Neumania (Lemienia) quadroa Ding & Jin, 2025

K, Zhu-Hui Ding, YiK, Tian-Ci, GuoK, Jian-Jun & K, Dao-Chao Jin, 2025, Studies on the subgenus Lemienia Koenike, 1910 new to China (Acari, Hydrachnidia, Neumania), Acarologia 65 (2), pp. 313-330 : 321-324

Neumania (Lemienia) quadroa Ding & Jin sp. nov.

Zoobank: AD05FA7F-74A7-46DD-9B5E-979EF27FAA81

( Figures 6–8 )

Diagnosis — Male idiosoma moderate sclerotization, with a dorsal plate. Female with weak sclerotization. Genital field with 8–15 pairs of acetabula. P-4 distally with one dagger-shaped sclerotized extension. IV-L-6 of male curved.

Etymology — The specific name is from Latin word: “ quadro- ” means quadrate, the name of this new species is derived from the quadrate idiosoma of the male.

Material examined — Holotype: ♂ ; Kunyushan National Nature Reserve , Shandong Province, China ; 37°17′49″N, 121°45′58″E, 84 m a.s.l. ; 20 Jul. 2017 ; Xin-Yao Gu and Zhu-Hui Ding leg.; GUGC . Paratypes: 1♂, 5♀♀ ; the same data as the holotype ; GUGC. 2♂♂, 2♀♀ ; Mount Huangshan Town, Mount Huangshan City, Anhui Province ; 30°9′25″N, 118°8′0″E, 768

m a.s.l.; 21 Jun. 2002 ; Tian-Ci Yi leg.; GUGC.

Description — Male: Idiosoma moderately sclerotized, dorsum with two pairs of dorsalia, a complete dorsal plate located beneath the boundary of the anterior dorsalia, surface lightly reticulated ( Figure 6A ), Cx-II and Cx-III almost connected, suture line between Cx-III/IV partly incomplete, posterior apodemes of ACG extending to one-fourth of Cx-IV, posterior projection of Cx-IV somewhat hook-shaped. Cx-IV connected in medial line ( Figure 6B ). Genital field located terminally, anterior margin connected with posterior margin of Cx-IV, each with 8–12 acetabula. V 4, V 1 and excretory pore all incorporated into genital field ( Figure 7E ).

Palp five-segmented. P-1 distally with one dorsal seta, P-4 features two small ventral projections, located close to each other, each bearing a single seta, along with one ventrodistal peg-like seta situated on a tubercle, lateromedially with a cluster of fine bristles, distally with a dagger-shaped sclerotized extension that extends beyond P-5 ( Figure 7A ). Gnathosoma pincershaped ( Figure 7C ). Chelicera with a well-developed claw ( Figure 7D ). II-L-4, 5 ventrodistally each with one swimming seta, respectively ( Figure 8B ). III-L-3, -4, -5 distally with one, four, three swimming setae, respectively ( Figure 8C ). IV-L-3, -4, -5 distally with two, five, three swimming setae, respectively. IV-L-5 with three blunt setae and with a distinct concavity near the subterminal region. IV-L-6 curved, with a peg-like projection at the bend, which bears a single seta, IV-L-6 shorter than IV-L-5. ( Figure 8D ).

Measurements — Male (n = 4): Idiosoma L 396–404, W 293–308 (L/W ratio 1.31–1.35)

; genital field L 66–74, W 194–195 (L/W ratio 0.34–0.38). LA 245–250; LP 175–196; medial distance between Cx-IV 0–1. Chelicera L 97–107. Gnathosoma L 89–113. Lengths of the palp segments (P-1–5): 21–25, 81–83, 20–25, 64–66, 42–44. Lengths of I-L-1–6: 52–56, 80–81,

84–89, 132–139, 148–150, 152–155. Lengths of II-L-1–6: 55–58, 77–81, 85–91, 138–141,

158–164, 159–161. Lengths of III-L-1–6: 56–58, 84–68, 65–66, 103–106, 123–125, 115–117.

Lengths of IV-L-1–6: 80–90, 83–85, 95–100, 139–145, 150–160, 99–101.

Female: Significant differences exist compared to male. Idiosoma elliptical, with weak sclerotization ( Figure 6C ), interspace between Cx-II and Cx-III wide, the mid-edge spacing of Cx-IV broad, posterior apodemes of ACG extending to one-third of Cx-IV ( Figure 6D ). Genital field with a pair of genital plates, each with 12–15 acetabula ( Figure 7E ). P-4 lacks a cluster of fine bristles, and distal sclerotized extension reaches halfway along P-5 ( Figure 7B ). Both IV-L-5 and IV-L-6 appear normal, with IV-L-6 being approximately equal in length to IV-L-5 ( Figure 8F ).

Measurements — Female (n = 7): Idiosoma L 598–606, W 478–494 (L/W ratio 1.22–1.25); genital field L 86–90, W 65–76 (L/W ratio 1.18–1.32). Gonopore L 130–136. LA 329–347;

LP 217–223; medial distance between Cx-IV 32–38. Chelicera L 120–127. Gnathosoma L 84–87. Lengths of the palp segments (P-1–5): 25–30, 86–99, 36–41, 82–89, 44–50. Lengths of I-L-1–6: 53–60, 90–102, 98–103, 158–163, 166–169, 159–161. Lengths of II-L-1–6:

64–67, 94–100, 107–114, 160–180, 178–188, 162–169. Lengths of III-L-1–6: 63–70, 80–82,

79–83, 136–138, 153–159, 153–168. Lengths of IV-L-1–6: 80–92, 97–102, 115–120, 166–170, 192–205, 185–189.

Remarks — The dorsal plate of this new species, delineated by the anterior dorsalia, is an exceptionally rare feature within the genus Neumania . This unique feature sets the species apart from others in the subgenus Lemienia . Additionally, the dagger-shaped sclerotized extension at the extremity of P-4, which extends to or even overlaps P-5, is another uncommon characteristic. To date, the sclerotized extension structure of P-4 has only been observed in N. megaspina . However, in N. megaspina , the extension is directed from below, whereas in this species, it extends from above.

Distribution — China (Shandong and Anhui Province), pond.

Figures

Figure 6 Neumania (Lemienia) quadroasp. nov. (Male A, B; Female C, D): A, C – Idiosoma, dorsal view; B, D – Idiosoma, ventral view; Scale bars = 100 μm.

Figure 7 Neumania (Lemienia) quadroasp. nov. (Male A, C–E; Female B, F): A, B – Palp; C – Gnathosoma; D – Chelicera; E, F – Genital field; Scale bars = 100 μm.

Figure 8 Neumania (Lemienia) quadroasp. nov. (Male A–D; Female E, F): A – I-L-1–6; B – II-L- 1–6; C – III-L-1–6; D – IV-L-1–6; E – I-L-5; F – IV-L-5, 6; Scale bars = 100 μm.