Dicranocentrus wangi, Ma, Yitong & Chen, Jian-Xiu, 2007

Ma, Yitong & Chen, Jian-Xiu, 2007, A new Dicranocentrus species (Collembola: Entomobryidae) from China with a key to all species in the genus from Asia, Zootaxa 1633, pp. 63-68 : 65-67

Dicranocentrus wangi sp. nov.

Figs. 1–22, Tabs. 1 –2

Description. Body length up to 2.5mm. Ground colour pale yellow. Eye patches dark blue. One small blue spot present between antennae. Blue pigment gradually darker from distal part of 2 nd to 6 th antennal segments and from distal part of femur to tibiotarsus ( Fig. 1).

Head. Eyes 8 + 8, G and H smaller than others ( Fig. 2). Antennae short, 0.50–0.76 times as long as body and 2.3–3.7 times as cephalic diagonal; ratio of length of ant. V to VI as 1.2–2.3; Ant. V and VI annulated except proximal part of ant. V ( Fig. 3); apex of Ant. VI with 1–2 finger-like bent setae and without pin-like seta ( Fig. 4). Dorsal cephalic chaetotaxy as in Fig. 5, A 1 and Ps absent and S 2 present, P group with 5 setae (after Mari Mutt 1979), 30–64 short ciliate setae present along posterior margin of head ( Fig. 5 and 6). Labral setae 4 /5,5,4, all smooth; distal margin of labrum with 4 broad, oval papillae, each papilla with 1 small seta ( Fig. 7). External differentiated seta of labial appendage thinner than normal setae, short, with tip reaching basal half of papilla ( Fig. 8). Apical seta of maxillary palp similar in shape and as long as or slightly longer than subapical seta ( Fig. 9). Setae of posterior row of labial triangle variable, internal to setae with 0–5 ciliate setae and 2–6 (9) smooth. Seta R of labial triangle 0.54–0.72 as long as M 1 ( Fig. 10).

Thorax. Macrochaetae as shown in Fig. 11 (setae with an arrow sometimes absent). Trochanteral organ with 25–41 setae ( Fig. 12). Besides numerous ciliate setae of different sizes, tibiotarsus with 0–2 smooth setae on outer side and 5–12 smooth setae arranged in 2–3 files on inner side. Tenent hair acuminate, 0.75 –1.00 times as long as inner edge of unguis. Unguis with 3 inner teeth, basal pair small and sub-equal, median one minute. Unguicular outer tooth usually absent, rarely present (in paratype, female 8717 -F) and minute ( Fig. 13).

Abdomen. Macrochaetae and bothriotricha as shown in Fig. 11. Length ratio of abd. IV to abd. III at dorsal midline as 1.3–1.8. Tenaculum with 4 + 4 teeth and 4–10 weakly ciliate setae on corpus ( Fig. 14). Ventral tube scaled on both faces, anterior face with 11–22 ciliate to weakly ciliate setae on each side ( Fig. 15); posterior face with 36–78 weakly ciliate to smooth setae ( Fig. 16); each lateral flap with 28–50 smooth setae ( Fig. 17). Manubrium with numerous ciliate setae of different sizes, 23 and 25 smooth setae on each side (in paratype, female 8717 -XXX) ( Fig. 18). Manubrium plaque with 1–2 smooth setae, 9–13 strongly ciliate setae and 2–3 pseudopores ( Fig. 19). Length ratio of manubrium to dens as 0.50–0.71. Proximal dens with 1–4 smooth setae. Dental lobe with a ciliate blunt seta and a row of 4–7 ciliate setae. Dental spines simple, 8–13, chestnut coloured, arranged in one file along inner edge of dentes ( Fig. 20). Ratio of length of uncrenulatd part of dens to mucro 3.1–4.3. Mucro bidentate, basal spine short, smooth, with tip reaching subapical tooth ( Fig. 21).

Scales chestnut coloured, hyaline and heavily striated ( Fig. 22).

Ecology. In leaf litter of deciduous trees.

Type material. Holotype female, China: Guangdong Province: Guangzhou: South China Plantation, 10.viii. 1999, coll. Chen Jian-xiu and Wang Song-jie, collection number 8717 -C; paratypes: 3 males and 53 females on slides, same data as holotype (8717 -series); in the Department of Biology, Nanjing University.

Etymology. The new species is named after Mr. Wang Song-jie who collected the specimens for the present study.

Remarks. The new species is clearly different from D. indicus , the only known Chinese species in the genus, by the characters given in Table 1.

The new species is most similar in the arrangement of dental spines to the Philippine species D. luzonensis Mari Mutt, 1985 and the Singapore species D. simplex Yosii, 1959 , but differs from them as shown in Table 2.

TABLE 2. The main differences between D. wangi , D. luzonensis and D. simplex .

Tables

TABLE 1. Main differences between D. indicus and D. wangi.

	indicus	wangi
Dental spines	absent	8–13
Smooth setae on tibiotarsus	absent	7–14
Apex of tenent hair	slightly clavate	acuminate
Macrochaetae on Abd. IV	absent	4+4 or 5+5