Forelia (Forelia) gereckei, Pešic & Smit, 2016

Pešic, V. & Smit, H., 2016, New records of water mites from Southeast Asia (Acari: Hydrachnidia) with the description of two new genera and 12 new species, Acarologia 56 (3), pp. 393-433 : 412

Forelia (Forelia) gereckei n. sp.

( Figure 12 )

Type material — Holotype female, dissected and slide mounted, Laos, 15-32-1, Kouangxi Waterfall , pond behind a artificial barrier within a branch near the main brook, 19°44’56"N, 101°59’33"E, alt. ca. 490 m a.s.l., water depth 0.4 m, substrate: travertine mud covered by a thick layer of leaves, 21.iv.2015 . Paratypes: 0/2/0, same data as holotype.

Diagnosis — (Male unknown). Anterior margin of idiosoma medially concave; genital plates with 13-16 pairs of acetabula; ventral margin of P-4 without setal tubercles, with setae located close to each and a blunt, peg-like mediodistal setal; leg claw and clawlet blunt.

Description — Female: Colour yellow with brown markings; anterior margin of idiosoma medially concave or straight, dorsum with three pairs of platelets, anterior platelets oblong, central platelets slightly more lateral and irregularly rounded, posterior platelets small, close to each other ( Figure 12A ). Genital plates slightly extended anteriorly with 13-16 pairs of acetabula, medial margin straight or slightly concave, pregenital sclerite large; excretory pore on platelet. P-4 stocky, ventral margin of P-4 with setae located close to each other, without setal tubercles ( Figures 12 C-D), distal margin with a short blunt seta; P-5 around 70 % L of P-4. Legs: number of swimming hairs: II-L- 4, 3; II-L-5, 4; III-L-4, 4; III-L-5, 6; IV-L-4, 3; IV-L-5, 5; claws of I-L large, claw and clawlet blunt.

Measurements — Idiosoma L/W 709/530; coxal field L/W 267/400; genital plate L/W 109-113/78; gonopore L 134, pregenital sclerite W 78; egg maximum diameter (n – 2) 147. Palp: total L 236, dL/H, dL/H ratio: P-1, 27/34, 0.78; P-2, 69/41, 1.68; P-3, 37/33, 1.12; P-4, 60/25, 2.4; P-5, 43/19, 2.3; dL ratio P-2/P-4, 1.15; gnathosoma (with posterior anchoral process) vL 93; chelicera total L 122, claw L 38, basal segment L 84, L basal segment/claw ratio 2.2. Legs: dL of I-L: 45, 43, 55, 61, 66, 89; dL/H I-L-6 ratio 2.8.

Etymology — Named after Reinhard Gerecke (Tübingen) in appreciation of his studies of water mites.

Remarks — Due to the similar morphology of the dorsum (three pairs of platelets), genital plates (medial margin extended anteriorly) and palp (P- 4 without setal tubercles) the specimens from Laos resemble Forelia flexipoda Jin, 1995 from Guizhou, China. The latter species differs in larger dimensions of idiosoma and palps, medially projecting anterior margin of idiosoma, a very small mediodistal peg-like seta of P-4, claws of I-L pointed (Jin 1999: figure 9) and in the increased number of acetabula (26-27 pairs, from Jin 1995).

Distribution — Laos; known only from the locus typicus ( Figure 25B ).

Figures

FIGURE 12: Forelia (Forelia) gereckei n. sp., female, Kauangxi Waterfall, Laos: A – idiosoma, dorsal view; B – idiosoma, ventral view; C – palp (P-1 lacking); D – palp; E – gnathosoma and chelicera, lateral view; G – I-L-5 and -6. Scale bars – 100 µm.

FIGURE 25: Photoghraphs of sampling sites: A – Laos, Kauangxi Waterfall (locus typicus of Monatractides laosensis n. sp., Hexaxonopsis laosensis n. sp., Sinaxonopsis laosensis n. sp. and Africasia purpurea n. sp.); B – Laos, Kouangxi Waterfall, pond behind artifical barrier (sampling site of Hygrobates hamatus K. Viets, 1935, H. henni Wiles, 2004 and locus typicus of Forelia gereckei n. sp.); C – Vietnam, Bach MAE National Park, brook with a pool (sampling site of Monatarctides sp. and locus typicus of Limnesia scharfi n. sp., Schwoerbelia pioniformis n. sp. and Arrenurus contortus n. sp.; D – Cambodia, moat around the main Angkor temple (locus typicus of Hexaxonopsis