Chthonius alpicola Beier, 1951

Gardini, Giulio, 2021, The Italian species of the Chthonius ischnocheles group (Arachnida, Pseudoscorpiones, Chthoniidae), with reference to neighbouring countries, Zootaxa 4987 (1), pp. 1-131 : 11-15

Chthonius alpicola Beier, 1951

( Figs 26–40 , 403 )

Chthonius (Neochthonius) alpicola Beier, 1951: 163 , fig. 1a.

Chthonius (N.) pygmaeus carinthiacus: Marcuzzi 1976: 377 .

Neochthonius cfr. alpicola: Callaini 1986a: 229 .

Type locality: Austria, Salzburg, Krizersberg am Nordhang des Untersberges (47°42’N, 12°59’E) .

Distribution. Southern Germany (Bavaria), Austria, Croatia, Slovenia, North-central Italy.

Diagnosis (♂ ♀). An eyed epigean Chthonius that differs from other species of the ischnocheles group in the following combination of characters: anterior margin of carapace with 1 or 2 preocular microsetae on each side; posterior margin of carapace with 2 macrosetae and 1 or 2 lateral microsetae; anterior eyes with convex lens; chelicerae with 1–3 lateral microsetae; chela length 0.57–0.84 mm; movable chelal finger length 0.39–0.56 mm; chelal fingers with contiguous teeth; fixed chelal finger with 47–62 teeth; ratio of pedipalpal femur/carapace 1.0–1.3.

Type material examined. AUSTRIA — Salzburg: 2 ♂ 1 ♀ (“ Typen ”), Krizersberg am Nordhang des Untersberges, 690 m a.s.l., 20.IX.1936, Schüller leg, Mischwald mit feuchtem Bodenlaub ( NMW) ; 4 ♀ (“ Paratypen ”), Glanegg am Nordhang des Untersberges, 460 m a.s.l., 10. V .1936, Schüller leg. ( NMW). Kärnten — 1 ♂ 1 ♀ (“Paratypen”), Graschlitzen bei Warmbad Villach , Eingang II der Tschamerhöhle, 550 m a.s.l., 18. VIII .1949, Strouhal leg. ( NMW); 2 ♀ (“ Paratypen ”), Gräflach bei Warmbad Villach, vor Versturzhöhle , 540 m a.s.l., 31. VIII .1949, Strouhal leg. ( NMW). Oberösterreich — 1 ♀ (“ Paratypus ”), Mauthausen, nördl. Bahnhof , 8.IX.1948, Strouhal leg. ( NMW) ; 2 ♂ 3 ♀ (“ Paratypen ”), Graben zwischen Grein a. d. [and der] Donau und Dimbach , 13.IX.1948, Strouhal leg. ( NMW) .

Other material examined. CROATIA — Istria — 2 ♀, Učka (Monte Maggiore), 800 m a.s.l., 17.VI.1982, M. Seriani leg. ; 1 ♀, Vodice, Dane , 650 m a.s.l., 27.VIII.1990, F. Gasparo leg.

ITALY — Venezia Giulia: Gorizia Prov. — 2 ♂, Cormons, Bosco di Plessiva, 6.III.1982, M. Seriani leg. Venezia Giulia: Trieste Prov. — 1 ♂ 1 ♀, near Aurisina, 29. V.1986, C. Torti leg.; 1 ♂ 7 ♀ 2 T, San Dorligo della Valle, Bagnoli della Rosandra, 22.IX.1983, M. Bodon leg.; 1 ♀, Sgonico, Grotta Ercole 6 VG/TS, 230 m a.s.l., 16.XII.1984, F. Gasparo leg.; 1 ♀, Trieste, Duino, 20 m a.s.l., 9.IV.1993, F. Gasparo leg. Friuli: Pordenone Prov. — 1 ♀, Campone, Forchia di Meduno, 23. VI.2000, R. Monguzzi leg. ( RMM); 2 ♀ 3 T 1 D, Chions, near Torrate, 23.I.1982, M. Seriani leg.; 8 ♂ 2 ♀, Montereale Valcellina, 360 m a.s.l., 27.VII.1995, F. Gasparo leg.; 3 ♀ 1 T, Sequals, peat bog near Sequals, 190 m a.s.l., 13.IV.2001, A., M. Zanetti, G. Tomasin, A. Tagliapietra & G. Governatori leg. ( MFNB); 1 ♀, id., 14. VI.2001, G. Colombetta leg. ( MFNB); 3 ♀, id., 14.X.2001, G. Colombetta leg., pitfall traps ( MFNB); 3 ♂ 1 ♀, id., 29.X.2001, G. Tomasin leg. ( MFNB); 1 ♂ 1 D, Valeriano, 3.I.1981, M. Seriani leg.; 2 ♀ 2 T, Vito d’Asio, Pielungo, 12. V.1985, M. Seriani leg., oak leaf litter; 2 ♂ 1 ♀ 1 T 1 D, Zoppola, Parco Fluviale del Meduna, 13.VII.1991, G. Governatori leg.; 4 ♂, Zoppola, Fiume Meduna, 22.X.1991, G. Governatori leg. Friuli: Udine Prov. — 2 ♂ 2 T, Artegna, 250 m a.s.l., 11. VIII.1992, F. Gasparo leg., pitfall traps; 3 ♂, near Bordano, 450 m a.s.l., 13. V.1992, F. Gasparo leg.; 7 ♂ 2 T, Cavazzo Carnico, 290 m a.s.l., 23.IX.1992, F. Gasparo leg., Picea abies wood; 1 ♀, Cervignano, Bosco Pradiziolo, 9.I.1982, M. Seriani leg., Querco–Carpinetum; 3 ♀, id., 16.I.1983, M. Seriani leg., oak wood; 3 ♂ 2 ♀ 1 T, id., 4.III.1983, M. Seriani leg.; 2 ♂ 1 ♀, id., 6. V.1983, M. Seriani leg., mosses; 2 ♂, Chiusaforte, Raccolana, 400 m a.s.l., 14. VIII.1993, F. Gasparo leg., mixed wood; 1 ♂, peat bog of Fagagna, 171 m a.s.l., 14.X.2001, G. Colombetta leg., pitfall trap ( MFNB); 4 ♂ 10 ♀ 1 T, near Losaz, S slope of Monte Matajur, 13. VI.1993, S. Zoia leg.; 1 ♂, Lusevera, Alta Val Torre, Isola Torrente Mea, 700 m a.s.l., 5. VIII.1992, G. Governatori leg. ( MFNB); 1 ♂, Lusevera, Plan di Tapou, 900 m a.s.l., 4.IX.2006, G. Colombetta & L. Dorigo leg., pitfall in beech wood ( MFNB); 1 ♂, Majano, peat bog of Casasola, 160 m a.s.l., 14. VI.2001, G. Colombetta leg., pitfall trap ( MFNB); 3 ♂ 3 T, id., 14.X.2001, G. Colombetta leg., pitfall traps ( MFNB); 1 ♀, Moggio Udinese, N slope of Monte Sernio, 1700 m a.s.l., 13. VI.2001, R. Monguzzi leg. ( RMM); 2 ♂, Moggio Udinese, Stavoli Cuel Lung Alto, slope of Monte Zovet, 700 m a.s.l., 19. VI.2001, G. Governatori leg., beech wood ( MFNB); 1 ♂, id., 30.X.2001, G. Governatori leg., beech wood ( MFNB); 1 ♂, id., 