Research Article |
Corresponding author: Peter Huemer ( p.huemer@tiroler-landesmuseen.at ) Academic editor: Mark Metz
© 2024 Lauri Kaila, Peter Huemer.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Kaila L, Huemer P (2024) Elachista dimicatella sensu auctt.—a complex of neglected species diversity (Lepidoptera, Elachistidae) from European mountain systems. ZooKeys 1212: 179-194. https://doi.org/10.3897/zookeys.1212.126598
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Elachista dimicatella Rebel, 1903, has so far been considered a species in Europe with restricted distribution from Ukraine to western France. The species occurs on mountainous regions. However, the in-depth analysis of a taxonomically uncertain species of Elachista from the Cottian Alps (Italy), especially through DNA barcoding and subsequent morphological studies, led to the realization that individuals previously identified as E. dimicatella from the Cottian Alps and the Pyrenees were misidentified. According to our research, a total of three species can be differentiated: E. dimicatella from Carpathians and its former junior synonym E. niphadophanes Meyrick, 1937, sp. rev., from the Pyrenees, as well as the newly described E. cottiella sp. nov. from southwestern Alps, hitherto incorrectly identified as E. dimicatella. Diagnostic features of the three species are discussed and illustrated. Elachista dimicatella and E. niphadophanes are redescribed.
Cryptic diversity, DNA barcoding, Elachistinae, endemic, montane, morphology systematics
Elachistinae is an extremely diverse subfamily of micromoths with more than 800 valid species worldwide placed in 10 genera (
The present paper is based on material from the following collections:
Material of the new species collected by PH was attracted to artificial light (UV tubes) or bred (
The terminology of genitalia follows the standard work of
Tissue samples (dried legs) of three specimens of the new species were prepared for DNA barcoding (
Sequences were assigned to Barcode Index Numbers (BIN). BINs were automatically calculated for records in BOLD that comply with the DNA Barcode standard (
A neighbour-joining tree was constructed using the Kimura-2-parameter model in MEGA7 (
Photographs of adults were taken with an Olympus OM-D Mark III camera and a 60 mm macro lens. Genitalia photographs of E. niphadophanes with a Zeiss Axiolab 5 microscope, mounted with an Olympus OM-D Mark III camera; 60 to 90 stacked photographs were edited using Helicon Focus 4.8 and Adobe Photoshop 6.0. Other genitalia images were taken with a Leica DM4000 B LED camera, and were edited, and the plates of each specimen assembled using several versions of Corel Photo-Paint included in CorelDRAW Graphics suite. Comparison of the length of the phallus in relation to the valva was measured as the longest line from the base of the sacculus to the apex of the cucullus. In the assembled male genital plates the true length of the phallus as compared with other parts of the genitalia is shown with the phallus positioned in the left side of the genitalia. The magnified images of the phallus and the juxta do not reflect their relative sizes among the species. The same applies to the “whole genitalia with phallus” part. These images are not at the same scale between images. The size of the genitalia correlates with the size of the specimen, so the wingspan can be used as a proxy for the relative sizes of the genitalia.
The background (Hillshade: transparency 27.4%) was integrated using WMS (Web Map Service) from the address osm-wms.de (license: CC BY-SA), whose original data is based on satellite data (https://srtm.csi.cgiar.org/). The administrative boundaries were taken from the European site https://ec.europa.eu/eurostat/web/gisco/geodata/administrative-units/countries (license: CC BY 4.0). The water network is from https://land.copernicus.eu/ (digital rights: full, open and free access).
Molecular analysis is based on 79 DNA barcodes sequences for nine Elachista species belonging to the Elachista bifasciella species group. The interspecific distances to the nearest neighbour in this dataset vary from 4.14% to 8.59% per species pair. Intraspecific barcode variation is distinctly lower but based on only limited material for few species. It exceeds 2% only in E. bifasciella which clusters in 2 BINs, one geographically limited to southern Austria, whereas all other specimens cluster in a single and unique BIN (Table
Intraspecific mean K2P (Kimura-2-Parameter) divergences, maximum pairwise distances, Barcode Index Number (BIN), nearest species, distance to nearest neighbor (NN) (distances in %) of Elachista spp. Source: DNA Barcode data from BOLD, DS-ELACDIMI (Barcode of Life Database, cf.
