Symphylella isabellae (Grassi, 1886); type locality: southern Italy.

Holotype : • female (slide no. CQ-JYS-SY2021014) (SNHM), China, Chongqing, Jinyunshan National Nature Reserve, extracted from soil samples of broad-leaf forest, alt. 650 m, 29°45'N, 106°21'E, 18-X-2021, coll. Y.L. Jin, Y. Bu & S.Q. Yang. Paratype: • 1 female (slide no. CQ-JYS-SY2021016) (SNHM), same data as holotype.

Symphylella obtusa sp. nov. is characterized by the 4/2/2 macrosetae on the frons, central rod divided by a weak node, 3+3 setae on the first tergite, broad processes with blunt end, inserted seta on processes absent, one and two central setae on tergites 2 and 3 respectively, long and narrow cerci. It is most similar to S. oligosetosa Scheller, 1971 from Peninsular India and Sri Lanka in the shapes of cerci, leg 12 and the chaetotaxy of the first tergite, but differs in the shape of central rod (divided by a weak node in S. obtusa sp. nov. vs not divided into two parts in S. oligosetosa), processes (with blunt end in S. obtusa sp. nov. vs with strongly pointed end in S. oligosetosa), and central setae of second and third tergite (respectively one and two central setae in S. obtusa sp. nov. vs without central seta in S. oligosetosa). It is also close to S. hintoni Edwards, 1959 from Britain in the shape of leg 12 and the chaetotaxy of the tergite, but can be easily separated by the shape of processes (broad in S. obtusa sp. nov. vs narrow in S. hintoni), and cerci (longer and narrow in S. obtusa sp. nov. vs short and stout in S. hintoni).

Adult body 1.5–1.7 mm long, holotype 1.7 mm.

Head length 168–183 μm, width 175–188 μm, with widest part on equal level of points of articulation of mandibles. Central rod (103 μm) distinct and divided into two parts by a weak node at the middle. Anterior branches normally developed, without median branches.

Head dorsally covered with setae of different length (Fig. 1A). Frons with 5+5 lateral setae, eight macrosetae (14–22 μm) arranged as 4/2/2 (counted from anterior row to posterior row) and 2–3× as long as antero-central seta (a0) (Fig. 2A). Cuticle with fine granulation, except on anterolateral part of head with coarse granules.

Tömösváry organ globular, diameter 12–13 μm, shorter than half of greatest diameter of third antennomere (28 μm), aperture small and round (7.5 μm), with striated inner wall (Fig. 1A).

Mouthparts. Mandible composed of three parts: pars incisivus with four distinct thick teeth, pars molaris with four smaller teeth and two proximal spines, and lacinia mobilis with one small and pointed process observed from lateral view (Fig. 2B). First maxilla has two lobes, inner lobe with four hook-shaped teeth, palp conical and pointed (Fig. 2C). Anterior part of second maxilla with many small protuberances, each carrying one seta. Cuticle of second maxilla covered with dense pubescence.

Antennae with 18–21 antennomeres (18 in holotype), ~ 0.2 of body length. First antennomere cylindrical, length ~ 0.8–1 of greatest diameter (width 23–27 μm, length 22–23 μm), with six or seven setae in one whorl, longest seta 12–13 μm. Second antennomere wider (25–28 μm) than long (19–25 μm), with seven or eight setae evenly inserted around antennal wall, longest setae 12–13 μm (Fig. 2D). Chaetotaxy of third antennomere similar to preceding ones (Fig. 2D). Setae on proximal antennomeres longer and on distal antennomeres shorter. Proximal antennomeres with only primary whorl of setae (Fig. 2D). Secondary whorl appearing ventrally on antennomeres 11. Four kinds of sensory organs observed on antenna (Fig. 2E): rudimentary spined sensory organs (ros) on dorsal side of subterminal antennomeres; spined sensory organs (so) consisting of three or four curved spines around one central pillar, only present on apical antennomere; cavity-shaped organs (co) on dorsal side of antennomeres 6 or 7 to penultimate; bladder-shaped organs (bo) on antennomeres 13–16 to penultimate increasing in number to maximum 15 . Apical antennomere sub-spherical, with its length as long as width (21–27 μm), with five so and 13–15 setae located distally (Fig. 2E). All antennomeres covered with short pubescence. Chaetotaxy and sensory organs on antennae of holotype are given in Table 2.

