Endonura incolorata Stach, 1951

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 : 31-34

Endonura incolorata Stach, 1951 comb. nov.

Figs 50–59 , Tab. 5

Biloba incolorata Stach, 1951: 31

Type material. Lectotype male on slide by present designation, Ukraine, East Carpathians, Chornohora Range, “Zaroślak”, 1935, leg. J. Stach, det. J. Stach,. Paralectotypes, female and 2 juveniles on slides, same data as lectotype.

Stach described Biloba incolorata based on numerous specimens collected in the forest reserve “Zaroślak” in the Chornohora Mts., but he did not designate the holotype. In Stach’s collection, housed at the Institute of Systematics and Evolution Animals PAS (Cracow), 4 syntypes on slides were found. One of them, in a best condition, was designated here as the lectotype.

Other material. Ukraine, East Carpathians, Chornohora Range, „Zaroślak”, 1400 m alt., Norway spruce forest (subalpine belt), decaying wood, under bark of rotting logs, 7.ix.1999, 10.ix.1999, 12.ix.1999, leg. R. J. Pomorski, D. SkarŻyński, A. Smolis, numerous individuals on slides; East Carpathians, Chornohora Range, south slope of Howerla Mt., 1000 m alt., Carpathian beech forest (montane belt), under bark of logs and in rooting wood, 11.ix.1999, leg. A. Smolis, 3 females and 3 juveniles on slides. Other 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 unpigmented eyes present. Buccal cone rather short. Labral chaetotaxy 4/2, 4. Mandible thin with 3 teeth. Head with 3 chaetae Oc, chaetae A, B, C and D. Chaeta O absent. Tubercles Dl and (L+So) on head wih 6 and 10 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 and 6 chaetae respectively. Abd. IV and V with 8 and 2 tubercles respectively. Claw without inner tooth. Tibiotarsi with chaetae B4 and B5 short.

Redescription. Habitus typical of the genus. Body length (without antennae): females 1.0–1.7 mm, males 1.0–1.2 mm, I instars 0.5 mm. Colour of the body white. 2+2 small unpigmented eyes ( Figs 50–51 , 53 ).

Types of dorsal ordinary chaetae. Macrochaetae Ml thin, relatively short, straight, narrowly sheathed, gradually tapered and apically pointed ( Figs 50–51 , 54 , 57 ); macrochaetae Mc and Mcc thin, straight, apically pointed; mesochaetae and microchaetae short, thin and pointed. Macrochaetae very similar in I instars and in adults ( Fig. 53 ). All macrochaetae feebly serrated. Same number and arrangement of chaetae in adults and I instars, except chaetotaxy of ant. IV (see: Tab. 5 c) and genital field (complete absence of chaetae in first instars).

a) Cephalic chaetotaxy–dorsal side.

b) Cephalic chaetotaxy—ventral side.

c) Chaetotaxy of antennae.

5 8 bs, 5 miA 8 bs, 5 miA d) Postcephalic chaetotaxy.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I 1 2 1 - 0 3 6 13 19 th. II 3 2+s 3+s+ms 3 2 7 6 12 19 th. III 3 3+s 3+ s 3 2 8 6 11 18

Sterna

abd. I 2 3+ s 2 2 VT: 4

abd. II 2 3+ s 2 2 Ve: 5 Ve1 - present

abd. III 2 3+ s 2 3 Vel: 5 Fu: 4–5 me 4–6 mi abd. IV 2 2+ s 3 6 Vel: 4 Vec: 2 Vei: 2 Vl: 4 abd. V 8 +s Ag: 3 Vl: 1 L': 1 abd. VI 7 Ve: 12– An: 1mi

13

Head. Buccal cone short ( Fig. 59 ). Labrum rounded, with ventral sclerifications as in Fig. 56 . Labrum chaetotaxy 4/2, 4. Chaetotaxy of labium as in Fig. 56 . Maxilla styliform, mandible thin tridentate. Chaetotaxy of antennae in adults and I instars as in Tab. 5 c. Apical vesicle distinct, simple. Sensilla S on ant.IV subequal, short and rather thick. Chaetotaxy of head as in Tab. 5 a, b, and Figs 51 , 56 , 59 . Tubercles Cl and Af separate ( Fig. 51 ). Chaetae O and E absent. Chaetae D and L4 free. Tubercle Dl with 6 chaetae, chaeta Dl3 present ( Fig. 59 ). Elementary tubercle BE absent. Chaeta A shorter than B.

