Endonura lusatica ( Dunger, 1966 ) Dunger, 1966

Smolis, Adrian, 2008, Redescription of four Polish Endonura Cassagnau, 1979 (Collembola, Neanuridae, Neanurinae), with a nomenclature of the ventral chaetae of antennae, Zootaxa 1858, pp. 9-36 : 12-17

Endonura lusatica ( Dunger, 1966) comb. nov.

Figs 7–22 , Tab. 1

Neanura tetrophtalma lusatica Dunger, 1966: 5

Type material. Holotype, adult female on slide, Germany, Halbendorf /Oberlausitz, north of Bautzen, peat bog, 20.X.1958, leg. Schlegel, det. Dunger. Paratype, juvenile on slide, same data as holotype.

Other material. Poland, Baltic Coast, Wolin Island, near Sułomino, flood debris on the bank of Szczeciński Flood, 23. III.1962, leg. A. Szeptycki, 2 females, male and juvenile on slides; Baltic Coast, Wolin island, reed communities on the bank of Kamieński Flood, flood debris, 10.IV.1991, leg. R. J. Pomorski, D. SkarŻyński, male on slide; Nizina Wielkopolsko-Kujawska (lowland), near Trzciel, reed communities on the bank of Wielkie Lake, flood debris, IX.1994, leg. M. Wożny, adult male on slide; Pojezierze Pomorskie (Lakeland), Charzykowska Plain, peat bogs, 3.XI.96, 28.IV.97, 19.IX.97, leg. M. Sławska, det. M. Sławska, 2 females and 9 males on slides; Polesie, Poleski National Park, peat bog, soil, 12.VI.1996, leg. R. J. Pomorski, female and 4 juveniles on slides; same locality, soil in sedge bog, 2.VI.1996, leg. R. J. Pomorski, female and juvenile on slide; Podlasie, Białowieski National Park, litter in alder forest, 9.IX.2000, leg. A. Smolis, numerous specimens on slides and in alcohol; Nizina Śląska (lowland), nature reserve "Zabór", near Miękinia, alder forest, litter and rotting wood, 1.IV.2001, 24.IV.2001, 1.IX.2001, leg. D. SkarŻyński, A. Smolis, leg. A. Smolis, 3 females and 2 males on slides. Ukraine, Roztocze, near Iwano–Frankowsk, nature reserve "Zalyvky", the river Vereszycia, wet willow shrubland on low river terrace, litter and soil, 5.VI.1987, leg. I. Kaprus’, male on slide. Material is deposited in the Department of Biodiversity and Evolutionary Taxonomy of Wrocław University, Poland.

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed, except tubercles Di on th. I. 2 +2 pigmented eyes present. Buccal cone elongated. Labral chaetotaxy 4/2, 4. Mandible thin with 3 teeth. Head with 3 chaetae Oc, chaetae A, B, C, D, E and O. Tubercles Dl and (L+So) on head wih 5 and 9 chaetae respectively. Tubercles De on thoracic terga II and III with 3 and 4 chaetae respectively. Tubercles L on abd. III and IV with 3–4 and 7 chaetae respectively. Abd. IV and V with 8 and 3 tubercles respectively. Claw with inner tooth. Tibiotarsi I, II with long and slightly clavate chaetae B4 and B5. Tibiotarsus III with only one long and slightly clavate chaeta B5.

Redescription. Habitus typical of the genus. Body length (without antennae): females 1.6–3.1 mm, males 1.4–2.6 mm, I instars 0.6–0.9 mm. Colour of the body dark blue. 2+2 large, dark pigmented eyes ( Figs 7–9 ).

Types of dorsal ordinary chaetae. Macrochaetae Ml relatively thin, arc-like or straight, narrowly sheathed, apically rounded or rarely pointed ( Figs 8 , 16 , 22 ); macrochaetae Mc and Mcc thin, straight, apically rounded or pointed; mesochaetae and microchaetae short, thin and pointed. Macrochaetae in I instars thin, arc-like or straight, narrowly sheathed, apically pointed ( Fig. 7 ). Same number and arrangement of chaetae in adults and I instars, except chaetotaxy of ant. IV (see Tab. 1 b) and genital plate (complete absence of chaetae in first instars).

