Paralobella sensilla Jiang, Wang & Zhu, 2025, sp. nov.

Paralobella sensilla sp. nov. Figs 2, 4–12, Tables 1–2 Type material. Holotype: Female, Congmuwan, Shaping Town, Taoyuan County, Hunan Province, China, coordinates: 28°35’13.52” N, 111°23’41.94” E, alt. 168m, under the leaves on the side of a road in evergreen and deciduous broad-leaved mixed forest (Fig. 1), leg. Ji-Gang Jiang, Yi Wang, Pei-Ting Zhu, Jing Shu, Hong Qi, 17.XI.2023 (2023111703). Paratypes: one female and one juvenile, same data as the holotype. Type material is deposited at the Key Laboratory of Zoology, Hunan University of Arts and Science (HUAS), Changde, Hunan Province, China. Etymology. The name of the species is derived from the word sensilla (= chaetae s), due to the presence of chaetae s with knobbed tips on dorsum. Diagnosis. Cephalic chaeta O present; cephalic tubercles Dl separate from tubercle L+ So; mandible with 2 basal teeth and four apical teeth; maxilla with only one tooth; body tubercles well differentiated; tubercle De fused to Dl on Abd. V; dorsal body sensilla clavate. Description. Body length: holotype female 2.7 mm, paratypes, one female 2.8 mm, one juvenile 1.3 mm. Color: living specimens red, whitish in ethanol (Fig. 2). Chaetal morphology. Dorsal ordinary chaetae of five types. Long macrochaetae (Ml) sheathed, toothed and with blunt or pointed tip (Fig. 4a–c). Short macrochaetae (Mc) morphologically similar to and shorter than Ml (Fig. 4d–f). Very short macrochaetae (Mcc), shorter than Mc and with blunt tip (Fig. 4g). Mesochaetae (me) on dorsum usually thicker than those on sternite, all me smooth, pointed and with variable lengths (Fig. 4h–m). Microchaetae (mi, shown in Fig. 4n, like chaeta Di2 or De2 on head) similar to me, and shorter than any me. S-chaetae (s) on terga thin, smooth, with knobbed tip (Fig. 4o), shorter than Mc and shorter than the longest me. Head. Eyes 3+3, black, two anterior but not included in Oc tubercle, the other one on the posterior part of tubercle Oc (Fig. 5). Antenna four-segmented (Fig. 6). Ant. I with 7 chaetae. Ant. II with 11 chaetae. Ant. III dorsally fused to Ant. IV. Guard chaeta sgd of Ant. III migrated distally, beyond the level of the two sensory rods. Ant. IV dorsally with eight subequal, slightly thickened and blunt sensilla (S1–8), apical bulb trilobed, organite (or) present. Ventral side of Ant. IV with some pointed or slightly blunt chaetae (Fig. 7). On ventral side of Ant. III, Vi, Vc and Ve with 4, 4, 5 chaetae respectively (Fig. 7). Oral cone normal, labrum truncated, labral formula as 0/4, 2. Labium with 11 chaetae, without papillae x (Fig. 8). Mandible with two basal teeth and four apical teeth on two branches, two apical teeth on a branch, and the other two subapical teeth with the two basal teeth on the same branch (Fig. 9). Maxilla consisting of two lamellae, usually stuck together, apically with two teeth (Fig. 10). Cephalic dorsal tubercles and chaetotaxy shown in Table 1 and Fig. 5. Central area of head with six tubercles: one Cl, one Fr, two Oc and two An; chaeta O present on tubercle Fr as a me. Dorso-posterior area with four separate tubercles: two Di and two De, Di2 and De 2 mi free from tubercle De. Line of chaetae Di1–De1 crossing line Di2–De2 on head (cross-type). Tubercle Dl independent, with 4 chaetae, tubercles L and So on dorsal lateral area fused, with 8 chaetae each. Ventral chaetotaxy of head. Group Vi with five chaetae, groups Vea with four, Vem with three and Vep with four chaetae, respectively (Fig. 8). Thorax (Fig. 5 and Table 2). Th. I with 3+3 tubercles, Di, De, Dl with 1, 2, 1 chaetae respectively. Th. II with 4+4 tubercles, Di with three chaetae, Di3 free from the tubercle Di, De with five (4+s) chaetae, one of them free from the tubercle, Dl with six (4+s+ms) chaetae, tubercle L with three chaetae. Th. III with 4+4 tubercles too, Di with three chaetae, chaetae arranging similar to Th. II, De