Species | Mean intra | Max intra | BIN | Nearest species | Distance to NN |
---|---|---|---|---|---|
Elachista apicipunctella | 0.12 | 1.24 | BOLD:AAE0019 | Elachista ipirosella | 6.65 |
Elachista argentifasciella | N/A | 0 | BOLD:ACT4739 | Elachista cottiella | 8.59 |
Elachista bifasciella | 0.75 | 2.89 |
BOLD:AAK9442
BOLD:AEC6228 |
Elachista dimicatella | 8.36 |
Elachista cottiella | 0.31 | 0.46 | BOLD:AEM6237 | Elachista dimicatella | 6.57 |
Elachista dimicatella | 0.21 | 0.24 | BOLD:AAV6449 | Elachista cottiella | 6.57 |
Elachista ipirosella | 0 | 0 | BOLD:ABA2345 | Elachista maculosella | 2.18 |
Elachista maculosella | 0.15 | 0.15 | BOLD:ABW4899 | Elachista ipirosella | 2.18 |
Elachista nobilella | 0.13 | 0.32 | BOLD:AAF6140 | Elachista dimicatella | 6.75 |
Elachista rufocinerea | 0.15 | 0.15 | BOLD:ABV9577 | Elachista sebastella | 4.75 |
Elachista sebastella | N/A | 0 | BOLD:ACE1105 | Elachista ipirosella | 4.14 |
Neighbour-joining tree of Elachista species (Kimura-2-parameter, built with MEGA7 cf.
Elachista dimicatella Rebel, 1903: 100. Type locality: Ukraine, Marmaros.
Lectotype
♂, designated by
Poland • 1♂; Tatra Mts., Kościeliska Valley; 1000 m a.s.l.; 49.30°N, 19.93°E; 22 Jun 1987; ex larva from Sesleria tatrae; J. Buszko leg.; L. Kaila prep. 587; Elachista dimicatella Hering, L. Kaila det. 2004; 1♀, same collecting data but host plant Alopecurus pratensis;
Ukraine • 6♂ 2♀; Ivano-Frankivsk oblast, Verkhovyna district, Mt. Chivchen; 1600–1760 m a.s.l.; 48.15°N, 24.82°E; J. Kullberg & T. Lievonen leg.; L. Kaila prep. 4653, 4827, 6383; DNA barcode vouchers 16160, 16161 Lepid. Phyl.;
Elachista dimicatella is externally characterized by the creamy white head, the white base of the nearly black forewing reminiscent of E. diederichsiella Hering, straight and relatively narrow median fascia, and the usually medially confluent subcostal (tornal) and costal spots, often forming a steep angle towards apex. The antennae of the male are unicolourous grey in the male, in the female paler in apical half; in E. cottiella the antennae of both sexes are unicolourously dark grey, in E. niphadophanes the antennae of the male vary. In the male genitalia E. dimicatella is close to E. niphadophanes from which it differs by the somewhat longer phallus. From E. cottiella it is distinguished by the white pattern of forewings, that being somewhat silvery in E. cottiella. Subcostal and tornal spots are clearly separate in E. cottiella. In the male genitalia the most distinctive difference between E. dimicatella and E. cottiella is the markedly longer phallus in E. cottiella in which the shape of the juxta lobes is more rounded than in the other species. The antrum is significantly longer and narrower in E. cottiella than in E. dimicatella in which it is distinctly convex. Apophyses anteriores are thinner in E. dimicatella than in E. cottiella. More detailed diagnosis between E. dimicatella and E. cottiella are presented in the diagnosis of the latter species. The female of E. niphadophanes is unknown.
Habitus (Figs
Male genitalia (Fig.
Female genitalia (Fig.
BIN: BOLD:AAV6449 (n = 3). Intraspecific average p-distance within BIN is 0.15%, maximum distance is 0.15%. The nearest neighbour is E. cottiella (BIN: BOLD:AEM6237) at a distance of 6.41%.
