Material. SLOVAKIA: MA: 17. Apr. – 16. May 2019, 1 ♂, 1 juv.; 16. May – 5. Jun. 2019, 18 ♂♂, 2 ♀♀, 1 sub. ♀; 05. – 25. Jun. 2019, 3 ♂♂, 1 ♀, 2 sub. ♂♂, 1 sub. ♀; 19. Aug. – 4. Sept. 2019, 5 sub. ♀♀. BK: 28. Mar. – 17. Apr. 2019, 1 sub. ♂, 5 sub. ♀♀, 6 juv.; 17. Apr. – 16. May 2019, 4 ♂♂, 2 sub. ♀♀, 1 sub. ♂, 5 juv.; 16. May – 5. Jun. 2019, 19 ♂♂, 1 ♀, 1 juv.; 5. – 25. Jun. 2019, 9 ♂♂, 2 ♀♀, 1 sub. ♂, 4 juv.; 24. Jul. – 19. Aug. 2019, 3 ♀♀, 2 sub. ♀♀, 3 juv.; 19. Aug. – 4. Sept. 2019, 8 sub. ♀♀, 10 juv.; 4. Sept. – 1. Oct. 2019, 1 sub. ♀; 27. Nov. 2019 – 9. Jan. 2020, 2 juv. (leg. P. Gajdoš, P. Purgat).

Diagnosis. Gnaphosa mongolica can be confused with G. muscorum (L. Koch, 1866), but differs by:

1) absence of the basal spur on the embolus (can be broken off in G. muscorum);

2) wider and larger epigynal scapus;

3) epigynal ducts extended anteriorly in comparison to closely spaced ducts in G. muscorum.

Taxonomic notes. Some old records from Europe were published as G. spinosa Kulczyński, 1897 and G. chaffanjoni Schenkel, 1963. Both names were later synonymised with G. mongolica by Ovtsharenko et al. (1992).

Measurements. Males. Total length 8.08–10.73 mm. Carapace 3.81–5.14 mm long, 3.14–4.00 mm wide. Opisthosoma 4.27–5.80 mm long, 3.32–3.95 mm wide. Females. Total length 9.03–13.6 mm. Carapace 4.74–5.18 mm long, 3.63–3.76 mm wide. Opisthosoma 4.48–8.42 mm long, 3.90–4.68 mm wide.

Distribution (Fig. 5). In Europe it is known from Hungary (Samu & Szinetár 1999), Serbia (Grbić et al. 2021), Romania (Weiss & Marcu 1988), Russia (Ponomarev 1981), Ukraine (Ovtsharenko et al. 1992) and Slovakia (this paper), and also from Turkey to China (WSC 2022).

Material. SLOVAKIA: DM: 17. May – 31. May 2017, 1 ♂; 4. – 17. May 2018, 7 ♂♂, 3 ♀♀ (leg. P. Gajdoš). VI: 12. Apr. – 4. May 2018, 1 ♀; 18. May – 7. Jun. 2018, 1 ♂. MA: 17. Apr. – 16. May 2019, 1 ♂, 1 ♀, 1 sub. ♂, 3 sub. ♀♀, 1 juv.; 16. May – 5. Jun. 2019, 1 ♂, 3 ♀♀, 1 sub. ♀; 5. – 25. Jun. 2019, 2 ♀♀. MP: 17. Apr. – 16. May 2019, 7 ♂♂, 2 ♀♀, 5 sub. ♂♂, 4 sub. ♀♀; 16. May – 5. Jun. 2019, 10 ♂♂, 10 ♀♀, 1 sub. ♀, 1 juv.; 5. – 25. Jun. 2019, 4 ♂♂, 3 ♀♀; 1. Oct. – 27. Nov. 2019, 1 ♀, 1 juv. BK: 28. Mar. – 17. Apr. 2019, 2 sub. ♀♀, 17. Apr. – 16. May 2019, 1 ♂, 1 sub. ♂, 1 sub. ♀; 19. Aug. – 4. Sept. 2019, 1 juv. (leg. P. Gajdoš & P. Purgat).

Comparative material.

