A new cave Sinella species from South China (Collembola: Entomobryidae) Zhang, Feng Deharveng, Louis Zootaxa 2009 2009 35 40 [151,341,843,869] Entognatha Entomobryidae Sinella Animalia Collembola 1 36 Arthropoda species whitteni sp. nov.    Typelocality. China, Guangxi Province, Yachang Nature Reserve, Huaping, Xia Yan Dong.   Typematerial. Holotypemale and 2 paratypeson slide, 28.v.2007, collected by hand, leg. Franck Brehier (sample n° CHIgx07–28/07): holotypein NJU, 2 paratypesin MNHN. 4 paratypeson slide, 14 inalcohol, 26.v.2007, collected by hand, leg. Franck Brehier (sample n° CHIgx07–26/16): 2 paratypeson slide and 8 paratypesin alcohol in NJU, 2 paratypeson slide and 6 paratypesin alcohol in MNHN.   Description.Body length: 1.4–1.7, up to 2.3 mm. Habitus and head. Eyes absent. Body colour totally white in alcohol ( Fig. 1). Antenna 2.4 times as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV = 1: 1.6–1.8: 1.3–1.6: 2.3–2.9. Antennal chaetae of 5 kinds: ciliated mesochaetae; very thin, rather long, finely ciliated mesochaetae; thin, smooth, acuminate short chaetae; rather long, parallel, thin s-chaetae; short thickened s-chaetae (including the 2 rods of Ant. III organ). Long, smooth chaetae absent on antennae. No apical bulb on Ant. IV.   FIGURE 1.  Sinella whitteni  sp. nov.: habitus.   FIGURES 2–16.  Sinella whitteni  sp. nov.: 2, lateral process of labial palp; 3, maxillary outer lobe; 4, chaetae on labial base; 5, cephalic dorsal chaetotaxy; 6, thoracic dorsal chaetotaxy; 7, trochanteral organ; 8, one of the inner differentiated tibiotarsal chaetae, and the outstanding macrochaeta; 9, hind claw; 10–12, abdominal dorsal chaetotaxy. 10, Abd. I–III; 11, Abd. IV; 12, Abd. V; 13, anterior face of ventral tube; 14, posterior face of ventral tube and lateral flap; 15, manubrial plate; 16, mucro. Chaetae figured in full on Figs 5-6 and 10-12 are s-chaetae and bothriotricha; chaetae figured by their sockets are ordinary chaetae. Labral papillae absent. Prelabral and labral chaetae 4/5,5,4, all smooth. Lateral process of labial palp thicker than normal chaetae, with tip reaching beyond apex of labial papilla ( Fig. 2). Subapical chaeta of maxillary outer lobe thin, subequal to apical one; 3 smooth hairs on sublobal plate ( Fig. 3). Labial base as M1,R,E,L1,L2, all smooth; R 0.65–0.80 length of chaeta M1; X, X2 and X4as ciliate microchaetae; chaeta X3absent ( Fig. 4). Cephalic dorsal chaetotaxy with 5 sutural and 4 macrochaetae in Gr. II ( Fig. 5). S-chaetae by half-tergites from Th. II to Abd. V as 3,2/2,2,3,±14,3. Thorax. Dorsal thoracic chaetotaxy shown in Fig. 6. Th. II with 5 (m1, m 1i, m2, m 2i, m 2i2) mediomedian, 2 medio-lateral (m4, m4p), 18–21 posterior macrochaetae and 3 s-chaetae (2 antero-lateral, 1 posterolateral) on each side; p4 as macrochaeta; m 1iand m 2i2 sometimes absent in juveniles. Th. III with 27–30 macrochaetae and 2 s-chaetae (1 antero-lateral, 1 postero-lateral); m 5iabsent; p5 as macrochaeta; m6p as macro- or mesochaeta; p2ep sometimes absent. Abdomen. Abd. IV 3.9–5.0 times as long as Abd. III along dorsal midline. Abd. I with 7 macrochaetae centrally and 2 s-chaetae laterally; m 2i, a2, a3 and m4p as macrochaetae. Abd. II with 3 dorso-central (m3, m3e, m3ep), one lateral (m5) macrochaetae and 2 s-chaetae. Abd. III with 1 dorso-central (m3), 3 lateral (am6, pm6, p6) macrochaetae and 3 s-chaetae ( Fig. 10). Abd. IV with 5 dorso-central (A3, A4, A6, B4, B5), 6 lateral macrochaetae and at least 12 s-chaetae on each side of which 2 short ones, in the middle and posterior part of the tergite, are constant ( Fig. 11). Abd. V with numerous chaetae and 3 s-chaetae; m2, m3 and m5 macrochaetae always much larger than others; homology of several chaetae not clear ( Fig. 12). Legs. Trochanteral organ with 19–30 smooth spiny chaetae; 9–13 inthe arms of “L” and 10–17 between them ( Fig. 7). Tibiotarsal meso- and macrochaetae ciliated, with ciliations not closely appressed to axis; a single smooth straight and acuminate ventro-distal chaeta on hind leg; a tenent hair smooth, pointed, subequal to unguiculus ( Fig. 9); an inner outstanding macrochaeta at about 1/3 from tibiotarsus base, ciliate and tapered, 1.5 (tibiotarsus