Friesea handschini Kseneman, 1938

Dányi, László, Traser, György & Kaprus’, Ighor J., 2010, Redescription of Friesea handschini Kseneman, 1938 (Collembola, Neanuridae) with notes on intraspecific variability of the species, Zootaxa 2620, pp. 45-55 : 46-53

Friesea handschini Kseneman, 1938

Figs 1–30 , Tab. 1

Friesea (Polyacanthella) handschini Kseneman, 1938: 461 , Figs 5 a–d; Gisin 1944: 18 (keyed); Rusek 1963: 266; Palissa 1964: 54 (keyed, diagnosis); Palacios-Vargas 2005: 93 (keyed).

Friesea handschini Kseneman : Stach 1949: 300, Pl. 31 (description); Stach 1955: 77, Figs 178–180 (keyed, description); Cassagnau 1958: 19 (keyed); Gisin 1960: 76 (keyed, diagnosis); Massoud 1967: 134 (keyed); Kaprus’ 1999: 260; Sterzyńska & Kaprus’ 2000: 132; Dányi et al. 2006: 49.

Friesea cf. handschini Kseneman : Dányi et al. 2006: 49.

? Friesea handschini Kseneman : Törne 1958: 661; Poinsot 1974: 116; Poinsot-Balaguer 1976: 16; Schulz 1991: 5.

non! Friesea handschini Kseneman : sensu Selga 1958: 64; Jordana et al. 1990: 10.

Type material. The original type material from “Bíly Potok, Trebušany” (on Mt. “Pop Ivan” (today Pip Ivan, at that time Czechoslovakia, today Ukraine) is considered to be lost with certitude. It could not be located in any collection of the Czech Republic (J. Rusek in litt.) and no type specimen was found in the heritage of Stach (W. M. Weiner in litt.) who was in active contact with Mirko Kseneman (J. Rusek in litt.). In view of these, an eligible specimen collected at the type locality is designated herein as neotype for the species.

Neotype adult female in alcohol by present designation, labelled: Ukraine, Marmarosh ridge, Pip Ivan Mt., near Dilove village (former Trebušany), Zakarpattia district, Rakhiv region, subalpine meadow, moss, 1750 m a.s.l., 18.0 8.1993, leg. Kaprus’ I.J., det. Kaprus’ I.J. (No. 5.1.4.5, collection of invertebrate animals in the State Natural History Museum of Ukrainian National Academy of Sciences, L'viv, Ukraine).

Other material. Four females and three males: same data as neotype; One subadult: Romania, Igniş Mts, Baia Mare (Nagybánya), Izvoare Station, near Tăul lui Dumitru, 31.viii.2004, N47º49.431’ EO23º41.870’, 1143 m a.s.l., turf bog, from moss, leg. D. Murányi & K.M. Orci; Four subadults: Romania, Igniş Mts, Baia Mare (Nagybánya), Izvoare Station, Cheile Tătarului 1.ix.2004, N47º48.438’ EO23º45.580’, 738 m a.s.l., leg. D. Murányi & K.M. Orci; Six subadults: Romania, Piatra Mts, Săpânţa (Szaplonca), Valea Brazi, 2.ix.2004, N47º49.775’ EO23º44.606’, 841 m a.s.l., leg. D. Murányi & K.M. Orci. ( Figs 8–9 , 17, 19, 24b, 25); Two subadults: Romania, Rodnei Mts, Borşa (Borsa), Borşa Station, source area of the Aranyos-Beszterce under Gargaló 3.ix.2004, 1688– 1711 m a.s.l., leg. D. Murányi & K.M Orci.; one male and one female: Romania, Rodnei Mts, Borşa, N slope of Pietrosul Rodnei (2303m), thereabout Iezer Meteorological Station, 1780 m a.s.l., under Pinus mugo , soil with Polytrichum sp., 26.vii.2004, leg. J.M. Radwański (in Dányi et al. (2006) erroneously published as “Munţii Rodnei, Borşa, soil under Picea abies and Pinus sylvestris with Vaccinium sp., 700 m a.s.l.“); one subadult: Romania, Rodnei Mts, Borşa, N slope of Pietrosul Rodnei (2303 m), c.a. 1200 m a.s.l. Plagiothecio-Piceetum association, litter and soil, 27.vii.2004, leg. J.M. Radwański; five males, five females and one subadult: Romania, Rodnei Mts, Vậrful Ineu Peak (Ünőkő), 2279 m a.s.l., 1.viii.2008, leg. Gy. Traser & S. Schiffer (males on Figs 1–7 , 10 –14, 16, 18, 21–23, 24a, 26–30; female on Fig. 15 and 20).

