Artículos

Metzneria neli Huemer, sp. n., a new species hitherto mixed with M. tristella Rebel, 1901 (Lepidoptera: Gelechiidae)

Metzneria neli Huemer, sp. n., una nueva especie hasta ahora mezclada con M. tristella Rebel, 1901 (Lepidoptera: Gelechiidae)

Introduction

Metzneria Zeller, 1839 is a diverse genus of mainly Palearctic Gelechiidae, covering 24 described species in Europe (HUEMER & KARSHOLT, 2020). Additional taxa attached to this genus and mainly originating from Africa require revisionary work but have been questioned as congeneric (ENGLERT, 1974), whereas two species from North America (HODGES, 1983) have been introduced from Europe. Metzneria, contrary to several other European Gelechiidae, with the review of ENGLERT (1974), gained early attention. This paper was one of the first generic revisions of Western Palearctic Gelechiidae following a modern attempt, which, beside examination of type material, also included detailed studies of male genitalia. It is therefore not surprising that only five additional species have been described from Europe since, three of them finally turned out as synonyms of already named taxa.

Metzneria tristellaRebel 1901, originally described from Cuenca (Spain), is one of the species firstly revised by ENGLERT (1974). The seemingly unmistakable male genitalia were illustrated, but adults were not figured, and female genitalia remained unknown. These shortcomings may be responsible for the subsequent misinterpretation of the species in a later study, with description of the biology, the female sex and a new record for France (NEL, 1994). Later genetic data of alleged M. tristella were published based on these French records (HUEMER et al., 2020). However, a detailed morphological assessment of a potential new species from Spain led to the suspicion that in fact this taxon could be the true M. tristella. Examination of the lectotype of M. tristella fully supported this revised identification. Conversely, the species from France, previously identified as M. tristella, turned out to be undescribed. It differs from M. tristella and other congeners by phenotypic appearance, genitalia morphology and DNA barcodes and is here introduced as new species.

Material and methods

Specimens: Material used in this study was traditionally set and dried or, particularly more recently, pinned and subsequently spread. Earlier genitalia preparations followed standard techniques (ROBINSON, 1976) more recent slides were adapted for the male genitalia of Gelechiidae by the “unrolling technique” as described by PITKIN (1986).

DNA barcoding is based on 208 European specimens of Metzneria from 24 species, the majority originating from own samples, partially supplemented by public data from BOLD. DNA samples to obtain the 658 base-pair long barcode segment of the mitochondrial COI gene (cytochrome c oxidase I) (from dried legs) were prepared according to the prescribed standards and processed at the Canadian Centre for DNA Barcoding (CCDB, Biodiversity Institute of Ontario, University of Guelph) using the standard high-throughput protocol described in deWAARD et al. (2008). Further details including complete voucher data and images can be accessed in the public dataset “DS-METZNERI Metzneria - new species” dx.doi.org/10.5883/DS-METZNERI in the Barcode of Life Data Systems (BOLD systems v. 4.0. http://www.boldsystems.org (RATNASINGHAM & HEBERT, 2007). Intra- and interspecific distances of DNA barcode fragment were calculated using analytical tools of BOLD with the Kimura 2-parameter model of nucleotide substitution. A Neighbor-joining tree of the successfully sequenced 24 species was constructed using MEGA 6 (TAMURA et al., 2013) under the Kimura 2- parameter model for nucleotide substitutions.

For each species, a Barcode Identification Number (BIN) is provided, which is automatically calculated for records in Bold Data Systems that are compliant with the DNA Barcode standard (RATNASINGHAM & HEBERT, 2013).

Photographic documentation: Photographs of the adults were taken with an Olympus SZX 10 binocular microscope and an Olympus E 3 digital camera and treated using the software Helicon Focus 4.3, Adobe Photoshop CS4, and Lightroom 2.3 softwares. Genitalia photographs were taken with an Olympus E1 Digital Camera through an Olympus BH2 microscope.

Abbreviations of collections:

NHMV = Naturhistorisches Museum, Vienna, Austria

RCTM = Research collection of Toni Mayr, Feldkirch, Austria

TLMF = Tiroler Landesmuseum Ferdinandeum, Innsbruck, Austria

Results

MOLECULAR ANALYSIS

DNA sequencing resulted in a full barcode fragment of 658 bp for 159 specimens and 49 sequences > 540 bp. Sequences of the COI barcode region of analysed nominal species reveal moderate intraspecific but significantly higher interspecific genetic distances. Mean distances within species are 0.90% with a maximum of 2.56%. However, species with an exceptional intraspecific divergence are to be re-assessed for potential cryptic diversity. Interspecific distances are much higher with 5.83% on average, ranging from minimum 1.12% to maximum 9.25% distance to the nearest neighbor (Table 1). All species, except for the morphologically well separated species pair M. fulva Labonne, Huemer, Thibault & Nel, 2019 and M. torosulella (Rebel, 1893) group in one or several unique BINs thus clearly supporting the specific status of M. tristella and the newly described M. neli (fig. 1).

