A new species of the genus Dahlica Enderlein, 1912, from Hungary (Lepidoptera, Psychidae)

In this paper a previously unknown species of the genus Dahlica Enderlein, 1912, from the subgenus Postsolenobia Meier, 1957, is described as Dahlica (Postsolenobia) weidlichi sp. nov. and compared with the already known species of this subgenus. Analysis of DNA barcodes for all five validly described taxa of the subgenus Postsolenobia show an unexpected pattern of genetic diversity. Careful re-examination of morphological traits fully supports this pattern and leads to the description of a new species. In addition, the habitat of the new species is characterised and the entire distribution of the subgenus is discussed. Zusammenfassung. In dieser Arbeit wird eine bisher unbekannte Art der Gattung Dahlica Enderlein, 1912, aus der Untergattung Postsolenobia Meier, 1957, als Dahlica (Postsolenobia) weidlichi sp. nov. beschrieben und mit den bereits bekannten Arten dieser Untergattung verglichen. Die Analyse der DNA-Barcodes aller fünf beschriebenen Taxa aus der Untergattung Postsolenobia zeigte ein unerwartetes Muster genetischer Vielfalt. Eine sorgfältige erneute Untersuchung der morphologischen Merkmale unterstützte dieses Muster und führte zur Beschreibung der neuen Art. Darüber hinaus wird der Lebensraum der neuen Art vorgestellt und die gesamte Verbreitung der Untergattung Postsolenobia diskutiert.


Introduction
For years Michael Weidlich and I have known about a population of small psychids belonging to the subfamily Naryciinae, whose larval cases (bags) apparently belong to an undescribed species of the subgenus Postsolenobia Meier, 1957, in the genus Dahlica Enderlein, 1912 Numerous adult males were found while working at the Psychidae collection of the Museum Witt Munich among the unsorted material which was collected in 1975 by Herbert Meier (Witt 1980) in Northern Hungary. Several more specimens, which apparently also belong to this new species, were detected by the author among the psychid collection of the SMNK (Arnscheid 2019), also collected by Meier and erroneously sorted by Leo Sieder (Arnscheid 1993) as belonging to other species of the genus. However, both the cases and the females were missing from the series but both are undoubtedly of high relevance for a correct taxonomic classification.
On his research trip to diverse biotopes on the Balkan Peninsula in 2019, Michael Weidlich again searched for fresh material at the locality for this cryptic species. He again found several larval cases and for the first time one male and one female emerged. This confirmed the identity of males from the Museum Witt's collection and the collection of SMNK as belonging to the same still undescribed species as well as their presumed membership of the subgenus Postsolenobia. In addition, it was possible to achieve a complete sequencing of the DNA barcode of the male within the framework of the BOLD project, whereby a comparison of the relationship to the previously known species of the subgenus Postsolenobia became possible, since a number of sequences of other taxa are already available in the mentioned database.
The new species is described below as Dahlica (Postsolenobia) weidlichi sp. nov. The holotype was selected from the specimens collected by Meier and is deposited in the Psychidae collection of the SMNK.

Material and methods
Images of male genitalia (procedure as described in Arnscheid and Weidlich 2017) were taken with an Olympus OMD EM10 Mark II digital camera using an Olympus stereomicroscope with photo adapter and stacked with Combine ZP using Soft Stack; sharpened and de-noised with Neat Image V8 and post-processed with PhotoScape V.37. Images of the holotype were taken with an Olympus E1 digital camera with a 35-50 mm macro lens and a series of 12 single shots stacked with Combine ZP using Soft Stack; sharpened and de-noised with Neat Image V8. DNA barcode sequences are based on a 658 base-pair long segment of the mitochondrial COI gene (cytochrome c oxidase 1). DNA samples of the new species (dried legs) were prepared and successfully processed at the Canadian Centre for DNA Barcoding (CCDB, Biodiversity Institute of Ontario, University of Guelph) to obtain DNA barcodes using the standard high-throughput protocol described in de-Waard et al. (2008), supplemented by public sequences available from BOLD. Further details including complete voucher data and images of the other already in BOLD available species can be accessed in the public dataset "Psychidae of East-and South Europe (POESE)" in the Barcode of Life Data Systems (BOLD; Ratnasingham and Hebert 2007). Percentages of interspecific variation of DNA barcode fragments were calculated under the Kimura 2 parameter model of nucleotide substitution using analytical tools of BOLD systems v. 4.0. (http://www.boldsystems.org). A Neighbor-Joining tree of DNA barcode data was constructed using MEGA 7 under the Kimura 2 parameter model for nucleotide substitutions.
The terminology in the description of the morphology of the species as well as the genitalia follows Arnscheid and Weidlich (2017). The classification of wing scales refers to Sauter (1956). Classification of the venation follows Comstock (1918). The calculation of the genital index according to Sauter (1956) is phallus length / valvae length.
The holotype is here designated for deposition in the SMNK. Both the holotype and all paratypes in MWM and SMNK were subsequently labelled after the original pencil-written label written by Meier was found on the pin of the first specimen of the series in the MWM. This sole original label remains with the paratype series in the MWM and will later be accessioned to ZSM.
Only hindlegs with a short pair of spurs. Anal hair-tuft (corethrogyne) ventral only, whitish. Female genitalia have not yet been examined, as only one female was available.
Pupa. Light brown. Antennal sheaths longer than leg sheaths. Larval case (Fig. 3a). Small, about 2 mm long and about 1 mm in diameter. A dorsal edge is usually clearly visible. The cases are covered with very small particles of weathered rock and detritus and the colour ranges from dark grey to blackish brown.  Etymology. It is a pleasure for me to dedicate this new species to my friend Dr Michael Weidlich, Neißemünde. As a leading authority of the Naryciinae worldwide, he has not only collected fresh material to solve the taxonomic questions about new species after years of laborious search, but he has also produced outstanding contributions to the Psychidae research in numerous publications.
Habitat. The type material was collected by M. Weidlich at the site called "Burgberg" near Szarvaskö (Fig. 4). This place likely represents the original location of the males collected by Meier in 1975. The Burgberg is volcanically shaped and consists mainly of Triassic basalts and Jurassic diabases (dolerites). Manganese-containing slate formations were also found in the rocks. Altogether these rock formations form the basis for a xerothermic fauna and flora.
Distribution. D. (P.) weidlichi sp. nov. is exclusively known so far only from the type locality in Hungary and this represents the northernmost record of a Postsolenobia species thus found (Fig. 6). Based on the distribution and analysis of the current habitats, all species of the subgenus Postsolenobia appear to be xero-thermophilic.  Molecular results. Mean intraspecific distances for the barcode region are not known for Dahlica (P.) weidlichi sp. nov. because only one specimen was sequenced. The analysis of DNA barcodes (mt COI-5P) for all five validly described taxa of the subgenus Postsolenobia shows an unexpected pattern of genetic diversity. The maximum distance of Dahlica (P.) weidlichi to other species of the Postsolenobia-group is 6.4%. The minimum distance to the nearest neighbour, Dahlica (P.) juliella nanosella, is 4.80% (Fig. 5).
The sequences of Dahlica (Postsolenobia) weidlichi sp. nov. are generated as new for this study. These as well as the public sequences from the BOLD Systems database are available under the following Barcode Index numbers: