Chthonius ilvensis Beier, 1963

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 : 68-72

Chthonius ilvensis Beier, 1963

( Figs 212–228 , 405 )

Chthonius (Neochthonius) ilvensis Beier, 1963c: 148 , fig. 1.

Chthonius (N.) ilvensis: Callaini 1979b: 339 , figs Ia–b.

Type locality: Italy, Tuscany Archipelago, Elba Isl., Capoliveri , canaloni presso miniera Monte Calamita (42°44’N, 10°23’E) .

Distribution. France ( Corsica), Italy (Eastern Liguria to Campania).

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 a prominent epistome and with 1 or 2 preocular microsetae on each side; posterior margin of carapace with 2 macrosetae, without lateral microsetae; chelicerae with 2 (rarely 1 or 3) lateral microsetae; chelal fingers with contiguous teeth; chela length 0.56–0.77 mm; chela 4.2–5.2 times as long as deep; ratio of pedipalpal femur/carapace 0.95–1.15; male genital opening mainly with partly scattered setae.

Material examined. FRANCE — Corse — 4 ♀, Sartene, 1.VI.1982, A. Torchia & S. Zoia leg., cork oak wood ; 1 ♀, near Sartene, 280 m a.s.l., 19.IV.1992, S. Zoia leg., Quercus ilex wood; 2 ♂ 3 ♀, Nocario, Monte San Petrone, 1200–1600 m a.s.l., 25.V.1982, A. Torchia & S. Zoia leg., beech wood.