Diagnosis. Friesea handschini Kseneman, 1938 belongs to the Polyacanthella Schäffer subgenus of Friesea Dalla Torre. Six well developed anal spines and one spiniform seta (according to the terminology of Palacios-Vargas (1987)), anal spines straight, without papillae. 8+8 eyes, furcula vestigial: mucro absent, dens shortened with 2–3 setae (type 3 and 4 according to Cassagnau (1958) and Massoud (1967)). Tita I–III with 2,3,3 knobbed tenent hairs dorsally and 2,2,2 ventrally.

Redescription. Habitus as in Fig. 1 with dark blue colour. Body length 0.6–0.8 mm (without antennae).

Head. Head 0.12–0.16 mm, length of antennae 0.09–0.12 mm. Head/antenna ratio: 1.1–1.2 ( Fig. 1 ). Ant. I–IV ratio 24:24:20:22 (ventrally). Ant. III and IV dorsally fused, ventrally weakly separated ( Fig. 2 ). Ant. IV with deeply retracted unilobed apical bulb ( Fig. 3 ), and 6 curved sensilla ( Fig. 2 ). Ant. III with one curved sensillum ventrally and one dorsally ( Fig 2 ). AOIII typical of the genus. Ant. I with 7, Ant. II with 13 setae.

8+8 pigmented ocelli, ‘E’ and ‘F’ smaller than the other ones ( Fig. 6 ). Ocular area with 3 setae (oc 1–3 in Fig. 6 ).

Prelabral/labral chaetotaxy as in Fig. 4 and Fig. 5. 4 prelabral and 10 labral setae (4/334), medial setae in first and second labral row longer. Two median prelabral setae situated close together in midline, two other much more laterally ( Fig. 7 ). Labium as in Fig. 7 . Mandible with 7–8 teeth ( Fig. 8 ). Maxilla as in Fig. 9 . Head dorsal chaetotaxy as in Fig. 6 and Tab. 1, setae a0, d0 and p1 present.

a) Cephalic chaetotaxy.

Type of setae sd d a0 oc c p Number of setae 5 1+4 1 3 3 4 Setae sd1–5 d0+d1–4 a0 oc1–3 c1–3 p1–4

b) Postcephalic chaetotaxy.

Row of setae a m p Remarks

Th. I – 4 – m1–4

Th. II 5 2 5 a1–5; m4,5; p1–5; m5 and p3 are ‘s’, m 4 may be missing, m5 can be considered

also as m6

Th. III 4 2 5 a1,3,4,5; m4,5; p1–5; m5 and p3 are ‘s’, a2 always missing, sometimes a3 too Abd. I–III 3 2 5 a1,3,5; m3,4; p1–5; p4 is ‘s’; frequently asymmetrical arrangement of setae in

these segments, m4 often moved forward to the ‘a’ row Abd. IV 3 2 5 a1,2,5; m3,4; p1–5; p4 is ‘s’, a3 sometimes present Abd. V 2 – 3 a1,4; p1,3,4; p3 is ‘s’

Abd. VI 2 – 1 +2 a1,2; p0,1,3; a1,2 and p1 spines; p0 spiniform seta

Thorax, abdomen, legs. Dorsal chaetotaxy of Th. I–III as in Figs 6 , 10, 12 and in Tab. 1. Dorsal chaetotaxy of Abd. I–VI as in Figs 11 –16 and in Tab. 1. Dorsal chaetotaxy often with some variation (e.g. Figs 14–15). Body setae smooth and acuminate, but large macrosetae on Abd. V–VI often with knobbed tips (Fig. 17 and 19). Abd. VI with 6 anal spines without distinct papillae in positions of a1, a2, p1 (Figs 17–20). Anal spines a1 shorter. Seta p0 on Abd. VI short, spiniform, thicker than other setae (Figs 17–20). Anal spines in subadult specimens more or less knobbed at the apex (Fig. 17 and 19), seem to tend to break down (Fig. 18 and 20).

