Nigorella Wesolowska & Tomasiewicz, 2008

Prószyński, Jerzy, 2018, Review of genera Evarcha and Nigorella, with comments on Emertonius, Padilothorax, Stagetillus, and description of five new genera and two new species (Araneae: Salticidae) *, Ecologica Montenegrina 16, pp. 130-179 : 157-160

Gen. Nigorella Wesolowska & Tomasiewicz, 2008 (8 species)

Figures 16-18

Type species: Nigorella aethiopica Wesolowska & Tomasiewicz, 2008

Remarks. Several species of Evarcha s. l. described from China resembles African genus Nigorella Wesolowska & Tomasiewicz, 2008 by appearance of embolus and anterior half of bulbus ( Fig. 16C , compare with 16B), however differs by posterior end of bulbus, which is not rounded but drawn into prominent, horizontal protuberance. So there is a possibility that similarity of embolus shape and position could prevail over shape of bulbus (which would allow to merge these species into genus Nigorella ), or its alternative - description as one more new genus resembling Evarcha s. l. However, description of a new genus would require more data, not yet available, and it may be left for future students of these spiders in China.

The taxonomic decision in this matter must be delayed because of difficulty in precise documentation of structure of embolus. Under higher power of dissecting microscope (magnification about 200x) embolus of Nigorella resembles sclerotized, semitransparent, elongate plate, loose corkscrew-like ( Figs 16 B-C, 17GG1, J), with stronger sclerotized, dark edges. However, under lower power only sclerotized dark edges are visible, looking as separate, angularly bent needles ( Figs 16A , 17 H-I, and other). Emboli of all species shown on Figs 16-18 should be therefore revised to clarify their fine structure.

Diagnosis. Key characters are shown on Figs 16 , 17 G-N, 18.

Description. Recognizable by embolus located atop anterior edge of bulbus, resembling elongated, semitransparent plate with sclerotized dark edges, twisted loosely corkscrew-like ( Fig. 17 G-G1), which under low power of microscope may appear like a pair of separate, bent needles ( Fig. 17H, M ). Bulbus in African species is round like in genus Evaneg nigricans ( Fig. 10J compare 17G), in Chinese species is extended posteriorly by huge, horizontal protuberance like in Evawes patagiata ( Figs 13A compare 18A-C). Epigyne resembles various Evarcha s. l. species ( Fig. 17 ), body shape with moderately elongated oval abdomen ( Figs 16A 1, B1, C1, D1 ).

Composition (diagnostic documentation indicated in brackets). Type species: Nigorella aethiopica Wesolowska & Tomasiewicz, 2008 ( Fig. 17N - Ethiopia). Other species: Nigorella albimana ( Simon, 1902) ( Fig. 17 G-I - W Africa), Nigorella hirsuta Wesolowska, 2009 ( Fig 17J - Zimbabwe, South Africa), Nigorella manica (Peckham & Peckham, 1903) ( Fig. 17M - Zimbabwe). Tentatively included species: A - Nigorella hirticeps ( Song & Chai, 1992) comb. n. ( Fig. 18A , D-E - China), Nigorella hunanensis (Peng, Xie & Kim, 1993) comb. n., reinstated from synonymy ( Figs 18 B-C - China), Nigorella petrae (Prószyński, 1992) comb. n. ( Fig 18J - Thailand: Chiang Mai Prov.: Doi Suthep), Nigorella sichuanensis (Peng, Xie & Kim, 1993) comb. n. ( Fig. 18I - China). F -H – N. contortospinosa

SOURCES: A -B1 - Wesolowska, 2009: Annales Zoologici: 59: 519, f. 30, 32; 521, f. 31, 33, C -D1 - Zha & Zhang, 2014: Acta Arachnologica 63(2): 83, f. 1-6,. All ©copyrights are retained by the original authors and copyright holders, used here by their courtesy.

Methodogical problems of accumulating mistakes. History of classification of species shown on Figs 16- 18 illustrate methodical problems of accumulating mistakes, frequently encountered in taxonomy of Salticidae . Nigorella albimana ( Figs 17 G-H) was first mistaken by Karsch (1879: 362) with Euophrys plebeja Koch L., 1875 , who misplaced it further as Hasarius plebeja , this misplacement was continued by Simon (1902 a: 399) who next has changed alignment to Pachypoessa , followed by de Lessert (1927: 452, f. 29), by Clark when identified specimen in Simon's collection and by Prószyński (1987: 71). None of these authors compared identification with relevant type specimens ( Figs 17 A-F). Final position of the species was clarified by Wesolowska (2009: 521, f. 9-15, see also Fig. 17I ).

Similar problem was encountered by Song & Chai (1992: 80, f. 7A-C) describing Evarcha hirticeps as Pharacocerus , apparently by similarity to drawing of Pharacocerus ephippiatus (Thorell 1899) in Prószyński (1984 a: 105), overlooking prohibitive difference with type species Pharacocerus sessor Simon, 1902 in Prószyński (1984 a: 105, see Fig. 17B ).