Head. Buccal cone strongly elongated ( Fig. 14 ). Labrum pointed, with ventral sclerifications ogival as in Figs 14, 15, 18 . Labrum chaetotaxy 4/2, 4 ( Fig. 19 ). Chaetotaxy of labium as in Fig. 14 . Maxilla styliform, mandible thin and tridentate. Chaetotaxy of antennae in adults and I instars as in Tab. 1 c and in Fig. 10 . Apical vesicle distinct, trilobate. Sensilla S on ant.IV subequal, long and thin ( Fig. 10 ). Chaetotaxy of head as in Tab.1 a and b, and Figs 9 , 15 . Tubercles Cl and Af separate ( Fig. 9 ). Chaeta O present, chaetae D and E free. Tubercle Dl with 5 chaetae, chaeta Dl3 absent ( Fig. 9 ). Chaeta A shorter than B.

Thorax, abdomen, legs. Body sensilla fine and smooth, distinctly shorter than nearby macrochaetae ( Figs 8 , 16 , 20 ). Chaetotaxy of th. and abd. as in Tab. 1 d and in Figs 7–8 , 16–17 , 20–21 . Tubercles Di on th. I not differentiated ( Figs 7–8 ). Chaetae De3 on abd. I–III shorter than De2. Chaetae De2 on th. II–III and De3 on th. III free. Chaetae De3 on abd. I–III free ( Figs 7–8 , 16 ). The line of chaetae De1-sensillum parallel the dorsomedian line on abd. I–III ( Figs 16–17 ). Tubercle L on abd. III and IV with 3–4 and 7 chaetae respectively (see: Variability, Fig. 21 ). Tubercles Di on abd. V fused ( Fig. 16 ). Chaeta L' on abd. V present ( Fig. 21 ). Cryptopygy absent or slightly developed. Chaetotaxy of legs as in Tab. 1 d and Figs 11–13 . Tibiotarsi I–II with elongate and slightly clavate chaetae B4 and B5. Tibiotarsi III with elongate and slightly clavate chaeta B5. Claw with distinct inner tooth ( Figs 11–13 ).

Discussion. Because of the presence of tooth on claw and elongate chaetae B5 and B4 on tibiotarsi, Endonura lusatica appears to be close to Endonura tetrophtalma ( Stach, 1929) and Endonura dentifera Smolis et al. 2007 , described from Hungary and Ukraine respectively. Nevertheless, they significantly differ in the following combination of characters: number of chaetae on tubercle D1 on head (in lusatica 5 chaetae, in dentifera 6 chaetae, in tetrophtalma 3 chaetae), edge of labrum (in lusatica ogival, in dentifera non–ogival, in tetrophtalma unknown), number of chaetae Di on th. II–III (in lusatica and dentifera 3 chaetae, in tetrophtalma 2 chaetae), number of chaetae De on th. III (in lusatica and dentifera 4 chaetae, in tetrophtalma 3 chaetae) and number of chaetae L on abd. IV (in lusatica 7 chaetae, in dentifera 8–9 chaetae, in tetrophtalma 4 chaetae).

Variability. The number of chaetae on tubercle L of abd. III is variable, e.g. among studied material from Poland (34 individuals), 10 (29,4%) specimens have 3+3 chaetae, 17 (49%) spp. 3+4 chaetae and 7 (20,6%) spp. 4+4 chaetae.

Distribution. The species known to date from Germany, Ukraine (as E. tetrophthalma , Kaprus’1998) and Poland (as E. tetrophthalma lusatica, Sławska 2000, 2001 ). More localities of the species from Poland are herein added (see: Other material). The Polish record of E. tetrophtalma from a alder forest in Kampinoski National Park (Nizina Mazowiecka, Kaczmarek 1973) probably pertains to this species.

a) Cephalic chaetotaxy–dorsal side.

b) Cephalic chaetotaxy-ventral side.

c) Chaetotaxy of antennae.

d) Postcephalic chaetotaxy.