Trunk with 17 tergites. Tergites 2–13, and 15 each with one pair of triangular processes. Length from base to tip of processes somewhat longer than or same as its basal width; basal distance between processes distinctly longer than their length from base to tip (Table 3). All processes without end-swellings (Fig. 1B, C, E, G). Definition of chaetotaxy on tergite as follows: anterolateral setae (als) located on anterolateral angle of each tergite; apical seta (as) close to process apex; lateromarginal setae (lms) located on lateral margin of process and including als and as; inner basal setae (ibs) located on inner base of processes; inserted setae (is) present between ibs and as; central setae (cs) present at base of processes between ibs; other setae including all setae except above nominated ones. Anterolateral setae of tergites 2, 3, 4, 6, 7, 9, 10, and 12 distinctly longer than other lms of same tergite, those of tergites 5, 8, 11, 13 and 15 subequal or slightly shorter than longest ones of other lms. All processes without is seta. All tergites pubescent (Fig. 1B, C, E, G).

Tergites. Tergite 1 reduced, with 3+3 setae of different lengths (Fig. 1B). Tergite 2 complete, with two triangular posterior processes, four or five lms, one cs, with als 0.7–0.8 as long as length of process, length of processes almost as long as broad, basal distance between processes 1.4–1.6× as long as their length (Fig. 1B, E). Tergite 3 complete, broader and longer than preceding one with ratios of 0.8–0.9, 0.9–1.0, and 1.5 respectively, 5–6 lms, two cs (Fig. 1B, G). Tergite 4 broader than tergite 3, with ratios 0.9–1.3, 0.8–0.9 and 1.8–2.5 respectively, four lms, two cs (Fig. 1C). Chaetotaxy of tergites 5–7, 8–10, and 11–13 similar to tergites 2–4 (Fig. 1C). Pattern of alternating tergite lengths of two short tergites followed by a long tergite only disrupted at caudal end (Table 3). Tergites 14, 16, and 17 without processes, with 17–20, 10 or 11, and 14 or 15 setae, respectively. Chaetotaxy and measurements of tergites are given in Tables 3, 4.

Legs. First pair of legs reduced to two small hairy cupules, each with one long seta (9 μm) (Fig. 1D). Basal areas of legs 2–12 each with 3–6 setae (Fig. 1F). Leg 12 somewhat shorter than length of head (Fig. 2F), trochanter 1.1–1.5× as long as wide (33–47 μm, 30–31 μm), with 6–9 subequal setae; femur almost as long as wide (27–28 μm, 26–27 μm), with five setae, four on dorsal or outer side, one on ventral side, longest dorsal setae (11–12 μm) ~ 0.4 of greatest diameter of podomere; tibia ~1.7–1.9× longer than wide (35–38 μm, 20–21 μm), with five dorsal setae and one ventral seta, longest dorsal seta (13 μm) ~ 0.6 of greatest diameter of tibia; tarsus cylindrical, ~ 3.3–3.5× as long as wide (35–38 μm, 20–21 μm) with six dorsal setae, two of them close to claw, longest dorsal seta (12–13 μm) slightly shorter than greatest width of tarsus, two ventral setae close to claw distinctly shorter than dorsal one. Claws curved, anterior one somewhat broader than posterior one, the latter more curved than former (Fig. 2F). All legs covered with dense pubescence.

Coxal sacs present at bases of legs 3–9, fully developed, each with four or five setae on surface. Corresponding areas of legs 2, 10, 11, and 12 replaced by one or two setae (Fig. 1F).

Styli present at base of legs 3–12, short and sub-cylindrical (length 3–4 μm, width 3 μm), basal part with dense straight hairs; distal hairless, with an apical hair (2 μm) (Fig. 1F).

Sense calicles located on two ventral protuberances of last tergite, posterior to base of leg 12, with smooth margin around pit. Sensory seta inserted in cup center, extremely long (138–163 μm).

Cerci narrow and tapered, 3.9–4.3× as long as its greatest width (90–98 μm, 21–25 μm), sparsely covered with 25 or 26 setae (Fig. 2G). Proximal setae somewhat longer than distal ones. Four or five long and straight setae located on dorsal and outer side, other setae slightly curved. Longest outer seta (17–18 μm) straight and slightly longer than greatest width of cerci. Terminal area short (18 μm), 0.7–0.9 as long as greatest width of cerci, circled by several layers of curved ridges. Terminal seta (23–25 μm) longer than terminal area (Fig. 2G).

The species name obtusa derived from the Latin word obtus means blunt, referring to the blunt end of the process on the tergite.

China (Chongqing).

