Teratothyasides (Hansvietsia) vanilla Gerecke 2020, sp. nov.
Creators: name: Gerecke, Reinhard
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Teratothyadidae
Teratothyasides
Teratothyasides vanilla

description: Teratothyasides (Hansvietsia) vanilla sp. nov.
Fig. 29 a–d
Type series: Holotype ♀, MNHN Ac 1466, MD 040, 21.08.2001 Ranomena (Fianarantsoa), spring at right margin of the stream (MD 035) NW from the 1.07 km-railway-tunnel, 950 m, in liquid. Paratypes: Same site and date (1/2/1) slide mounted, Ac 1409-1412; (0/17/0) in liquid, Ac 1467; MD 043, 21.08.2001 Ranomena (Fianarantsoa), spring area of the stream NW from the 1.07 km-railway-tunnel (right affluent of MD 034), 1100 m, (0/1/1) slide mounted, Ac 1413; MD 234, Ranomena (Fianarantsoa), spring area of the stream NW from the 1.07 km-railwaytunnel (same site: MD 043, right affluent of MD 034), 1017 m, S 21°29’45.9’’, E 047°24’07.5’’, 26.04.2011, (0/3/1) slide mounted, Ac 1414-1417.
Diagnosis: Genital field (Fig. 29 c) relatively large (L ♂ 200, ♀ 200–230), with about 20 (15–37) pairs of rather large acetabula (diameter Ac-1, ♂ 38, ♀ 33–40), most of them close to their neighbours. Mouth parts (Fig. 29 a–b) comparatively large (gnathosoma L 230–250, chelicera total L 490–540, palp total L 428–458), palp segments strongly elongated (L/H P-2, 1.8–2.0, P-3, 1.7–2.0; P-4, 5.4–6.1).
Description: Membranous integument with densely arranged, long papillae. Sclerite plates lattice-like, with a high number of often +/- angular pores (10–12 along an imaginary transect crossing dorsocentral plates see Fig. 29 d–e). Genital field (Fig. 29 c) with 15–37 pairs of acetabula, often asymmetric in number right/left, at lateral genital plate margin arranged in a triple line; Ac-1 separated by a distinct gap from the remaining, posteriormost Ac slightly enlarged. Each genital plate with about 30 (14-27 medial, 7-20 posterior) setae. Leg claws proximoventrally with a pointed, tooth-like projection. Gnathosoma and appendages as described for T. ravenala, but palp segments distinctly more slender (Fig. 29 b).
Measurements: Male: Idiosoma L/W 1430/1050; coxal field 760/850; Cx-I+II 440/320; Cx-III+IV 550/440; genital field L/W 200/250, Ac n right/left 15/16, L Ac-1 38, posterior Ac 30; genital skeleton L/W 75/23; gnathosoma L 230; chelicera basal segment proximal/total L 230/340, total L 490, ratio basal segment/claw 0.88, L/H 6.13. Palp total L 428; L, L/H ratio, relative L [% total L] palp segments: P-1, 70, 1.75, 16; P-2, 75, 1.88, 18; P-3, 78, 1.94, 18; P-4, 163, 5.4, 38; P-5, 43, 2.83, 10; L ratio P-2/-3, 0.97; P-2/-4, 0.46; P-3/-4, 0.48. Legs not measured.
Females: Idiosoma L/W 1420–1800/1000–1450; coxal field 660–830, Cx-I+II 360–470/225–360; Cx-III+IV 300–600/280–470; genital field L/W 200–230/230–280; Ac n right/left 8 [! misshapen]-37/21–33, L Ac-1 33–40, posterior Ac 25–35; gnathosoma L 2380–250; chelicera total L 500–540, basal segment/claw 0.86–0.96, L/H 5,4– 7,5; Palp total L 435–458; L, L/H ratio, relative L [% total L] palp segments: P-1, 68–75, 1.56–2.14, 15–16; P-2, 73–81, 1.81–2.03, 17–18; P-3, 73–80, 1.76–2.00, 16–18; P-4, 168–178, 5.38–6.09, 38–40; P-5, 45–50, 3.00–3.64, 10–11. L ratio P-2/-3, 0.94–1.12; P-2/–4, 0.43–0.46; P-3/-4, 0.41–0.46. Leg segments L/H, L/H ratio: I-L-2, 110– 125, 1.63–1.92; I-L-3, 120–135, 1.78–1.93; I-L-4, 175–195, 2.69–2.88; I-L-5, 195–215, 3.57–3.91; I-L-6, 170–190, 2.92–3.14; claw L 45–50. II-L-2, 140–150, 1.93–2.07; II-L-3, 140–158, 2.07–2.25; I-L-4, 245–263, 3.77–4.16; II-L-5, 240–265, 4.08–4.61; II-L-6, 195–225, 3.00–3.55; claw L 50–53. III-L-2, 110–125, 1.64–1.92; III-L-3, 130– 140, 2.08–2.17; III-L-4, 225–235, 3.75–4.23; III-L-5, 225–240, 4.09–4.84; III-L-6, 195–220, 3.25–3.87; claw L 50–60. IV-L-2, 150–170, 2.07–2.36; IV-L-3, 175–190, 2.50–2.71; IV-L-4, 305–325, 4.77–4.88; IV-L-5, 260–300, 4.52–5.45; IV-L-6, 235–250, 3.62–4.26; claw L 58–63. Total L segments 2–6: I-L, 785–840; II-L, 985–1048; III-L, 905–950; IV-L, 1145–1210.
Derivatio nominis: The climbing plant Vanilla (Orchidaceae), of great importance in Madagascan agriculture. The name is a noun in apposition.
Remarks: In comparison with the previously described species of the subgenus, the same differences are found in T. vanilla as discussed above for T. ravenala. In addition to generally smaller measurements of idiosoma and mouthparts (as given in the diagnosis, see above), the latter (in parentheses) differs from T. vanilla in stouter palp segments (L/H P-2 <1.7, P-3 <1.8; P-4 <4.8), a lower number of acetabula in females (9–17 pairs) and the pointed proximoventral extension of leg claws. A further difference is found in comparatively longer legs (only females measured in T. vanilla, Σ L segments 2–6, T. ravenala in parentheses): I-L 785–840 (613–725); II-L 985–1048 (718–923); III-L 905–950 (660–785); IV-L 1145–1210 (860–1113), with more slender segments IV-L-3, L/H 2.5– 2.7 (2.2–2.4), and IV-L-4, L/H 4.8–4.9 (4.1–4.8). Differences in comparison to T. scutulatus from the Comoros are discussed above, under T. ravenala.
Habitat: Weakly seeping helocrenic springs.
Distribution: Madagascar, endemic. Only found in a restricted area around 1000 m a.s.l., in the central part of the eastern rainforest belt.
description: Published as part of Gerecke, Reinhard, 2020, The early derivative water mites (Acari: Hydrachnidia, superfamilies Eylaoidea, Hydrachnoidea and Hydryphantoidea) of Madagascar, pp. 1-77 in Zootaxa 4727 (1) on pages 63-64, DOI: 10.11646/zootaxa.4727.1.1, http://zenodo.org/record/3613302