31. V.2002, A. Dall’Asta & G. Governatori leg., beech wood ( MFNB); 1 ♂, id., 25. VI.2002, A. Dall’Asta & L. Lapini leg., beech wood ( MFNB); 1 ♂ 7 T 14 D, id., 22.VII.2002, A. Dall’Asta leg., beech wood ( MFNB); 1 ♂, Muzzana, 15.X.1982, M. Seriani leg., Querco-Carpinetum; 3 ♂, Pagnacco, peat bog of Lazzacco, 195 m a.s.l., 16.X.2001, G. Colombetta leg., pitfall traps ( MFNB); 1 ♀, Pontebba, 600 m a.s.l., 20.IX.1990, F. Gasparo leg.; 1 ♀, Raveo, 430 m a.s.l., 1. V.1997, F. Gasparo leg., mixed wood; 1 ♂ 5 ♀ 1 T, Resia, near Uccea, 780 m a.s.l., 1. VI.1986, C. Torti & S. Zoia leg., beech wood; 1 ♂ 1 ♀, Rivignano, Risorgive Zarnicco, 13 m a.s.l., 19. VI.2001, G. Colombetta leg. ( MFNB); 2 ♂ 20 ♀, near Savogna, 26. VI.1994, S. Zoia leg., beech wood; 2 ♀, Taipana, Platischis, 700 m a.s.l., 9. V.1990, F. Gasparo leg.; 1 ♂, Tolmezzo, Caneva, 360 m a.s.l., 10. VI.1993, F. Gasparo leg., mixed wood; 1 ♂, Torreano, Prestento, 190 m a.s.l., 10.VII.1993, F. Gasparo leg., Carpinus wood; 5 ♂ 1 ♀ 6 T 1 D, Trasaghis, Peonis, 180 m a.s.l., 13.XI.1991, F. Gasparo leg.; 1 ♀, Venzone, 270 m a.s.l., 25. V.1993, F. Gasparo leg.; 1 ♀, Villa Santina, 400 m a.s.l., 30.IV.1991, F. Gasparo leg., Carpinus wood. Veneto: Belluno Prov. —2 T ( C. pygmaeus carinthiacus , det. M. Beier), Cadore, [no date, G. Marcuzzi leg.] ( MZUP). Veneto: Treviso Prov. — 1 ♂, Susegana, Castello San Salvatore, 100 m a.s.l., 23.IX.2013, G. Gardini & C. Giusto leg., mixed wood. Veneto: Venezia Prov. — 6 ♂ 4 ♀ 2 T 1 D, Lison, Bosco di Lison, 25.IX.1986, M. R. Favretto leg. Veneto: Verona Prov. — 1 ♂, Velo Veronese, Covoli di Velo, 22.VII.1996, A. Zanetti leg. Piedmont: Turin Prov. — 1 ♀, Caselette, Cascina Farchetto, 400 m a.s.l., 2.VII.1992, G.B. Delmastro leg.; 3 ♂ 2 ♀, Val della Torre, Truc di Brione, 390 m a.s.l., 27. V.1992, G.B. Delmastro leg. Liguria: Genoa Prov. — 2 ♀, Neirone, slope of Monte Caucaso, 1000 m a.s.l., 21. VIII.1973, R. Poggi leg.; 1 ♀, Rezzoaglio, 22.III.1978, S. Zoia leg. Emilia: Reggio Emilia Prov. — 1 ♀ 2 T, Collagna, Passo del Cerreto, 1100 m a.s.l., 31. VIII.1980, G. Gardini, C. Giusto & S. Zoia leg., beech wood. Tuscany: Lucca Prov. — 2 ♀, Fornovolasco, NE slope of Pania della Croce, 1600 m a.s.l., 25. VI.1983, S. Zoia leg.; 5 ♀ 1 T, Seravezza, N slope of Monte Altissimo, 1200 m a.s.l., 13. VI.1977, G. Parodi & S. Zoia leg., beech wood; 2 ♂ 1 ♀ 4 T 3 D, Seravezza, E slope of Monte Altissimo, 15.VII.1984, S. Zoia leg., beech wood; 1 ♂ 1 ♀, Vagli di Sotto, slope of Monte Tambura, 1200 m a.s.l., 4. V.1979, S. Zoia leg. Tuscany: Massa–Carrara Prov. — 1 ♂ 4 ♀, Carrara, Campocecina, 10. VIII.1980, S. Zoia leg.; 1 ♀, Zeri, near Lago Verde, 4.X.1980, A., L. Briganti leg.

