Pierce N. 2015. Ancient Neotropical origin and recent recolonisation: Phylogeny, biogeography and diversification of the Riodinidae (Lepidoptera: Papilionoidea). — Molecular Phylogenetics and Evolution 93: 296-306, fig. https://doi:10.1016/j.ympev.2015.08.006

Heikkilä M., Kaila L., Mutanen M., Peña C. & Wahlberg N. 2012. Cretaceous origin and repeated tertiary diversification of the redefined butterflies. — Proceedings of the Royal Society B 279(1731): 1093-1099, fig. https://doi.org/10.1098/rspb.2011.1430

Kawahara A., Storer C., Carvalho A., Plotkin D., Condamine F., Braga M., Ellis E., St Laurent R., Li X., Barve V., Cai L., Earl C., Frandsen B., Owens H., Valencia-Montoya W., Aduse-Poku K., Toussaint E., Dexter K., Doleck T., Markee A., Messcher R., Nguyen Y., Badon J., Benítez H., Braby M., Buenavente P., Chan W., Collins S., Rabideau Childers R., Dankowicz E., Eastwood R., Fric Z., Gott R., Hall J., Hallwachs W., Hardy N., Hawkins Sipe R., Heath A., Hinolan J., Homziak N., Hsu Y., Inayoshi Y, Itliong M., Janzen D., Kitching I., Kunte K., Lamas G., Landis M., Larsen E., Larsen T., Leong J., Lukhtanov V., Maier C., Martinez J., Martins D., Maruyama K., Maunsell S., Mega N., Monastyrskii A., Morais A., Müller C., Naive M., Nielsen G., Padrón P., Peggie D., Romanowski H., Sáfián S., Saito M., Schröder S., Shirey V., Soltis D., Soltis P., Sourakov A., Talavera G., Vila R., Vlasanek P., Wang H., Warren A., Willmott K., Yago M., Jetz W., Jarzyna M., Breinholt J., Espeland M., Ries L., Guralnick R., Pierce N. & Lohman D. 2023. A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins. — Nature Ecology & Evolution 7: 903-913. Article: https://doi.org/10.1038/s41559-023-02041-9 . Supplementary Materials: (url).

Liu G., Chang Z., Chen L., He J., Dong Z., Yang J., Lu S., Zhao R., Wan W., Ma G., Li J., Zhang R., Wang W. & Li X. 2020. Genome size variation in butterflies (Insecta, Lepidotera, Papilionoidea): a thorough phylogenetic comparison. — Systematic Entomology 45(3): 571-582, fig.  https://doi.org/10.1111/syen.12417

Pierce N., Braby M., Heath A., Lohman D., Mathew J., Rand D. & Travassos M. 2002. The ecology and evolution of ant association in the Lycaenidae (Lepidoptera). — Annual Review of Entomology 47: 733–771, fig. https://doi.org/10.1146/annurev.ento.47.091201.145257

Taymans M. & Cuvelier S. A dynamic checklist of the Western Palearctic butterflies hyperlinked to the original descriptions at species, genus and family level (Lepidoptera, Papilionoidea). — Archives of Western Palearctic Lepidoptera 2025(1): 1-70. https://doi.org/10.5281/zenodo.14733224

Wiemers M., Chazot N., Wheat C. W., Schweiger O. & Wahlberg N. 2020. A complete time-calibrated multi-gene phylogeny of the European butterflies. — ZooKeys 938: 97–124, fig. https://doi.org/10.3897/zookeys.938.50878. https://doi.org/10.1111/zsc.12075.

Zhang J., Cong Q., Shen J., Song L. & Grishin N.2023. Butterfly classification and species discovery using genomics. — The Taxonomic Report of the International Lepidoptera Survey 11(3): 1-93, fig. (url).