I) to 2 times (tibiotarsus III) longer than inner edge of claw; several inner differentiated chaetae ( sensu Chen & Christiansen 1993) slightly thicker and shorter than ordinary chaetae, with shorter cilia ( Fig. 8). Claws I and II moderately elongated, claw III normal. Inner basal paired teeth of claw tiny, at 25 –30% from base of inner edge of claw; distal unpaired tooth absent; 1+1 latero-basal minute teeth, often difficult to see. Unguiculus truncate with outer edge very finely serrated. Tenaculum with 4 + 4 teeth and one large striate chaeta. Ventral tube anteriorly with 8–10 ciliate chaetae on each side ( Fig. 13); posteriorly with 16–28 chaetae of which 6–8 are smooth; each lateral flap with 7 –8 smooth chaetae with 1 additional ciliate chaeta rarely present ( Fig. 14). Manubrium and dentes without smooth outstanding chaetae, manubrium without thick and finely ciliated chaetae (unlike  S. trogla). Manubrial plate with 2 pseudopores and 3(4) ciliate chaetae ( Fig. 15). Distal smooth part of dens equal to mucro in length ( Fig. 16). Mucro bidentate, not elongated, its basal tooth as large as the apical one, with basal spine short, its tip reaching the apex of the subapical tooth ( Fig. 16).  Ecology.  S. whitteniis the fifth large, strictly troglobitic species of Chinese  Sinella, though only moderately modified in relation to cave life. However, the species is likely to be a strict troglobite as we never got it from samples made in humid and dark habitats outside caves, where oculated  Sinellaare abundant.   Etymology.Named in honour of Tony Whitten for his enthusiastic support of biodiversity surveys and conservation of the caves in southern China.   Remarks.This cave species is most close to  S. trogla Chen & Christiansen, 1993, the other cave species of Guangxi, described from a Guilin cave about 370 kmfrom Yachang. They share absence of eyes, cephalic dorsal chaetotaxy, ciliate post-labial chaetae X, X2 and X4, inner differentiated tibiotarsal chaetae finely ciliate, abundant chaetae on each side of ventral tube and chaetotaxy of Abd. I–IV.  S. trogladiffers from  S. whitteni sp. nov.by its much longer antennae (Antenna / cephalic diagonal =3.5-4.3 against 2.4 in  S. whitteni; Ant. IV / cephalic diagonal = 2 against 1 in  S. whitteni), and by several characters listed in Table 1.   S. whitteniis only moderately troglomorphic, by its rather large size (like the four other troglobitic  Sinellaof China, and in contrast with non-cave species of the genus), the slight elongation of its claw compared to outside species of the genus and the absence of unpaired inner tooth on it, a character often observed in troglomorphic Entomobryidae. Ordinary chaetae in  Sinellaas in many other Entombryidae are only materialized by their socket after specimen mounting. s-chaetae have the same kind of sockets, but as they are less labile, they are usually kept on the body of mounted specimens, which allows to reconstruct their pattern. The number and arrangement of s-chaetae on tergites in this species are stable, and do not vary during postembryonic development except for Abd. IV.   TABLE 1.Comparison between  S. whitteni  sp. nov.and  S. troglaChen & Christiansen, 1993.    Characters   S. whitteni   S. trogla  Post-labial chaeta X3 absent present  Th. II dorsal macrochaetae m1i m2i2 m4i p4 present present absent present absent absent present absent  Th. III dorsal macrochaetae m6ai2 present absent  Ungual inner unpaired tooth absent present  Outer edge of unguiculus serrate with a small tooth  Thickened chaetae on manubrium absent present  Number of pseudopores on manubrial plate 2 3  Mucro elongated no yes  Mucronal basal spine short long Chaetotaxy of Entomobryidaeincluding s-chaetae (‘setulae’) was first explored by Szeptycki (1972, 1979), in a wide diversity of taxa, but he did not focus on their arrangement as a potential taxonomic character, and most records of s-chaetae in previous literature are incomplete or inaccurate for this family. Schaetotaxy is now used as a powerful tool for the taxonomy of different Collembolan families ( Potapov 1989; Deharveng 2004), but its interest in Entomobryidae, Paronellidaeand Tomoceridaeremains to be assessed.