SLOVENIA — Goriška regija — 2 ♂ 1 ♀, Idrija, between Godovič and Crni vrh, 700 m a.s.l., 8.IX.1991, F. Gasparo leg. ; 1 ♂ 1 ♀, Kobarid, Fiume Natisone near Hurja, Potoki , 25.VII.1996, M. Bodon, S. Cianfanelli & G. Manganelli leg. Notranjsko-kraška regija — 2 ♂ 2 ♀, between Postojna and Planina , 600 m a.s.l., 2. VI.1991, F. Gasparo leg. , beech wood. Obalno-kraška regija — 1 ♂ 1 ♀, Škocjanske Jame (= San Canziano ), 29. VIII.1987, G. Gardini & R. Rizzerio leg. , entrance. Posavska regija — 1 ♀, Krško, Gruska jama n. 1374, 20.VII.1978, T. Novak leg. Spodnjeposavska regija — 9 ♂ 10 ♀ 10 T, Brežice, 28. VIII.1987, G. Gardini & R. Rizzerio leg.

Description of adults (♂ ♀). Integument slightly pigmented, carapace, tergites, chelicerae and pedipalps pale brown; weak hispid granulation on lateral surfaces of carapace, on cheliceral palm and on base of fixed chelal finger. Carapace ( Fig. 28 ) 0.8–0.9 times longer than broad, trapezoidal, constricted posteriorly; anterior margin between median macrosetae with a prominent epistome in both sexes ( Figs 26–27 ); ocular area as in fig. 28, anterior eyes with convex lens (diameter 0.035 –0.045 mm), posterior eyes with flat lens, all eyes with a tapetum; distance from anterior eyes to anterior margin of carapace 0.025 –0.035 mm; standard chaetotaxy m 4m:6:4:2:m 2m (22), but note substantial variability in the number of preocular microsetae (m 4mm, mm 4mm, mm4mmm) and in both the number and length of microsetae on posterior margin of carapace (m2, m 2mm, mm 2mm) even within the same population; length of anteromedian macrosetae 0.09–0.14 mm. Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0. Chaetotaxy of sternites 10:(3)7–10(3):(2)7–8(2):8:6:6:6:6:2T1T2:0:2; genital opening of males flanked by 6–7 (rarely 5) setae on each side. Chelicerae ( Fig. 29 ) 1.9–2.1 (♂) or 1.9–2.05 (♀) times as long as broad, palm with 6 setae and 1–3 lateral microsetae; fixed finger with 7–10 teeth and 3–5 proximal microtubercles; movable finger with an isolated subapical tooth (di) at level with the spinneret, and 7–10 teeth proximally reduced in size; gs ratio 0.57–0.61; spinneret large and apically rounded, similar in both sexes ( Figs 29–30 ); rallum with 11 blades; serrulae interior and exterior with 12–14 and 15–17 blades respectively. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 3 marginal microsetae, II 4, III 5, IV 6; coxa II with 5–9 coxal spines, coxa III with 3–5 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.2–4.9 (♂) or 4.2–4.8 (♀) times as long as broad, femoral chaetotaxy 3:5–6:2:5:1; chela ( Figs 33, 37 ) 4.9–5.8 (♂) or 4.8–5.3 (♀) times as long as deep; hand of chela 1.65–1.9 (♂) or 1.55–1.75 (♀) times as long as deep, ovoid in dorsal view ( Figs 31–32 ); fixed chelal finger with 47–62 contiguous teeth slightly inclined backwards, all cuspidate except the 6–12 proximal ones, which are apically rounded ( Figs 34–36, 38–40 ); all teeth with dental canal; base of fixed chelal finger with 2–4 microtubercles; fixed finger at level of est-it with 9–14 teeth occupying 0.1 mm, distance between successive apices 0.007 –0.011 mm; tip of fixed chelal finger with apical sensilla af 1- 2, distal paraxial seta gradually curved and thin; movable chelal finger with 36–50 contiguous teeth, cuspidate and reclined in the distal half of the finger, increasingly reduced towards finger base, reaching back near b (between sb and b they are mainly recognizable only by the presence of dental canal) ( Figs 34–36, 38–40 ); movable finger at level of st-t with 9–11 teeth occupying 0.1 mm, distance between successive apices 0.009 –0.011 mm; coupled sensilla pc mainly just distad of sb, rarely at level of sb; tip of movable chelal finger with apical sensilla am 1- 2; trichobothria as in figs 33, 37; ratio sb -st/sb -b = 1.5–2.0; ratio of movable finger/hand of chela 1.8–2.1 (♂ ♀); ratio of pedipalpal femur/movable finger 0.9–1.0 (♂ ♀); ratio of pedipalpal femur/carapace 1.0–1.3 (♂ ♀).

Measurements (in mm). Body length 1.1–1.45 (♂) or 1.2–1.65 (♀). Carapace 0.33–0.43 × 0.38–0.47 (0.35–0.44 anteriorly) (♂) or 0.37–0.50 × 0.41–0.55 (0.39–0.52 anteriorly) (♀). Chelicerae 0.32–0.41 × 0.155 –0.205 (♂) or 0.36–0.48 × 0.175 –0.245 (♀); movable finger length 0.16–0.22 (♂) or 0.185–0.26 (♀). Pedipalp: femur 0.36–0.49 × 0.085–0.11 (♂) or 0.41–0.54 × 0.09–0.12 (♀); chela 0.57–0.75 × 0.115 –0.145 (♂) or 0.63–0.84 × 0.13–0.16 (♀); hand length 0.19–0.25 (♂) or 0.20–0.28 (♀); movable finger length 0.39–0.50 (♂) or 0.42–0.56 (♀).

