Atractides (Atractides) bitergumus Zhang & Guo 2023
Creators: name: Zhang, Yu-Hao
name: Li, Hai-Tao
name: Hu, Zhan-Yu
name: Guo, Jian-Jun
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Hygrobatidae
Atractides
Atractides bitergumus

description: Atractides (Atractides) bitergumus Zhang & Guo, 2023
Figs 19–21, 25
Diagnosis
Genital field with four pairs of acetabula, V 1 fused with V 2, excretory pore surrounded by sclerotized ring and between V 1 and V 2. P-4 with numerous dorsal hairs and two hair-like ventral setae, sword seta near distoventral hair. I-L-5 thicken from base to end, S-2 longer than S-1, both with blunt tips and similar in shape; I-L-6 curved, and distally little thicker than base.
Material examined
P.R. CHINA • 1 ♀; Hainan Province, Qionghai City, Longjiang Town; 19.1730° N, 110.3459° E; 4 m a.s.l.; 11 Apr. 2023; Hai-Tao Li, Yu-Lin Zheng and Yu-Hao Zhang leg.; main river (Wanquan River) with wide surface, slowly flowing, with sandy soil and humus on bottom; slide no. HN-HY-2023041108; GUGC.
Description
Female (n = 1)
Idiosoma oval; O 1 between A 1 and A 2 but closer to A 1, O 2 between D 1 and surrounded by pair of platelets; dorsum with three pairs of muscle attachments: pair of muscle attachments between L 2, pair of muscle attachments near D 2, and pair of muscle attachments between D 3; all slit organs visible, So 1 near A 1, So 2 at same level of D 1, So 3 between L 2 and L 3 but closer to L 3, So 4 near L 4, So 5 behind of D 4 (Figs 19A, 21A). ACG fused and with suture line, medial posterior margin of ACG ligulate, apodemes of ACG strong and horn-like; PCG separated, and suture line of Cx-III and Cv-IV nearly straight. Genital field with four pairs of acetabula, pregenital sclerite longer than postgenital sclerite. V 1 fused to V 2, V 4 at same level of Ac1, V 3 near pregenital sclerite, pair of sclerites anterior to pregenital sclerite and approximately between V 3, V 3 and V 4 forming trapezoid; excretory pore surrounded by sclerotized ring and between V 1 and V 2 (Figs 19B, 21B).
Palp five-segmented and without obvious sexual dimorphism; P-2 short and stout with straight ventral margin, P-3 straight, P-4 with numerous dorsal hairs and two hair-like ventral setae, ventral sectors 3:2:3, sword seta near distoventral hair (Fig. 19C). I-L-5 thickening from base to end, S-2 longer than S-1, both with blunt tips and similar in shape; I-L-6 curved, and end little thicker than base (Fig. 20).
MEASUREMENTS. Idiosoma L 745, W 579; coxal field L 330, Cx-III W 390, ACG IL 228, mL 132, W 272; gnathosoma bay L 122; gonopore L 107, pregenital sclerite L 142, postgenital sclerite L 52; Ac1–4 L 29, 29, 29, 30; chelicera L 288, cheliceral claw L 93, basal segment L 202; gnathosoma L 218; palp dL: P-1 30, P-2 66, P-3 63, P-4 97, P-5 36; leg segments: I-L-1 dL 41, I-L-2 dL 78, I-L-3 dL 90, I-L-4 dL 131, I-L-5 dL 130, HB 39, I-L-6 dL 98, HB 23, S-1 L 52, W 5, S-2 L 51, W 5; dL: II-L-1 55, II-L-2 73, II-L-3 81, II-L-4 108, II-L-5 119, II-L-6 114; dL: III-L-1 56, III-L-2 69, III-L-3 85, III-L-4 122, III-L-5 148, III-L-6 129; dL: IV-L-1 121, IV-L-2 91, IV-L-3 137, IV-L-4 170, IV-L-5 187, IV-L-6 159.
Distribution
China (Hainan Province).
Remarks
Due to the genital field with four pairs of acetabula and similar shape of the palp, chelicera and gnathosoma, the specimen from Hainan Province matches the description of A. (A.) bitergumus Zhang & Guo, 2023.The collection site is very close to type locality, all in Hainan Province (Zhang et al. 2023). This is the first description of the female.
description: Published as part of Zhang, Yu-Hao, Li, Hai-Tao, Hu, Zhan-Yu & Guo, Jian-Jun, 2025, Two new species in the genus Atractides Koch, 1837 (Acari: Hydrachnidiae: Hygrobatidae), with the first descriptions of the female of two species from China, pp. 47-76 in European Journal of Taxonomy 976 on pages 65-69, DOI: 10.5852/ejt.2025.976.2775, http://zenodo.org/record/14771799