H. bohemicus. Czech Republic: Louny, Raná: 50.40655°N, 13.77120°E; 400 m a. s. l., rocky steppe, 4. Oct. – 1. Nov. 1963, 1 ♀ (paratype, coll. National Museum Prague, Czech Republic: P6A 5351), leg. J. Buchar (Miller & Buchar 1977); Bzenec: 48.92657°N, 17.26802°E, 190 m a. s. l., sand dunes, 30. May 1998, 1 ♂, leg. Bezděčka (Růžička & Bezděčka 2000); Bulgaria: Tsarev Vrah (near peak, above Paril vill.): 41.418°N, 23.664°E, 1100 m a. s. l., 29. Jun. 1937, 1 ♀, leg. P. Drensky (Naumova 2009); old border post 1 (above Paril vill.): 41.413°N, 23.659°E, 1300 m a. s. l., 2. Jul. 1937, 1 ♀, leg. Drensky (unpublished); Plovdiv: 42.14883°N, 24.6845°E, 160 m a. s. l., spring 2020, rural habitat on the bank river, 1 gynandromorph, leg. I. Delev (this paper).

H. pseudosignifer. Russia: Altai Republic (Katun' River valley): 50.133°N, 86.083°E, 895 m a. s. l., 22. Jun. – 26. Jul. 1983, 1 ♂ (paratype, ISEA (Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia) 000.122, ex-BI-1405), leg. H. Hippa (Marusik et al. 1996); Novosibirsk Area (Karasuk District): 53.72272°N, 77.72887°E, 101 m a. s. l., under birch, 01. Jul. 2007, 9 ♂♂, 1 ♀ (ISEA 001.1872), leg. I.I. Lubechankii; 53.73167°N, 77.86467°E, 102 m a. s. l., 13. May 2001, 1 ♂(ISEA 001.8928), leg. G.N. Azarkina.

Diagnosis. In Slovakia and neighbouring countries, H. bohemicus is most similar to H. signifer (C. L. Koch, 1839), but males of H. bohemicus differ by:

1) a shorter embolic apophysis and embolus (Fig. 9);

2) the base of the embolic division reaching 1/2 of bulbus length in comparison to 2/3 in H. signifer;

3) the retrolateral tibial apophysis has a step-like dorsal margin and is apically oblique, not rounded as in H. signifer;

4) the female epigyne of H. bohemicus has narrower sub-parallel lateral pockets in comparison to a wide and reniform one;

5) hood is narrower than areola, not wider as in the latter species.

Gynandromorphy. One recently collected specimen from Bulgaria was found to have a lateral gynandromorphy, type 1 sensu Roberts & Parker (1973). Male characters are on the left (bulbus, darker coxa 1, darker and slimer half of the opisthosoma) and female on the right (half of the epigyne with lateral developed pocket, larger opisthosoma). The left and right eyes are different as well (by shape and size) especially the posterior median ones (Fig. 6d, 7d, 8b, d-e). It represents the first record of gynandry for the species and first gynandromorph spider found in Bulgaria as well.

Taxonomic notes. While studying the two fundamental works on the genus Haplodrassus (Kovblyuk et al. 2012, Bosmans et al. 2018), we noted the absence of some important diagnostic features. For example, it is necessary for determination to extract the cymbium because from the commonly used ventral view a certain sclerite behind the embolus is usually not visible (Fig. 10, sclerite “X”). This sclerite is only rarely mentioned in the genus Haplodrassus (e.g. Grimm 1985: Dorsalbereich des Embolus [“a dorsal side of embolus”]; Chatzaki 2021: dorsal apophysis). According to its position, it could be a terminal apophysis and appears to be important for the delimitation of related species (e.g. Grimm 1985, Marusik et al. 1996, Kamura 2007). Unfortunately, in H. bohemicus, this sclerite was drawn only from an apical view by Kovblyuk et al. (2012). In addition, slightly different angles of the bulbus may cause a significantly different appearance of sclerites, e.g. the presence, width or shape of the apical embolic lamella; the shape and edges of the embolic apophysis; the presence of a step-like dorsal margin in the retrolateral tibial apophysis. Thaler (1984) also observed a further diagnostic feature on the tip of the embolus in the genus Haplodrassus, but its detailed structure is only apparent by SEM or probably on microscopic slides.

