Koreanurina alba, Wu & Bedos & Deharveng, 2014

Wu, Donghui, Bedos, Anne & Deharveng, Louis, 2014, First record of the genus Koreanurina Najt and Weiner (Collembola: Neanuridae: Pseudachorutinae) from China, with description of two new species from Changbai mountain, Journal of Natural History 48 (41 - 42), pp. 2579-2593 : 2587-2592

Koreanurina alba sp. nov.

( Figures 6–8 ; Table 1)

Type material

Holotype male and 11 paratypes (six males, four females, one juvenile): China: Jilin Province, Changbai county, Changbai Mountain ( GPS coordinates: 41°45 ′ 19 ″ N, 127° 56 ′ 29 ″ E, altitude 1724 m), in coniferous forest, litter and soil, Berlese funnel extraction, 28 July to 3 August 2009, Donghui Wu and Jiangfeng You leg. (sample 16); 2 paratypes (one female and one juvenile): same data (sample CHI-Wu07).

Holotype and eight paratypes (three males, two female, on juvenile from sample 16, and one female and one juvenile from sample CHI-Wu07)) on slides in NEIGAE- CAS; five paratypes (three males, two females from sample 16) on slides in MNHN.

Species name derivation

After the white colour of the body.

Description

Body appearance. Length: 0.73 mm (holotype male); 0.60–0.80 mm (paratypes). Habitus ovoid, 2.2 times as long as wide ( Figure 7 ). Body colour in alcohol white. Ocular patch reduced, transversally elongated ( Figure 6D–E ), blue-black, with a number of ocelli uncertain, as they have the size of secondary granules (3 + 3 or possibly more). Th I not fused to head dorsally, but with its lateral chaetae close to the posteriori chaetae of the head ( Figure 7 ).

Dorsal ornamentation. Dorsally, integument covered with very strong, rounded secondary granulations, underlined by extensive reticulations, from head to Abd V; secondary granules in groups of 1–3, each group underlined by a mesh of polygonal reticulation, well marked but weaker than in K. weinerae . Groups of granules arranged in large tertiary plates covering most of the head and tergites ( Figure 7 ); five such plates on head (one central, two posterior separated by a narrow axial stripe devoid of reticulation and two ocular, with strong secondary granules but no reticulations); 1 + 1 on each tergites from Th I to Abd IV, separated by a narrow stripe devoid of reticulations; and one uneven on Abd V, strongly V-inverted into Abd IV. Abd VI small, devoid of well-marked reticulations. Secondary granules outside plates smaller, except laterally where they can be very large. The narrow axial stripe devoid of reticulations that runs from posterior part of head to Abd IV is constituted of two parallel lines of small secondary granules.

Antennae ( Figure 6A–B ). Antennae shorter than head ( Figure 7 ). Ant I with 7 chaetae, Ant II with 12 chaetae. Ant III and Ant IV fused dorsally. Sensory organ of Ant III consisting of two small bent S-microchaetae, two long subcylindrical guard S-chaetae (the ventral shorter), and a small ventral S-microchaeta. Ant IV with 6 thick subcylindrical S-chaetae shorter than the dorsal guard of Ant III, an external Smicrochaeta, a subapical organite, and a distinctly trilobed apical bulb.

Head. PAO oval-rounded with 10–15 vesicles (N = 6; Figure 6C–E ), located dorsolaterally on head ( Figure 7 ). Buccal cone short and truncated. Mandible ( Figure 6F ) thin with five teeth (two strong basal, one strong apical and two smaller subapical). Maxilla ( Figure 6F ) with three lamellae: one external (with more than 10 minute teeth, the 2–3 apical ones larger), two internal (one short with two teeth, the other one long and styliform). Labrum formula: 2/2,3,5,2. Labium ( Figure 6G ) short, with 4 basal (E, F, G, f), 3 distal (A or B, C, D) and 3 lateral (c, d, e) chaetae; papillated chaeta L absent; 2 + 2 small hyaline vesicles arranged one above the other between chaetae A and C (X papillae of Deharveng 1983).

Dorsal chaetotaxy ( Figure 7 ). Dorsal clothing of short, thin pointed, smooth ordinary microchaetae and long, thin S-chaetae. Head without uneven chaeta a0 (N = 5). Central plate of head with most chaetae shifted laterally to the edge of the plate, and 3 + 3 posterior chaetae (a, b, c, Figure 7 ) within it, with chaeta b posterolateral to chaeta a, distance between chaetae a about half the distance between chaetae b, and chaetae a at same level as chaetae c (N = 6); frequent asymmetries. Thorax I weakly separated from head, with 2–3 + 2–3 minute dorsointernal chaetae. Dorsolateral chaetae of Th II and Th III in one group (S and two ordinary chaetae, probably a6 and p6). S-chaetae formula per half tergite: 0,2 + ms,2/1,1,1,1,1; S-microchaeta close and anteroexternal to the lateral S-chaeta; S-chaetae thicker and shorter on Abd IV than on other tergites. Th II–III with 2–(3) chaetae in p-row between axis and internal S-chaeta (N = 2). Abd I–III with 3 chaetae in p-row between axis and S-chaeta (N = 2). Abd V anterior edge curved, but not V-inverted, with a1 and p1 chaetae close each other, often asymmetrically arranged, and a1 posterior to the line of the S-chaetae or at level (N = 5). Abd VI very reduced and partly hidden under Abd V.

Ventral chaetotaxy and appendages. Thoracic sternites without ventral chaetae. Leg chaetotaxy as in Figure 8A–B . Tibiotarsi I, II, III with 19, 19, 18 chaetae (M present); ventral chaetae B4 and B5 short, not reaching the claw basis; 1 + 1 pretarsal chaetae, unusually long; claw short and thick, toothless. Ventral tube with 4 + 4 chaetae. Vestigial furca reduced to two small swellings with 1 chaeta each ( Figure 8C ); 1 + 1 chaetae posterior to furcal rest and closest large chaetae (N = 10). Male genital plate as in Figure 8D . Anal valves with 3 hr chaetae each (sensu Hüther 1962). Anal valves of the male with 5 modified chaetae (thickened and ciliated) each ( Figure 8D ).

Discussion

Chaetotaxic differences between the two new species listed in Table 1 for the central plate of head, Abd V and furcal rest were retrieved in several specimens, in spite of

frequent asymmetries in position. K. alba sp. nov. is differentiated by many significant characters from the three other species of the genus Koreanurina ( Table 1)

Figures

Figure 6. Koreanurina alba sp. nov. (A) left antenna in dorsal view; (B) antennal segments III– IV of left antenna in ventral view; (C) PAO; (D, E) PAO and ocular plate; (F) maxilla (left) and mandible (right); (G) labium.

Figure 7. Koreanurina alba sp. nov., dorsal chaetotaxy. Specimen body length 0.73 mm.

Figure 8. Koreanurina alba sp. nov. (A) leg I; (B) tibiotarsus of leg I, other side; (C) furcal area; (D) ventral chaetotaxy of abdomen V–VI in a male.