2. Classification of tribes and genera

2.1. Subfamily Aphnaeinae
The West Palaearctic fauna of Aphnaeinae comprises only a few species, all associated with the genus Cigaritis. In a study of the global phylogeny of Aphnaeinae, Boyle et al. (2014) proposed a revised generic structure without subgeneric divisions; the genus Cigaritis remains valid for all West Palaearctic species. In Zhang et al. (2023), the subfamily is divided into several tribes (mostly newly established); the genus Cigaritis is assigned to the tribe Cigaritini Grishin, 2023, trib. nov. This arrangement needs to be taken into account in a future version of the checklist.
Weidenhoffer & Bozano (2007), who consider Cigaritis belonging to the tribe Aphnaeini within the subfamily Theclinae, divide the genus Cigaritis into three subgenera: Cigaritis Donzel, 1847, Apharitis Riley, 1925 and Sphindasis Wallengren, 1857; only the first two include West Palaearctic species. In that study, C. myrmecophila Dumont, 1922 and C. acamas (Klug, 1834) are placed in the subgenus Apharitis. However, the genitalia structure of these two species is very similar to that of the other species of the genus. The checklist therefore treats all species within the single genus (and subgenus) Cigaritis, in accordance with the results of the above-mentioned phylogenetic studies.

2.2. Subfamily Lycaeninae
Several studies have addressed the phylogeny of this subfamily (Cassulo et al., 1989; Marabuto et al., 2023; Walia et al., 2025; etc.), but most have been either partial or based on a limited number of species. A recent study (Zhang et al., 2022) provides a very comprehensive overview, including the type species of all taxa at the generic level. For the West Palaearctic species, this results in the following structure:
Genus Lycaena with the subgenera Heodes*, Alciphronia, Lycaena and Thersamolycaena + genus Helleia with the subgenus Helleia + genus Tharsalea with five subgenera, of which only one is West Palaearctic, Phoenicurusia.
*Heodes consists of two distinct clades, the Heodes sensu stricto clade and the hippothoe/candens clade, which was nevertheless retained within the subgenus Heodes.
In order to avoid fragmenting the genus Lycaena, and primarily in the interest of nomenclatural stability, the checklist does not follow the conclusions of this latter study. Instead, all species are retained within a single genus, Lycaena, with subgenera composed of species sharing a homogeneous genitalia structure.
This arrangement largely corresponds to the clades defined above by Zhang et al. (2022), with the exception of the following species:
L. hippothoe (Linnaeus, 1761) and L. candens (Herrich-Schäffer, [1844]), placed in the subgenus Heodes Dalman, 1816 by Zhang et al. (2022), are treated in a distinct subgenus, Palaeochrysophanus Verity, 1943, in the checklist. This is justified by the markedly different structure of their genitalia and by the fact that these two species form a distinct clade from the other species of Heodes.
L. alciphron (Rottemburg, 1775), placed in a separate subgenus, Alciphronia Koçak, 1992, by Zhang et al. (2022), is included in the subgenus Heodes Dalman, 1816 in the checklist. This is justified by the very similar genitalia structure shared with the other species of Heodes.

2.3. Subfamily Theclinae
Apart from Zhang et al. (2023) and Kawahara et al. (2023), no study has addressed the subfamily Theclinae as a whole, despite its high species richness and worldwide distribution. Consequently, no comparative data could be found for the two West Palaearctic genera Favonius and Neolycaena.
For the remaining genera, their placement in the checklist follows the two studies cited above. The two uncertain genera were assigned based on similarities in genitalia structure with the classified genera: Favonius is placed in the tribe Theclini and Neolycaena in the tribe Eumaeini.

2.4. References
Boyle J., Kaliszewska Z., Espeland M., Suderman T., Fleming J., Heath A. & Pierce N. 2014. Phylogeny of the Aphnaeinae: myrmecophilous African butterflies with carnivorous and herbivorous life histories. — Systematic Entomology 40(1) : 169-182, fig. https://doi.org/10.1111/syen.12098

Bozano G. & Weidenhoffer Z. 2001. In: Bozano, Guide to the Butterflies of the Palearctic Region. Lycaenidae part I, Subfamily Lycaeninae. — Milano: Omnes Artes (Ed.). 62 p., fig.

Cassulo L. A., Mensi P. & Balletto E. 1989. Taxonomy and evolution in Lycaena (subgenus Heodes) (Lycaenidae). — Nota Lepidopterologica 12(suppl.): 23-25. (url)

Dorp K. van -. 2004. Molecular systematics of Lycaena F., 1807 (Lepidoptera: Lycaenidae) Some preliminary results. — Procceedings of the Netherlands Entomological Society 15 (1995), 65–70.

