Endonura transcaucasica ( Stach, 1951 )

Smolis, Adrian, 2016, On the identity of some poorly known species of the genus Endonura Cassagnau, 1979 (Collembola, Neanuridae, Neanurinae), Zootaxa 4173 (3), pp. 237-250 : 238-239

Endonura transcaucasica ( Stach, 1951)

Figs 1–7 , Tab. 1

Biloba transcaucasica: Stach 1951: 34 .

Type material. Lectotype by present designation: adult female on slide, Georgia, Caucasus , Tbilisi, 21.IV.1918, leg. Roszkowski, coll. J. Stach ( ISEA).

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed. 2+2 pigmented eyes. Buccal cone short, labrum nonogival. Head with chaetae A, B, D, E, F and G. Chaetae O and C absent. Tubercles Cl and Af separate. Chaetae D free. Tubercles Dl and (L+So) on head with 6 and 7 chaetae respectively. Tubercles Di and De on th. I present and separate. Tubercles De on th. 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 3 tubercles respectively. Claw without inner tooth. Tibiotarsi with chaetae B4 and B5 short.

Redescription. Habitus typical of the genus. Body length of lectotype (without antennae): 1.65 mm. Colour of the body white. 2+2 large pigmented eyes ( Fig. 1 ).

Types of dorsal ordinary chaetae. Macrochaetae Ml relatively long, strongly thickened, almost cylindrical, arclike or straight, narrowly sheathed, densely serrated, apically rounded ( Figs 1, 5–7 ); macrochaetae Mc and Mcc thickened, straight and rounded at apex or pointed; mesochaetae and microchaetae short, thin, feebly serrated and pointed.

Head. Buccal cone short. Labrum nonogival, with ventral sclerifications as in Fig. 2 . Labrum chaetotaxy 2/2, 4. Labium with four basal, three distal and four lateral chaetae, papillae x absent. Maxilla and mandible as in Figs 3, 4 . Antennal segments I and II with 7 and 11 chaetae respectively. Chaetotaxy of antennal segments III and IV impossible to recognize. Apical vesicle poorly visible, trilobed. Chaetotaxy of head as in Tab. 1 a, b, and Fig. 1 . Head with chaetae A, B, D, E, F and G. Chaetae O and C absent. Tubercles Cl and Af separate. Chaeta D free. Tubercle Dl with 6 chaetae, chaeta Dl3 present. Tubercle (L+So) with 7 chaetae, chaetae So2, So5 and L3 absent ( Fig. 1 ). Elementary tubercles BE and CD present. Chaeta E connected with tubercle Af. Chaeta A shorter than B. Tubercle Oc with two chaetae, chaeta Oca absent ( Fig. 1 ). Chaetae Ocp longer than A. Chaeta De2 as mesochaeta.

Thorax, abdomen, legs. Body s–chaeta thin and smooth, distinctly shorter than nearby macrochaetae ( Fig. 5 ). Chaetotaxy of th. and abd. as in Tab. 1 d and in Figs 1, 5–7 . Tubercles Di on th.I well differentiated and not fused with De. Tubercles De on th. II and III with 3 and 4 chaetae respectively. 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 ( Fig. 5 ). Chaetae De3 on Th. III and abd. I-III slightly longer than De2. The line of chaetae De1–chaeta s perpendicular to the dorsomedian line on abd. I–III ( Fig. 5 ). Furca rudiment without microchaetae. Abd. IV and V with 8 and 3 tubercles respectively, tubercles Di on abd. V fused ( Fig. 6 ). Tubercle L on abd. IV with 6 chaetae ( Fig. 7 ). Chaetae L' and Vl on abd. V present. No cryptopygy. Chaetotaxy of legs as in Tab. 1 d.. Claw without inner tooth. Tibiotarsi with chaetae B4 and B5 short.

a) Cephalic chaetotaxy––dorsal side.

b) Cephalic chaetotaxy––ventral side.

c) Postcephalic chaetotaxy.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I 1 2 1 - 0 3 6 1 2 1 9 th. II 3 2+s 3+s+ms 3 2 7 6 11 19 th. III 3 3+s 3+s 3 2 8 6 1 0 1 8

Sterna

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

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

abd. III 2 3+ s 2 3 Vel :4 Fu: 5–6 me 0 mi abd . IV 2 2+ s 3 6 Vel : 3 Vec : 2 Vei : 2 Vl : 4 abd. V (3+3) 5+s Ag: 3 Vl: 1 L': 1 abd . VI 7 Ve :13-14 An : 2mi Discussion. Because of the absence of chaetae C and O on head, feature generally very rarely observed within Endonura , E. transcaucasica resembles E. baculifer Deharveng, 1979 described from Portugal. However , both species differ in a few characters, important from Neanurinae taxonomy point of view: presence/absence of chaetae E on head (in transcaucasica present, in baculifer absent) number of chaetae Dl on head (in transcaucasica 6, in baculifer 5) and number of chaetae (L+So) on head (in transcaucasica 8, in baculifer 7–9). In addition, the scientific name of Portugal species was derived from an unusual shape of its macrochaetae Di 1 of abdomen V which are extremely thickened and blunt at apex ( Deharveng 1979: Figs 9 B, C).

Figures

FIGURES 1 – 7. Endonura transcaucasica: 1, head and th. I, dorsal and lateral chaetotaxy; 2, ventral sclerifications of labrum; 3, left and right mandible; 4, maxilla; 5, tubercle De of abd. I; 6, dorsal chaetotaxy of abd. V – VI; 7, tubercle L of abd. IV.

FIGURES 8 – 12. Endonura centaurea: 8, head, thorax and abd. I, dorsal and lateral chaetotaxy; 9, central area of head; 10, chaetotaxy of labium and group Vi; 11, dorsal chaetotaxy of abd. IV – VI; 12, furca rudiment.

Tables

TABLE 1. Chaetotaxy of Endonura transcaucasica.

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml Mc	F G
Af	8	Ml Mc me	A, B E D
Oc	2	Ml	Ocm, Ocp
Di	2	Ml Mc	Di1 Di2
De	2	Ml me	De1 De2
Dl	6	Ml Mc Mcc mi	Dl1, Dl5 Dl4, Dl3 Dl2 Dl6
(L+So)	7	Ml Mcc me	L1, L4, So1 L2 So3–4, So6