Leeonychiurus zijinensis, Zhang & Sun & Wu, 2020

Zhang, Shaoqing, Sun, Xin & Wu, Donghui, 2020, A new species of the genus Leeonychiurus Sun & Arbea, 2014 (Collembola Onychiurinae, Onychiurini) from China, with a checklist of Chinese Onychiurini, Zootaxa 4743 (1), pp. 137-143 : 138-140

Leeonychiurus zijinensis sp. nov.

Figs 1–9

Type material. Holotype, male; paratypes, 4 females and 1 males on slides, and about 20 individuals in alcohol, China: Jiangsu prov.: Nanjing: Zijinshan: Xiamafang Park , 04 July 2015, litter, Berlese extraction, Daoyuan Yu leg. (201507ZJSXMF).

Diagnosis. Pso formula as 32/133/33343 dorsally and 11/000/01110 ventrally; parapseudocelli only visible on base of ventral tube; subcoxa 1 of legs I–III with 1 pso each; PAO with 18–20 compound vesicles; Th. I tergum with 7–8+7–8 chaetae; Abd. IV tergum with unpaired axial chaetae m0 and p0; Th. I–III sterna with 0+0, 1+1, 1+1(2) chaetae between legs; upper valve with chaetae a0, 2a1, b0, 2b1, 2b2, c0, 2c1 and 2c2; anal spines as long as inner edge of hind unguis.

Description. Body length: females 1.40–1.50 mm, males 1.10–1.24 mm; holotype 1.24 mm. Shape of body cylindrical with anal spines, Abd. III–IV more or less broadened ( Fig. 1 ). Color in alcohol white.

Pso formulae: 32/133/33343 dorsally and 11/000/01110 ventrally ( Figs 1 & 6 ). Subcoxae 1 of legs I–III with 1 pso each. Parapseudocelli only visible on base of ventral tube. Pseudopore formulae as 0/011/11110 dorsally and 0/111/0001 m 0 ventrally ( Figs 1 & 6 ).

Head.Antennae short, 0.9 times as long as head. Length ratio of antennal segments I: II: III: IV = 1: 1.5: 1.5: 2.0. Subapical organite on Ant. IV with globular apex, invaginated apical bulb absent; basolateral ms above the second proximal row of chaetae; numerous S-chaetae present and clearly distinguished from ordinary chaetae. Ant. III sensory organ composed of 5 papillae, 5 guard chaetae, 2 small rods, and 2 granulated sensory clubs ( Fig. 2 ); lateral ms just behind sensory organ next to the basis of outer papilla. Ant. II with 16 chaetae. Ant. I with 9 chaetae. Antennal base well marked. PAO with 18–20 compound vesicles arranged in two rows along axis of organ ( Fig. 3 ). Dorsal cephalic chaeta d0 present ( Fig. 1 ). 4+4 p-chaetae between two inner posterior pso on head, p1 anteriorly to others ( Fig. 1 ). Mandible and maxilla typical for the genus. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae 4/342 ( Fig. 4 ). Labium with 6 proximal, 4 basomedian (E, F, G, and f) and 6 basolateral (a, b, c, d, e, e’) chaetae ( Fig. 7 ). Labial palp of AC type, labial papillae A–E with 1, 4, 0, 3 and 3 guard chaetae respectively. Postlabial chaetae 4+4 along ventral groove ( Fig. 7 ).

Body chaetotaxy. S-chaetae slightly distinguished from ordinary chaetae, formulae as 11/012/222120 dorsally and 2/000/00010 ventrally ( Figs 1 & 6 ). Tiny and blunt ms present on Th. II and III dorso-laterally ( Fig. 1 ). Th. I tergum with 7–8+7–8 chaetae. Th. II–III terga each with 3–4+3–4 chaetae, and Abd. I–III terga each with 3+3 chaetae along axial line. Abd. IV tergum with unpaired axial chaetae m0 and p0; Abd. V tergum with unpaired axial chaeta m0; Abd. VI tergum with a0 and m0 ( Fig. 1 ). Th. I–III sterna with 0+0, 1+1, 1+1(2) chaetae between legs.

Appendages. Subcoxae 1 of legs I–III with 4, 5 and 5 chaetae, subcoxae 2 with 1, 4 and 4 chaetae respectively. Tibiotarsi of legs I, II and III with 22 (11, 8, 3), 21 (11, 8, 2) and 21 (11, 8, 2) chaetae ( Fig. 5 ). Unguis without teeth. Unguiculus slender and pointed, 0.6 times as long as inner edge of unguis, without inner basal lamella ( Fig. 5 ). Ventral tube with 6–7+6–7 distal, and without basal and anterior chaetae. Furca reduced to a finely granulated area with 4 dental chaetae in one row posterior to furcal rudiment; three manubrial rows of chaetae present ( Fig. 8 ).

Genital plate with 16–21 chaetae in females, 36–40 in males. Male ventral organ absent. Anal valves with following chaetae: each lateral valve with chaetae a0 and 2a1; upper valve with chaetae a0, 2a1, b0, 2b1, 2b2, c0, 2c1 and 2c2 ( Fig. 9 ). Anal spines set on indistinct papillae, as long as inner edge of hind unguis.

Derivatio nominis. Named for the mountain of the type locality.

Discussion. The new species is similar to L. fusongensis Sun & Arbea, 2014 and L. mai ( Wray, 1950) sensu Bernard (2015) , as having the same dorsal pso formula (32/133/33343). However, they can be recognized easily by the pso formula on Abd. sterna II–IV (111 in the new species, 112 in L. fusongensis , and 001 in L. mai ), unpaired axial chaetae m0 on Abd. tergum V (present in the new species, and absent in L. fusongensis and L. mai ), and number of vesicles of PAO (18–20 in the new species, 13–16 in L. fusongensis , and 15 in L. mai ).

Figures

FIGRUES 1–6. Leeonychiurus zijinensis sp. nov. 1, dorsal side of body; 2, clubs, rods and papillae of Ant. III sensory organ; 3, postantennal organ; 4, labrum; 5, tibiotarsus of leg III; 6, ventral side of Abd. II–VI. Scales: 0.1 mm (1, 5, 6), 0.01 mm (2–4).

FIGURES 7–9. Leeonychiurus zijinensis sp. nov. 7, ventral side of head; 8, furcal area; 9, anal valves. Scales: 0.1 mm.