Dimorphaphorura jingyueensis, Sun, Xin & Wu, Donghui, 2012

Sun, Xin & Wu, Donghui, 2012, Two new species of the tribe Oligaphorurini Bagnall, 1949 (Collembola: Onychiuridae) from northeast China, Zootaxa 3526, pp. 45-52 : 46-49

Dimorphaphorura jingyueensis sp. nov.

Figs 1–15

Type material. Holotype female, 9 females and 4 males paratypes. China: Jilin Province: Jingyuetan National Forest Park (alt. ca 250 m, 43°47'26" S, 125°28'35" W), litter and soil, Berlese extraction, 18.V.2007, leg. Wu Donghui. Holotype and 13 paratypes on slides are deposited in the collection of the Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun.

Description. Body color white in alcohol. Size 0.8–1.2 mm in females, 0.6–0.7 mm in males; holotype: 1.02 mm. Body slender and elongated.

Pseudocellar formula dorsally: 32/133/33353, ventrally: 11/000/00000; subcoxa 1 of legs I–III with 1 pso each ( Figs 1 & 2 ). Parapseudocellar formula ventrally: 00/000/212101, absent dorsally ( Figs 1 & 2 ); subcoxa 1 of legs I–III with 1, 1 and 1 psx each. Pseudopore formula dorsally: 00/011/ 111100, ventrally: 00/111/000 x00 ( Figs 1 & 2 ).

Head. Antennae short and distinctly segmented, as long as head. Length ratio of antennal segments I: II: III: IV = 1: 1.5: 1.5: 1.5. Ant. IV with two distinct thickened S-chaetae, subapical organite with apex globular and basolateral ms just above posterior chaetae. Ant. III sensory organ composed of 5 papillae, 5 guard chaetae, 2 small sensory rods, 2 granulated sensory clubs, the outer about twice as large as the inner, and a lateral ms ( Fig. 7 ). Ant. II with 14–15 chaetae. Ant. I with 8 chaetae. Antennal base with distinct granulation ( Fig. 4 ). PAO located on cuticular furrow built with a 3-lobed vesicle ( Fig. 4 ). Dorsal cephalic chaeta d0 absent, 3+3 p-chaetae between posterior a-pso on head ( Fig. 1 ). Mandible with a strong molar plate and 4 apical teeth. Maxilla bearing 3 teeth and 6 lamellae. Maxillary palp simple with 1 basal chaeta and 2 sublobal hairs ( Fig. 6 ). Labral chaetae formula 4/342 ( Fig. 5 ). Labium with 6 proximal, 4 basomedian (E, F, G, f) and 5 basolateral (b, c, d, e, e’) chaetae ( Figs 3 & 10 ); labial type A, papillae A–E with 1, 4, 0, 3, and 2 guard chaetae respectively ( Fig. 3 ). Postlabial chaetae 4+4 along ventral groove ( Fig. 10 ).

Body chaetotaxy. S-chaetae cylindrical, well differentiated, their formula 11/011/222110 dorsally, 11/000/ 0 0 0 100 ventrally ( Figs 1, 2 & 10 ); subcoxae 2 of I, II and III legs with 0, 0 and 1 S-chaeta, respectively. Smicrochaetae tiny and blunt, present on Th. II–III ( Fig. 1 ). Ordinary chaetae differentiated in meso- and macrochaetae. Th. I tergum with 7+7 chaetae. Th. II–III and Abd. I–III terga with three chaetae on both sides of axial line and no dorsal axial chaetae ( Fig. 1 ). Abd. IV tergum with one axial chaeta (m0), Abd. V tergum without axial chaetae, Abd. VI tergum with two axial chaetae ( Figs 1 & 16 ). Th. I, II and III sterna with 0+0, 1+1, 1+1 chaetae, respectively.