Ecological remarks. A lowland hydrophilous species, occurs in damp and wet habitats, e.g. alder forests, willow shrubes, bogs and reed communities on a bank of rivers, lakes and hyaline floods. It inhabits wet or submerged litter and soil, mosses, flood debris and rooting wood. First instars were collected in July and September.

Remarks. Stach (1929) described Achorutes tetrophtalmus from Hungary (the bank of Balaton Lake). Later, in 1951, he classified the mentioned species to newly established genus Biloba (later placed as synonymous of Neanura ) and described a new subspecies Biloba tetrophtalma tatricola from Tatra Mts. (Polish Carpathians). Additionaly, in the same paper, Stach treated the Hungarian species as Biloba tetrophtalma f. principialis. Gisin (1960) elevated the Polish subspecies to the species rank and this taxonomic act was usually accepted by other authors. Later Dunger (1966) described the further subspecies Neanura tetrophtalma lusatica on the basis of two specimens collected in the extreme south–eastern Gemany (Oberlausitz, near German –Polish border). Cassagnau (1979) established the subgenus Endonura and designated Neanura tetrophtalma as its type species.

A detailed analysis of original descriptions, type and new material (types of E. tetrophtalma have been lost, W. M. Weiner pers. comm.) showed that E. tetrophtalma , E. lusatica and E. tatricola are a good and distinct species clearly differing in many important taxonomic characters (see: Discussions of E. lusatica and E. tatricola ). At the same time it turned out that all mentioned taxa needed a comment and modern redescription to establish and explain their identity. In my opinion, however, the redescription of E. tetrophtalma is presently impossible and should be prepared by a study of a new material from the type locality.

According to the original description and figures ( Dunger 1966), macrochaetae of E. lusatica are densely covered by large oval scale–like structures. However, a study of available material (types have been checked) did not confirm the presence of such structures. In adition, the type material of the species is generally in a bad condition and the present redescription and figures are therefore based mainly on a new material.

Figures

FIGURES 7 – 8. Endonura lusatica: 7, chaetotaxy and distribution of tubercles, first instar (dorsal view); 8, chaetotaxy and distribution of tubercles, adult (dorsal view).

FIGURES 9 – 13. Endonura lusatica: 9, dorsolateral chaetotaxy of head; 10, dorsal chaetotaxy of ant. III – IV; 11, tibiotarsus and claw III (ventrolateral view); 12, tibiotarsus and claw II (ventrolateral view): 13, femur, tibiotarsus and claw III (lateral view).

FIGURES 14 – 19. Endonura lusatica: 14, chaetotaxy of labium and group Vi; 15, ventral chaetotaxy of head; 16, dorsal chaetotaxy of abd. III – VI; 17, scheme of position of sensillum and chaeta De 1 on abd. I – IV (dm –– dorsomedian line); 18, ventral sclerifications of labrum; 19, chaetotaxy of labrum.

FIGURES 20 – 22. Endonura lusatica: 20, chaetotaxy of thorax (lateral view); 21, chaetotaxy of abdomen (ventrolateral view); 22, chaeta Di 1 of abd. V (adult).

Tables

TABLE 1. Chaetotaxy of Endonura lusatica:

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml me	F G
Af	11	Ml Mc Mcc or mi mi	B A C, E, O D
Oc	3	Ml Mc mi	Ocm Ocp Oca
Di	2	Ml Mcc or mi	Di1 Di2
De	2	Ml Mcc or mi	De1 De2
Dl	5	Ml Mc Mcc or mi mi	Dl1, Dl5 Dl4 Dl6 Dl2
(L+So)	9	Ml Mcc mi me	L1, L4, So1 L2 L3 So3–6