Taxonomic conclusions

Metzneria neli Huemer, sp. n.

Material examined: Holotype ♂, “NEL Jacques Mt-Coudon, VAR e.l. m. 15-05-1996 % Centaurea intybaceus” “BC TLMF Lep 06937” “P. Huemer GEL 1313 ♂” (TLMF). Paratypes: France, BdR, la Ciotat, rte des Crètes, 1 ♂, 15-V-1993, leg. J. Nel (gen. slide 0963 J.N.); ditto, but 1 ♂, 17-V-1993 (gen. slide 0948 J.N.); ditto, but 1 ♀, 8-VI-1993 (gen. slide 0972 J.N.); ditto, but 1 ♂, 1 ♀, 11-VI-1993; ditto, but 1 ♂, 13-VI-1993; ditto, but 2 ♂♂, 14-VI-1993; ditto, but 1 ♂, 15-VI-1993; ditto, but 1 ♀, 16-VI-1993; ditto, but 1 ♀, 18-VI-1993; ditto, but 1 ♀, 19-VI-1993; ditto, but 1 ♀, 20-VI-1993 (gen. slide 01132 J.N.); ditto, but 1 ♀, 23-VI-1993; ditto, but 1 ♀, 27-VI-1993; ditto, but 1 ♂, 21-VI1995; Var, Mt-Faron, 1 ♂, 17-VI-1996 e.l. (Centaurea intybaceus), leg. J. Nel; BdR, la Ciotat, Brusquièras de Cassis, 1 ♀, 26-IV-2003, leg. J. Nel (gen. slide GEL 1317 ♀ P. Huemer) (TLMF).

Excluded from type series: SPAIN, Alicante, Agost, 1 ♀, 21-VI-2019, leg. F. Graf, DNA Barcode ID TLMF Lep 26268 (Research collection Friedmar Graf).

Description: Adult (figs 2-3). Head pale ochreous; antenna serrate in male, filiform in female, greyish brown, weakly annulated; labial palpus dark greyish brown, with pale ochreous mottling, particularly at upper surface of segment 2, segment 2 thickened with appressed scales, segment 3 about half length of segment 2, distinctly thickened from appressed dorsal scale brush; thorax and tegula pale ochreous with some dark mottling. Forewing length ♂ 6.6-7.2 mm (n=5), ♀ 7.2-7.6 mm (n=5). Forewing upper side greyish brown, light orange-yellow line along fold, short orange-yellow streaks and patches along veins, particularly at discal spot and along subcostal area and wing base, oblique transverse streak at end of cell extended to costa; stigmata black, first in distal part of fold, plical and discal spots widely separated; termen weakly concave, terminal line fuscous; fringes light greyish, with distinct dark grey fringe line and dark grey apices. Hindwing narrow, grey, fringes ochreous-grey without fringe line. Underside of forewings without lighter costal spot and distinctly divided fringes.

Male genitalia (fig. 8): Uncus with rounded lateral humps; tegumen much wider than long, anterior margin weakly emarginated; pedunculi small; valva basally narrow, distal part strongly dilated to about twice width, convex dorsal and nearly straight ventral margin, with tooth-like apex pointed ventrad; sacculus evenly thorn-shaped; saccus sub-triangular, short; phallus stout, about 3 times longer than wide, subapical area with band like structure covered with spinules, apex with finger-shaped narrow projection, vesica with two moderately long and one shorter cornuti.

Female genitalia (fig. 11): Papilla analis broadly sub-oval, weakly setose; apophysis anterioris about three times length of papilla analis, rod-like, with forked posterior end; segment VIII ventromedially and dorsomedially membranous without modifications, posterior edge with long and stiff setae; entrance of membranous ductus bursae with irregular shortly funnel-shaped colliculum; corpus bursae small, membranous without any modifications.

