Sinella pauciseta, Qu & Zhang & Chen, 2010

Qu, Jiqiang, Zhang, Feng & Chen, Jian-Xiu, 2010, Two new species of the genus Sinella Brook, 1882 (Collembola: Entomobryidae) from East China, Journal of Natural History 44 (41 - 42), pp. 2535-2541 : 2538-2541

Sinella pauciseta sp. nov.

( Figure 2 , Table 2)

Types

Female holotype, three female and one male paratypes. China: Zhejiang Province, Wenzhou, Wuyanling National Nature Reserve, in deciduous woods or under rotting timbers, 1 August 2005, J-X. Chen .

Description

Body length. Up to 1.07 mm.

Colour. White to pale yellow.

Head. Eyes 1+1. Antennae about 1.76 times as long as cephalic diagonal. Ant. III organ with setae 2 and 3 rod-like, others not clearly seen. Apical bulb absent on Ant. IV. Labral setae 4/5, 5, 4, all smooth; labral papillae absent. Lateral process of labial palp slightly thicker than normal setae with tip exceeding apex of same papilla by 0.15 of its length. Labial setae M 1 REL 1 L 2 all smooth; seta R about 0.54 as long as seta M 1. Postlabial setae G 1–4 smooth; setae H 1–4 ciliate; seta X ciliate, 1.60 times as long as seta R of labial triangle; setae X 2 and X 3 absent; seta X 4 not clearly seen ( Figure 2A ). Dorsal cephalic chaetotaxy with four macrochaetae in Gr. I and five in Gr. II ( Figure 2B ).

Thorax. Th. II with three (m1, m2, m2i) macrochaetae in Gr. I, four (a5, m4, m4i, m4p) in Gr. II, three (p1a, p1, p1i) in Gr. III, four to six in Gr. IV, five plus five in Gr. V and one (p4) in Gr. VI; Th. III with eight or nine in Gr. I and nine in Gr. II, macrochaetae in Gr. III and IV not clearly seen ( Figure 2C ).

Abdomen. Abd. I with six (m2i, m2, m3, m4, m4p, a3) macrochaetae on each side; Abd. II with three (m3e, m3ep, m3) in M 3 arch and one (m5) lateral macrochaeta; Abd. III with one (m3) central and three (am6, pm6, p6) lateral macrochaetae; Abd. IV with three (B4, B5, A6) central and six (F1, E2, E2p, E3, E4, D3) lateral macrochaetae on each side ( Figure 2D ).

Appendages. Trochanteral organ not clearly seen. Inner differentiated setae of tibiotarsus ciliate with ciliation moderately appressed to setal axis. Outstanding inner macrochaeta of hind tibiotarsus at about 0.41 from base, basal half somewhat swollen, distal half gradually tapered and strongly tapered at extreme tip. Unguis only with two paired subequal inner teeth, with tip reaching 0.69 distance from base to tip of inner edge. Unguiculus with large outer tooth. Tenent hair acuminate and longer than unguiculus ( Figure 2E ). Ventral tube with eight ciliate setae on anterior face, eight smooth setae on posterior face and six smooth setae on each lateral flap ( Figure 2F,G ). Manubrium without posterior smooth setae. Distal smooth part of dens about 2.75 times as long as mucro. Mucronal apical tooth about 1.59 times as long as subapical tooth, distal base of latter at about 0.75 distance of mucro. Mucronal basal spine short, with tip at most reaching apex of subapical tooth ( Figure 2H ). Male genital plate not clearly seen.

Etymology

The name of the species is derived from the Latin paucus and seta referring to the few macrochaetae (3+3) on central Abd. IV.

Remarks

The new species is characterized by the small body size, 1+1 eyes, postlabial setae H 1–4 ciliate and the unique chaetotaxic pattern of Abd. IV, recorded for the first time in the genus. This pattern was named, following Chen and Christiansen (1993, 1997), as Pattern XII by the present authors.

So far, seven Sinella species have been reported with 1+1 eyes worldwide. Two Chinese species, Sinella affluens Chen and Christiansen, 1993 and Sinella fuyanensis Chen and Christiansen, 1993 , show a close relationship with the new species for the similarity of the type locations and the morphological characters. However, the new species can be separated distinctly from them by the characters in Table 2.

Figures

Figure 2. Sinella pauciseta sp. nov. (A) Setae on labial base; (B) dorsal cephalic chaetotaxy; (C) dorsal thoracic chaetotaxy; (D) dorsal abdominal chaetotaxy; (E) middle foot; (F) anterior face of ventral tube and lateral flap; (G) posterior face of ventral tube; (H) mucro. Symbols used for setae in (B–D): full circle: macrochaeta; circle with diagonal line: pseudopore; cross: bothriotrichum.