taxonID	type	description	language	source
7E7B82087B04FFD737A5F8C838F5FB2D.taxon	description	Figs 1, 2, 4 – 7, 10, 11, 13 – 18, 22	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B04FFD737A5F8C838F5FB2D.taxon	materials_examined	Material examined. Bulgaria: 1 ♂, Pirin Mts., 41.7877, 23.3248, Pinus forest, under stone, 23 August 2023, leg. Viktor StřeštÍk (CVS); 1 ♀ (DD 196), Sofia Basin, Balsha Village 42.85854, 23.25959, xerothermic grassland, inside a Messor sp. ant nest under a stone, 15 March 2024, leg. Simeon Indzhov (NMNHS); 1 ♂, Vitosha Mts., Knyazhevo 42.65573, 23.240804, old growth Pinus forest plantation, under stone, 12 November 2024, leg. Simeon Indzhov (NMNHS); 1 ♀ (DD 200), Belasitsa Mts., above Kongura Hut, 41.3414, 23.1853, Fagus forest, pitfall trap, 15 November 2024, leg. Vihra Haynadzhieva (NMNHS); 1 ♀ (DD 194), Sofia Basin, Sofia, Seminary Wall 42.67644, 23.33653, 30 January 2025, leg. Simeon Indzhov (NMNHS); 3 ♂♂ (DD 193), 1 ♀ (DD 195), Black Sea Coast, Nessebar 42.66570, 27.71162, beach, in a rotting log, 17 November 2024, leg. Galin Ivanov (NMNHS). (https: // www. inaturalist. org / observations / 251684457).	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B04FFD737A5F8C838F5FB2D.taxon	diagnosis	Diagnosis. Diameter of conductor of male palp above 1.5 mm; conductor diameter / cephalothorax length ratio> 1 (see Castellucci et al. 2024), RTA with a hook-shaped tip and VTA long and thin (Figs 5, 7). Female vulva approximately 0.33 mm long, copulatory ducts with multiple dense coils and wide lumen (Figs 13, 16). Posterior eyes variable but small, usually separated by at least one eye diameter (Figs 1, 2, 10, 11).	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B04FFD737A5F8C838F5FB2D.taxon	discussion	Remarks. This species is currently known from several localities in Bulgaria, primarily located in the Western part of the country, with the exception of the somewhat different population from the Black Sea coast (Fig. 22). However, the territory of Bulgaria has not been completely sampled and further faunistic research is needed. The species is generally considered myrmecophilous but most individuals we collected were not found near ant nests, except specimen DD 196 from the vicinity of Balsha, which was found in the nest of Messor cf. structor. The male from Knyazhevo was found under a stone, not near an ant nest. As the area has been searched by the first author multiple times over the years, this species may be generally subterranean and difficult to find, with only wandering males occasionally being found under stones. Nests of black-coloured Lasius sp (Formicidae: Formicinae) were found in the general area. It is also unclear whether the specimen from the Pirin Mts. was found in an ant nest, as the collector does not recall observing ants at the collection spot. Both male specimens were found in pine forests / plantations. The specimen from the city of Sofia was walking on the outer wall of a building in broad daylight, so it was presumably disturbed and was not in its typical microhabitat. As the old and forest-covered park Borisova Gradina is in the immediate vicinity, it is likely a population exists there. Although the individuals from Western Bulgaria fit into the clade containing the other European specimens in the tree, the ones from the Black Sea coast form a distinct subclade but are still within the M. arietina clade (DD 193 + DD 195; Fig. 23). The support for this subclade is very low. There are subtle differences in the male palp morphology, with a more curved VTA and a longer and slimmer CdP (Figs 6, 7), more similar to M. diversa (Figs 8, 9) than to the typical M. arietina (Figs 4, 5). No other differences were observed, neither in the shape of the RTA, nor in the female morphology or eye size (Figs. 10, 11, 13 – 18), between this population and the typical M. arietina. Given that Castellucci et al. (2024) did not split the genetically much more distinct populations from Georgia and Finland into separate species, we consider these differences a polymorphism until further material, ideally from a broader area is available. FIGURES 13 – 21. Female genitalia. 13 – 18. M. arietina. 19 – 21. M. macrophthalma. 13, 16, 19 epigyna; 14, 17, 20 vulva ventral, 15, 18, 21 vulva dorsal. Scale line: 0.2 mm.	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B03FFD737A5FB5B39D4F885.taxon	description	Figs 3, 8, 9, 12, 19 – 21, 22? Mastigusa macrophthalma: Deltshev & Blagoev, 1992 [not examined]	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B03FFD737A5FB5B39D4F885.taxon	materials_examined	Material examined. Bulgaria: 1 ♂, West Balkan Mts., near Druzhevo Vill. 43.13906, 23.38246, Fagus forest, 18 September 2022, leg. Simeon Indzhov (CSI); 1 ♂, 1 ♀ (pair, female DD 198), 3 ♀♀, West Balkan Mts., Vrachanski Balkan, Borov Kamak 43.1654, 23.5040, Fagus forest, 24 September 2022, leg. Simeon Indzhov (NMNHS, CSI); 2 ♂♂, 1 ♀, West Balkan Mts., near Gara Lakatnik 43.08916, 23.38098, Carpinus-Quercus forest, 07 September 2023, leg. Simeon Indzhov (CSI); (https: // www. inaturalist. org / observations / 185178787).	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B03FFD737A5FB5B39D4F885.taxon	diagnosis	Diagnosis. Diameter of conductor of male palp below 1.5 mm; conductor diameter / cephalothorax length ratio <1 (see Castellucci et al. 2024), RTA with a blunt tip (Fig. 9). Female vulva approximately 0.27 mm long, copulatory ducts with less dense coils and narrower lumen than in arietina (Figs 20, 21). Posterior eyes variable but usually large separated by less than one eye diameter (Figs 3, 12)	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
7E7B82087B03FFD737A5FB5B39D4F885.taxon	discussion	Remarks. This species likely shows a contiguous distribution in Bulgaria across the karstic parts of the West Balkan Mt. (Fig. 22). There it lives on the forest floor of Carpinus and Fagus forests under stones and can be locally common. None of the specimens observed were found in ant nests.	en	Indzhov, Simeon, Haynadzhieva, Vihra, Střeštík, Viktor, Dimitrov, Dragomir, Dimitrov, Dimitar (2025): We have two of them: A review of the genus Mastigusa (Araneae: Cybaeidae) in Bulgaria. Zootaxa 5711 (4): 579-588, DOI: 10.11646/zootaxa.5711.4.7, URL: https://doi.org/10.11646/zootaxa.5711.4.7