In the Polish Tatra Mountains the larvae were collected in late May and June, preferably feeding on Sesleria tatrae and Deschampsia caespitosa, and furthermore on Alopecurus pratensis, Calamagrostis arundinacea, C. villosa, Dactylis glomerata, Milium effusum, and Poa alpina. Adults were observed from late June to July. The habitat is described as grassland on sunny slopes, exclusively on calcareous soil at altitudes between 1000 and 1800 m (
Several additional host-plants published by
Carpathians: Poland (mainly Tatra mts.) (
Elachista niphadophanes
Meyrick, 1937: 100. Type locality: France, Forges d’Abel. Lectotype ♂, designated by
France • 2♂; Pyrenees Orientales, Mosset, Col de Jau; 1450 m a.s.l.; 42.72°N, 2.25°E; 24 Jun.1998 [one without abdomen]; genitalia slide 7419JN; coll. Thierry Varenne • 1♂; Départment des Hautes-Pyrénees, Gripp, Col de Jau, Gripp; 42.96°N, 0.21°E; 8 Jul 1982; C. Gielis leg;
Elachista niphadophanes is overall very similar to E. dimicatella, but the known specimens are somewhat smaller than males of E. dimicatella. They differ by the distally lighter colour of the antenna and the broader median fascia of the forewing in E. niphadophanes. From the similar E. cottiella it furthermore differs by several characters, particularly the colour of the antenna, white tipped tegulae, larger extension and white colour of forewing markings, and the white termen of the forewing. In the male genitalia the most distinctive difference between E. niphadophanes and E. cottiella is the much larger phallus in E. cottiella. The male genitalia are similar to those of E. dimicatella, but the phallus is somewhat smaller in E. niphadophanes.
Habitus [based on two worn male specimens and figure of lectotype] (Fig.
Male genitalia (Fig.
Female unknown.
Unfortunately, no DNA barcode could be retrieved for this species.
Host-plant and early stages are unknown. Host-plants from the Polish Tatra Mountains attributed to the former senior synonym E. dimicatella are not applicable for E. niphadophanes. Furthermore, host-plants published by
Pyrenees. With certainty only known from the type locality Forges d’Abel, from Col de Jau and Gripp (Pyrenees, France), from Cole de Jau published as E. dimicatella (
Elachista niphadophanes was described from two specimens (suggesting male and female sex) collected by Lhomme in the French Pyrenees (Forges d’Abel).
Holotype. Italy • ♂; Prov. Torino, Fenestrelle, Umg. Pracatinat, Forte delle Valli [type locality part of Orsiera-Rocciavrè Nature Park]; 45°2'17"N, 7°4'14"E; 1700–1720 m; 02 Jun 2022; P. Huemer leg.; DNA Barcode ID
Paratypes. Italy • 7♂; prov. Torino, N.N. Conca Cialancia, Umg. Lago Lauson; 2030–2050 m; 44°53'16"N, 7°7'36"E; 17 Jul 2022; P. Huemer leg.; DNA Barcode IDs TLMF_Lep_33427, TLMF_Lep _33428;
Elachista cottiella differs from the closely related E. dimicatella and E. niphadophanes by the entirely grey antennae in both male and female, entirely grey tegulae, a narrower silvery-white medial fascia and smaller and separate subcostal and tornal spots of the forewing, and entirely dark fringe. In the former mentioned species, wing markings are broader with costal and tornal spots medially fused, and the tip of forewing fringe is white. The digitate process is shorter in E. cottiella and E. niphadophanes than in E. dimicatella. The lateral margins of the juxta lobes are more convex in E. niphadophanes than in E. cottiella and E. dimicatella thus making it more round than in the other species. The phallus of E. niphadophanes is shorter than in either other species, 0.6 × as long as valva, basally bulbous. The antrum is significantly longer and narrower in E. cottiella than in E. dimicatella in which it is distinctly convex. Apophyses anteriores are stouter in E. cottiella than in E. dimicatella. The female of E. niphadophanes is unknown.
Habitus (Figs
Male genitalia (Fig.
Female genitalia (Fig.
BIN: BOLD:AEM6237 (n = 4). Intraspecific average p-distance within BIN is considerable with 1.1%, maximum distance is 2.09%. The nearest neighbour is BIN BOLD:ACG7227 (E. wieseriella and an unspecified Elachista sp.) at a distance of 6.19%, and E. dimicatella (BIN: BOLD:AAV6449) with 6.41% distance.
Host-plants insufficiently documented. All reared specimens available to us have been reared from Avenella flexuosa and Festuca sp. in rubra group. Several host-plants from the Polish Tatra Mountains attributed to the former senior synonym E. dimicatella are not applicable for the new species. However, additional host-plants published by
Alps. With certainty only known from Piemont (Cottian Alps, Italy) (Fig.
The new species name refers to the known distribution area.
The documentation of the diversity of European Elachista species has advanced considerably, not in the least due to the increasing implementation of molecular methods. The status of described species is still largely supported by the study of historical type material (
For instance,
We thank Sabine Gaal-Haszler (
The authors have declared that no competing interests exist.
No ethical statement was reported.
No funding was reported.
All authors have contributed equally.
Lauri Kaila https://orcid.org/0000-0003-0277-1872
Peter Huemer https://orcid.org/0000-0002-0630-545X
All of the data that support the findings of this study are available in the main text.