ITALY — Liguria: Genoa Prov. — 1 ♀, Camogli, Monte di Portofino , 4.X.1972, G. Bartoli leg. ; 22 ♂ 34 ♀ 2 T, id., 2.XI.1972, G. Bartoli leg. ; 5 ♂ 15 ♀, id., 7.III.1974, G. Bartoli leg.; 3 ♂ 6 ♀, id., 20. V.1974, G. Gardini leg., sieved under Ostrya ; 2 ♂ 6 ♀, id., 15.II.1976, G. Gardini & R. Poggi leg. , under Ostrya ; 8 ♂ 9 ♀, id., 600 m a.s.l., 15.XI.1981, G. Gardini leg., Ostrya carpinifolia wood on conglomerate; 1 ♂ 1 ♀, id., 24.I.1982, C. Giusto & S. Durante leg., Ostrya carpinifolia wood; 12 ♂ 20 ♀, Camogli, Monte di Portofino, Pietre Strette , 2.III.1972, G. Bartoli leg.; 2 ♀, id., 30.I.1973, G. Bartoli leg. ; 1 ♂, id., 400 m a.s.l., 2.XII.1997, S. Zoia & F. Polese leg.; 10 ♂ 23 ♀, Camogli, San Rocco , 21.I.1983, S. Vit leg. , base of ferns; 4 ♂ 4 ♀ 23 T, Camogli, N slope of Monte di Portofino , 25.IX.1975, G. Bartoli & R. Poggi leg. , Ostrya carpinifolia wood; 1 ♂, Ne, W slope of Monte Carmona , 5. V.1998, G. Gardini leg. , oak wood; 1 ♂ 1 ♀, Santa Margherita Ligure, 30.XI.1982, C. Giusto leg.; 2 ♀, Sestri Levante, Monte Domenico, 340 m a.s.l., 18.III.1984, S. Zoia leg., Quercus ilex wood; 2 ♂, Sestri Levante, San Sebastiano , 7.X.1995, M. Bodon leg. Liguria: La Spezia Prov. — 6 ♂ 2 ♀ 2 T, Deiva Marina, 22.X.1972, G. Gardini leg. , cork oak wood; 1 ♂ 1 ♀ 1 T (det. M. Beier), id., 26.X.1972, G. Bartoli & G. Gardini leg. , cork oak wood; 6 ♂ 4 ♀, id., 4.XI.1972, G. Gardini leg., cork oak wood; 1 ♂ 2 ♀, id., 22.XI.1972, G. Bartoli leg., cork oak wood; 11 ♂ 9 ♀, id., 26.XI.1972, G. Bartoli & R. Poggi leg. , cork oak wood; 3 ♂ 7 ♀, id., 14.XII.1972, G. Bartoli leg., cork oak wood; 2 ♂ 1 ♀, id., 13.IV.1975, L. Briganti & R. Poggi leg. , cork oak wood; 6 ♂ 3 ♀, id., 21.XI.1976, L. Briganti, G. Gardini & S. Zoia leg.; 9 ♂ 9 ♀, Moneglia, Punta Baffe , 11.I.1993, G. Gardini, C. Giusto & S. Zoia leg. , Quercus ilex wood. Tuscany: Florence Prov. — 1 ♀, Greve, IX.1996, G. Castellini leg. ; 2 ♀, Reggello, Vallombrosa, 1200 m a.s.l., 28. V.1977, G. Castellini leg.; 1 ♂ 1 ♀, id., 1150 m a.s.l., 1. V.1986, S. Zoia leg., beech wood; 3 ♂ 9 ♀, Reggello, near Vallombrosa, 1150 m a.s.l., 26. VI.1986, S. Zoia leg., beech wood; 4 ♂ 7 ♀, Reggello, Vallombrosa, Monte Secchieta, 1400 m a.s.l., 30.IV.2012, A. Paladini leg. Tuscany: Grosseto Prov. — 1 ♂, near Grosseto, XII.1978, G. Castellini leg. ; 1 ♀, Grosseto, VI.1984, G. Castellini leg.; 2 ♀, Grosseto, Poggio di Moscona , 5.X.1990, P. Magrini leg. ; 1 ♀, Roccastrada, Val di Farma , VII.1978, G. Castellini leg. Tuscany: Livorno Prov. — 2 ♂ 5 ♀, Collesalvetti, 13. V.1980, S. Zoia leg. , Quercus ilex wood; 1 ♂, Colognole, 150 m a.s.l., 19. VIII.2004, E. Minari leg. ( CNBFVR) ; 2 ♂, id., 18. V.2005, F. Iaccarino & F. Bongianni leg. ( CNBFVR) ; 1 ♂ 1 ♀, Livorno, near Rio Maroccone , 21.XII.2020, P. Gardini leg. , Quercus ilex wood; 1 ♀, Livorno, Le Ferriere, 100 m a.s.l., 21.XII.2020, P. Gardini leg., Quercus ilex wood; 1 ♂ 1 ♀, Piombino, Promontorio di Piombino , IV.1977, G. Castellini leg. Tuscany: Lucca Prov. — 1 ♂, Stazzema, NE slope of Monte Forato, 1100 m a.s.l., 23. VI.1983, S. Zoia & R. Sciaky leg. Tuscany: Pisa Prov. — 1 ♀, Buti, Monte Pisano, towards C. Cucco, 30 m a.s.l., 6.III.1999, M. Bodon leg. ; 3 ♀, near Tirrenia , 27.III.1987, R. Poggi leg. ( MSNG) . Tuscany: Siena Prov. — 1 ♂ 5 T, Abbadia San Salvatore, S slope of Monte Amiata , 1600 m a.s.l., 25. VI.2017, G. Gardini & C. Giusto leg. , beech wood. Tuscany Archipelago: Grosseto Prov. — 3 ♂ 3 ♀, Monte Argentario, 1. V.1973, G. Gardini leg. ; 3 ♂ 7 ♀, id., 200 m a.s.l., 27.XII.1975, N. Sanfilippo leg., Quercus ilex wood; 2 ♂ 2 ♀, id., 5. VI.1978, G. Castellini leg.; 3 ♀, id., 4. VI.1979, G. Castellini leg.; 2 ♀, Monte Argentario, Santa Liberata , 28.IV.1979, G. Gardini & S. Zoia leg. Tuscany Archipelago: Livorno Prov. — 4 ♂ 3 ♀ 4 T, Isola d’Elba, Capoliveri , 19.X.1983, M. Bodon leg. ; 1 ♂, id., 130 m a.s.l., 15.III.1994, F. Gasparo leg., Mediterranean shrubs; 1 ♀, Is. Elba, Capoliveri, Punta Buzzancone , 1 m a.s.l., 3.XI.2007, G. Gardini leg. , sieved under Phragmites ; 2 ♂ 1 ♀, Is. Elba, Cavo, Capo Castello , 3.XI.2007, G. Gardini leg. , Quercus ilex wood; 6 ♂ 4 ♀ 1 T, Is. Elba, Lacona, Colle alle Vacche , 250 m a.s.l., 4.XI.2007, G. Gardini leg. , Quercus ilex wood; 6 ♂ 10 ♀, Is. Elba, Marciana, near Monte Capanne, 400 m a.s.l., 8.XII.1990, M. Bodon leg., chestnut wood; 5 ♂ 8 ♀ 1 T, Is. Elba, near Marciana, 350 m a.s.l., 5.XII.1999, S. Zoia & F. Polese leg. ; 1 ♂ 2 ♀, Is. Elba, Poggio, 400 m a.s.l., 1.I.1975, N. Sanfilippo leg.; 6 ♂ 12 ♀, Is. Elba, Portoferraio, NW slope of Monte Orello , 8.XII.1999, S. Zoia & F. Polese leg. ; 1 ♂ 3 ♀, Is. Elba, near Villa di Napoleone , 23.XII.1975, G. Gardini leg. , Quercus ilex wood. Marche: Pesaro Prov. — 1 ♂ 12 ♀, Cagli, Monte Catria, Fonte Avellana, 800 m a.s.l., 18. VI.1989, G. Gardini & S. Zoia leg. , beech wood; 1 ♂ 2 T, Cagli, Monte Catria , 650 m a.s.l., 4.X.1992, L. Latella leg. Abruzzo: L’Aquila Prov. — 1 ♂, Montereale, Fonte Fra Clemente , 22.X.1994, G. Osella leg. ; 1 ♂ 1 ♀, id., 19.III.1995, G. Osella leg. Campania: Salerno Prov. — 1 ♀, Novi Velia, Monte Sacro, 1600 m a.s.l., 2. VIII.1989, F. Angelini leg. , beech wood.