Legs’ chaetotaxy from I to III: subcoxae I: 0,2,2; subcoxae II: 0,2,2; coxae: 3,8,8; trochanters: 5,5,5(4); femora: 12,11,10. Tita I–III with 18, 18, 17 setae respectively (11 in the distal verticil and 6 or 7 further ones more proximally as in Fig. 23 and Fig. 24). Tita I–III respectively with 2,2,2 knobbed tenent hairs ventrally and 2,3,3 dorsally (Fig. 24). Setae on legs as in Figs 21–24. One longer seta on the ventral side of each femur (Figs 22a–c). Claws without teeth (Figs 23–24). Empodial appendage absent.

Ventral chaetotaxy as in Figs 25–26 . Thoracic sterna without setae (Fig. 21). Ventral tube with 4+4(3–5) distal setae ( Fig. 30 ). Furcula reduced, mucro absent, dens with 3(2)+3(2) setae ( Figs 27–28 ). Chaetotaxy of manubrium as in Fig. 28 . Retinaculum with two teeth, without seta ( Figs 27–28 ). Male genital plate with 4(5)+4(5) eugenital and about 30 circumgenital setae ( Fig. 26 ). Chaetotaxy of anal lobes as in Fig. 29 .

Discussion. Using the key of Massoud (1967) we can identify Friesea mauriesi Cassagnau, 1958 having larger size (about 1.3 mm, instead of 0.6–0.8 mm in F. handschini ) and 8 knobbed anal spines (6 spines in F. handschini ). Among the North-American Friesea species of 8+8 eyes we find Friesea fara Christiansen & Bellinger, 1974 with highly similar character composition, but differing in seta a2 on Abd. V (present in F. fara , missing in F. handschini ) and in the spine-like feature of seta p0 on Abd. VI (simple seta in F. f a r a, spiniform seta in F. handschini ).

Distribution and ecology. Till date F. handschini was reported from Austria ( Törne 1958, Querner 2008), France ( Poinsot-Balaguer 1976), Germany ( Schulz 1991), Poland ( Skarżyński et al. 2002), Romania ( Fiera 2007), Slovakia ( Rusek 1963) and Ukraine (Kaprus’ et al. 2006). The records suggest a Central European montane chorotype, but the misinterpreted characters of the species question the reliability of all West- European data. Thus, the identities of the Austrian, French and German specimens need to be confirmed. The necessity for this is also indicated by the species’ Spanish data ( Selga 1958, Jordana et al. 1990) that were later proved to be Friesea nigrimontana Cassagnau ( Jordana et al. 1997) . According to this, the species was considered as Carpathian endemic by Kaprus’ (1999), Kaprus’ et al. (2006) and Sterzyńska and Kaprus’ (2000).

F. handschini seems to be a mountain species. Similarily to Ksenemans’ (1938) and Stachs’ (1949) our specimens were collected in higher altitudes (700–2279 m a.s.l.). Just like us, Stach (1949) found it in wet microhabitats, mostly in moss and deep leaf litter. Nosek and Vysotskaya (1973) reported on the occurrence of F. handschini in small mammal nests, too.

FIGURES 14–18. Friesea handschini : 14, dorsal chaetotaxy of Abd. III–V, arrows indicate missing setae; 15, dorsal chaetotaxy of Abd. I–III, arrows indicate missing or supernumerary (a3’) setae; 16, dorsal chaetotaxy of Abd. IV–VI in adult male with pointed setae and anal spines; 17, Abd. VI in subadult with knobbed setae and anal spines (dorsolateral view); 18, Abd. VI in adult male (dorsolateral view).

