Chthonius (Neochthonius) jonicus Beier, 1931: 53

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 : 91-95

Chthonius (Neochthonius) jonicus Beier, 1931: 53 ; 1963b: 21, fig. 14.

Type locality: Greece, Ionia nisia, Lefkada, Kalligoni (38°49’12”N, 20°42’10”E) .

Distribution. Lebanon, Israel, Turkey, Greece, Albania, Romania, Italy, Malta, Spain, Portugal.

Diagnosis (♂ ♀). An epigean Chthonius that differs from other species of the ischnocheles group in the following combination of characters: anterior margin of carapace without preocular microsetae; posterior margin of carapace with 4 macrosetae, without lateral microsetae; anterior eyes with flat lens; chelicerae without lateral microsetae; chela length 0.40–0.51 mm; movable chelal finger length 0.275–0.34 mm; chelal fingers with contiguous teeth; both fixed and movable chelal fingers at level of est-ist and st-t with 8–10 teeth occupying 0.05 mm; movable chelal finger with coupled sensilla pc not on a tubercle.

Type material examined. GREECE — 1 ♂ 2 ♀ (syntypes, in poor condition), “Levkas, Kaligoni, 14.IV.29 [M. Beier leg.]”, “1282” “ Chthonius jonicus n. sp. det. Beier, Typen” ( NHMW) .

Other material examined. ALBANIA — Shkodër — 46 ♂ 32 ♀ 26 T 12 D, Theth , 740 m a.s.l., 29.IX.2016, J. Christophoryová leg. ( DZCUB; 5 ♂ 5 ♀ in G. Gardini coll., Genoa) .

GREECE — Thessalia — 1 ♂ 1 ♀, Pindos, Timfi, near Kalivia, 28.V.1989, S. Zoia leg.