Holotype : • female (slide no. CQ-YTL-SY2022013) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Tianchiba, extracted from soil samples of broad-leaf forest, alt. 2100 m, 31°28'N, 109°47'E, 12-VIII-2022, coll. Y. Bu & Y. L. Jin. Paratypes: • 1 male (slide no. CQ-YTL-SY2022014) (SNHM), same data as holotype; 2 females (slides no. CQ-YTL-SY2022015, CQ-YTL-SY2022016) (SNHM), same data as holotype; • 1 female (slide no. CQ-YTL-SY2022025) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Linkouzi, extracted from soil samples of broad-leaf forest, alt.1595 m, 31°28'N, 109°52'E, 14-VIII-2022, coll. Y. Bu & Y. L. Jin; • 4 females (slides no. CQ-YTL-SY2022030–CQ-YTL-SY2022033) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Linkouzi, Zhuanping, extracted from soil samples of broad-leaf forest, alt. 1250 m, 31°29'N, 109°54'E, 15-VIII-2022, coll. Y. Bu & Y. L. Jin.

Symphylella yintiaolingensis sp. nov. is characterized by 4+4 setae arranged in two groups on the first tergite, 1–3 inserted setae on processes, moderately swollen ends of processes, pointed apical seta of the stylus, long and erect setae present on the outer and ventral sides of cerci. It belongs to the group of species with inserted setae present on the process of the tergite. It is most similar to S. communa Jin & Bu, 2020 from East China in the chaetotaxy of tergites, the shapes of the styli and the cercus, but differs in the shape of the Tömösváry organ (with larger aperture in S. yintiaolingensis sp. nov. vs smaller aperture in S. communa), and in the shape of the stylus (with pointed apical seta in S. yintiaolingensis sp. nov. vs blunt apical seta in S. communa). The new species is also similar to the widespread S. vulgaris Hansen, 1903 in the shape of the tergites, but they can be easily separated by the chaetotaxy of first tergite (4+4 setae in S. yintiaolingensis sp. nov. vs 3+3 setae in S. vulgaris), the erect setae on cercus (present on outer and ventral sides in S. yintiaolingensis sp. nov. vs present only on ventral side in S. vulgaris).

Adult body 2.4 mm long on average (2.0–2.7 mm, n = 9), holotype 2.6 mm.

Head as long as wide, length 230–270 μm, width 190–225 μm, with widest part on equal level as points of articulation of mandibles. Central rod well developed, divided into two portions by a node-like sub-middle interruption, with anterior part 60–75 μm and posterior part 63–75 μm. Dorsal side of head moderately covered with setae of different length (Fig. 3A). Frons with 5+5 lateral setae, macrosetae (21–30 μm) arranged as 4/2/2 and 2.0–2.5× as long as antero-central seta (a0), and 18 normal setae (Fig. 4A). Cuticle on anterolateral part of head with coarse granules (Fig. 3A).

Tömösváry organ globular, diameter 15–20 μm, almost half of greatest diameter of third antennomere (30–32 μm), aperture round (8–13 μm), with distinct vertical inner striae (Fig. 3A).

Mouthparts. Mandible composed of three parts: pars incisivus (pi) with four distinct thick teeth, pars molaris (pm) with four teeth and two proximal spines, and lacinia mobilis (lm) with one blunt process observed from lateral view (Fig. 4B). First maxilla with two lobes, inner lobe with four hook-shaped teeth, palp pointed and sharp (Fig. 4F). Anterior part of second maxilla with many small protuberances, each carrying one seta, distal setae thick; posterior part with sparse setae. Cuticle of second maxilla covered with dense pubescence.

Antennae with 14–19 antennomeres (16 in holotype), ~ 0.2 of body length. First antennomere cylindrical, 1.3–1.6× as wide as long (width 35–42 μm, length 24–30 μm), with 5–6 setae in one whorl, one minute seta on dorsal side of antennomere. Second antennomere wider (35–43 μm) than long (29–32 μm), with 8 setae inserted around antennal wall, interior setae (21–22 μm) longer than exterior ones (17–18 μm). Chaetotaxy of third antennomere similar to preceding ones (Fig. 4C). Setae on proximal antennomeres longer and on distal antennomeres shorter. Proximal antennomeres with only primary whorl of setae, in middle and subapical antennomeres with several minute setae in secondary whorl. Four kinds of sensory organs observed on antenna (Fig. 4D): rso on dorsal side from second to subterminal antennomeres; so only present on apical antennomere; co on antennomeres 5 and 6 to apical one (absent on apical antennomere in some specimens), increasing in number to maximum three on subterminal antennomere; bo irregular, oblate or curved, present on antennomeres 5–7 to penultimate, increasing in number to maximum 22 on penultimate antennomere. Apical antennomere sub-spherical, somewhat wider than long (width 30–32 μm, length 27–28 μm), with five so and 15–18 short setae apically (Fig. 4D). All antennomeres covered with short pubescence. Chaetotaxy and sensory organs of antennae of holotype are given in Table 5.