Appendages. Subcoxa 1 of legs I–III with 4, 5 and 6 chaetae, subcoxa 2 with 1, 4 and 4 chaetae, respectively. Tibiotarsi of legs I, II and III with 20 (11, 8, 1), 20 (11, 8, 1) and 19 (11, 7, 1) chaetae, respectively ( Figs 8 & 9 ). Unguis without teeth. Unguiculus slender and pointed, as long as inner edge of unguis, without inner basal lamella ( Figs 8 & 9 ). Ventral tube with 8+8 distal chaetae and 3–4+3–4 basal chaetae, without anterior chaetae ( Fig. 11 ). Furca reduced to a finely granulated area with 2+1 chaetae posteriorly and further two manubrial rows of chaetae present ( Fig. 14 ).

Female genital plate with 15–21 chaetae ( Fig. 13 ), male genital plate with 24–28 chaetae. Male ventral organ present, being as 7+7 inflated chaetae on ventral tube and several on Abd. II–IV ( Figs 2 & 12 ). Anal valves with numerous acuminate chaetae; each lateral valve with a0 and 2a1; upper valve with chaetae a0, 2b1, 2b2, c0, 2c1, 2c2 ( Fig. 15 ). Anal spines present on indistinct papillae, as long as inner edge of unguis ( Fig. 16 ).

Etymology. Named for the name of the park where we found the new species.

Ecology. The new species found in a coniferous and broad-leaved mixed forest.

Remarks. The new species is similar to Dimorphaphorura pseudoraxensis ( Nosek & Christian, 1983) in having 1+1, 3+3, and 3+3 pso on Th. I–III, respectively. Yet both can be distinguished by the number of pso on Abd. IV–V (5+5, 3+ 3 in D. jingyueensis sp. nov. versus 4+4, 4+ 4 in D. pseudoraxensis , respectively), the ratio of unguiculus/unguis (1 in D. jingyueensis sp. nov. versus 0.8 in D. pseudoraxensis ), the inner basal lamella of unguiculus (indistinct in D. jingyueensis sp. nov. versus distinct in D. pseudoraxensis ), the number of chaetae in distal whorl of tibiotarsi (11 in D. jingyueensis sp. nov. versus 9 in D. pseudoraxensis ) and the apical teeth on the mandible (4+ 4 in D. jingyueensis sp. nov. versus 4+ 3 in D. pseudoraxensis ).

D. jingyueensis sp. nov. is very different from the only other known Chinese congener, D. sanjiangensis Sun & Wu, 2012 . They can easily be separated by the dorsal pso formula (32/133/ 33353 in D. jingyueensis sp. nov. versus 32/033/ 33343 in D. sanjiangensis ), the ventral psx formula (00/000/ 212101 in D. jingyueensis sp. nov. versus 00/ 000/ 122203 in D. sanjiangensis ), the inner basal lamella of unguiculus (indistinct in D. jingyueensis sp. nov. versus distinct in D. sanjiangensis ), the ratio of unguiculus/unguis (1 in D. jingyueensis sp. nov. versus 0.7 in D. sanjiangensis ) and the chaetae on the upper valves (a0, 2b1, 2b2, c0, 2c1, 2c 2 in D. jingyueensis sp. nov. versus a0, 2a1, b0, 2b1, 2b2, c0, 2c1, 2c 2 in D. sanjiangensis ).

Figures

FIGURES 1 – 9. Dimorphaphorura jingyueensis sp. nov. 1, dorsal chaetotaxy; 2, ventral side of Abd. II – VI (male); 3, labium; 4, PAO and anterior cephalic pso; 5, labrum; 6, maxillary palp; 7, Ant. III sensory organ; 8, distal part of leg I; 9, distal part of leg III. Scales: 0.1 mm (1 – 2), 0.01 mm (3 – 9).

FIGURES 10 – 16. Dimorphaphorura jingyueensis sp. nov. 10, ventral side of head; 11, ventral tube (female); 12, ventral tube (male); 13, female genital plate; 14, central part of Abd. IV sternum (female); 15, anal valves; 16, dorsal part of Abd. IV – VI. Scales: 0.1 mm (10, 13 & 16), 0.01 mm (11 – 12, 14 – 15).