Neumania (Lemienia) flectata 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 : 325-327

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

Zoobank: 8A4A5A99-AB42-4F71-B50D-D1B8B27ED02A

( Figures 9–11 )

Diagnosis — Idiosoma weakly sclerotized. P-4 bears two thin setae ventrally, positioned on its tubercles. Suture line between Cx-III/IV complete, male genital field contains 8–9 pairs of acetabula, along with V 1, V 3, V 4, C 4, excretory pore and posterior margins of Cx-IV. IV-L-5 without swimming seta in males.

Etymology — The specific name is from Latin word: “ flect- ” means bend, the name of this new species is derived from IV-L-6 curved in males.

Material examined — Holotype: ♂ ; Diaoluo Mountain National Nature Reserve , Hainan Province, China ; 18°42′73″N, 109°50′26″E, 578 m a.s.l. ; 30 Jan. 2018 ; Zhu-Hui Ding and Xin-Yao Gu leg.; GUGC . Paratypes: 3♂♂, 4♀♀ ; the same data as the holotype ; GUGC.

Description — Male: Idiosoma weakly sclerotized, dorsum with two pairs of irregular dorsalia ( Figure 9A ). Coxal plates in four groups, surface lightly reticulated, interspace between Cx-II and Cx-III narrow, suture line between Cx-III/IV complete, posterior apodemes of ACG extending to half of Cx-IV, posterior projection of Cx-IV forming the shape of a mountain mound ( Figure 9B ). Genital plates wider than long, with 8–9 pairs of acetabula, along with V 1, V 3, V 4, C 4, excretory pore and posterior margins of Cx-IV ( Figure 10E ).

Palp five-segmented. P-1 slender, mediodorsal with one seta, P-4 with two ventral projections, each bearing one seta, and one ventrodistal peg-like seta on a tubercle, the claws of P-5 distinctly trifurcated ( Figure 10A ). Ventral apodeme of gnathosoma almost as long as dorsal apodeme ( Figure 10C ). Chelicera with a well-developed claw ( Figure 10D ). I-L-4, -5 ventrodistally each with one short swimming seta ( Figure 11A ). II-L -5 ventrodistally with one swimming seta ( Figure 11B ). III-L-3, -4, -5 distally with one, three, three swimming setae, respectively ( Figure 11C ). IV-L-3, -4, -5 distally with three, five, zero swimming setae, respectively. IV-L-5 subterminal part has no depression but significantly narrowed, IV-L-6 curved and much shorter than IV-L-5 ( Figure 11D ).

Measurements — Male (n = 4): Idiosoma L 436–450, W 378–405 (L/W ratio 1.11–1.15); genital field L 93–107, W 156–171 (L/W ratio 0.59–0.63). LA 287–290; LP 202–210; medial distance between Cx-IV 0–4. Chelicera L 99–109. Gnathosoma L 73–80. Lengths of the palp segments (P-1–5): 23–24, 75–77, 41–43, 73–77, 29–32. Lengths of I-L-1–6: 57–60, 91–94, 103–107, 138–145, 170–174, 168–177. Lengths of II-L-1–6: 62–64, 84–86, 112–115, 151–155, 179–186, 147–150. Lengths of III-L-1–6: 58–63, 69–70, 89–91, 114–116, 147–148, 132–135.

Lengths of IV-L-1–6: 62–65, 88–91, 107–112, 145–147, 197–202, 138–140.

Female: Significant differences exist compared to male ( Figure 9C ), interspace between Cx-II and Cx-III wide, the mid-edge spacing of Cx-IV broad, posterior apodemes of ACG extending to one-fourth of Cx-IV, posterior projection of Cx-IV hook-like ( Figure 9D ). Genital field contains 8–10 pairs of acetabula and 7 pairs of genital setae, five of which located on the genital plate, while two outside the plate ( Figure 10F ). P-3 and P-4 both without lateral fine seta ( Figure 10B ). IV-L-3, -4, -5 distally with three, five, three swimming setae, respectively. Both IV-L-5 and IV-L-6 appear normal, IV-L-6 with two ventral setae ( Figure 11E ).

Measurements — Female (n = 4): Idiosoma L 706–740, W 582–633 (L/W ratio 1.16–1.21); genital field L 78–83, W 69–71 (L/W ratio 1.13–1.16); gonopore L 136–160. LA 378–395; LP 258–265; medial distance between Cx-IV 41–54. Chelicera L 130–140. Gnathosoma L 90–99. Lengths of the palp segments (P-1–5): 27–28, 94–103, 52–54, 96–98, 36–38. Lengths of

I-L-1–6: 71–74, 102–121, 141–143, 190–195, 205–206, 188–189. Lengths of II-L-1–6: 76–81, 109–118, 124–127, 174–197, 214–216, 188–190. Lengths of III-L-1–6: 72–77, 82–87, 99–101, 149–158, 199–201, 171–204. Lengths of IV-L-1–6: 79–84, 104–112, 130–132, 182–184, 235–236, 204–213.

Remarks — The male genital field of the new species is located terminally. Its anterior margin connects to the center of the posterior margin of Cx-IV, while its posterior margin is fused with the excretory pore and bilateral V 1. The enlarged V 4 is fused with the genital plate through its lateral wing. The C 4 heals from the anterior margin, and V 3 connects to the anterior edge of the plate through a corridor-shaped, secondary-sclerotized edge. It is evident that the above features are rare in the entire species of the subgenus Lemienia , thus they can serve as distinguishing features. Although Neumania (Lemienia) maharashtris Cook, 1967 also exhibits a similar structure, the following features can clearly distinguish it from the new species: male IV-L-5 of this species bears swimming setae, the suture line between Cx-III/IV is incomplete, and the dorsal seta on P-1 is absent.

Distribution — China (Hainan Province), marsh.

Figures

Figure 9 Neumania (Lemienia) flectata sp. nov. (Male A, B; Female C, D): A, C – Idiosoma, dorsal view; B, D – Idiosoma, ventral view; Scale bars = 100 μm.

Figure 10 Neumania (Lemienia) flectata sp. nov. (Male A, C–E; Female B, F): A, B – Palp; C – Gnathosoma; D – Chelicera; E, F – Genital field; Scale bars = 100 μm.

Figure 11 Neumania (Lemienia) flectata sp. nov. (Male A–D; Female E): A – I-L-1–6; B – II-L-1–6; C – III-L-1–6; D – III-L-1–5, 6; E – IV-L-3–6; Scale bars = 100 μm.