The Slovak specimens match the original description by Miller & Buchar (1977), and to the paratype female. Unfortunately, the female holotype and male allotype were not found, probably because they were accidentally moved to another storage box (Petr Dolejš pers. comm.). Compared to other published drawings or photographs of this species, with the exception of those by Bosmans et al. (2018), all visible structures match the drawings by Miller. In our opinion, specimens from Ukraine and Russia described by Kovblyuk et al. (2012) could represent a variability, or the differences may be due to slightly different angles shown. The apical view shows the beak-shaped tip of sclerite X (Kovblyuk et al. 2012: figs 3, 6), as in our Slovak specimens. A comparison of our material with photographs of this species from North Ossetia (Ponomarev et al. 2021) and Rostov (unpublished, photographed by Ponomarev) confirm the presence of such a sclerite at least in other specimens of H. bohemicus collected from the eastern part of the distribution. However, it must be said that modern genetic methods would certainly help to solve the problems of species identity within this group.

The male specimens in Bosmans et al. (2018), tentatively designated as H. bohemicus, correspond to the description of H. pseudosignifer Marusik, Hippa & Koponen, 1996 according to:

1) apically rounded retrolateral tibial apophysis without a step-like dorsal margin;

2) shorter and more massive median apophysis;

3) tip of embolus directed upwards;

4) embolic apophysis with distinct ridge.

Other important characters of the male palp are not easily comparable with published descriptions and figures. Also, a comparison with H. pseudosignifer from Russia (including a paratype from Altai) does not solve the problem, because we cannot see further details that are only visible after the extraction of the endaparatus or cymbium. The female epigyne depicted in Bosmans et al. (2018) has a broad sclerotised areola compared to a very narrow one in H. bohemicus. It resembles H. concertor (Simon, 1878), but it differs by a wider hood. In addition, it is very similar to the drawings of the epigyne of H. pseudosignifer from Crimea in Kovblyuk et al. (2012). However, in both cases (Bosmans et al. 2018: fig 204; Kovblyuk et al. 2012: fig. 75) there are also differences (possible variability) that distinguish them from the original description (Marusik et al. 1996: fig. 69):

1) epigyne has a narrower hood than areola;

2) fovea is narrower with constricted lateral sclerotised edges;

3) areola is rounded at its outer edge.

Unfortunately, without re-examination of the specimens by Bosmans et al. (2018) we cannot make a final decision on species status of the specimens collected by us. However, it should be noted that the occurrence of H. bohemicus in Greece has not been questioned by this assessment. The identification of the first country record (Van Keer et al. 2010) was recently discussed with Johan Van Keer (pers. comm.), and he confirmed that two females are identical to the original species description.

Measurements. Males. Body length 5.21–6.65 mm. Carapace 2.17–2.80 mm long, 1.75–2.17 mm wide. Opisthosoma 3.04–3.72 mm long, 1.71–2.01 mm wide. Females. Body length 5.63–7.32 mm. Carapace 2.26–2.65 mm long, 1.66–2.12 mm wide. Opisthosoma 3.37–4.67 mm long, 2.10–2.81 mm wide. Gynandromorph. Body length 7.50 mm. Carapace 3.36 mm long, 2.71 mm wide. Opisthosoma 4.28 mm long, 3.07 mm wide, strongly asymmetric.

Distribution (Fig. 5). Austria (Milasowszky et al. 2008), Bulgaria (Naumova 2009), Czech Republic (Miller & Buchar 1977), Greece (Van Keer et al. 2010), North Macedonia (Stefanovska et al. 2008), Russia (Esyunin & Tuneva 2020), Serbia (Grbić et al. 2021), Ukraine (Polchaninova & Prokopenko 2019), Hungary (Keresztes et al. 2012, Szinetár pers. comm.) and now known from Slovakia (this paper).

Comments. The species was described from the Raná National Nature Reserve (Czech Republic) in the 1960s, but during a repeated survey in 1988, Buchar did not find it there (Růžička & Bezděčka 2000). The latest findings in the Czech Republic come from South Moravian sandy sites (Hula et al. 2004, Hula 2014). The species were recorded in 1937 in Bulgaria (Naumova 2009; revision of Drensky's collection in 2021 by M. Naumova & C. Deltshev) and in 1975 in Russia (Kalmykia) (Ponomarev & Tsvetkov 2006). It is interesting that two of the earliest findings in Europe were collected far away from the type locality, which could indicate a relict-like character of the species' localities and a scattered distribution in the Western Palearctic.