Description of adults (♂ ♀). Integument pigmented, carapace, tergites, chelicerae and pedipalps reddish-brown; weak hispid granulation on lateral surfaces of carapace, on cheliceral palm, on chelal hand and on base of fixed and movable chelal finger. Carapace ( Fig. 214 ) 0.85–0.95 times longer than broad, quadrate, slightly constricted posteriorly; anterior margin between median macrosetae with a prominent, triangular epistome in both sexes ( Figs 212–213 ); ocular area as in fig. 214, anterior eyes with convex lens (diameter 0.035 –0.045 mm), posterior eyes with flat lens or reduced to a pale cuticular area, all eyes with a tapetum; distance from anterior eyes to anterior margin of carapace 0.030 –0.040 mm; standard chaetotaxy m 4m:6:4:2:2(20), anterior row rarely m 4mm or mm 4mm, macrosetae thick; length of anteromedian macrosetae 0.09–0.11 mm. Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0. Chaetotaxy of sternites 9–11:(2)8–10(2):(2)7–10(2):6–9:6:6:6:6:2T1T2:0:2; genital opening of males flanked by 8–13 setae on each side and partly scattered ( Figs 219–220 ). Chelicerae ( Fig. 215 ) 1.95–2.05 (♂) or 1.85–2.0 (♀) times as long as broad, palm with 6 setae and 2 (rarely 1 or 3) lateral microsetae; fixed finger with 7–10 teeth and 3– 6 proximal microtubercles; movable finger with an isolated subapical tooth (di) at level with the spinneret, and 7–19 teeth proximally reduced in size; gs ratio 0.57–0.65; spinneret weakly raised in males, large and apically rounded in females ( Figs 215–216 ); rallum with 11 blades; serrulae interior and exterior with 12–14 and 14–15 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 6–10 (mainly 7–8) coxal spines, coxa III with 3–6 (mainly 4) coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.0–4.5 (♂) or 3.9–4.3 (♀) times as long as broad, femoral chaetotaxy 3:4–5:1–2:5:1; chela ( Figs 221, 225 ) 4.7–5.2 (♂) or 4.2–4.9 (♀) times as long as deep; hand of chela 1.6–1.8 (♂) or 1.45–1.65 (♀) times as long as deep, shortly ovoid in dorsal view ( Figs 217–218 ); fixed chelal finger with 43–57 contiguous teeth slightly inclined backwards, all cuspidate except the 4–8 proximal ones, which are apically rounded ( Figs 222–224, 226–228 ); all teeth with dental canal; base of fixed chelal finger with 2–3 microtubercles; fixed finger at level of est-it with 11– 14 teeth occupying 0.1 mm, distance between successive apices 0.007 –0.009 mm; tip of fixed chelal finger with apical sensilla af 1- 2, distal paraxial seta gradually curved and thin; movable chelal finger with 36–53 contiguous teeth, cuspidate and reclined in the distal half of the finger, increasingly reduced towards the finger base, reaching back near b, all teeth with dental canal ( Figs 222–224, 226–228 ); 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 at level of sb or just distad of sb; tip of movable chelal finger with apical sensilla am 1- 2; trichobothria as in figs 221, 225; ratio sb -st/sb -b = 1.3–1.8, mainly 1.4–1.5; ratio of movable finger/hand of chela 1.85–2.15 (♂) or 1.8–2.0 (♀); ratio of pedipalpal femur/movable finger 0.95–1.0 (♂ ♀); ratio of pedipalpal femur/carapace 0.95–1.15 (♂ ♀).

Measurements (in mm). Body length 1.05–1.4 (♂) or 1.15–1.5 (♀). Carapace 0.32–0.42 × 0.36–0.49 (0.37–0.43 anteriorly) (♂) or 0.37–0.50 × 0.47–0.55 (0.43–0.51 anteriorly) (♀). Chelicerae 0.33–0.40 × 0.16–0.20 (♂) or 0.38–0.45 × 0.195–0.23 (♀); movable finger length 0.165–0.20 (♂) or 0.195 –0.225 (♀). Pedipalp: femur 0.34–0.48 × 0.09–0.11 (♂) or 0.39–0.51 × 0.10–0.12 (♀); chela 0.56–0.70 × 0.12–0.14 (♂) or 0.59–0.77 × 0.13–0.175 (♀); hand length 0.18–0.25 (♂) or 0.21–0.28 (♀); movable finger length 0.38–0.48 (♂) or 0.42–0.50 (♀).

