Plumachaetas sunae, Zhang, Feng & Deharveng, Louis, 2015

Zhang, Feng & Deharveng, Louis, 2015, A revision of Pseudoparonella, Plumachaetas, Parachaetoceras and Lawrenceana (Collembola: Paronellidae), with description of three new species from New Caledonia, Zootaxa 4058 (4), pp. 561-577 : 573-575

Plumachaetas sunae sp. nov.

Figs 37 ‒56

Types. Holotype: female on slide, New Caledonia: Riviere Bleue, alt. 160 m, Malaise trap, 25.xii.1986 ‒ 5.i.1987, L. Bonnet de Larbogne, J. Chazeau and S. Tillier leg. (# ρ6(22)ε1). Paratypes: 1 female on slide and 2 in alcohol, same data as holotype. Other records: 1 female on slide and many in alcohol, New Caledonia: Col d’Amieu, 165°46’E 21°34’S, alt. 412 m, Malaise trap, 19.xii.2007 ‒ 11.i.2008, Thomas Théry leg. (# NC08-Théry02). 1 paratype on slide and 9 topotypes in alcohol in NJAU and others in MNHN.

Description. Body length up to 2.8 mm.

Ground colour pale yellow in alcohol. Antennae gradually darkening from I to IV. Lateral stripes on Th. II‒Abd. VI. A transverse band on dorsal Abd. III. A pair of small patches on posterior Abd. IV. Ant. I‒II and legs with some long straight chaetae ( Fig. 37). Scales mostly pointed, coarsely striate, and present on Ant. I‒II, head, terga, legs, ventral tube, and ventral side of furcula.

Antenna 1.8 times as long as body length. Antennal segments ratios I: II: III: IV = 1: 1.4: 1.0: 3.2. Ant. III organ with 2 thin rod-like chaetae. Ant. IV apically with a thick spiny chaeta and without apical bulb (Fig. 38).

Eyes 8+8; G and H much smaller than others. Prelabral and labral chaetae 4/5, 5, 4; prelabrals ciliate; median three chaetae of the p-row long and thick. Lateral process of labial palp extremely short. Subapical chaeta of maxillary outer lobe thick and blunt (Fig. 39); 3 chaetae on sublobal plate. Labial chaetae as MREL1L2; all ciliate ( Fig. 30 ). Dorsal cephalic chaetotaxy as in Fig. 40.

Th. II with 5 median and 14 posterior macrochaetae. Th. III with about 23 macrochaetae (Fig. 41). Trochanteral organ with more than 35 smooth spiny chaetae (Fig. 42). A small ventrodistal swelling present on tibiotarsi. Unguis with 2 lateral and 3 minute inner teeth; lateral one at 0.45‒0.55 from base, inner pair with tip reaching 0.24‒0.35 from base of ventral edge. Unguiculus I‒III truncate with a corner tooth. Tenent hairs clavate and subequal to unguis (Figs 43‒45).

Abd. IV 4.7‒5.6 times as long as Abd. III along dorsal midline. Abd. I with 7 macrochaetae. Abd. II with 5 central and 2 lateral macrochaetae. Abd. III with 1 central and 6 lateral macrochaetae. Abd. IV centrally with 10‒14 and 6‒7 posterior macrochaetae, and laterally with 9‒11 macrochaetae (Fig. 41). Accessory microchaetae of bothriotrichal complexes on Abd. II‒IV modified as scale-like chaetae. Tenaculum with 4 + 4 teeth and one large striate chaeta. Ventral tube not clearly seen. Dorsum of manubrium without modified chaetae. Dens with many thick ciliate chaetae and distal one much larger than others. Mucro bidentate with two teeth subequal (Fig. 46).

Etymology. Named after Sun Xin, who provided assistance during preparation of the Ph.D. dissertation of the first author.

Remarks. This new species is characterised by its unique colour pattern, bidentate mucro, and 2 lateral macrochaetae on Abd. I. It is similar to Pl. yoshii sp. nov., Pl. halmaherae and Pl. queenslandica , but differs from them by shape of Abd. IV patches, modified labral chaetae of the first row, and dorsal chaetotaxy ( Table 2 ). See remarks on Pl. yoshii sp. nov. for more detailed comparison. Tergal S-chaetotaxy (2, 2|1, 2, 2,?, 3 ordinary Schaetae, 1, 0|1, 0, 1, 0, 0 S-microchaetae) was examined by Zhang et al. (2015) in a species of Plumachaetas designated as Pseudoparonella sp. in the cited paper.

Figures

FIGURES 24 – 36. Plumachaetas yoshii sp. nov.: 24, body scales, tip rounded in the left and pointed in the right; 25, Ant. III organ; 26, Ant. IV apical chaetae; 27, labrum; 28, lateral process of labial palp; 29, maxillary outer lobe; 30, labial triangle chaetae, same as other two new species; 31, dorsal cephalic chaetotaxy; 32, dorsal body chaetotaxy from Th. II to Abd. IV (pseudopore not clearly seen on Abd. IV); 33, trochanteral organ; 34, mid claw; 35, hind claw; 36, mucro.