Javalbia (Javalbia) vietnamica, 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 : 422-424

Javalbia (Javalbia) vietnamica n. sp.

( Figure 19 )

Type material — Holotype male, dissected and slide mounted, Vietnam, 15-41-1, Bach MAE National Park, 5-falls-brook, 16°11’33"N, 107°51’21"E, alt. 1210 m a.s.l., pool with detritus of leaves, 1.v.2015.

Diagnosis — Anterior lateroglandularia fused with dorsal shield; postocularia lying much closer and at the same level of glandularia pair; genital field with four pairs of acetabula; I-L-6 distally strongly tapering.

Description — Male: Idiosoma egg-shaped. Posterior margin of the dorsal shield forming an indistinct cauda. Dorsal shield flanked by three pairs of lateroglandularia in posterior half of the dorsal furrow, anterior lateroglandularia fused with dorsal shield ( Figure 19A ): postocularia at the same level of glandularia pair; A2 fused with dorsal shield. Genital field with four pairs of acetabula ( Figure 19B ). Genital field fused with ventral shield, suture lines indistinct. Palp slender, P-2 ventral margin straight, P-3 ventral margin concave, P-4 with convex dorsal and almost straight ventral margins bearing two fine ventral setae (one of them elongated) ( Figures 19 C-D). Glandularia (Vgl-4) flanking genital field on enlarged platelets in posterolateral indentations of the ventral shield. Excretory pore on a transverse oval platelet immediately posterior to genital field. Legs: I-L-6 distally strongly tapering; swimming setae absent.

Measurements — Dorsal shield L/W 442/303; ventral shield (including genital field) L/W 422/369, gnathosomal bay 88; W between the most lateral pair of Ac 109, gonopore L/W 43/30, ratio 1.43; ejaculatory complex L 81. Palp: total L 183, dL/H, dL/H ratio: P-1, 22/15, 1.5; P-2, 39/26, 1.49; P-3, 31/22, 1.44; P-4, 62/15, 4.1; P-5, 29/8, 3.4; L ratio P-2/P-4, 0.63; gnathosoma vL 69; chelicera total L 123. Legs: dL of I-L: 35, 29, 42, 51, 54, 52; dL of IV-L: 75, 48, 65, 69, 71, 68. Female: Unknown.

Etymology — Named after the country where the new species was found.

Remarks — Due to the presence of four pairs of acetabula the new Javalbia species from Vietnam should be assigned to the subgenus Javalbicula K.O. Viets, 1974 . This subgenus includes three species, i.e. J. lata K. O. Viets & Böttger, 1974 ( South Africa), J. turcica Esen , Peši´c & Erman, 2011 ( Turkey) and J. ovata Kim & Chung, 1996 ( Korea) . Recently, Smit (2016) proposes to synonymize Javalbicula with Javalbiopsis Cook , and to transfer the two four-acetabulate species having the excretory pore on a separate platelet (i.e., J. ovata and J. siamis Smit, 2016 ) to Javalbia s.s. The new species from this study can be separated from J. ovata in I-L-6 distally strongly tapering (equally narrowed in J. ovata , see Kim and Chung 1996). Javalbia siamis from Thailand differs from the species from our study in freelying anterolateral dorsal glandularia and the postocularia distanced and posteromedially from the nearest pair of dorsal glandularia ( Smit 2016).

Distribution — Vietnam; known only from the locus typicus.

Figures

FIGURE 19: Javalbia (Javalbia) vietnamica n. sp., male, Bach MAE National Park, Vietnam: A – dorsal shield; B – ventral shield; C – palp (P-1 lacking); D – palp; E – gnathosoma; F – ejaculatory complex; G – I-L-2-6. Scale bars – 100 µm.