Trunk. Length from base to tip of triangular processes somewhat shorter than or the same as its basal width; basal distance between processes of tergites distinctly longer than their length from base to tip except for tergites 2 and 3, in which basal distances shorter than lengths of processes (Table 6). All processes with moderate swollen ends. Anterolateral setae of tergites 2, 3, 4, 6, 7, 9, 10, and 12 distinctly longer than other lms of same tergite, those of tergites 5, 8, 11, 13, and 15 subequal or slightly shorter than longest ones of other lms. Anterolateral setae of tergites shorter than or subequal to process of same tergite. Processes with 1–3 is. All tergites pubescent (Fig. 3B–E).

Tergites. Tergite 1 reduced, with 4+4 subequal setae, asymmetrically lacking one seta in three paratypes (Fig. 3B). Tergite 2 complete, with two triangular posterior processes, 6–7 lms, one or two is, 1–3 cs, als 0.8–0.9 of length of process, processes 0.8–1.0 time as long as broad, basal distance between processes 0.6–0.9 as long as their length (Fig. 3B, E). Tergite 3 complete, broader, and longer than preceding one with ratios of 0.8–1.2, 0.8–1.0 and 0.8–1.0 respectively, 8–9 lms, 1–3 is, 2–4 cs (Fig. 3C). Tergite 4 broader than tergite 3, with ratios 0.9–1.2, 0.6–0.7 and 1.7–2.6 respectively, 5–7 lms, one or two is, 3–5 cs. Chaetotaxy of tergites 5–7, 8–10 and 11–13 similar to tergites 2–4 (Fig. 3D). Pattern of alternating tergite lengths of two short tergites followed by one long tergite only disrupted at caudal end. Tergites 14, 16, and 17 without processes, with 16–31, 11–21, and 16–34 setae, respectively. Chaetotaxy and measurements of tergites are given in Tables 6, 7.

Legs. First pair of legs reduced to two small hairy cupules, each with one long seta (10–11 μm) (Fig. 3F). Basal areas of legs 2–12 each with 5–11 setae (Fig. 3G). Leg 12 as long as head length, trochanter 1.1–1.6× longer than wide (64–80 μm, 45–60 μm), with 6–9 subequal setae in total (Fig. 4G); femur almost as long as wide (38–50 μm, 35–50 μm), with five or six setae, longest dorsal seta (18–23 μm) 0.5–0.7 of greatest diameter of podomere in length, pubescent dorsally, laterally with cuticular thickenings in pattern of scales; tibia nearly 1.4–1.9× longer than wide (45–58 μm, 28–35 μm), with 6–8 setae, longest dorsal one (20–25 μm) 0.7–0.9 of greatest diameter of tibia; tarsus sub-cylindrical, 3.2–5.4× as long as wide (63–95 μm,18–20 μm) with six dorsal setae: four straight and protruding, two depressed, longest seta (15–22 μm) almost as long as greatest diameter of tarsus, one ventral setae close to claw and distinctly shorter than dorsal ones. Claws slightly curved, anterior one broader and more curved than posterior one (Fig. 4H). All legs covered with dense pubescence except areas with cuticular thickenings.

Coxal sacs present at bases of legs 3–9, fully developed, each with four or five setae on surface (Fig. 3G). Corresponding areas of legs 2, 10, 11, and 12 replaced by 1–4 setae, respectively.

Styli present at base of legs 3–12, short and sub-conical (length 8 μm, width 5 μm), basal part with straight hairs; distal quarter hairless, with an apical seta (2 μm) (Figs 3G, 4E).

Sense calicles with smooth margin around pit. Sensory seta inserted in cup center, extremely long (138–200 μm).

Cerci ~ 0.7 of head in length, 2.9–3.5× as long as its greatest width (150–183 μm, 43–63 μm), densely covered with 65–96 setae (Fig. 4I). Two types of setae inserted on cercus: several long and erect setae located on outer and ventral side, other setae slightly curved and depressed. Longest outer long and erect seta (24–28 μm) ~ 1/2 of greatest width of cerci, terminal area short (24–35 μm), circled by 7–9 layers of curved ridges. Terminal seta (25–33 μm) close in length with terminal area (Fig. 4I, J).

The new species is named after the type locality Yingtiaoling National Nature Reserve.