Diagnosis: Metznerianeli Huemer, sp. n. from genitalia morphology is most closely related to M. tristella. It differs from that species by several characters of adult phenotype, i.e. the scale brush of the third segment of labial palpus, the comparatively broad and serrated antenna of the male, and the overall the lighter ground colour of the forewing with lighter and more extended orange-yellowish markings, the concave terminal excavation and the presence of a distinct fringe line. Male and female genitalia are in fact much more similar to M. tristella but particularly differ in the male. Metzneria neli Huemer, sp. n. is characterized i.e. by the comparatively longer narrow base of the valva, the evenly thorn-shaped sacculus and the phallus with long apical projection. Particularly the shape of the sacculus is unique in the genus. The much stronger and longer setae on the posterior edge of segment VIII of M. neli sp. n. seem to be of diagnostic value in the overall very similar female genitalia but variation is insufficiently known.

Molecular data: BIN: BOLD:ABX1726. The intraspecific average distance of the barcode region is 1.45% (p-dist) (n=2). A unique specimen from Spain corresponding with M. neli sp. n. from external appearance is 2.25% distant (BIN: BOLD:AEB4629) and is considered as likely conspecific. The distance to the nearest neighbor M. metzneriella Stainton, 1851 is 5.06%.

Distribution: Currently only known from few localities in southern France and from the above mentioned single barcoded specimen from Spain but most likely more widely distributed on the Iberian Peninsula.

Bionomics: The larva lives in the flower and sead heads of Cheirolophus intybacea (Lam.) Dostál where it hibernates (NEL, 1994).

Remarks: A unique specimen from Spain is considered conspecific with M. neli from external appearance and the similarity of the DNA barcode. However, in absence of further morphological support it is only tentatively attached to this species and not included in the type series. Following Nel (1994) the number of cornuti varies from 0 to 3.

Derivatio nominis: The new species is dedicated to Dr. Jacques Nel (La Ciotat, France), eminent Lepidopterist and collector of the type series.

Metzneria tristellaRebel, 1901

Metzneria (Parasia) tristellaRebel, 1901. Dt. ent. Z., Iris, 13(2): 164

Material examined: Lectotype ♂, here designated: “Stgr. 900 Cuenca” “Metz. tristella Rbl. Type” “tristella 6212 Rbl. E. Jäckh 1971 % MUS. VIND. 723” (NHMV).

Other material: SPAIN, Aragon, Lake Riba-Roja, Mequienca, 1 ♂, 1-2-V-2000, leg. J. Ortner (gen. slide GEL 1312 ♂ P.H., DNA Barcode TLMF Lep 28251); Castilia - La Mancha, N Cuenca, 1065 m, 40º06.54’N, 02º10.0’W, 2 ♀♀, 17-V-2012, leg. T. Mayr (gen. slide GEL 1316 ♀ P.H., DNA Barcode TLMF Lep 25480, DNA Barcode TLMF Lep 25481) (TLMF, RCTM).

Description Adult (figs 4-5): Head fuscous to greyish brown; antenna filiform, dark greyish brown, weakly annulated; labial palpus greyish brown, lighter at upper surface of segment 2, segment 2 thickened with appressed scales, segment 3 about half length of segment 2, weakly thickened; thorax and tegula fuscous with few lighter scales. Forewing length ♂ 5.8–7.0 mm (n=2), ♀ 5.2–5.6 mm (n=2). Forewing upper side dull brownish grey, orange-brown line along fold, short orange-brown streaks along veins, particularly along discal spot and at subcosta; stigmata black, first in distal part of fold, plical and discal spots widely separated; terminal line fuscous; fringes fuscous, without fringe line. Hindwing narrow, grey, concolorous fringes without fringe line. Underside of wings without any markings.

Male genitalia (figs 9-10): Uncus with lateral humps; tegumen much wider than long, anterior margin weakly emarginated; pedunculi small; valva with short and narrow base, strongly dilated distal part of about twice width, convex dorsal and nearly straight ventral margin, with tooth-like apex pointed ventrad; sacculus thorn-shaped, with particularly broad base and abruptly narrowed apex; saccus sub-triangular, short; phallus stout, about 3 times longer than wide, subapical area with band like structure covered with spinules, apex with short sub-triangular projection and vesica with two moderately long cornuti.

Female genitalia (fig. 12): Papilla analis broadly sub-oval, weakly setose; apophysis anterioris about three times length of papilla analis, rod-like, with forked posterior end; segment VIII ventromedially and dorsomedially membranous without modifications, posterior edge with short setae; entrance of membranous ductus bursae with irregularly funnel-shaped colliculum; corpus bursae small, membranous without any modifications.

Diagnosis: Easily separated from other congeneric species y the dull colour of the forewing. For other diagnostic characters see above.

Molecular data: BIN: BOLD:ADM8252. The intraspecific average distance of the barcode region is 0.16% (p-dist) (n=2). The minimum distance to the nearest neighbor M. metzneriella is 5.81%.

