Abbreviations

a1, 2, … -- setae 1, 2, … of the anterior row, counted from the “middle line”, m1, 2, … -- setae 1, 2, … of the middle row, counted from the “middle line”, p1, 2, … -- setae 1, 2, … of the posterior row, counted from the “middle line”, c1, 2, … -- cervical setae 1, 2, … of area occipitalis, counted from the “middle line”, La1, 2, …-- setae 1, 2, … of the lateral anterior row in thoracic segments, L1, 2, …-- lateral setae 1, 2, …. in head (Yosii 1960; Gama 1988).

Type Materials

Holotype: Female, from the grassland of Leymus chinensis, 44°35’N, 123°30’E, 141 m altitude, Changling county, Jilin Province, Northeast China, 6-5-2005, collected by Dr. Donghui Wu. Paratypes: Two females, 3 males, same data as holotype. Holotype and paratypes deposited in Shanghai Institute of Plant Physiology & Ecology.

Description

Body length up to 0.95 mm. Body color in alcohol dark blue-violet. With 5+5 ommatidia in head (Fig. 1). Antennal segment I with 7 setae, antennal segment II with 12 setae. Sensory organ of antennal segment III consists of 2 microsensilla which are embedded in a tegumentary fold and flanked by 2 longer guard sensillum. Antennae IV with a simple apical bulb and 4 weakly thickened sensillum, of which 3 are dorso-external and 1 dorso-internal, and 2 internal sensillum, which are thinner and shorter than the others (Fig. 8). External maxillary lobe with 2 sublobal hairs.

Tibiotarsi each with 2 capitate, dorsal tenent hairs, which are longer than the inner edge of the claws. Claws with a small, distal internal tooth, 2/3 as long as tibiotarsal hairs (Fig. 9). Mucro well separated from the dens with 2 posterior setae, 1/2 as long as the dens but dens and mucro particularly slender, width of dens at distal seta about an eighth its length, mucro straight and without teeth (Fig. 10). Ventral tube with 4+4 setae. Retinaculum with 3+3 teeth (Fig. 5). Female genital (Fig. 6) and male genital plate (Fig. 7) normal. Anal spines small, on weakly developed papillae separated at the base, 1/4 as long as claws (Fig. 3).

Chaetotaxy, consisting of short setae and longer and fine sensorial setae. Dorsally head without seta c2 (a2 a/c to Babenko), cephalic setae l1 and l3 subequal (Fig. 1), thoracic segments II-III with central setae in 3 rows, on thoracic segments II-III p2 displaced apically relative to p1, and on thoracic segment III a2 displaced distally compared with a1 (Fig. 2), on abdominal segments I-III p5 present, abdominal segments IV with a3. Abd. V with a2 (Fig.3). Ventrally head without seta p1 (Fig. 4), thoracic segments II and III with a pair of medial setae, abdominal segments II without p2 and a5, abdominal segments III with 1 median seta above the retinaculum (Fig. 5).

Comment

The new species is distinguished from all the known species of the genus Xenylla by the absence of mucronal teeth, dorsal side of head without c2 seta, seta p2 on tergite of thoracic segments II-III set in front of p1 seta, head without ventral seta p1, thoracic segments II and III with a pair of ventral medial setae, abdominal segment II without ventral setae p2 and a5, abdominal segment III with 1 median ventral seta above the retinaculum, abdominal segment IV with ventral seta m1, unguis with 1 internal tooth.

Etymology

This species is named after the type locality.

Taxonomic Remarks

This species keys out to X. piceeta Stebaeva & Potapov, 1994 (Babenko et al. 1994), from Far East, southern maritime province, Russia, which was collected in litter of a fir forest (Babenko et al. 1994), but the new species clearly differs from X. piceeta by the presence of dorsal la2 of thoracic segments II and III, which is stable on the tergites, and the absence of ventral seta p2 on abdominal segment II. On abdominal segment III, X. changlingensis has only 1 median ventral seta above the retinaculum, while X. piceeta has a pair of medial setae. In addition, the mucro of X. changlingensis is straight and thin, but lacking teeth.

Type Materials

Holotype: Female, from the deciduous-coniferous mixed forest of Jingyuetan Park, 43°45’N, 125°27’E, 242 m altitude, Changchun city, Jilin Province, Northeast China, 3-9-2003, collected by Dr. Donghui Wu. Paratypes: Two females, same data as holotype. Holotype and paratypes deposited in Shanghai Institute of Plant Physiology & Ecology.

Description

Body length up to 0.81 mm. Body color in alcohol red-brown. Antennal segment I with 7 setae, antennal segment II with 12 setae. Sensory organ of antennal segment III consists of 2 microsensilla, embedded in a tegumentary fold and flanked by 2 longer guard sensillum. Antennae IV with a simple apical bulb and 4 weakly thickened sensillum, of which 3 dorso-external and 1 dorso-internal, and 2 internal sensillum, thinner and longer than the others (Fig. 11). External maxillary lobe with 3 sublobal hairs.

Tibiotarsi each with 2 capitate, dorsal tenent hairs, longer than the inner edge of the claws. Claws toothless, 11/15 as long as tibiotarsal hairs (Fig. 12). Dens with 2 posterior setae. Mucro well separated from the dens, straight and fine without teeth, dens broad, at level of distal setae length of dens about 3 times breadth, ratio mucro: dens = 1/2 (Fig. 13). There are 4+4 setae on ventral tube. Retinaculum with 3+3 teeth (Fig. 18). Female genital plate (Fig. 19). Anal spines short, inserted on poorly developed papillae, 1/4 as long as claws (Fig. 16).

Chaetotaxy, consisting of short setae and longer and fine sensorial setae. Dorsally head without seta c1, with both p1 and p2, l1 longer than l3 (Fig. 14), thoracic segments II-III with medial setae in 3 rows, seta p2 on tergite of thoracic segments II-III set in front of p1, on thoracic segments III a2 displaced distally relative to a1 (Fig. 15), on abdominal segments I-III, p5 present, abdominal segments IV without a3, abdominal segments V without a2 (Fig. 16). Ventrally head with seta p1 (Fig. 17), thoracic segments II and III with a pair of medial setae, abdominal segment II without p2 and a5, abdominal segment III with 1 median seta above the retinaculum (Fig. 18), abdominal segment IV without m1 (Fig. 19).

Comment

The new species is distinguished from other species of Xenylla by possessing a mucro without teeth, dorsal side of head with c1 (p1 a/cBabenko et al. 1994) seta absent, seta p2 on tergite of thoracic segments II-III set in front of p1 seta, thoracic segments II and III with a pair of ventral medial setae, abdominal segment II without ventral setae p2 and a5, abdominal segment III with 1 median ventral seta above the retinaculum, abdominal segment IV without ventral seta m1, unguis lacking teeth.

Etymology

Named changchunensis alluding to Changchun, the city where the species was found.

Taxonomic Remarks

The new species resembles X. osetica Stebaeva & Potapov, 1994 in general shape, antenna, tibiotarsi, and claws, especially in dorsal chaetotaxy, but distinctly differs from X. osetica in the following characters: (1) furca and tenaculum present, and (2) ventral chaetotaxy on abdominal segment III.