China (Chongqing).

Holotype : • female (slide no. CQ-YTL-SY2022026) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Linkouzi, alt. 1250 m, 31°28'N, 109°52'E, 14-VIII-2022, coll. Y. Bu & Y. L. Jin. Paratypes: • 1 female (slide no. CQ-YTL-SY2022023) (SNHM), same data as holotype; • 1 female (slide no. CQ-YTL-SY2022029) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Linkouzi, Zhuanping, extracted from soil samples of broad-leaf forest, alt. 1595 m, 31°29'N, 109°54'E, 15-VIII-2022, coll. Y. Bu & Y. L. Jin.

Symphylella flabella sp. nov. is characterized by distinct roundish swollen ends of processes, 1–3 inserted setae on processes, fan-shaped apex of styli at base of legs 3–10, sub-conical basically and with blunt, slightly swollen apex in legs 11 and 12, long and erect setae present on outer and ventral sides of cerci. It is affiliated to S. yintiaolingensis in the chaetotaxy of tergites, the shape of the Tömösváry organ, leg 12, and cercus, but can be easily distinguished by the shape of styli (with fan-shaped apex at base of legs 3–10 in S. flabella sp. nov. vs all styli with pointed apices in S. yintiaolingensis sp. nov.) and by the shape of processes (with distinct rounded swollen end in S. flabella sp. nov. vs moderately swollen end in S. yintiaolingensis sp. nov.).

Adult body 2.5 mm long on average (2.4–2.6 mm, n = 3), holotype 2.5 mm.

Head as long as wide, length 230–240 μm, width 220–230 μm, with widest part at level of points of articulation of mandibles. Central rod well developed, divided into two portions by node-like sub-middle interruption, both anterior and posterior parts 60–63 μm. Dorsal side of head moderately covered with setae of different length (Fig. 5A). Frons with 5+5 lateral setae, eight macrosetae (22–28 μm) arranged as 4/2/2 and 1.5× as long as antero-central seta (a0), and 15–16 other setae (Fig. 6A). Cuticle on anterolateral part of head with coarse granules (Fig. 5A).

Tömösváry organ globular, diameter 14–16 μm, shorter than half of greatest diameter of third antennomere (38–40 μm), aperture round, 8–9 μm (Fig. 5A).

Mouthparts. Mandible composed of three parts: pars incisivus (pi) with four distinct thick teeth, pars molaris (pm) with four smaller teeth and two proximal spines, and lacinia mobilis (lm) with one sharp process observed from lateral view. (Fig. 6B). First maxilla with two lobes, inner lobe with four hook-shaped teeth, palp of first maxilla sharp (Fig. 6F). Anterior part of second maxilla with many small protuberances, each carrying one seta, distal setae thick; posterior part with sparse setae. Cuticle of second maxilla covered with dense pubescence.

Antennae with 17–19 antennomeres (17 in holotype), ~ 0.2 of body length. First antennomere cylindrical, 1.4–1.7× as wide as long (width 36–40 μm, length 23–26 μm), with 5–6 setae in one whorl, one minute seta on dorsal side of antennomere (Fig. 6C). Second antennomere wider (36–40 μm) than long (28–30 μm), with 8–9 setae inserted around antennal wall, interior setae (20–22 μm) longer than exterior ones (17–18 μm). Chaetotaxy of third antennomere similar to preceding ones (Fig. 6C). Setae on proximal antennomeres longer and on distal antennomeres shorter (Fig. 6C, D). Proximal antennomeres with only primary whorl of setae, in middle and subapical antennomeres with several minute setae in secondary whorl. Four types of sensory organs observed on antennae (Fig. 6D): rso on dorsal side of most antennomeres except first antennomere; so only present on apical antennomere; co on antennomeres 5 and 6 to subapical one (absent on apical antennomere), increasing in number to maximum four on subterminal antennomere; bo irregular, oblate or curved, present on antennomere 6 to penultimate, increasing in number to maximum 17 on penultimate antennomere. Apical antennomere sub-spherical, somewhat wider than long (length 25–26 μm, width 33–32 μm), five so and 15–16 setae on distal half (Fig. 6D). All antennomeres covered with short pubescence. Chaetotaxy and sensory organs of antennae of holotype are given in Table 8.