Synonymy of Evarcha hirticeps with E. hunanensis does not look convincing because of much broader bulbus and different shape of embolus in the latter ( Fig. 18C compared with 18A). Newest documentation by Zha & Zhang, 2014: 83, f. 1-10 ( Fig. 17 D-E) confirms original drawings of E. hirticeps . Drawings purporting to illustrate E. hirticeps in Yin et al., 2012: 1364, f. 740a-d ( Fig. 17B ) are in fact copies of E. hunanensis ( Fig. 17C ).

Position of Evarcha petrae Prószyński, 1992 from Thailand, remains uncertain. It resembles somewhat E. hirticeps by shape of bulbus and by minute apical fork of tibial tibial apophysis, but shape of complicated embolus is not fully understood ( Fig. 18J ) and should be revised. Placement of Evarcha hirticeps , E. hunanensis , E. sichuanensis and E. petrae in the genus Evarcha s. l. cannot be sustained in view of splitting it into smaller genera, therefore transfer to the nearer genus Nigorella seems to be good solution, at least temporarily. But it should be confirmed, or amended by the future revisionary studies.

SOURCES: A - Koch L. 1875, Nürnberg: 90, f. 9, B -C - Prószyński 1984: Atlas .... Wyższa Szkola Rolniczo- Pedagogiczna, Siedlce: 105, D - Song & Chai, 1992: Journal of Xinjiang University 9(3): 80, f. 7A-C, E -G-G1 - Prószyński, 1987: Atlas .... Wyższa Szkola Rolniczo- Pedagogiczna, Siedlce 71- 72, F - Prószyński, 2003: Annales Zoologici 53: 68, f. 256-260, H - Lessert 1927: Revue Suisse de Zoologie 34: 452, f. 29, I -K, M-N - Wesolowska, 2009: Annales Zoologici: 59: 518, f. 2-8; 521, f. 16-25, 31, 33; 23, f. 26- 29, L - Peckham & Peckham 1903: Transactions of the Wisconsin Academy of Sciences, Arts and Letters 14:205, pl. 24, f. 1. All ©copyrights are retained by the original authors and copyright holders, used here by their courtesy.

SOURCES: A - Song & Chai 1992: Journal of Xinjiang University 9(3): 80, f. 7A-C, B - Peng, Xie & Kim, 1993: 9, f. 12-15, C-D - Song, Zhu & Chen, 1999: The Spiders of China 510, f. 294K-L; 511, f. 296G-H, E - Zha & Zhang, 2014: 83, f. 1- 10, F - Wesolowska 1981b: Annales Zoologici 36: 132-133, ff. 10-13, G -H - Peng, Xie, Xiao 1993. Hunan Normal University Press. 44, 83-84, ff. 254-263, I - Song et al., 1999: 511, figs 295H, 296G-H, J - Prószyński 1992 Annales Zoologici 44: 93, f. 8-12. All ©copyrights are retained by the original authors and copyright holders, used here by their courtesy.

Figures

Figure 1-I. For figure caption see under Figure 1-II.

Figure 10-I. For figure caption see under Figure 10-II.

Figure 13-I. For figure caption see under Figure 13-II.

Figure 16-I. For figure caption see under Figure 16-II.

Figure 17. Diversity of African species of Nigorella on the background of relevant type species of genera into which particular species were previously placed. A-F - Comparative type species: A - Euophrys plebeja Koch L., 1875, B - Pharacocerus sessor Simon, 1902, C -Pharacocerus ephippiatus (Thorell, 1899), D - Evarcha hirticeps (Song & Chai, 1992), E - Pachypoessa lacertosa Simon, 1902, F –Hasarius adansoni (Audouin, 1826). G-N - Diversity of African species: G –Pachypoessa plebeja(det. Karsch, 1879, nec Koch L., 1875) = Nigorella albimana (Simon, 1902), with embolus enlarged, G1 -Pachypoessa albimana: det. Clark = Nigorella albimana (Simon, 1902), with embolus enlarged, H –Pachypoessa albimana: Lessert, 1927: 452, f. 29 = Nigorella albimana (Simon, 1902), I - Nigorella albimana (Simon, 1902), J-K – Nigorella hirsuta Wesolowska, 2009, L –Philaeus manicus Peckham & Peckham, 1903 = Nigorella manica (Peckham & Peckham, 1903), M -Nigorella manica, N –Nigorella aethiopica Wesolowska, 2009.

Figure 18. Diversity of Chinese and Thai Evarcha species tentatively placed into Nigorella. A - Nigorella hirticeps - original drawing by Song & Chai 1992, B – N. hirticeps by Yin et al., 2012, possibly = N. hunanensis[?], C - N. hunanensis, D - N. hirticeps: by Song, Zhu & Chen, 1999, E - N. hirticeps: by Zha & Zhang, 2014, F-H – N. contortospinosa, I – N. sichuanensis, J - N.[?] petrae (Prószyński, 1992) - from Thailand.