Kawahara A., Storer C., Carvalho A., Plotkin D., Condamine F., Braga M., Ellis E., St Laurent R., Li X., Barve V., Cai L., Earl C., Frandsen B., Owens H., Valencia-Montoya W., Aduse-Poku K., Toussaint E., Dexter K., Doleck T., Markee A., Messcher R., Nguyen Y., Badon J., Benítez H., Braby M., Buenavente P., Chan W., Collins S., Rabideau Childers R., Dankowicz E., Eastwood R., Fric Z., Gott R., Hall J., Hallwachs W., Hardy N., Hawkins Sipe R., Heath A., Hinolan J., Homziak N., Hsu Y., Inayoshi Y, Itliong M., Janzen D., Kitching I., Kunte K., Lamas G., Landis M., Larsen E., Larsen T., Leong J., Lukhtanov V., Maier C., Martinez J., Martins D., Maruyama K., Maunsell S., Mega N., Monastyrskii A., Morais A., Müller C., Naive M., Nielsen G., Padrón P., Peggie D., Romanowski H., Sáfián S., Saito M., Schröder S., Shirey V., Soltis D., Soltis P., Sourakov A., Talavera G., Vila R., Vlasanek P., Wang H., Warren A., Willmott K., Yago M., Jetz W., Jarzyna M., Breinholt J., Espeland M., Ries L., Guralnick R., Pierce N. & Lohman D. 2023. A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins. — Nature Ecology & Evolution 7: 903-913. Article: https://doi.org/10.1038/s41559-023-02041-9 . Supplementary Materials: (url).

Marabuto E., Nunes M. S., Martins R., Mendes R., Moreira-Pinhal T., Raimundo J., Seabra S., Paulo O. 2023. Integrative analysis reveals the divergence and speciation between sister Sooty Copper butterflies Lycaena bleusei i and L. tityrus. — Molecular Phylogenetics and Evolution 180(107699): 1-16, fig.  https://doi.org/10.1016/j.ympev.2022.107699

Sáfián S., Saito M., Schröder S., Shirey V., Soltis D., Soltis P., Sourakov A., Talavera G., Vila R., Vlasanek P., Wang H., Warren A., Willmott K., Yago M., Jetz W., Jarzyna M., Breinholt J., Espeland M., Ries L., Guralnick R., Pierce N. & Lohman D. 2023. A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins. — Nature Ecology & Evolution 7: 903-913. Article: https://doi.org/10.1038/s41559-023-02041-9 . Supplementary Materials: url.

Taymans M. & Cuvelier S. A dynamic checklist of the Western Palearctic butterflies hyperlinked to the original descriptions at species, genus and family level (Lepidoptera, Papilionoidea). — Archives of Western Palearctic Lepidoptera 2025(1): 1-70. https://doi.org/10.5281/zenodo.14733224

Walia G., Sidhu A. & Chopra D. 2025. Phylogenetic Investigations on Subfamily Lycaeninae from the Northwestern Region of India. —  Proceedings of the Zoological Society 78: 223–232, fig. https://doi.org/10.1007/s12595-025-00577-1

Weidenhoffer Z. & Bozano G. 2007. In: Bozano, Guide to the Butterflies of the Palearctic Region. Lycaenidae part III, Subfamily Theclinae, tribes Tomarini, Aphnaeini and Theclini (partim). — Milano: Omnes Artes (Ed.). 97 p., fig.

Zhang J., Cong Q., Shen J., Opler P. & Grishin N. 2020. Genomic evidence suggests further changes of butterfly names. — The Taxonomic Report of the International Lepidoptera Survey 8(7): 1-40, fig. (url)

Zhang J., Cong Q., Shen J., Song L., Gott R., Boyer P. , Guppy C., Kohler S., Lamas G., Opler P.. & Grishin N. 2022. Taxonomic discoveries enabled by genomic analysis of butterflies. — The Taxonomic Report of the International Lepidoptera Survey 10(7): 1-59, fig. (url)

Zhang J., Cong Q., Shen J., Song L. & Grishin N. 2023. Butterfly classification and species discovery using genomics. — The Taxonomic Report of the International Lepidoptera Survey 11(3): 1-93, fig. (url)