Trunk. Length from base to tip of triangular processes somewhat shorter than or the same as its basal width; basal distance between processes of tergites distinctly longer than their length from base to tip except for tergites 2 and 3, in which basal distance shorter than length of processes (Table 9). All processes with obvious rounded swollen ends. Anterolateral setae of tergites 2, 3, 4, 6, 7, 9, 10, and 12 distinctly longer than other lms of same tergite, that of tergites 5, 8, 11, and 15 shorter than longest one of other lms of same tergite. Anterolateral setae of tergites close to length of process of same tergite. Processes with 1–3 is. All tergites pubescent (Fig. 5B–D).

Tergites. Tergite 1 reduced, with 4+5 subequal setae in holotype, 4+4 or 3+4 in paratypes (Fig. 5B). Tergite 2 complete, with two triangular posterior processes, 7–8 lms, 1–2 is, two cs, als 0.8–1.2 of length of process, processes 0.8–0.9 as long as broad, basal distance between processes 0.6–1.0 as long as their length (Fig. 5B, D). Tergite 3 complete, broader and longer than preceding one with ratios of 0.9–1.1, 0.9–1.0, and 0.8–1.2 respectively, 8–10 lms, 1–2 is, three cs (Fig. 5C). Tergite 4 broader than tergite 3, with ratios 1.1–1.3, 0.7–0.8, and 1.7–2.5 respectively, six or seven lms, one is, five cs. Chaetotaxy of tergites 5–7, 8–10, and 11–13 similar to tergites 2–4. Pattern of alternating tergite lengths of two short tergites followed by one long tergite only disrupted at caudal end (Table 10). Tergites 14, 16, and 17 without processes, with 17–23, 12–15, and 18–23 setae, respectively. Chaetotaxy and measurements of tergites are given in Tables 9, 10.

Legs. First pair of legs reduced to two small hairy cupules, each with one long seta (11 μm) (Fig. 5E). Basal areas of legs 2–12 each with 3–10 setae (Fig. 5F). Leg 12 almost as long as head length, trochanter 1.3–1.4× longer than wide (60–70 μm, 46–50 μm), with seven or eight subequal setae in total (Fig. 6H); femur almost as long as wide (38–45 μm, 35–40 μm), with five setae, longest dorsal seta (20–22 μm) longer than greatest diameter of podomere, pubescent dorsally, laterally with cuticular thickenings in pattern of scales; tibia nearly 1.7–1.8× longer than wide (50–55 μm, 28–30 μm), with six or seven setae, longest dorsal one (22 μm) 0.7–0.8 of greatest diameter of tibia; tarsus sub-cylindrical, 3.3–4.2× as long as wide (60–75 μm, 17–18 μm) with six dorsal setae: four straight and protruding, two depressed, longest seta (20–22 μm) slightly longer than greatest diameter of tarsus, other setae depressed and distinctly shorter. Claws slightly curved, anterior one broader and more curved than posterior one (Fig. 6I). All legs covered with dense pubescence except areas with cuticular thickenings.

Coxal sacs present at bases of legs 3–9, fully developed, each with four setae on surface (Fig. 5F). Corresponding areas of legs 2, 10–12 replaced by 1–3 setae.

Styli present at base of legs 3–12, with various shapes: short and wide base and fan-shaped apex in legs 3–10 (Figs 5F, 6E), while sub-conical basically and blunt, slightly swollen apex in legs 11 and 12 (Fig. 6G).

Sense calicles with smooth margin around pit. Sensory seta inserted in cup center, extremely long (163–200 μm).

Cerci ~ 0.7 of head in length, 3.3–3.7× as long as its greatest width (140–175 μm, 43–48 μm), densely covered with 58–71 setae (Fig. 6J, K). Two types of setae inserted on cercus: several long and erect setae located on outer and ventral sides, other setae slightly curved and depressed (Fig. 6J, K). Longest outer long and erect seta (24–25 μm) ~ 1/2 of greatest width of cerci, terminal area short (20–28 μm), circled by 8–10 layers of curved ridges (Fig. 6J, K). Terminal seta (22–28 μm) close in length with terminal area (Fig. 6J, K).

The species name flabella derived from the Latin word flabellum (fan) referring to the fan-shaped apex of styli at base of legs 3–10.

China (Chongqing).

Symphylella flabella sp. nov. belongs to the group of species with inserted setae present on the process of the tergite. The fan-shaped apex of styli is observed for the first time in this species of the genus.