Description of tritonymph. Integument with weak pigmentation, hispid granulation less marked than in adults. Carapace 0.90–0.95 times longer than broad, form of anterior margin and eyes as in adults; diameter of anterior eyes 0.032 –0.034 mm; chaetotaxy m 4m:6:4:2:m 2m (22), rarely 2 preocular microsetae on one side; length of anteromedian macrosetae 0.07 mm. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–IX 5:(2)8(2):(1)6(1):7:6:6:6:6. Chelicerae 1.95–2.05 times as long as broad, palm with 5 setae and 1 lateral microseta; fixed finger with 6–8 teeth, proximally reduced in size, and a few proximal microtubercles; movable finger with an isolated subapical tooth (di) and 6–7 teeth; gs ratio 0.57–0.60; spinneret prominent and apically rounded as in females. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 4–6 coxal spines, coxa III with 2–5 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.1–4.6 times as long as broad; chela 4.9–5.05 times as long as deep; hand of chela 1.7 times as long as deep; fixed chelal finger with 40–43 contiguous teeth, all with dental canal; movable chelal finger with 30–33 teeth, reduced in size towards finger base, reaching back between st and b; coupled sensilla pc nearer to b than to st; ratio of movable finger/hand of chela 1.9; ratio of pedipalpal femur/movable finger 1.0; ratio of pedipalpal femur/carapace 1.0–1.1.

Measurements (in mm). Body length 0.90–0.95. Carapace 0.305–0.34 × 0.32–0.37 (0.29–0.33 anteriorly). Chelicerae 0.28–0.33 × 0.14–0.16, movable finger length 0.145–0.17. Pedipalp: femur 0.31–0.37 × 0.075–0.08; chela 0.48–0.54 × 0.095–0.11; hand length 0.16–0.19; movable finger length 0.31–0.36.

Remarks. Among the Italian species with contiguous chelal teeth of the Chthonius ischnocheles group, the relationships of C. alpicola are uncertain. The presence of both preocular microsetae and lateral microsetae on the posterior margin of the carapace is shared only by highly specialised hypogean species, such as C. italicus Beier, 1930 , C. caoduroi Callaini, 1987 , C. multidentatus Beier, 1963 and C. gallettii n. sp. (see Key to species).

The measurements given by Beier (1963c) of a female from I Moi, Entratico (Lombardy) (palpal hand 0.28, finger 0.55 mm length) are consistent with the above description. Callaini (1986a) referred to Chthonius cfr. alpicola three males and one female from Pradis (Friuli), showing a ratio sb -st/sb -b = 1.72–2.03 instead of 1.5, as reported by Beier (1951), and est more distal than in Beier (1951: 165, fig. 1a). The relative position of trichobothria sb and est shows a high variability in studied populations and thus the specimens from Pradis are referred to C. alpicola .

The above description of Chthonius alpicola incorporates the measurements of Callaini (1986a). The species is newly recorded from Slovenia and Croatia.

Figures

FIGURES 26–32. Chthonius alpicola Beier, 1951, slope of Mt. Matajur (Losaz, Udine). 26, male, anterior margin of carapace; 27, female, id.; 28, male, carapace; 29, male, right chelicera; 30, female, movable finger of right chelicera; 31, male, right chelal hand, dorsal view; 32, female, id.

FIGURES 33–40. Chthonius alpicola Beier, 1951, slope of Mt. Matajur (Losaz, Udine). 33, male, right chela, antiaxial view; 34, male, detail of fingers at the chelal tip, antiaxial view; 35, male, detail of fingers at level of trichobothria est-it and st-t, antiaxial view; 36, male, detail of fingers at level of trichobothrium sb, antiaxial view; 37, female, right chela, antiaxial view; 38, female, detail of fingers at the chelal tip, antiaxial view; 39, female, detail of fingers at level of trichobothria est-it and st-t, antiaxial view; 40, female, detail of fingers at level of trichobothrium sb, antiaxial view.

FIGURES 402–405. Distribution maps for the Italian species of the Chthonius ischnocheles group. 402, Chthonius agazzii Beier, 1966 and Chthonius comottii Inzaghi, 1987; 403, Chthonius alpicola Beier, 1951; 404, Chthonius carinthiacus Beier, 1951; 405, Chthonius guglielmii Callaini, 1986 and Chthonius ilvensis Beier, 1963.