Sinella zhangi, Xu, Guo-Liang & Chen, Wei-Yu, 2016

Xu, Guo-Liang & Chen, Wei-Yu, 2016, Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae), ZooKeys 611, pp. 1-10 : 3-6

Taxon classification Animalia Collembola Entomobryidae

Sinella zhangi sp. n. Figs 17-25, 26-27

Type material.

Holotype: ♂ on slide, China, Guangdong Province, He Mountain, in soil of secondary eucalypt forest, 22 October 2012, Guoliang Xu leg. (# Xu-2012). Paratypes: 1 ♀ on slide and 1 juvenile in alcohol, same data as holotype.

Diagnosis.

No eyes. Long smooth straight chaetae absent on antennae. Labial chaeta r and postlabial chaetae X and X4 minute. “Smooth” inner differentiated tibiotarsal chaetae present. Tenent hairs clavate. Manubrium without smooth chaetae. Mucronal spine short, with tip reaching subapical tooth. Chaeta p5 as mac on Th. II. Abd. I with 5+5 mac. Abd. II with 4+4 central mac. Abd. IV with 4+4 central and 5+5 lateral mac.

Description.

Body length up to 1.32 mm. Body pale in alcohol.

Antenna 2.04 times as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV = 1: 1.71: 1.86: 2.71. Smooth spiny mic at base of antennae three dorsal, three ventral on Ant. I: one internal, one external and one ventral on Ant. II. Ant. II distally with one rod-like S-chaeta. Two internal sens of Ant. III organ rod-like. Long smooth straight chaetae absent on antennae.

Eyes absent in all specimens. Prelabral and labral chaetae 4/ 5, 5, 4, all smooth; three chaetae of first row longer than lateral chaetae. Clypeal chaetae not clearly seen. Dorsal cephalic chaetotaxy with four antennal, three median (M) and eight sutural (S) mac; Gr. II with four mac (Fig. 17). Mandibles with 4/5 (left/right) teeth. Subapical chaeta of maxillary outer lobe subequal to apical chaeta; three smooth sublobal hairs on maxillary outer lobe. Lateral process of labial palp thicker than normal chaetae, with tip extending beyond apex of labial papilla (Fig. 18). Labial chaetae as mrel1l2, all smooth, r/m=0.20; chaetae X and X4 smooth, minute; chaetae X2‒3 absent; H1, H2 and H4 ciliate. Cephalic groove with eight chaetae, two smooth and others ciliate (Fig. 19).

Trochanteral organ with nine smooth spiny chaetae; five in arms and four internal. Some inner differentiated tibiotarsal chaetae “smooth” with ciliations closely appressed to axis. Tibiotarsi distally with ten chaetae in a whorl. Unguis with three inner teeth; two paired teeth unequal, outer one larger. Unguiculus with a large outer tooth. Tenent hairs clavate (Fig. 20). Abd. IV 3.42 times as long as Abd. III along dorsal midline. Ventral tube anteriorly with seven ciliate chaetae; two of them much larger than oth ers; posteriorly not clearly seen; each lateral flap with seven smooth and one ciliate chaetae (Fig. 21). Manubrium without smooth chaetae. Manubrial plaque with 2+2 pseudopores and 3+3 ciliate chaetae (Fig. 22). Distal smooth part of dens 1.72 times as long as mucro. Mucro bidentate with apical tooth longer than subapical tooth; basal spine short, reaching tip of subapical tooth (Fig. 23).

Th. II with three medio-medial mac (m1, m2, m2i), three medio-lateral mac (m4, m4i, m4p), 19 posterior mac, one ms and two sens; ms interior to sens al. Th. III with 30 mac and two lateral sens (Fig. 24). Abd. I with five mac (m2-4, m2i, m4p), one ms and one sens; sens interior to ms. Abd. II with four central mac (a2, m3, m3e, m3ep), one lateral mac (m5) and two sens. Abd. III with one central mac (m3), three lateral mac (am6, pm6, p6) and two sens; ms absent (Fig. 25). Abd. IV with four central mac (I, M, B5, A6), five lateral mac (E2-4, E2p, F1), and at least 11 sens; as and ps shorter than others (Fig. 26). Abd.V with three sens; chaetae m2, m3, m5, a6, p1, p3-5 and ap6 present as mac (Fig. 27).

Etymology.

Named after the Chinese collembologist Dr. Feng ZHANG, who has made great contributions to the taxonomy of Sinella .

Ecology.

In decomposing leaves along the roads.

Remarks.

Sinella zhangi sp. n. is most similar to Sinella quadriseta Zhang, Bedos & Deharveng, 2014 in absence of eyes, tip of lateral process of labial palp beyond apex of labial papilla, morphology of unguis and unguiculus, and mucronal spine, but differs from it in smooth, minute labial and postlabial chaetae r, X and X4, clavate tenent hairs, “smooth” inner differentiated tibiotarsal chaetae, 4+4 mac in Gr. II on dorsal head, absence of mac m2, m2i, m4i and m4p on Th. II, 5+5 mac on Abd. I (m4p present), and 4+4 central mac on Abd. II (m3ep present). It is also similar to Chinese species Sinella affluens Chen & Christiansen, 1993 in 4+4 mac on dorsal head, “smooth” inner differentiated tibiotarsal chaetae, clavate tenent hairs, number of teeth on unguis and unguiculus, minute postlabial chaetae X and X4, 2+2 pseudopores and 3+3 ciliate chaetae on manubrial plaque, medial mac on Th. II, 1+1 central mac on Abd. III, and 4+4 central mac on Abd. IV, but differs from the latter in absence of eyes, short mucronal spine, minute labial chaeta r, p5 present as mac on Th. II, m5i present as mac on Th. III, 5+5 mac on Abd. I (a3) as mes, 4+4 central mac on Abd. II (a2 as mac), 5+5 lateral mac on Abd. IV (F1 as mac).