Holotype : • female (slide no. CQ-YTL-SY2022010) (SNHM), China, Chongqing Municipality, Wuxi County, ShuangyangTown, Yintiaoling National Natural Reserve, Daqiaowan, alt. 1022 m, 31°29'N, 109°49'E, 11-VIII-2022, coll. Y. Bu & Y. L. Jin. Paratypes: • 1 female (slide no. CQ-YTL-SY2022024) (SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Linkouzi, alt. 1250 m, 31°28'N, 109°52'E, 14-VIII-2022, coll. Y. Bu & Y. L. Jin; • 2 females (slides no. CQ-JYS-SY2021015, CQ-JYS-SY2021029) (SNHM), China, Chongqing, Jinyunshan National Nature Reserve, extracted from soil samples of broad-leaf forest, alt. 650 m, 29°45'N, 106°21'E, 18-X-2021, coll. Y. L. Jin, Y. Bu & S.Q. Yang.

• 1 juvenile (slide no. CQ-JYS-SY2021017)(SNHM), same data as previous. • 2 juveniles (slides no. CQ-YTL-SY2022005, CQ-YTL-SY2022006)(SNHM), China, Chongqing Municipality, Wuxi County, Shuangyang Town, Yintiaoling National Natural Reserve, Hongqi, alt. 1263 m, 31°31'N, 109°49'E, 10-VIII-2022, coll. Y. Bu & Y. L. Jin. • 1 juvenile (slide no. CQ-YTL-SY2022036)(SNHM), China, Chongqing Municipality, Wuxi County, Yintiaoling National Natural Reserve, Lanying Grand Canyon, 31°26'N, 109°48'E, alt. 662 m, 16-VIII-2022, coll. Y. Bu & Y. L. Jin. • 1 juvenile (slide no. CQ-YTL-SY2022043)(SNHM), ibidem, 19-VIII-2022, coll. Y. Bu & Y. L. Jin.

Symphylella micropora sp. nov. is characterized by the distinctly small aperture of the Tömösváry organ, 4+4 setae on tergite 1, 1–3 inserted setae on processes, without swollen ends of processes, stylus with pointed apex, and long erect setae only present on the ventral side of cerci. It is most similar to S. vulgaris (Hansen, 1903) in the chaetotaxy of tergites, the shape of leg 12, and the chaetotaxy of the cercus. However, they differ in the chaetotaxy of tergite 1 (4+4 setae in S. micropora sp. nov. vs uniformly 3+3 setae in S. vulgaris) and the position of apical setae (not very close to the apical end in S. micropora sp. nov. vs very close to the apical end in S. vulgaris).

Adult body 2.2 mm long on average (2.0–2.6 mm, n = 4), holotype 2.1 mm.

Head as long as wide, length 250–260 μm, width 240–260 μm, with widest part on equal level of points of articulation of mandibles. Central rod well developed, divided into two portions by node-like sub-middle interruption, both anterior and posterior part 60–65 μm. Dorsal side of head moderately covered with setae of different length (Fig. 7A). Frons with 5+5 lateral setae, eight macrosetae (25–30 μm) arranged as 4/2/2 and 1.5–1.9× as long as antero-central seta (a0), and 18 or 19 other setae (Fig. 8A). Cuticle on anterolateral part of head with coarse granules (Fig. 7A).

Tömösváry organ globular, diameter 15–20 μm, almost half of greatest diameter of third antennomere (35–40 μm), aperture round and distinct small, 8–13 μm (Fig. 7A).

Mouthparts. Mandible composed of three parts: pars incisivus (pi) with four distinct thick teeth, pars molaris (pm) with four teeth and two proximal spines, and lacinia mobilis (lm) with one sharp process observed from lateral view. (Fig. 8B). First maxilla typically, with sharp palp (Fig. 8F). Anterior part of second maxilla with many small protuberances, each carrying one seta, distal setae thick; posterior part with sparse setae. Cuticle of second maxilla covered with dense pubescence.

Antennae with 16 or 17 antennomeres (16 in holotype), ~ 0.2 of body length. First antennomere cylindrical, 1.1–1.4× as wide as long (width 35–35 μm, length 28–33 μm), with six setae (Fig. 8C). Second antennomere wider (35–38 μm) than long (30–35 μm), with eight setae inserted around antennal wall and interior setae slightly longer than exterior ones (Fig. 8C). Chaetotaxy of third antennomere similar to second one. Setae on proximal antennomeres longer and on distal antennomeres shorter (Fig. 8C). Proximal antennomeres with only primary whorl of setae, in middle and subapical antennomeres with several minute setae in secondary whorl (Fig. 8C, D). Four types of sensory organs observed on antenna (Fig. 8D): rso on dorsal side from first or second to subterminal antennomeres; so only present on apical antennomere; co on antennomeres 5–6 to subapical one, increasing in number to a maximum of three on subterminal antennomere; bo irregular, oblate or curved, present on antennomeres 6 and 7 to penultimate, increasing in number to a maximum of 13 on penultimate antennomere. Apical antennomere sub-spherical, somewhat longer than wide (32–33 μm, 29–30 μm), five so and 16–18 setae on distal half (Fig. 8D). All antennomeres covered with short pubescence. Chaetotaxy and sensory organs of antennae of holotype are given in Table 11.