Notes on ecology and conservation

Phenology

Both species have adult stages that are active from May to June (Fig. 11), which means that damaged traps in later periods (see “Material and methods”) did not affect the data on the phenology of adult specimens. Adults of G. mongolica were recorded in Slovakia from April to August with the highest abundance in June. In comparison with other records from Europe, our results correspond to the central European findings (Fig. 11a). Although only a few records from southern Europe have been published, we assume a shift in the occurrence of adults to August. In Hungary, G. mongolica overwinters as juveniles or subadults (Szita et al. 2006). The same was confirmed in Slovakia by our findings of immature stages from September to April.

Adults of H. bohemicus were recorded in Slovakia mainly from May to June, with the highest abundance in June. Only one female was sampled late in November, suggesting that some adults may be overwintering. In comparison with other records from Europe, our results correspond to findings from Central Europe, where H. bohemicus was mostly collected in May and June (Fig. 11b). On the other hand, in southern Europe more than 80% of all adults were recorded in June. In eastern Europe, the highest activity was found in June and July.

A comparison of the phenology of H. bohemicus and H. signifer collected on our study sites in Slovakia suggests that H. bohemicus is mostly active in May and June, while H. signifer is significantly active only in May (Fig. 12).

Habitat

Both species inhabit xerothermic steppe habitats. Gnaphosa mongolica was recorded in Europe mainly from sandy meadows, which also fits to our recent findings from Slovakia (Fig. 13). In Hungary (Szinetár et al. 2005, Szita et al. 2006) it seems to be the dominant species on sandy grasslands and on clearings of Juniperus downs on sand. Several specimens were found on sand dunes with sparse vegetation in Romania (Weiss & Marcu 1988) and Russia (Ponomarev et al. 2011, 2017, Ponomarev & Abdurakhmanov 2014). One study site in Slovakia (Bašovský kopec) was located very close to the sand pit where this species was most abundantly collected (Fig. 14). Its retreat was found built under stones, which is characteristic for ground spiders (Seyyar et al. 2008, Grbić et al. 2021).

Haplodrassus bohemicus occurs in meadows, steppes and sand dunes (Kovblyuk et al. 2012). In central Europe, the majority of findings derive from sandy grasslands. In Serbia (Southern Europe), the species has been recorded from a sandy meadow that was dominated by xerophilic steppe vegetation on brown sand (Grbić et al. 2021). The findings from Slovakia presented herein are also mostly from a sandy grass steppe, with only two specimens that were recorded from an intensively used vineyard (see above). However, specimens from south-eastern and eastern Europe were frequently collected on mesophilic meadows and meadows with a xerothermic character (low precipitation, typical plant composition), which can be explained by the different climate compared to central Europe (Fig. 13). O. Machač observed this species under stones and fallen trunks (ČAS 2021).

Discussion on the red list status

The abundance (in each site and in total) of H. bohemicus (82 ind.) and G. mongolica (145 ind.) appears to be, at least partly, influenced by anthropogenic disturbances of the habitat. Horváth et al. (2015) found that increasing isolation of grassland fragments decreases the abundance of G. mongolica, a habitat specialist, which also seems unable to settle down permanently in adjacent lands altered by human activities. Grbić et al. (2021) suggest that G. mongolica should be classified as an endangered species due to the limited geographical distribution in Europe and its apparently narrow ecological niche that is under increasing economic pressure. In Slovakia, G. mongolica inhabits only natural sandy habitats and seems to avoid sites with anthropogenic influences (pastures and vineyard), judging by the fact that all sites are very close to each other without significant migration barriers. In contrast, H. bohemicus, whose occurrence was most likely overlooked in Slovakia, seems to cope better with anthropogenic influence in its habitat, as shown by the high numbers collected at Marcelovské piesky (Fig. 14) and the presence of the species at each of the five Slovak locations that were investigated. A quick revision of a spider collection from Gönyű (Hungary) showed that H. bohemicus has been confused with the similar H. signifer in some cases (Szinetár, pers. comm.). The latter situation could also have happened in Slovakia, but it should be noted that these habitats have not been studied intensively in the past.