Distribution: Proved specimens originate from Spain, whereas records from Portugal (CORLEY et al., 2000) and Tunisia (NEL, 1994) require verification.

Bionomics: The larva has been recorded from Cheirolophus sempervirens Pomel (CORLEY et al., 2000) but it remains uncertain if this record refers to M. tristella or to another related species.

Remarks: Metzneria tristella was described from an unspecified number of specimens collected nearby Cuenca (REBEL, 1901). The re-examined lectotype was designated by ENGLERT (1974) in order to fix the identity of the species and conserve stability of nomenclature (figs 6-7, 10).

Acknowledgments

The author is particularly grateful to Paul D. N. Hebert and the staff at the Canadian Centre for DNA Barcoding for sequence analysis and support with BOLD. Several DNA barcodes from this platform were generated by various colleagues, i.e. Kai Berggren, Marko Mutanen, Andreas Segerer and Friedmar Graf. Stefan Heim kindly helped with photographic work. Antonio Vives is thanked for editorial tasks, Toni Mayr and Sabine Gaal-Haszler for important loans. Last but not least Jacques Nel is gratefully acknowledged for his continuous support in many aspects.

BIBLIOGRAPHY

DEWAARD, J. R., IVANOVA, N. V., HAJIBABAEI, M. & HEBERT, P. D. N., 2008.– Assembling DNA Barcodes: Analytical Protocols. Pp. 275-293.– In C. C. MARTIN (ed.). Methods in Molecular Biology: Environmental Genomics: 364 pp. Humana Press Inc., Totowa. https://doi.org/10.1007/978-1-59745-548-0_15.

ENGLERT, W. D., 1974.– Revision der Gattung Metzneria Zeller (Lepid., Gelechiidae) mit Beiträgen zur Biologie der Arten.– Zeitschrift für angewandte Entomologie, 75: 381-421.

CORLEY, M. F. V., GARDINER, A. J., CLEERE, N. & WALLIS, P. D., 2000.– Further additions to the Lepidoptera of Algarve, Portugal. (Insecta: Lepidoptera).– SHILAP Revista de lepidopterología, 28(111): 245-319.

HODGES, R. W., 1983.– Check List of the Lepidoptera of America North of Mexico: 284 pp. E. W. Classey limited and The Wedge Entomological Research Foundation, London.

HUEMER, P. & KARSHOLT, O., 2020.– Commented checklist of European Gelechiidae (Lepidoptera).– ZooKeys, 921: 65-140. https://doi.org/10.3897/zookeys.921.49197

HUEMER, P., KARSHOLT, O., AARVIK, L., BERGGREN, K., BIDZILYA, O., JUNNILAINEN, J., LANDRY, J.- F., MUTANEN, M., NUPPONEN, K., SEGERER, A., SUMPICH, J., WIESER, C., WIESMAIR, B. & HEBERT, P. D. N., 2020a.– DNA barcode library for European Gelechiidae (Lepidoptera) suggests greatly underestimated species diversity.– ZooKeys, 921: 141-157. https://doi.org/10.3897/zookeys.921.49199.

NEL, J., 1994.– Metzneria tenuiella (Mann, 1864) et M. tristella Rebel, 1901, espèces nouvelles pour la France (Lepidoptera, Gelechiidae).– Bulletin de la Société entomologique de France, 99(4): 385-388.

PITKIN, L. M., 1986.– A technique for the preparation of complex male genitalia in Microlepidoptera.– Entomologist’s Gazette, 37: 173-179.

RATNASINGHAM, S. & HEBERT, P. D. N., 2007.– BOLD: The Barcode of Life Data System (http://www.barcodinglife.org).– Molecular Ecology Notes, 7: 355-364. https://doi.org/10.1111/j.1471-8286.2007.01678.x.

RATNASINGHAM, S. & HEBERT, P. D. N., 2013.– A DNA-based registry for all animal species: The Barcode Index Number (BIN) system.– PLoS ONE, 8(7), e66213. https://doi.org/10.1371/journal.pone.0066213.

REBEL, H., 1901.– Neue palaearctische Tineen.– Deutsche Entomologische Zeitschrift Iris, 13(2): 161-188.

ROBINSON, G. S., 1976.– The preparation of slides of Lepidoptera genitalia with special reference to the Microlepidoptera.– Entomologist’s Gazette, 27: 127-132.

TAMURA, K., STECHER, G., PETERSON, D., FILIPSKI, A. & KUMAR, S., 2013.– MEGA6: Molecular Evolutionary Genetics Analysis version 6.0.– Molecular Biology and Evolution, 30: 2725-2729. https://doi.org/10.1093/molbev/mst197.