Thorax, abdomen, legs. Body sensilla fine and smooth, shorter than nearby macrochaetae ( Figs 54 , 57 ). Chaetotaxy of th. and abd. as in Tab. 5 d and in Figs 50, 52–55 , 57–58 . Tubercles Di on th. I not differentiated ( Figs 50 , 53–54 ). Chaetae De3 on abd. I–III shorter than De2. Chaetae De2 on th. II–III and De3 on th. III connected with tubercle De. Chaetae De3 on abd. I–III connected with tubercle De ( Figs 54 , 57 ). The line of chaetae De1–sensillum perpendicular to the dorsomedian line on abd. I–IV ( Figs 54–55 ). Tubercle L on abd. III and IV with 3 and 6 chaetae respectively ( Figs 57–58 ). One chaeta L on abd. IV free. Furca rudiment with 4–6 microchaetae.Tubercles Di on abd. V separate, fused with tubercles De, Dl and L ( Figs 50 , 53 , 57 ). Chaeta L' on abd. V present. Cryptopygy absent. Chaetotaxy of legs as in Tab. 5 d. Tibiotarsi with short chaetae B4 and B5. Claw without inner tooth.

Discussion. See: Discussion of E. tatricola .

Variability. According to the original description ( Stach 1951), chaeta Di3 on abd. V was absent. Analysis of available material showed that the chaeta was absent only in approx. 50% specimens and present in remaining ones.

Distribution. E. incolorata was recorded from Ukraine (Eastern Carpathians, Stach 1951, Kaprus’ et al. 2006), Slovakia (Western Carpathians, Low Tatra Mts., Nosek 1964, 1969), Poland (Western Carpathians, Beskid Żywiecki Mts., Stach 1964) and recently from Rumania (Eastern Carpathians, Dányi et al. 2006).

Ecological remarks. A mountain saproxylic species, occurs in beech, fir–spruce (montane belt) and spruce forests (subalpine belt), not reported above tree line. Found mostly in humid rotting wood and under bark of decaying logs, but also in litter and soil with fine woody debris. First instars were collected in September.

Remarks. Stach (1951) described Biloba incolorata based on specimens from Czornohora Mountains (Ukrainian Carpathians). Later the species was considered as member of Neanura (e.g. Gisin 1960, Salmon 1964, Stach 1964, Massoud 1967), Adbiloba ( Cassagnau 1979) or as “ Biloba ” incolorata ( Babenko et al. 1988) . A detailed analysis of types and a new material (collected in the type locality) made it possible to ascertain that B. incolorata undoubtedly belonged to the genus Endonura (see: Discussion of Endonura ). Furthermore, this allowed me to redescribe this species using a set of modern, diagnostic characters.

Figures

FIGURES 50 – 52. Endonura incolorata: 50, chaetotaxy and distribution of tubercles, adult (dorsal view); 51, chaetotaxy of central area of head; 52 chaetotaxy and distribution of tubercles on abdomen, adult (ventral view).

FIGURES 53 – 56. Endonura incolorata: 53, chaetotaxy and distribution of tubercles, first instar (dorsal view); 54, dorsal chaetotaxy of th. and abd. I; 55, scheme of position of sensillum and chaeta De 1 on abd. I – IV (dm –– dorsomedian line); 56, chaetotaxy of labium and group Vi.

FIGURES 57 – 59. Endonura incolorata: 57, chaetotaxy of abd. III – VI (dorsolateral view); 58, chaetotaxy of tubercles L of abd. I – IV (left side); 59, chaetotaxy of head (ventrolateral view).

Tables

TABLE 5. Chaetotaxy of Endonura incolorata:

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml Mc or Mcc	F G
Af	8	Ml Mc or Mcc mi	B A, C D
Oc	3	Ml Ml or Mc mi	Ocm Ocp Oca
Di	2	Mc Mcc or mi	Di1 Di2
De	2	Ml Mcc or mi	De1 De2
Dl	6	Ml Mcc mi	Dl1, Dl5 Dl3, Dl4 Dl2, Dl6
(L+So)	10	Ml Ml or Mc me mi	L1, So1 L4 So3–6 L2, L3, So2