ITALY — Lazio: Latina Prov. — 1 ♂ 2 ♀ 2 T 1 D, Sabaudia, Parco Nazionale del Circeo, 8.XII.1990, L. Latella & S. Zoia leg. Campania: Caserta Prov. — 1 ♀, Sessa Aurunca, Cascano, 29.IX.1982, G. Gardini & S. Zoia leg. Campania: Neaples Prov. — 7 ♂ 17 ♀ 6 T 1 D, Torre del Greco, Camaldoli della Torre, 29.IX.1982, G. Gardini & S. Zoia leg. Apulia: Foggia Prov. — 1 ♀, near Apricena, 290 m a.s.l., 4. V.2002, S. Zoia & F. Polese leg.; 1 ♂, Mattinata, necropolis of Monte Saraceno, 194 m a.s.l., 22.IV.2019, G. Gardini & P. Gardini leg., garrigue; 1 ♀, Tremiti Isl., San Nicola Is., 28.XI.1992, R. Poggi leg. ( MSNG); 5 ♂ 19 ♀, Vico del Gargano, Foresta Umbra, 760 m a.s.l., 23.IV.2019, G. Gardini & P. Gardini leg., beech wood; 3 ♂ 7 ♀, Vico del Gargano, Calenelle beach, 10 m a.s.l., 23.IV.2019, G. Gardini & P. Gardini leg., Mediterranean bush; 2 ♀, near Vieste, 1.III.1984, S. Vit leg., leaf litter. Basilicata: Matera Prov. — 2 ♂ 3 ♀, Tricarico, Bosco Tre Cancelli, 900 m a.s.l., 20.IV.2018, S. Zoia leg., under Quercus sp. Sicily: Agrigento Prov. — 1 ♀, Santo Stefano di Quisquina, 9.VII.1996, B. Massa leg., soil under Cedrus atlantica ; 3 ♀ 1 T, id., 13.XI.1996, B. Massa leg., soil under Pinus ans Cedrus ; 6 ♀ 3 T, id., 24.II.1997, B. Massa leg., soil under Pinus and Cedrus ; 22 ♀ 7 T, id., 7. V.1997, B. Massa leg., soil under Pinus and Cedrus . Sicily: Palermo Prov. — 1 ♀, Campofiorito, 18.III.2017, C. Baviera & C. Bellò leg. Sicily: Trapani Prov. — 1 ♀, Erice, 2.I.1995, G. Gardini leg., Quercus ilex wood; 2 ♀, Mazara del Vallo, Gorghi Tondi, 3.I.1995, G. Gardini leg.; 2 ♀, id., 30.IV.2000, S. Zoia & F. Polese leg., Quercus ilex wood; 7 ♂ 8 ♀, Scopello, Riserva Naturale dello Zingaro, 31.XII.1994, G. Gardini & S. Zoia leg., Quercus ilex wood; 1 ♂, id., 17.I.1997, B. Massa leg. Sardinia: Cagliari Prov. — 1 ♀, Quartu Sant’Elena, Bingia Spada, Stagno Quartu, 16.VII.2018, E. Bazzato, M. Caria & C. Ancona leg.; 1 ♀, id., 3.XII.2018, E. Bazzato, M. Caria & C. Ancona leg.; 1 ♀, Quartu Sant’Elena, Cani Nieddu, 17. VIII.2018, E. Bazzato, M. Caria & C. Ancona leg.; 3 ♀, id., 21.III.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 2 ♀, id., 27. V.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 1 ♀, Quartu Sant’Elena, Foxi, 27. V.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 1 ♀, Quartu Sant’Elena, Porticciolo, 27. V.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 2 ♀, Quartu Sant’Elena, Sant’Andrea, 14.IV.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 3 ♀, id., 27. V.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 1 ♀, Quartu Sant’Elena, Stagno Quartu, 11.III.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 1 ♀, id., 16.IV.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 1 ♀, Quartu Sant’Elena, via Ischia, Foxi, 25.IX.2018, E. Bazzato, M. Caria & C. Ancona leg.; 1 ♀, id., 21.III.2019, E. Bazzato, F. Alamanni & C. Ancona leg.; 8 ♀, Quartu Sant’Elena, via Rimini, Sant’Andrea, 21.III.2019, E. Bazzato, F. Alamanni & C. Ancona 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 the base of fixed chelal finger. Carapace ( Fig. 284 ) 0.9–1.1 times longer than broad, quadrate, weakly constricted posteriorly; anterior margin between median macrosetae with prominent epistome in both sexes ( Figs 282–283 ); ocular area as in fig. 284, anterior eyes with flat lens (diameter 0.020 –0.030 mm), posterior eyes reduced to a pale cuticular area, all eyes with tapetum; distance from anterior eyes to anterior margin of carapace 0.020 –0.025 mm; chaetotaxy 4:6:4:2:4(20), lateral setae of posterior row mostly shorter than median ones; length of anteromedian macrosetae 0.06–0.07 mm. Chaetotaxy of tergites 4:4:4:4:6:6:6:6:1T2T1:4:1T2T1:0. Chaetotaxy of sternites 9–10:(3)8–9(3):(2)6–8(2):8:6– 7:6:6:6:2T1T2:0:2; genital opening of males flanked by 6 (rarely 5) setae on each side. Chelicerae ( Fig. 285 ) 1.85– 2.15 (♂ ♀) times as long as broad, palm with 6 setae, without lateral microsetae; fixed finger with 7–9 teeth, the two distal teeth largest; movable finger with an isolated subapical tooth (di) at level of the spinneret, a large tooth and 4–8 teeth proximally reduced in size; gs ratio 0.57–0.60; spinneret weakly prominent, rounded and similar in both sexes ( Figs 285–286 ); 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 5–6, IV 6–7; coxa II with 6–8 coxal spines, coxa III with 2–4 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 4.0–4.7 (♂) or 4.0–4.3 (♀) times as long as broad, femoral chaetotaxy 3:6:2:5:1; chela ( Figs 289, 293 ) 4.1–5.4 (♂) or 4.2–5.0 (♀) times as long as deep; hand of chela 1.5–1.75 (♂) or 1.45–1.7 (♀) times as long as deep, ovoid in dorsal view ( Figs 287–288 ); fixed chelal finger with 46–58 contiguous, tall teeth, slightly inclined backwards, all cuspidate except the 7–11 proximal ones that are apically rounded ( Figs 290–292, 294–296 ); all teeth with dental canal; fixed finger at level of est-it with about 9–10 teeth occupying 0.05 mm; tip of fixed chelal finger with apical sensilla af 1- 2, distal paraxial seta gradually curved and thin; movable chelal finger with 39–49 contiguous teeth that are similar to those of the fixed chelal finger from the finger apex to level of trichobothrium st, apically rounded and increasingly reduced from st towards finger base, reaching back near b ( Figs 290–292, 294–296 ); movable finger at level of st-t with about 8–9 teeth occupying 0.05 mm; coupled sensilla pc just proximad of sb to just distad of sb; tip of movable chelal finger with apical sensilla am 1- 2; trichobothria as in figs 289, 293; trichobothrium sb mainly just closer to b; ratio of movable finger/hand of chela 1.9–2.0 (♂) or 1.8–1.95 (♀); ratio of pedipalpal femur/movable finger 0.9–1.05 (♂ ♀); ratio of pedipalpal femur/carapace 0.95–1.1 (♂ ♀).

Measurements (in mm). Body length 0.8–0.9 (♂) or 0.9–1.1 (♀). Carapace 0.24–0.31 × 0.25–0.305 (0.23–0.27 anteriorly) (♂) or 0.28–0.34 × 0.29–0.35 (0.275 –0.325 anteriorly) (♀). Chelicerae 0.22–0.28 × 0.11–0.13 (♂) or 0.26–0.305 × 0.135–0.15 (♀); movable finger length 0.11–0.125 (♂) or 0.13–0.155 (♀). Pedipalp: femur 0.25–0.33 × 0.06–0.08 (♂) or 0.285 –0.345 × 0.07–0.085 (♀); chela 0.40–0.47 × 0.085 –0.115 (♂) or 0.45–0.51 × 0.10–0.12 (♀); hand length 0.135–0.17 (♂) or 0.155–0.18 (♀); movable finger length 0.275–0.32 (♂) or 0.29–0.34 (♀).