3. Notes on the status of Lycaena dimorphus (Staudinger, 1881)

3.1. Context
Nekrutenko & Effendi (1983) described Lycaena japhetica as a new species in the Lycaena phoenicurus (Lederer, 1872) group, from the valley of the Dizavarchay River in Azerbaijan.
Nekrutenko (1985) described Lycaena japhetica irghiza, a new subspecies, from the Aktobe River in the Irgiz region of Kazakhstan.
Lukhtanov (2000), in a study of this group of Lycaena, retained the specific status of japhetica but transferred its subspecies irghiza to Lycaena dimorpha (Staudinger, 1881).
Tshikolovets (2003), in his book on the butterflies of Eastern Europe, included Lycaena japhetica and indicated three localities on its distribution map: one in Azerbaijan and two in the Irgiz region of Kazakhstan, referring to Nekrutenko & Effendi (1983) and Nekrutenko (1985).
Lvovsky & Morgun (2007) reported the presence of Lycaena dimorpha irghiza in Orenburg Oblast (southern Urals, Russian Federation), relatively close to the border with Kazakhstan.
Wiemers et al. (2018) included Lycaena dimorpha (Staudinger, 1881) in their checklist, based on the record published by Lvovsky & Morgun (2007).
Following Wiemers et al. (2018), Taymans & Cuvelier (2023) included this species in the checklist under its original, non-agreement form Lycaena dimorphus (Staudinger, 1881).
Tshikolovets (2025) mentioned Lycaena japhetica irghiza from the Orenburg region (southern Urals, Russian Federation) and clearly justified his choice of species, correctly noting that Lukhtanov (2000) did not provide a valid justification for the species transfer he proposed. Moreover, the habitus and the male and female genitalia of L. japhetica differ markedly from those of L. dimorpha and in fact show closer similarity to L. athamantis.
As the diagnosis provided by Tshikolovets (2025) appears convincing, Lycaena dimorphus (Staudinger, 1881) will be removed from the checklist and replaced by Lycaena japhetica Nekrutenko & Effendi, 1983.

3.2. References
Lukhtanov V. 2000. Zur Systematik und Verbreitung der Taxa der Athamanthia dimorpha – Gruppe. Atalanta 31(1/2): 179-192. (url).

Lvovsky A. L. & Morgun D. V. 2007. Butterflies of the Eastern Europe. — Moscow: KMK Scientific Press Ltd. (Ed.). 443 p. (in Russian)

Nekrutenko, Y. 1985. Новые таксоны голубянок (Lepidoptera, Lycaenidae) из Закавказья и Центральной Азии. [New blue butterfly taxa (Lepidoptera, Lycaenidae) from Transcaucasia and Middle Asia]. — Вестник зоологии [Vestnik Zoologii] 1985 (4): 29-35. (url) (in Russian)

Nekrutenko Y. &  Effendi R. 1983. Обзор голубянок группы Lycaena phoenicurus (Lepidoptera, Lycaenidae) с описанием нового вида из Азербайджана [Révision du groupe de Lycaena phoenicurus (Lepidoptera, Lycaenidae) avec la description d'une nouvelle espèce d'Azerbaïdjan]. — Вестник зоологии [Vestnik Zoologii] 1983(4): 8-15, fig.(url) (in Russian)

Taymans M. & Cuvelier S. A dynamic checklist of the Western Palearctic butterflies hyperlinked to the original descriptions at species, genus and family level (Lepidoptera, Papilionoidea). — Archives of Western Palearctic Lepidoptera 2025(1): 1-70. https://doi.org/10.5281/zenodo.14733224

Tshikolovets V. 2003. Butterflies of Eastern Europe, Urals and Caucasus. — Kyiv/Brno: Tshikolovets V. (Ed.). 176 p.

Tshikolovets V. 2025. Butterflies of the Western Palaearctic. Volume I, Hesperiidae, Papilionidae, Pieridae, Lycaenidae (partim). — Pardubice: Tshikolovets publications (Ed.). 352 p.

Wiemers M., Balletto E., Dincă V., Fric Z., Lamas G., Lukhtanov V., Munguira M., van Swaay C., Vila R., Vliegenthart A., Wahlberg N. & Verovnik R. 2018. An updated checklist of the European Butterflies (Lepidoptera, Papilionoidea). — ZooKeys 811: 9-45. doi.org/10.3897/zookeys.811.28712

Author contribution
Michel Taymans: conceptualisation, analysis, visualisation, writing - original draft, writing – review and editing.
Sylvain Cuvelier: analysis, validation, visualisation, writing – review and editing.

Acknowledgements
We are sincerely grateful to Theo Garrevoet for his careful and thorough review of the final draft, and we wish to acknowledge Bénédicte Jonckers for her invaluable administrative support as production editor.