Onychiurus qingchuanensis, Liu & Gao & Xie & Sun, 2019

Liu, Jie, Gao, Meixiang, Xie, Zhijing & Sun, Xin, 2019, Two new onychiurid species (Collembola, Onychiurinae) inhabiting morel fruit bodies in southwest China, Zootaxa 4576 (2), pp. 367-374 : 371-373

Onychiurus qingchuanensis sp. nov. Liu & Sun

Figs 11–23, Table 2

Type material. Holotype, female; paratypes, 6 females on slides– – China: Sichuan: Guangyuan: Qingchuan: Yaodu , 20 March 2017, on surface and inside fruiting bodies of Morchella vulgaris in farmland, by hand, Xie Zhijing leg. ( SCQC201703 ).

Description. Body length: females 1.60–1.90 mm; holotype 1.90 mm. Shape of body cylindrical with anal spines, Abd. III–IV more or less broadened (Fig. 11). Color in alcohol white.

Pso formulae: 32/022/33353 dorsally and 3/000/11120 ventrally (Figs 11 & 17). Subcoxae 1 of legs I–III with 2 pso each. Parapseudocellar formula: 0/000/ 101001 + 1 m ventrally, dorsal psx absent (Figs 11 & 17). Pseudopore formulae as 0/011/11110 dorsally and 0/111/0001 m 0 ventrally (Figs 11 & 17).

Head. Antennae short, as long as head. Length ratio of antennal segments I: II: III: IV = 1: 1.7: 1.7: 2.5. Ant. IV with a subapical organ, consists of two pits, from which the first is deep and ampulla like, the second is shallow with small sensillum (Fig. 12); basolateral ms above the second proximal row of chaetae (Fig. 12). Ant. III sensory organ composed of 5 papillae, 5(4) guard chaetae, 2 small rods, and 2 smooth sensory clubs (Figs 12 & 13); lateral ms just behind sensory organ (Fig. 12). Ant. II with 14 chaetae. Ant. I with 8 chaetae. Antennal base well marked. PAO with 12–14 compound vesicles arranged in two rows along axis of organ (Fig. 14). Dorsal cephalic chaeta d0 present ( Fig. 18 ). 3+3 p-chaetae between two inner posterior pso on head, p1 anterior to others ( Fig. 18 ). Mandible and maxilla of common type. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs. Labral chaetae 4/142 (Fig. 15). Labium with 6 proximal, 4 basomedian (E, F, G, and f) and 5 basolateral (b, c, d, e, e’) chaetae ( Fig. 19 ). Labial palp of AB type, labial papillae A–E with 1, 4, 0, 3 and 3 guard chaetae respectively (Fig. 16). Postlabial chaetae 4+4 along ventral groove ( Fig. 19 ).

Body chaetotaxy. S-chaetae not distinguishable from ordinary chaetae. Tiny and blunt ms, present on Th. II and III dorso-laterally (Fig. 11). Dorsal chaetae poorly differentiated into macro- and microchaetae, symmetrical in general. Th. I tergum with 7–10+7–10 chaetae (Fig. 11). Th. II–Abd. III terga with 3+3 chaetae along axial line. Abd. IV tergum with unpaired axial chaeta p0; Abd. V tergum without unpaired axial chaeta; Abd. VI tergum with m0 (Fig. 11). Th. I–III sterna without chaetae between legs.

Appendages. Subcoxae 1 of legs I–III with 4, 4 and 4 chaetae, subcoxae 2 with 0, 3 and 3 chaetae respectively. Coxae of legs I, II and III with 3, 9 and 12 chaetae, trochanters with 9 chaetae each and femora with 15, 16 and 16 chaetae. Tibiotarsi of legs I, II and III with 18 (9, 7, 2), 18 (9, 7, 2) and 17 (9, 7, 1) chaetae ( Figs 20 & 21 ). Unguis without teeth. Unguiculus slender and pointed, 0.7 times as long as inner edge of unguis, without inner basal lamella ( Figs 20 & 21 ). Ventral tube with 6+6 distal chaetae, without anterior or basal chaetae. Furca reduced to a finely granulated area; three manubrial rows of chaetae present (Fig. 17).

Genital plate with 15–19 chaetae in females (Fig. 17). Anal valves with following chaetae: each lateral valve with chaetae a0 and 2a1; upper valve with chaetae a0, 2b1, 2b2, c0, 2c1 and 2c2 ( Fig. 22 ). Anal spines set on distinct papillae, 0.6 times as long as inner edge of hind unguis (Figs 11 & 23).

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

FIGRUES 11–17. Onychiurus qingchuanensis sp. nov. 11, dorsal side of body; 12, antenna; 13, clubs, rods and papillae of AIIIO; 14, postantennal organ; 15, labrum; 16, labial palp; 17, ventral side of Abd. II–VI. Scales: 0.1 mm (11, 12, 17), 0.01 mm (13–16).

Discussion. The new species shares the same dorsal pso formula (32/022/33353) with three known species of the genus Onychiurus , O. bhattii Yosii, 1963 , O. fraterculi Babenko & Fjellberg, 2016 and O. steinmanni Pomorski, Furgoł & Christiansen, 2009 . However, they can easily be distinguished by the number of ventral pso, ventral psx, pso on subcoxae 1 and papillae on AIIIO. The main diagnostic characters of these four species are summarized in Table 2.

Figures

FIGURES 18–23. Onychiurus qingchuanensis sp. nov. 18, dorsal side of head; 19, ventral side of head; 20, tibiotarsus of leg I; 21, tibiotarsus of leg III; 22, anal valves; 23, anal spines. Scales: 0.1 mm (18–22), 0.01 mm (23).