Willowsia pseudobuskii, Pan & Zhang, 2016

Pan, Zhixiang & Zhang, Feng, 2016, Contribution to the Willowsia species having body scales of the long basal rib type: four new species and a redescription of W. qui (Collembola: Entomobryidae), European Journal of Taxonomy 245, pp. 1-25 : 11-15

Willowsia pseudobuskii sp. nov.

urn:lsid:zoobank.org:act:60F5152B-4228-40B2-B1C7-E8EE3A4E6C39

Figs 7–9 ; Table 2

Diagnosis

Transverse bands on Th. III, posterior margin of Abd. II, and Abd. III; cephalic mac S 0 and S 0 ’ present; Th. II with 1 (m1) medio-medial and 12 (p1̅6, p1i, p2a, p2p, p2a, p2e, p3p) posterior mac; chaetae a2 and a3 as mac on Th. III; Abd. I with 3 (m2̅4) mac; Abd. III with 2 (a2, m3) central mac; Abd. IV with 5 (A6, B4̅6 and one of unclear homology) central mac.

Etymology

Named after the great similarities between the new species and W. buskii (Lubbock, 1869) .

Material examined

Holotype

CHINA: ³ on slide, Anhui Province, Liuan, Jinzhai County, Tiantangzhai , 31.188° N, 115.802° E, altitude 564 m, 2 Aug. 2012, Z.X. Pan and Q. P. Ren leg. (slide # 4368_1, sample # 4368), deposited in NJAU.

Paratypes

CHINA: 4 ♀♀ on slides and 2 in alcohol, same data as holotype. One paratype on slide (slide # 4368_5) deposited in MNHN, 2 in alcohol deposited in TZU and others (slide # 4368_2–4) in NJAU.

Description

Body length up to 1.50 mm.

Ground colour pale in alcohol. Ant. I̅IV gradually darker. A transverse band between the eye patches. Dark stripe on lateral margin of Th. II–Abd. IV. Transverse bands on Th. III, posterior margin of Abd. II, and Abd. III. Irregular longitudinal stripes on lateral part of Abd. IV. Abd. V and Abd. IV posteriorly dark. Base of legs, distal femora, and tibiotarsi pigmented ( Fig. 7 A–C). Scales brown, pointed, heavily striate with basal ribs longer than distal ones, and only present dorsally on head and terga. Partial chaetae of the row along the posterior margin of each tergum transformed into scales and larger than other scales ( Fig. 7 E–H).

Based on 7 measured specimens, antenna 2.22–2.53 times as long as cephalic diagonal.Antennal segment ratio as I: II: III: IV = 1: 1.68–2.20: 1.88–2.25: 2.81–3.23. Smooth spiny mic at base of antennae: 3 dorsal and 4 ventral on Ant. I; 1 internal, 1 external and 2 ventral on Ant. II.

Labral intrusion U-shaped. Clypeal chaetae 10 in number, all ciliate and 5 of them smaller ( Fig. 8B ). Dorsal cephalic chaetotaxy with 4 antennal (An), 4 median (M) and 8 sutural (S) mac; mac S 1 absent; S 0 and S 0 ' as mac on middle line; A 0 as mic in one specimen ( Fig. 8C ); interocular chaeta r absent on one side in one specimen. Tip of lateral process of labial palp just reaching apex of labial papilla ( Fig. 8E ). Labial chaeta R/M = 0.58–0.70; chaeta R as a scale on one side in one specimen. Cephalic groove with 7+7(8) ciliate chaetae ( Fig. 8F ).

Metatrochanteral organ with 10̅17 smooth spine-like chaetae; 8̅ 12 in L-shaped arms and 2̅5 between arms ( Fig. 8G ). Ungual basal paired inner teeth with tip reaching 55% from base, median one at 75% and distal one at 87%. Tenent hairs subequal to unguis in length ( Fig. 8H ). Abd. IV 2.76–3.55 times as long as Abd. III along dorsal midline. Ventral tube anteriorly with about 13 ciliate chaetae, 3 of them larger than others ( Fig. 8I ); posteriorly with 7–11 chaetae and most of them weakly ciliate except most apical two ( Fig. 8J ); each lateral flap with 10 chaetae and 3 of them ciliate ( Fig. 8K ). Male genital plate papillate with 15 projections ( Fig. 8L ). Manubrium and base of dens dorsally with 5–6 and 3 large differentiated chaetae, respectively ( Fig. 8M ); ventrally with 6+6 distal chaetae ( Fig. 8N ). Manubrial plaque with 2 pseudopores and 4 ciliate chaetae ( Fig. 8M ). Distal smooth part of dens 1.46̅1.82 times as long as mucro.

Th. II with 1 (m1) medio-medial, 2 (m4, m 4i) medio-lateral, and 12 posterior mac; m5 and p6 as mac. Th. III with 15 mac; a1 as mic ( Fig. 9A ). Abd. I with 3 (m2̅4) mac. Abd. II with 3 (a2, m3, m3e) central

and 1 (m5) lateral mac. Abd. III with 2 (a2, m3) central and 3 (am6, pm6, p6) lateral mac. Abd. IV with 5 central and about 9 lateral mac ( Fig. 9B ).

Ecology

In decomposing litter of Oryza sativa Linnaeus, 1753 .

DNA barcodes

KU833223 , KU833224 .

Remarks

Willowsia pseudobuskii sp. nov. is characterized by the unique colour pattern and the dorsal chaetotaxy of the head and Abd. IV. The new species is closest to W. buskii in many features, particularly the chaetotaxy of Abd. II–IV. However, if differs from the latter in colour pattern, number of sutural chaetae, and thoracic chaetotaxy ( Table 2). The genetic distances of COI between the new species and W. buskii (five COI sequences from GenBank, LK024534 – LK024536 , HG422601 , KM610129 ) are 0.178 –0.191, indicating two independent species.

Figures

Fig. 7. Willowsia pseudobuskii sp. nov. A‒C. Habitus, A and C dorsal view, B ventral view. D. Ant. IV apical bulb. E‒H. Body scales. E. Abd. II. F. Abd. III. G. Abd. IV. H. Abd. V. Scale bars: A–C = 500 μm; D–H = 20 μm.

Fig. 8. Willowsia pseudobuskii sp. nov. A. Ant. III organ. B. Clypeal chaetae. C. Dorsal cephalic chaetotaxy. D. Maxillary outer lobe. E. Lateral process of labial palp. F. Chaetae on ventral side of head. G. Trochanteral organ. H. Hind claw. I–K. Ventral tube. I. Anterior face. J. Posterior face. K. Lateral flap. L. Male genital plate. M. Manubrium and base of dens, dorsal view. N. Distal part of ventral face of manubrium. O. Mucro. Scale bars: A–B, D–O = 20 μm; C = 100 μm.

Fig. 9. Willowsia pseudobuskii sp. nov. A. Thoracic chaetotaxy. B–C. Abdominal chaetotaxy. B. Abd. I–IV. C. Abd. V. Scale bars: 100 μm.