The species Xysticus lendli is known only from its original description of a single male and one doubtful record so far. Here, we illustrate and redescribe the species based on 34 specimens in total and describe its female for the first time. We illustrated the male palp via compound micrographs and scanning electron micrographs. We generated a DNA barcode and placed it into a current phylogenetic scaffold to confirm the species’ placement of Spiracme, a long-debated sister- or subgroup of Xysticus; hence, a new combination of Spiracme lendli (Kulczyński, 1897), comb. nov. is proposed. We illustrated the visually similar Xysticus mongolicus and the type species of Spiracme, S. striatipes, and compared them to S. lendli to aid future distinctions between those species.

Central Europe, crab spiders, new combination, redescription, Spiracme

Hungary has a rich arachnofauna, which has been well studied for a long time. Due to its unique location, glaciation history, and topological arrangement (the Carpathian Basin), numerous species have been described in this region. The Pannonian biogeographic region lies on a unique meeting point of various other biogeographic regions (Molnár et al. 2008; Fekete et al. 2016); for instance, the Eurasian steppe/forest steppe zone’s westernmost part is located here (Bátori et al. 2018). On the eastern part of Hungary, the forest steppe biome is present in the Kiskunság National Park, offering a unique opportunity to study the forest steppe biota (Gallé et al. 2022a) (Fig. 1A). The arachnofauna of Kiskunság National Park has been intensively studied due to the increased interest of ecologists and conservation biologists, who have conducted frequent studies in the last few decades (Gallé et al. 2022a, 2022b, 2022c, and references therein). During these studies, several new species have been discovered (Parasyrisca arrabonica Szinetár & Eichard, 2009; Sernokorba betyar Gallé-Szpisjak et al., 2023), and a few other “forgotten” taxa have been rediscovered as well. One of these taxa is Xysticus lendli Kulczyński, 1897, an enigmatic thomisid that was known by a single male specimen and did not have a verified record besides its original description more than a century ago.

Figure 1. 

A. Map of Europe and Hungary with the forest-steppe zone (green patches), the Hungarian sampling site (black circle), the Slovakian sampling site (black star, Purgat et al. 2021), and the Serbian sampling site (black square, Grbić et al. 2019); B. Forest-steppe patch; C. Open sand grassland.

Xysticus has been the subject of several classification attempts in the past 50 or so years (see Lehtinen 2002; Jantscher 2002; and Breitling 2019 for details). Almost all of these papers used morphological data, whereas the last treatment by Breitling (2019) used the phylogeny of barcode sequences alone. One main result of the latter was the resurrection of the genus Spiracme Menge, 1876, with the type species Spiracme striatipes (L. Koch, 1870) and including nine other species: Spiracme baltistana (Caporiacco, 1935), Spiracme dura (Sørensen, 1898), Spiracme keyserlingi (Bryant, 1930), Spiracme lehtineni (Fomichev, Marusik & Koponen, 2014), Spiracme nigromaculata (Keyserling, 1884), Spiracme quadrata (Tang & Song, 1988), Spiracme triangulosa (Emerton, 1894), Spiracme vachoni (Schenkel, 1963). Later, Purgat et al. (2021) added Spiracme mongolica (Schenkel, 1963) to the genus.

While identifying our specimens, we noticed that the palp shows a high overall similarity to that of S. mongolica, as illustrated by Purgat et al. (2021). Still, at the same time, significant differences could be observed between the illustrations of the original description of Schenkel (1963) and the specimen identified and pictured by Fomichev (2015).

The aims of this paper are to provide illustrations and a description for Xysticus lendli Kulczyński, 1897, based on freshly collected material, describe the hitherto unknown female of the species, and reevaluate current faunistic records that may involve this species. We provide a DNA barcode for the species and test its phylogenetic position by reanalysing the matrix of Breitling (2019) with this new sequence added, and we discuss the accompanying results using a comparison with the type species of Spiracme.

Specimens were collected in the Kiskunság region, Hungary, in 2017, 2018, and 2021 by sweep net from semi-natural sandy forest steppe patches (Fig. 1B, C). The specimens were photographed with a Nikon D300S camera attached to a Nikon S800 stereomicroscope and a Tucsen Truechrome Metrics camera attached to an Eclipse E200 compound microscope. Multifocal images were compiled using HeliconFocus. The female vulva and palps in Fig. 5 were illustrated while immersed in methyl salicylate. Scanning electron micrographs were made in a low vacuum on a Hitachi SV1000 FlexSEM scanning electron microscope in the Plant Protection Institute (NÖVI) HUN-REN Centre for Agricultural Research. Drawings were made by the first author using a fineliner and 80 g/m² of printing paper. The maps were made using Adobe Illustrator CS6 software. All measurements are given in millimetres. The material is deposited in the Museum of Natural History, Budapest (MNHB) and the first author’s personal collection in Szeged.

