Pseudachorutella ellisi, Smolis & Skarżyński & Gwiazdowicz, 2023

Smolis, Adrian, Skarżyński, Dariusz & Gwiazdowicz, Dariusz J., 2023, New species of Neanuridae (Collembola) living on the endemic tree Zelkova abelicea in Crete, Zootaxa 5278 (2), pp. 333-350 : 338

Pseudachorutella ellisi sp. nov.

Figs 13–22

Type material. Holotype: female, bark of Zelkova abelicea trees, slope of Mt. Kedros near Gerakari village (35.194829 N, 24.606713 E), 1255 m a. s. l., Crete, Greece, 11.X.2018, leg. D.J. Gwiazdowicz. Paratype: subadult male, same data as holotype.

Description. Body length: 1.05 mm (holotype), 0.58 mm (paratype). Colour of the body dark blue-grey. Granulation coarse and uniform.

Antennae equal to head. Ant. I with 7 chaetae, Ant. II with 13 chaetae. Ant. III and IV fused dorsally. AOIII with two small internal curved sensilla, one ventral microsensillum and two cylindrical guard sensilla, ventral one longer than dorsal ( Figs 16, 17 ). Ant. IV with trilobed apical vesicle, subapical organite, microsensillum, chaeta i, 8 cylindrical sensilla and numerous modified small sensilla in ventral file ( Figs 16, 17 ).

Ocelli 8 + 8. Postantennal organ absent. Buccal cone very long ( Fig. 13 ). Labrum with 3, 3, 4 chaetae. Prelabral chetae 4–6. Labral sclerifications ogival ( Fig. 14 ). Labium 4.5–5 times longer than distance between chaetae a 1 and m 1 on ventral part of head, with 12 + 12 chaetae and 1 + 1 subapical denticles ( Fig. 15 ). Mandible delicate with 2 teeth, maxilla styliform with a tiny hook at apex.

Dorsal chaetotaxy as in Figs 13, 20 . Chaetae short and smooth, body sensilla 2 x longer than ordinary chaetae, fine and smooth. Sensillar formula per half tergum: 022/11111. Microsensillum on Th. II present. Head with two dorsal chaetae d 1, chaeta a 0 absent. Th. II with chaetae a 2 present and m 3 absent. Th. III with chaetae a 2 absent and m 3 present. On lateral parts of Th. II–III two ordinary chaetae present. Abd. IV without chaetae m 1. Chaetae p 2 on Abd. V present.

Thoracic sterna without chaetae. Each anal valve with 2 small chaetae hr.

Tibiotarsi I, II, III with 19, 19, 18 chaetae respectively, A 1 elongated and pointed. Femora I, II, III with 13, 12, 11 chaetae respectively, trochanters with 6 chaetae each, coxae I, II, III with 3, 8, 8 chaetae, subcoxae 2 of legs I, II and III with 0, 2 and 2 chaetae, subcoxae 1 of legs I, II and III with 1, 2 and 2 chaetae. Claws with one inner tooth and two small lateral teeth ( Figs 18, 19 ). Empodial appendage absent.

Ventral tube with 4 + 4 chaetae. Retinaculum with 3 + 3 teeth. Furca well developed. Dens with 6 chaetae ( Fig. 21 ). Mucro 2.3–2.4 times shorter than dens, slightly curved, with blunt tip and low outer lamella ( Figs 21, 22 ).

Etymology. Dedicated to dr. Willem N. Ellis, who initiated the research on Collembola of Crete.

Remarks. Pseudachorutella ellisi sp. nov. resembles three European species: P. asigillata (B̂rner 1901), P. balcanica Cassagnau & Péja, 1979 and P. bescidica Smolis & Skarżyński 2007 having mandibles with reduced number of teeth (2–4) and 6 chaetae on dens (Börner 1901, Cassagnau & Péja 1979, Smolis & Skarżyński 2007). A new species differs from all of them in a very long buccal cone. Part of it, labium is 4.5–5 times longer than distance between chaetae a 1 and m 1 on ventral part of the head (vs ca. 2.5 in P. asigillata and P. balcanica and 3.5 in P. bescidica ). The new species is easily distinguished from P. asigillata because of Ant. IV with numerous modified small sensilla in ventral file (vs a few slightly modified) and the absence of papillae x on labium (vs two papillae x present). P. bescidica has a moderately plurichaetotic chaetotaxy, which is manifested, for example, by the presence of 4–5 chaetae on lateral parts of Th. II–III and the presence of chaetae m 1 on Abd. IV (vs 2 chaetae on lateral parts of Th. II–III and chaetae m 1 on Abd. IV absent). P. balcanica is also easy to separate from P. ellisi sp. nov. as it has only 6 cylindrical sensilla on Ant. IV and straight mucro (vs 8 cylindrical sensilla and slightly curved mucro).

Figures

FIGURES 13–22. Pseudachorutella ellisi sp. nov.: 13, dorsal chaetotaxy of head, Th. and Abd. I; 14, chaetotaxy of labrum; 15, chaetotaxy of labium and group Vi; 16, dorsal chaetotaxy of Ant. III–IV; 17, ventral chaetotaxy of Ant. III–IV; 18, claw III, lateral view; 19, claw III, dorsal view; 20, dorsal chaetotaxy of Abd. IV–VI; 21, furca, dorsal view; 22 mucro, lateral view.