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 as in adults, eyes hardly distinguishable; chaetotaxy 4:6:4:2:4(20) (6 basal setae in a tritonymph from S. Stefano di Quisquina); length of anteromedian macrosetae 0.05 mm. Chaetotaxy of tergites as in adults. Chaetotaxy of sternites not seen. Chelicerae 1.8–2.1 times as long as broad, palm with 5 setae, without lateral microsetae; fixed finger with 5–7 teeth, proximally reduced in size; movable finger with an isolated subapical tooth (di) and 5–6 teeth; gs ratio 0.54–0.57; spinneret as in adults. Coxal setae: pedipalp 5 (including 2 on manducatory process), I 3 + 2 marginal microsetae, II 4, III 5, IV 5; coxa II with 5–6 coxal spines, coxa III with 2–3 coxal spines; intercoxal tubercle bisetose. Pedipalp: femur 3.5–4.0 times as long as broad; chela 4.35–4.4 times as long as deep; hand of chela 1.55 times as long as deep; fixed chelal finger with 42–48 contiguous teeth, all with dental canal; movable chelal finger with 37–40 teeth, reduced in size towards finger base, reaching back between st and b; coupled sensilla pc halfway between b -st; ratio of movable finger/hand of chela 1.8–1.85; ratio of pedipalpal femur/movable finger 0.95–1.0; ratio of pedipalpal femur/carapace 0.9–0.95.

Measurements (in mm). Body length 0.70–0.80. Carapace 0.23–0.24 × 0.25 (0.225–0.23 anteriorly). Chelicerae 0.20–0.21 × 0.10–0.11, movable finger length 0.10–0.105. Pedipalp: femur 0.21–0.225 × 0.055–0.06; chela 0.35– 0.355 × 0.08; hand length 0.125; movable finger length 0.225–0.23.

Remarks. Among the species of the Chthonius ischnocheles group, C. jonicus is morphologically similar to the epigean C. leoi from Sardinia and to C. caprai from Liguria, Sicily and Sardinia. Comparisons between C. jonicus and C. halberti are provided in the Remarks section of the latter species.

Chthonius jonicus differs from C. leoi in the following main characters: anterior eyes with flat lens, posterior eyes reduced to a pale cuticular area (no eyes in C. leoi ); chelicerae without lateral microsetae (with 1 or 2 microsetae in C. leoi ); chela length 0.40–0.51 mm (0.38–0.40 mm in C. leoi ); movable chelal finger length 0.275–0.34 mm (0.225 –0.265 mm in C. leoi ); movable chelal finger with coupled sensilla pc not on a tubercle (coupled sensilla pc on a noticeable tubercle in C. leoi ).

Chthonius jonicus differs from C. caprai in the following main characters: posterior margin of carapace with 4 macrosetae (mainly with 6 macrosetae in C. caprai ); anterior eyes with flat lens, posterior eyes reduced to a pale cuticular area (no eyes in C. caprai ); chelicerae without lateral microsetae (with 1 or 2 microsetae in C. caprai ); chela length 0.40–0.51 mm (0.31–0.43 mm in C. caprai ); movable chelal finger length 0.275–0.34 mm (0.21–0.28 mm in C. leoi ); movable chelal finger with coupled sensilla pc not on a tubercle (coupled sensilla pc on a weak tubercle in C. caprai ).

Records of Chthonius jonicus from Guardiaregia (Molise), Sambiase (Calabria) and from San Pietro Vernotico (Apulia) ( Gardini 1995: 44) are misidentifications of Zaragozachthonius karamanianus ( Hadži, 1937) ( Gardini 2020) . Italian records of C. jonicus established by Gardini (2000), chiefly those from Sicily, remain to be verified.

Figures

FIGURES 282–288. Chthonius jonicus Beier, 1931, Riserva Naturale dello Zingaro, 31.XII.1994 (Scopello, Trapani). 282, male, anterior margin of carapace; 283, female, id.; 284, male, carapace; 285, male, right chelicera; 286, female, movable finger of right chelicera; 287, male, right chelal hand, dorsal view; 288, female, id.

FIGURES 289–296. Chthonius jonicus Beier, 1931, Riserva Naturale dello Zingaro, 31.XII.1994 (Scopello, Trapani). 289, male, right chela, antiaxial view; 290, male, detail of fingers at the chelal tip, antiaxial view; 291, male, detail of fingers at level of trichobothria est-it and st-t, antiaxial view; 292, male, detail of fingers at level of trichobothrium sb, antiaxial view; 293, female, right chela, antiaxial view; 294, female, detail of fingers at the chelal tip, antiaxial view; 295, female, detail of fingers at level of trichobothria est-it and st-t, antiaxial view; 296, female, detail of fingers at level of trichobothrium sb, antiaxial view.