Description of tritonymph. Integument with weak pigmentation, hispid granulation less marked than in adults. Carapace 0.85–0.95 times longer than broad, form of anterior margin and eyes as in adults; diameter of anterior eyes 0.035 mm; chaetotaxy m 4m:6:4:2:2(20). Chaetotaxy of tergites as in adults. Chaetotaxy of sternites II–IX 5:(1)8(1):(1)7–8(1):8:6:6:6:6. Chelicerae 1.90–2.15 times as long as broad, palm with 5 setae and 1 lateral microseta; fixed finger with 5–7 teeth, proximally reduced in size, and a few proximal microtubercles; movable finger with an isolated subapical tooth (di) and 5 teeth; gs ratio 0.55–0.57; 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 5–8 coxal spines, coxa III with 3–4 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 3.7–3.9 times as long as broad; chela 3.8–4.6 times as long as deep; hand of chela 1.3–1.6 times as long as deep; fixed chelal finger with 45–49 contiguous teeth, all with dental canal; movable chelal finger with 38–41 teeth, reduced in size towards finger base, reaching back near b; coupled sensilla pc halfway between b-st or nearer to b than to st; ratio of movable finger/hand of chela 1.9–2.0; ratio of pedipalpal femur/movable finger 0.9–1.0; ratio of pedipalpal femur/carapace 0.9–1.0.

Measurements (in mm). Body length 0.96–1.1. Carapace 0.29–0.32 × 0.34–0.36 (0.30–0.33 anteriorly). Chelicerae 0.26–0.30 × 0.135–0.14, movable finger length 0.13–0.15. Pedipalp: femur 0.28–0.31 × 0.075–0.08; chela 0.44–0.49 × 0.10–0.13; hand length 0.155–0.17; movable finger length 0.30–0.32.

Remarks. Among the species of the Chthonius ischnocheles group, C. ilvensis is morphologically similar to the epigean C. guglielmii , known from Veneto to western Liguria in Italy and south-eastern France. It differs from C. guglielmii mainly in the following characters: setae of carapace thick, the anterior ones 0.09–0.11 mm long (setae of carapace long and fine, the anterior ones 0.12–0.15 mm long in C. guglielmii ); anterior margin of carapace with 1 or 2 preocular microsetae on each side (without preocular microsetae in C. guglielmii ); chelicerae usually with 2 lateral microsetae (usually with 1 lateral microseta in C. guglielmii ); chela length 0.56–0.77 mm (0.71–0.98 mm in C. guglielmii ); movable finger length 0.38–0.50 mm (0.48–0.65 mm in C. guglielmii ); fixed finger at level of est-it with 11–14 teeth occupying 0.1 mm (with 8–11 teeth occupying 0.1 mm in C. guglielmii ); ratio of pedipalpal femur/carapace 0.95–1.15 (1.15–1.3 in C. guglielmii ); male genital opening flanked by partly scattered setae (by aligned setae in C. guglielmii ).

The above description of Chthonius ilvensis incorporates the measurements given by Callaini (1979b). The species is newly recorded here from France ( Corsica).

Records of Chthonius ilvensis for the caves Büsa del Baorsì 36 Lo/BS and Büs del Cargadùr 308 Lo/BS, Lombardy ( Costantini 1976) are misidentifications and refer to C. guglielmii .

Figures

FIGURES 212–220. Chthonius ilvensis Beier, 1963, Capoliveri (Elba Isl.) (unless otherwise stated). 212, male, anterior margin of carapace; 213, female, id.; 214, male, carapace; 215, male, right chelicera; 216, female, movable finger of right chelicera; 217, male, right chelal hand, dorsal view; 218, female, id.; 219, male, genital opening; 220, male, id. (Pietre Strette, Mt. Portofino, Camogli).

FIGURES 221–228. Chthonius ilvensis Beier, 1963, Capoliveri (Elba Isl.). 221, male, right chela, antiaxial view; 222, male, detail of fingers at the chelal tip, antiaxial view; 223, male, detail of fingers at level of trichobothria est-it and st-t, antiaxial view; 224, male, detail of fingers at level of trichobothrium sb, antiaxial view; 225, female, right chela, antiaxial view; 226, female, detail of fingers at the chelal tip, antiaxial view; 227, female, detail of fingers at level of trichobothria st-t, antiaxial view; 228, 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.