Whole genomic DNA was extracted from one leg using standard extraction kits. For the barcoding, the LCO1940/HCO2198 primers (Folmer et al. 1994) were used. PCR has been carried out in the Department of Zoology of the University of Veterinary Medicine Budapest, and capillary electrophoresis has been done at Commercial Biomi Services (Gödöllő, Hungary). Sequences were edited using Gap4 of the Staden Packge (Staden et al. 2000) and deposited in GenBank with the accession number PP545308. Phylogenetic relationships were inferred via both maximum likelihood and Bayesian methods based on the dataset that has been published so far (Breitling 2019). MAFFT v.7.450 online (https://mafft.cbrc.jp/alignment/server/) was used with default settings to align the sequences. A maximum likelihood phylogram was constructed using IQ-TREE (Nguyen et al. 2015) under the GTR+F+I+G model, performing 1000 ultrafast bootstrap replicates. Bayesian inference was performed using MrBayes v. 3.2.6 (Ronquist and Huelsenbeck 2003), using the GTR+I+G model of sequence evolution. Analyses consisted of two independent runs with one cold chain and five hot chains from random starting trees, run for 10 million generations, and sampled every 1000 generations. Convergence was assessed through examination of the standard deviation of split frequencies, which was well below recommended thresholds (0.01). The two MrBayes runs were combined after the deletion of burn-in generations (25%), and a majority-rule consensus phylogram was created. The resulting phylograms were edited and visualised with FigTree v.1.4 (Rambaut 2014).

With the revalidation of Spiracme, perhaps Pandora’s box has been opened. As it stands, the genus contains other species groups (durus and nigromaculatus). From the original description of the genus erected for S. striatipes (L. Koch, 1870) by Menge (1876), it is now clear that he not only specifically listed the unique shape of the embolus of the type species (“spitze schraubenförmig gewundenen eindringer” [=embolus spirally twisted]) as diagnostic, but the etymology is also based on the spirally twisted embolus (“spira and cuspis... Von der schraubenfürmigen spitze des eindringers”) as well. We assume that the genus concept of the auctor was to include species with spirally twisted emboli on top of an anapophysate tegulum. In the genus, as delimited currently by Breitling (2019), most of the species have filiform emboli and various tegular outgrowths. Considering all available information, including any species with filiform embolus in the genus Spiracme, on the basis of DNA barcode data alone might have been premature.

Menge erected another genus, Psammitis Menge, 1876, of which at least the type species, Psammitis sabulosus (Hahn, 1832), has a similar indentation on the embolus (Jantscher 2001). There is little to no consensus among the plethora of opinions regarding the limits and placement of Spiracme or Psammitis. However, placing Spiracme lendli based on morphology alone provides a challenge. It does not have a prominent tutaculum (Figs 3, 4, 7) versus Spiracme striatipes, which has a large, promiment triangular one (Figs 3H, 4H), and the tutaculum of Psammitis species is thin and points upward. Spiracme lendli has indentations on the bent embolus (Figs 5–7), S. striatipes has deeper indentations and a straight embolus; P. sabulosus has weaker indentations and a bent embolus; and finally, S. lendli has a tegular pocket similar to P. sabulosus, which is absent in S. striatipes (Figs 3I, 4I). Due to the inconsistent distribution of the morphological characters used to place species into these genera, we decided to use the grouping with the type species of Spiracme and place Xysticus lendli Kulczyński, 1897, to Spiracme Menge, 1876.

We are thankful to Peter Batáry for his support and the free use of the equipment for identification. This work was supported by the Hungarian Research and Developmental Fund (Grant ID: NKFIH FK 142926). Barna Páll-Gergely and Jenő Kontschán have granted us access to their scanning electron microscope in the Plant Protection Institute (NÖVI) HUN-REN Centre for Agricultural Research, which is highly appreciated. We are especially grateful to Galina Azarkina and Alexander A. Fomichev in the Institute for Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, for giving us access to the Xysticus mongolicus specimen. We are indebted to Gordana Grbić, Ambros Hänggi, and Nina Polchaninova for their efforts and help to confirm their identification. Ábris Tóth kindly translated the Latin original description of Xysticus lendli, which is highly appreciated. We are grateful to Eszter Lazányi for facilitating several opportunities to revise and search through the whole Xysticus material in the Hungarian Natural History Museum’s collection to find the type specimen. We would like to thank Suresh Benjamin and Yura Marusik for their reviews of an earlier version of the manuscript. Grant McDonald has helped with the English grammar, which is highly appreciated.