Arachnologische Mitteilungen 56

Two sibling species: Pardosa proxima and P. tenuipes 7 rope differ in a very specific way. Males of Lyc. proxima C. L. Koch have the femora of the first leg pair much darker than the others, almost unicolour, while in the form from south- western Europe, which L. Koch named Pard. tenuipes (cf. 1881 [should be 1882]), the first femora are not darker and annulated like the others]. In addition, it is worth noting that in the original descrip- tion of P. proxima, C. L. Koch (1847: 53) mentioned and il- lustrated the dark femur of leg I of males (see Fig. 24, arrow). The same characteristic was also emphasized by de Lessert (1910: 516, footnote). Den Hollander et al. (1972) published a paper on the occurrence of wolf spiders of the genus Pardosa in southern France. In this work, they observed that specimens previously identified as P. proxima showed different courtship behaviour compared to the typical form.They found these “aberrant spe- cimens” in two localities (Pas d’Esculette, near Millau and Le Pin, near Auxerre), occurring together with P. proxima auct. and P. hortensis . According to den Hollander et al. (1972), the preliminary examination of the external genital structu- res of the “aberrant specimens” showed intermediate features between P. proxima auct. and P. hortensis . A few years later, the same material was examined by den Hollander & Dijks- tra (1974) who described the “aberrant specimens” as a new ethospecies, P. vlijmi den Hollander & Dijkstra, 1974 . Etho- species are defined as pair or complex of species that can be hardly distinguished on a morphological basis, if at all, but are easily separable through behavioural characters (O’Connor et al. 2011, see also Vlijm 1986).The concept of ethospecies was defined by Emerson (1956) to describe species belonging to the genus Apicotermes (Isoptera) that could only be distinguis- hed by the different construction of the nests. Among spiders, ethospecies are particularly known in wolf spiders (e. g., Uetz & Denterlein 1979, Cordes & von Helversen 1990, Töpfer- Hofmann et al. 2000, Roberts & Uetz 2004). Chiarle & Isaia (2013) confirmed that courtship behaviour is a valuable tool to discriminate P. proxima auct. from P. vlijmi . However, it seems likely that the concept of ethospecies only reflects the inability of the researcher to detect useful morphological fea- tures. The fact that the description of P. vlijmi as a new species was only based on courtship behaviour created nomenclature problems (see also Vlijm 1986). In particular, den Hollander & Dijkstra (1974) considered P. proxima auct. and P. vlijmi “morphologically indistinguishable”, implying that it was not necessary to see any type material of P. proxima C. L. Koch, 1847. In their work, they assigned the new name vlijmi to the less common species: “It therefore seems plausible that the widespread P. “proxima” refers to Pardosa proxima (Koch, 1848) [sic!] and that the aberrant specimens belong to a new species”.This kind of conclusion is rather arbitrary, given that there is no evidence that Carl Ludwig Koch had described P. proxima on specimens that performs the “normal” or the “aberrant” courtship behaviour observed by den Hollander & Dijkstra (1974). Although the authors provided some pre- liminary measurements of the body and the external genital structures, the drawings of palps and epigynes are poor and lack details. Moreover, given the apparent lack of documen- ted morphological characters useful to distinguish the new species, it is likely that P. vlijmi has been routinely overlooked and often confused with its sibling species, P. proxima auct. The results obtained in our previous studies on the court- ship behaviour of these two species (Chiarle et al. 2013, Chi- arle & Isaia 2013) concur with those reported by den Hollan- der & Dijkstra (1974). A closer examination of the specimens used for the behavioural analysis, together with the exami- nation of material from different parts of Europe, revealed that the two species were in fact mostly confused in the past, and that a revision of the current nomenclature was needed. Further support for our assumption, linking morphological and ethological traits, is found in the molecular analysis pre- viously conducted (Chiarle 2013), providing evidence for a clear separation of the two species, and justifying our use of morphological characters for species identification. Here we present the results obtained from the morpho- logical examination, we point out the characters useful for separating the two species and we revise their nomenclatural status. Material and methods Samples were photographed using an Olympus E-520 came- ra attached on an Olympus SZX16 stereomicroscope at the Zoological Museum, University of Turku and a Leica EC3 camera attached on an Leica MS5 stereomicroscope at the Department of Life Sciences and Systems Biology of the Uni- versity of Torino. Dishes of different size with paraffin at the bottom were used to photograph the specimens in the correct position. Images have been subsequently fixed using “Com- bineZP” image stacking software. SEM micrographs were taken with a Hitachi S-4300 scanning electron microscope at the Swedish Museum of Natural History in Stockholm. The digital photo (stacked) in Fig. 26 was taken using an Infini- tyX camera on an Olympus SZX12 stereomicroscope at the Swedish Museum of Natural History in Stockholm. Part of the examined material (marked with an asterisk*) has been formerly identified on an ethological basis (see Chiarle et al. 2013, Chiarle & Isaia 2013). For both species, total body length, prosoma length and width, leg I length is reported (minimum and maximum). For males, we also measured palp tibia length and width. De- scription and measurements of females are based on presu- med “pure” populations (i.e. populations where we only found males of one of the two species). All measurements are given in millimetres. Apart from types, all studied materials are preserved at: Museo Civico di Storia Naturale di Verona, Italy (MSNVR); Museo Civico di Scienze Naturali “E. Caffi” di Bergamo, Italy (MCSNB); Museo Regionale di Scienze Naturali di Torino, Italy (MRSN); Entomology Department of the Ro- yal Belgian Institute of Natural Science in Brussels, Belgi- um (RBINS); National Museum in Prague, Czech Republic (NMP), Collezione Isaia stored at Dipartimento di Scienze della Vita e Biologia dei Sistemi, University of Torino, Italy (CI), and Swedish Museum of Natural History of Stockholm, Sweden (NHRS). Taxonomy Family Lycosidae Sundevall, 1833 Pardosa proxima (C. L. Koch, 1847) (Figs 1, 2, 5-10, 19, 21, 22, 24-26) Lycosa proxima C. L. Koch, 1847: 53, figs 1453-1454 ( )( ) Pardosa proxima (C. L. Koch): Tongiorgi 1966: 306