Trunk. Length from base to tip of triangular processes somewhat shorter than or the same as its basal width; basal distance between processes of tergites distinctly longer than their lengths from base to tip except for tergites 2 and 3, in which basal distance shorter than or the same as length of processes (Table 13). All processes without swollen ends (Fig. 7B–D). Anterolateral setae of tergites 2–4, 6, 7, 9, and 10 distinctly longer than other lms of same tergite, those of tergites 5, 8, 11–13, and 15 subequal or slightly shorter than longest ones of other lms. Anterolateral setae of tergites shorter than or subequal to process of same tergite. Processes with 1–3 is. All tergites pubescent (Fig. 7B–D).

Tergites. Tergite 1 reduced, with 4+4 subequal setae (Fig. 7B), asymmetrically lacking one seta in two paratypes. Tergite 2 complete, with two triangular posterior processes, 6–7 lms, 1–2 is, two cs, als 0.8–0.9 of length of process, processes 0.9 as long as broad, basal distance between processes 0.8–0.9 as long as their lengths (Fig. 7B, D). Tergite 3 complete, broader, and longer than preceding one with ratios of 0.7–0.9, 0.8–0.9, and 0.8–1.5 respectively, 9–10 lms, 1–3 is, 2–3 cs (Fig. 7C). Tergite 4 broader than tergite 3, with ratios 1, 0.6–0.7, and 1.7–2.5 respectively, 6–8 lms, 1–2 is, 4–6 cs. Chaetotaxy of tergites 5–7, 8–10 and 11–13 similar to tergites 2–4. Pattern of alternating tergite lengths of two short tergites followed by one long tergite only disrupted at caudal end. Tergites 14, 16, and 17 without processes, with 19–27, 11–14, and 26–33 setae, respectively. Chaetotaxy and measurements of tergites are given in Tables 12, 13.

Legs. First pair of legs reduced to two small hairy cupules, each with one long seta (10–12 μm) (Fig. 7E). Basal areas of legs 2–12 each with 2–10 setae. Leg 12 almost as long as head (Fig. 7F), trochanter 1.3–1.6× longer than wide (60–73 μm, 43–50 μm), with 5–7 subequal setae; femur slightly longer than wide (40–42 μm, 38–40 μm), with five setae (Fig. 8G), longest dorsal seta (22–23 μm) longer than half of greatest diameter of podomere, pubescent dorsally, laterally with cuticular thickenings in pattern of scales (Fig. 8G); tibia nearly 1.6–1.8× longer than wide (48–55 μm, 28–30 μm), with six or seven setae, longest dorsal one (19–20 μm) longer than greatest diameter of tibia; tarsus sub-cylindrical, 3.6–4.4× as long as wide (73–78 μm, 18–20 μm) with seven or eight dorsal setae: four straight and protruding, two depressed, longest seta (15–18 μm) close to greatest diameter of tarsus, two setae close to claw and distinctly shorter than others. Claws slightly curved, anterior one broader and more curved than posterior one (Fig. 8H). All legs covered with dense pubescence except areas with cuticular thickenings.

Coxal sacs present at bases of legs 3–9, fully developed, each with 4–6 setae on surface (Fig. 7F). Corresponding areas of legs 2, 10–12 replaced by 1–5 setae.

Styli present at base of legs 3–12, short and sub-conical, 8 μm in length, 5 μm in width, basal part with dense straight hairs, distal quarter hairless, with pointed apex (2–3 μm) (Figs 7F, 8E).

Sense calicles with smooth margin around pit. Sensory seta inserted in cup center, extremely long (175–200 μm).

Cerci length ~ 0.7 of head, 3.2–3.5× as long as its greatest width (163–175 μm, 50–53 μm), densely covered with 82–104 setae (Fig. 8I, J). Two types of setae inserted on cercus: three or four long and erect setae located only on ventral side, other setae slightly curved and depressed (Fig. 8I, J). Longest ventral seta (23 μm) not more than half of greatest width of cerci, terminal area short (20–30 μm), circled by several layers of curved ridges (Fig. 8I, J). Terminal setae (25–30 μm) longer than terminal area (Fig. 8I, J).

The species epithet micropora refers to the small aperture of Tömösváry organ in the new species.

China (Chongqing).