Tomocerus nan Yu & Yang & Liu 2018, sp. nov.
Creators: name: Yu, Daoyuan
name: Yang, Xiaodong
name: Liu, Manqiang
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Collembola
Entomobryomorpha
Tomoceridae
Tomocerus
Tomocerus nan

description: Tomocerus nan sp. nov.
Figs 1B, 4, 5
Type material. Holotype: female on slide, Mt. Diaoluo National Nature Reserve, Lingshui Autonomous County, Hainan Province, China, 109°52'3"E, 18°43'40"N, alt. 933 m, 25.xii.2015, litters and rotten woods, leg. Daoyuan Yu and Chunyan Qin (15HN2). Paratypes: 2 females, 3 males and 1 subadult on slides, 9 adults and juveniles in alcohol, same data as holotype. All types in NJAU.
Description. Body length 2.2–3.1 mm. General background colouration of body light yellow. Ant. I and Ant. II distally with light purple pigment, Ant. III and Ant. IV purple. Eye patch black. Tibiotarsi and distal half of hind femur purple (Fig. 1B).
Antenna 0.8–1.0× length of body. Length ratio of Ant I:II:III:IV = 1.0:1.2–1.3:8.8–9.8:1.1–1.3. Cephalic dorsal macrochaetotaxy: anterior area: 2 (A2), 4 (A3, A5); interocular area: 2 (M2), 6 (S2, S5, S 5i); postocular area: 2+2 (Pa5, Pa6); posterior area: 1+1 (Pa2). Posterior margin of head with 20–35 chaetae on each side (Fig. 4A).
Pattern of body chaetotaxy as in Fig. 4B. Th. II with macrochaetae a3, a4, a4a and a5a behind anterior marginal macrochaetae cluster; central area with single macrochaeta m3.
Trochantero-femoral organ with 1, 1 slender chaetae. Tibiotarsi I, II, III ventrally with 6, 5–7, 6–7 strong chaetae, 3–4, 4–5, 4–6 of them blunt (Fig. 4C). Tenent hair 1.0–1.1× length of inner edge of unguis; accessory chaetae shorter and thinner than pretarsal chaetae; guard chaetae subequal to tenent hair in length. Unguis slender, with baso-internal ridges about 1/4–1/3 distance from base; lateral teeth pointed, of moderate size. Inner edge of unguis with basal tooth and 3–5 more distal teeth, sub-basal tooth slightly stronger than more distal teeth. Unguiculus lanceolate, about 0.60–0.85× length of unguis, its inner edge with one tooth (Fig. 4D).
Ventral tube scaled on both faces. Anterior face with 14–20 chaetae on each side, posterior face with 50–70 chaetae, each lateral flap unscaled, with 25–45 chaetae. Anterior face of tenaculum with 3–6 chaetae and without scales (Fig. 4E). Ratio of manubrium:dens:mucro = 2.4–2.9:3.2–3.7:1.0. Manubrium ventrally scaled without chaetae; laterally with large round scales and 9–11 chaetae, proximal 1–2 chaetae slender and almost smooth, distal chaetae strong and slightly serrated; each dorsal chaetal strip with 95–120 chaetae of different sizes, an irregular row of scales from base to 1/2–3/5 length of manubrium along inner edge, and 8–13 pseudopores on lateral side; without distinct prominent chaetae (Fig. 5A); distal corner chaeta as large as small mesochaetae in chaetal strip. Dens basally without prominent dorsal chaeta. Dental spine formula as 3–6/2–5, 2 (Fig. 5B); denticles on spines unevenly distributed, all spines with mainly basal moderate to large and a few small denticles, large spines ventrally with additional distal small to moderate denticles (Fig. 5C). Mucro with 4–8 intermediate teeth (Fig. 5D).
Etymology. Chinese word nan: south.
Habitat. Mixed forest of Dacrydium pierrei and broad leaf trees, in litters and on rotten woods.
Remarks. Tomocerus nan sp. nov. can be diagnosed by absence of macrochaetae S0 and Pp3 on the head, presence of only one central macrochaeta m3 on Th. II, absence of distinct prominent chaetae on the furca, presence of dorsal scales on the manubrium and uneven distribution of denticles on large dental spines. The new species resembles most Tomocerus virgatus Yu, 2018 in absence of cephalic macrochaeta S0, presence of single mesothoracic central macrochaeta m3 and absence of prominent chaetae on the furca, but differs from the latter in colour pattern on the body and legs, absence of cephalic macrochaeta Pp3, presence of manubrial dorsal scales and pattern of denticles on large dental spines. Critical characters discriminating T. nan sp. nov. from similar species are listed in Table 1. A malformed dental spine formula is found on only one side of dens in two individuals as 5/3– 4, 1, with proximal spines irregularly arranged.
description: Published as part of Yu, Daoyuan, Yang, Xiaodong & Liu, Manqiang, 2018, Three new species of Tomocerus from tropical zone of China (Collembola, Tomoceridae), pp. 225-236 in Zootaxa 4508 (2) on pages 230-232, DOI: 10.11646/zootaxa.4508.2.5, http://zenodo.org/record/2607034