Arachnologische Mitteilungen 56

Arachnologische Mitteilungen / Arachnology Letters 56: 6-16 Karlsruhe, September 2018 Pardosa C. L. Koch, 1847 is the largest genus within the fami- ly Lycosidae with 549 known species and subspecies (WSC 2018) and represents one of the largest spider genera in the world. Most of the species have been placed in informal phe- netic species-groups based on similarities in the copulatory organs (Zyuzin 1979, Dondale & Redner 1990, Almquist 2005, Chiarle et al. 2013). The proxima -group includes nine Palaearctic species (Zy- uzin 1979): P. proxima (C. L. Koch, 1847), P. hortensis (Thorell, 1872), P. morosa (L. Koch, 1870), P. tatarica (Thorell, 1875) [= P. strigillata sensu Zyuzin 1979], P. atomaria (C. L. Koch, 1847) [= P. strigillata sensu Buchar &Thaler 2002], P. cribrata Simon, 1876, P. roscai (Roewer, 1951), P. pseudostrigillata Ton- giorgi, 1966 and P. vlijmi den Hollander & Dijkstra, 1974. The subspecies P. proxima poetica Simon, 1876 was also de- scribed from Europe, although Tongiorgi (1966) considered it doubtful since it does not display a well-defined geographical separation from the typical form (see remarks below on P. proxima poetica ). Zyuzin (1979) showed clearly outlined characters for the proxima -group such as a small, trapezoidal tegular apophysis and, in some cases, a sclerotized lamellar process on the palea in males. Females are characterized by a more or less narrow anterior part of the septum, which is not connected with the anterior margin of the epigyne, and a broadened posterior part usually characterized by a triangular or anchor-like shape. Historical background Carl Ludwig Koch originally described Pardosa (sub Lycosa ) proxima on material from unspecified localities in Greece in 1847. According to the original description, specimens were collected by the Bavarian explorer Franz Joseph Schuch (1808-1863). He was a military physician serving in the Ba- varian Auxiliary Corps in Greece around 1834-1837. The Corps was stationed in Nauplia (now Nafplio, Ναύπλιο ) in the Peloponnese. Supposedly, Dr. Schuch collected the type material of Pardosa proxima in the vicinity of Nafplio, as this locality was mentioned for other spiders collected by him and described by C. L. Koch (Koch 1847).The distribution of the species was later considered Euro-Mediterranean (Tongiorgi 1966, Vlijm 1971, den Hollander & Dijkstra 1974), although Dahl (1908) already considered that specimens from south- eastern Europe differed from specimens in south-western Europe. More specifically, Dahl (1908: 507) stated that the south-western specimens showed the same characters that were described by Koch (1882) for Pardosa tenuipes , such as the uniform colouration of the male femur of leg I: “Die Exemplare aus Südwesteuropa weichen in ganz bestimmter Weise ab. Beim Männchen von Lyc. proxima C. L. Koch sind die Schenkel des ersten Beinpaares stets viel dunkler als die andern, fast einfarbig, bei der südwesteuropäischen Form, welche L. Koch Pard. tenuipes genannt hat (vgl. 1881), sind die Vorderschenkel nicht dunkler und meist ähnlich wie die andern geringelt.” [The specimens from south-western Eu- On the morphological separation of two sibling species: Pardosa proxima ( P. vlijmi syn. nov.) and P. tenuipes (Araneae: Lycosidae) Marco Isaia, Torbjörn Kronestedt, Francesco Ballarin & Alberto Chiarle doi: 10.30963/aramit5602 Abstract. Morphological descriptions of P. proxima (C. L. Koch, 1847) (= P. vlijmi den Hollander & Dijkstra, 1974, syn. nov. ) and its sister species P. tenuipes L. Koch, 1882 (= P. proxima auct.), a pair of species hardly distinguishable on a morphological basis but easily separable through behavioural characters, are given. The identification on an ethological basis allowed us to study the morphology of the males and to point out the morphological characteristics that can be used to discriminate the two species. Moreover, the examination of type material of Pardosa proxima and P. tenuipes , together with details given in the original descriptions, led us to conclude that P. vlijmi is a junior synonym of P. proxima and that P. tenuipes has been long overlooked . However, females remain hard to distinguish due to high intraspecific variability in the shape of the epigyne, vulva and habitus. According to the examination of material from different parts of Europe, P. proxima seems to be quite common in Italy and in the south of the Balkan Peninsula (mainly Greece and Bulgaria) while P. tenu- ipes is more widely distributed in western Europe, reaching central Europe. Contact zones between the two species were found in north- western Italy and France. Far from detailing the precise distribution of the two species, we suggest that material previously identified as “ Pardosa proxima ” should be checked for establishing the occurrence of one or both species in different countries. Keywords: ethospecies, synonymy, taxonomy, wolf spiders Zusammenfassung. Zur morphologischen Unterscheidung von zwei Schwesterarten: Pardosa proxima ( P. vlijmi syn. nov.) und P. tenuipes (Araneae: Lycosidae). Es werden morphologische Beschreibungen von P. proxima (C. L. Koch, 1847) (= P. vlijmi den Hollander & Dijkstra, 1974, syn. nov. ) und ihrer Schwesterart P. tenuipes L. Koch, 1882 (= P. proxima auct.) präsentiert. Es handelt sich um ein Artenpaar, das morphologisch nur schwer, aber durch ihr Verhalten leicht zu unterscheiden ist. Die Bestimmung auf ethologischer Basis ermöglichte uns die Morphologie der Männchen genauer zu untersuchen und morphologische Merkmale zu finden, die es möglich machen die beiden Arten zu trennen. Weiterhin führte die Untersuchung von Typusmaterial von Pardosa proxima und P. tenuipes , zusammen mit in den Orginalbeschreibungen genannten Details, zu dem Schluss das P. vlijmi ein jüngeres Synonym von P. proxima ist und dass P. tenuipes lange übersehen wurde. Jedoch bleiben die Weibchen, bedingt durch eine hohe intraspezifische Variabilität der Form von Epigyne und Vulva sowie ihremHabitus, schwer unterscheidbar. Nach Untersuchung von Material aus verschiedenenTeilen Europas scheint P. proxima in Italien und dem Süden der Balkanhalbinsel (vor allem in Griechenland und Bulgarien) häufig zu sein, während P. tenuipes imwestlichen Europa, bis Mitteleuropa, verbreitet ist. Kontaktzonen beider Arten sind aus Nordwest-Italien und Frankreich belegt. Bisherige Nachwei- se von„ Pardosa proxima” sollten überprüft werden um die genaue Verbreitung beider Arten in den verschiedenen Ländern zu belegen. Marco ISAIA, Alberto CHIARLE, Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina, 13, 10123 Torino, Italy; E-mail: marco.isaia@unito.it; alb_chiarle@gmail.com Torbjörn KRONESTEDT, Department of Zoology, Swedish Museum of Natural Histo- ry, Box 50007, 104 05 Stockholm, Sweden; E-mail: torbjorn.kronestedt@nrm.se Francesco BALLARIN, Institute of Zoology, Chinese Academy of Sciences (IOZCAS), 1 Beichen West Road, Chaoyang District, Beijing 100101, P.R. China; E-mail: ballarin.francesco@gmail.com submitted 17.4.2018, accepted 11.6.2018, online 28.6.2018