with five (4+s) chaetae, one of them not included in the tubercle, Dl with five (4+s) chaetae, and L with three chaetae. Chaetotaxy of thorax and legs as in Table 2. Unguis with a basal inner tooth; unguiculus absent. Chaeta M present on tibiotarsus. Abdomen (Figs 11–12 and Table 2). Abd. I–III with 4+4 tubercles each, Di with two, De with four (3+s), Dl with two and L with 6 (5+s) chaetae, respectively, mi of tubercle De free from the tubercle. Abd. IV with 4+4 tubercles, Di with two, De with three (2+s), Dl with three and L with 8 (7+s) chaetae, respectively, mi of tubercle De not included on the tubercle either. Abd. V dorsally with 3+3 tubercles, two separated Di, each with three chaetae, tubercle De with only one sensillum and fused to Dl, each Dl with four chaetae. Tubercle L on Abd. V located on the ventral side of the abdomen, with five or six chaetae. Abd. VI with 1+1 tubercles, with seven chaetae on each tubercle (Fig. 11). VT with 4+4 chaetae (Fig. 12). Furcular remnant with 4 (sometimes 3) chaetae (Fig. 12). Chaetotaxy on ventral side of abdomen listed in Table 2. Ecology. The new species was found in the forest litter. Remarks. So far, fourteen species of Paralobella have been reported, all from Asia, they are listed below. P. apsala (Yosii, 1976) from Thailand P. breviseta Luo & Palacios-Vargas, 2016 from China P. erawan Yosii, 1976 from Thailand P. khaochongensis (Yosii, 1976) from Thailand P. kinabaluensis (Yoshii, 1981) from Malaysia P. kuchierabu Kasai, Hayasaka & Sawahata, 2022 from Japan P. orousseti Cassagnau & Deharveng, 1984 from Philippines P. palustris Jiang, Luan & Yin, 2012 from China P. paraperfusa (Gapud, 1968) from Philippines P. penangensis (Yosii, 1976) from Malaysia P. perfusa (Denis, 1934) from Indochina P. sabahna (Yoshii, 1981) from Malaysia P. selangorica (Yosii, 1976) from Malaysia P. tianmuna Jiang, Wang & Xia, 2018 from China The genus Paralobella can be divided into two groups of species due to the presence or absence of the O chaeta on cephalic Fr tubercle. Four species belong to the group without the O chaeta on head: Paralobella erawan, P. selangorica, P. penangensis, and P. apsala. The rest 10 species, i.e., P. breviseta, P. khaochongensis, P. kinabaluensis, P. kuchierabu, P. orousseti, P. palustris, P. paraperfusa, P. perfusa, P. sabahna, and P. tianmuna belong to the group of species with the O chaeta on head. Paralobella sensilla sp. nov. falls into the latter species group by having the above mentioned structure on Fr. By having fused tubercle De and Dl on Abd. V, the new species is similar to P. orousseti. However, these species can be distinguished by: on the head of P. sensilla sp. nov. there is a Dl tubercle with four chaetae vs. the absence of this tubercle in P. orousseti, there are only 3–4 microchaetae. Alive specimens of P. sensilla sp. nov. are red, while in P. orousseti they are bi or tricolored. Paralobella sensilla sp. nov. is also similar to P. tianmuna in having chaeta O on head, five (4+s) chaetae on tubercle De of Th. II–III respectively, one chaeta on tubercle Di of Th. I, and three chaetae on tubercle Di of Th. II– III. However, the new species is clearly distinguishable from P. tianmuna by the number of mandibular teeth (six in P. sensilla sp. nov., seven in P. tianmuna), number of chaetae on tubercle L of Abd. I–III (six in P. sensilla sp. nov., seven in P. tianmuna), and the shape of chaetae s on body, (in P. sensilla sp. nov. chaetae s clavate, in P. tianmuna, chaetae s pointed). The new species is likely also close to P. palustris, P. breviseta and P. perfusa in having chaeta O on head, 4+4 chaetae on VT and red body. However, the new species can be separated from the above species by fused tubercles De and Dl on Abd. V (versus separate tubercles De and Dl on Abd. V in P. palustris, P. breviseta and P. perfusa), and clavate chaetae s on body (versus pointed chaetae s on body in the other species).