FIGURES 19–24. Friesea handschini : 19, Abd. VI in subadult with knobbed setae and anal spines (dorsal view); 20, Abd. VI in adult male with anal spines p1 knobbed, anal spines a1 and right p1 seem shorter because of the observation’ angle (dorsal view); 21, coxal and trochanteral chaetotaxy, ventral view; 22a–c, femora I–III respectively (ventral view); 23a–c, chaetotaxy of Tita I–III respectively (circles: ventral side, dots: dorsal side); 24, knobbed tenent hairs on Tita III (lateral view).

General discussion. Chaetotaxy has a great importance in Collembola taxonomy, however, it is only useful if its intraspecific variability is known ( Grow & Christiansen 1974). For the relatively large genus Friesea, Grow and Christiansen (1974) investigated this topic in detail on some of its North-American representatives. Subsequently, variability found in Friesea was mentioned in several works e.g. Palacios-Vargas (2005), Smolis and Skarżyński (2006). In case of F. handschini the variability observed in the setal number on the dens is of special interest, as several authors (e.g. Cassagnau 1958, Massoud 1967) considered the number of setae on dens to have special importance and used as a main character in identification keys. Most of the F.

handschini specimens investigated by us showed 3+3 setae on dens contrarily to 2+ 2 in the original description. In some specimens we found asymmetry (3+2) of this character, and another specimen having 2+2 setae on dens occurring together with specimens of 3+3 setae was observed (I. Kaprus’ pers. obs.). Grow and Christiansen (1974) already reported on intraspecific variability of this character in North-American Friesea species, and a further example of variability in dens’ chaetotaxy was mentioned by Jordana et al. (1997: Fig. 126j, in Friesea albida Stach, 1949 ). Thus we can conclude that F. handschini has been originally described on specimens representing a rare state of this character.

The number of knobbed tenent hairs on the dorsal side of tibiotarsi I–III was 2,3,3 respectively in each specimen investigated by us, contrarily to 2,2,2 stated by Stach (1949: 300; repeated by Gisin 1960, Palissa 1964, Palacios-Vargas 2005). However, the illustration given by him ( Stach 1949: Pl. 31, Fig. 6 ) might indicate miscounting, as the third tenent hair could be hidden behind the claw. For justification, an attempt was made to revise this character on the F. handschini specimens in Stach’s collection (housed in the Institute of Systematics and Evolution of Animals, PAS, Kraków). However, this material could not clarify the situation, as they are in a condition that does not allow any recognition of knobbed tenent hairs with confidence (W.M. Weiner in litt.).

Clavate setae on Abd. VI and the knobbed form of the anal spines occurring mainly in subadult specimens have never been mentioned before in descriptions of the species. The presence of this special features in F. handschini may have ecomorphological or cyclomorphological background, a question which to answer may be a task of further investigations. Intraspecific variability in the knobbed setae (“Abd. VI clavate seta”) was found in Friesea grandis Mills by Christiansen and Bellinger (1998), however only on an interpopulation level.

Figures

FIGURES 1 – 7. Friesea handschini: 1, habitus (dorsal view); 2, chaetotaxy of Ant. III – IV (dorsal view); 3, apical tip of Ant. IV, arrow shows apical bulb (dorsal view); 4, labral chaetotaxy (ventral view); 5, labrum, arrows show prelabral setae (frontal view); 6, ocelli, dorsal chaetotaxy of the head and Th. I (dorsal view); 7, labial chaetotaxy (ventral view).

FIGURES 8 – 13. Friesea handschini: 8, mandibles; 9, maxillae; 10, dorsal chaetotaxy of Th. II; 11, dorsal chaetotaxy of Abd. I; 12, dorsal chaetotaxy of Th. III – Abd. II; 13, dorsal chaetotaxy of Abd. III – IV.

FIGURES 25 – 28. Friesea handschini: 25, ventral chaetotaxy of abdomen; 26, Abd. III – V (ventral view); 27, retinaculum and furcula (lateral view); 28, retinaculum and furcula (ventral view).

FIGURES 29 – 30. Friesea handschini: 29, Abd. V – VI ventral view; 30, ventral tube, arrow shows supernumerary seta.