Atractides (Atractides) ermilovi, Pesic, Vladimir, Semenchenko, Ksenia A. & Lee, Wonchoel, 2015

Pesic, Vladimir, Semenchenko, Ksenia A. & Lee, Wonchoel, 2015, Further studies on water mites from Korea, with description of two new species (Acari, Hydrachnidia), ZooKeys 507, pp. 1-24 : 7-10

Taxon classification Animalia Trombidiformes Hygrobatidae

Atractides (Atractides) ermilovi sp. n. Fig. 11

Type series.

Holotype male (NIBR), dissected and slide mounted, SOUTH KOREA: CR19 Chungcheongbuk Province, Sobaeksan NP, shaded stream, 36°57.660'N, 128°25.534'E, 24.v.2013 Pešić & Karanović.

Diagnosis

(Female unknown). Median suture line relatively Cx-I+II long (> 100 μm); acetabula large (maximum diameter> 50 μm) in triangular position; ven trodistal protrusion of P-2 conus- shaped; S-1 distally truncated, S-2 thicker and shorter, small setal interspace (8 μm): I-L-6 short (L I-L-5/6 ratio 1.59) and stout (L/H ratio 5.0).

General features.

Integument striated, muscle insertions unsclerotized. Coxal field: caudal margin Cx-I straight, apodemes of Cx-II directed laterally. Genital field: anterior margin of primary sclerotization slightly concave, but secondary sclerotization forming narrow semicircular border, posterior margin slightly indented, Ac in triangular position (Fig. 11A). Excretory pore smooth; Vgl-1 not fused to Vgl-2. Palp (Fig. 11 C–D): strong ventrodistal protrusion of P-2; P-3 weakly concave proximally; P-4 sword seta between ventral setae, but approached to distoventral seta. I-L-5 (Fig. 11B): dorsal and ventral margins subparallel basally and centrally but diverging near the distal edge, S-1 and -2 close together, S-1 distally truncated, S-2 thicker and shorter, bluntly pointed; I-L-6 stout and curved, basally thickened, distally equally narrowed.

Measurements - Idiosoma L/W 550/425; coxal field: L 319; Cx-III W 366; Cx-I+II mL 121, lL 231; genital field L/W 112/120, L Ac 1-3: 34, 42, 51-55.

Palp: Total L 289, dL/H, dL/H ratio: P-1, 31/25, 1.25; P-2, 66/51, 1.3; P-3, 62/44, 1.39; P-4, 96/26, 3.67; P-5, 34/13, 2.5; L P-2/P-4 ratio 0.96.

Legs: I-L-5 dL 171, vL 132, dL/vL ratio 1.3, maximum H 48, dL/maximum H 3.59, S-1 L 77, L/W ratio 8.4, S-2 L 65, L/W ratio 6.0, distance S-1-2, 8, L ratio S-1/2, 1.19; I-L-6 dL 108, central H 22, dL/central H ratio 5.0; dL I-L-5/6 ratio 1.59.

Female: unknown.

Etymology.

Named after Dr Sergey Ermilov (Tyumen, Russia), for his contribution to the taxonomy of oribatid mites.

Remarks.

The new species resembles Atractides samsoni (Sokolow, 1936) in the small S-1/2 interspace, I-L-6 stocky, postgenital area with smooth excretory pore and unfused Vgl-1/2 and a palp with a conus shaped ventrodistal protrusion in male. The latter species can be distinguished by the shorter medial suture line of Cx-I, smaller acetabula, more slender S-1 and -2, and I-L-6 only weakly curved and longer (see Gerecke 2003). Males of Atractides constrictus (Sokolow, 1934), a species similar in the shape of palp (double ventral protrusion on P-2), a larger Ac (maximum diameter> 39 μm), and I-L-6 relatively short compared to I-L-5 (L I-L-5/6 ratio 1.4-1.6), differ in wider setal interspace on I-L-5, I-L-6 more slender and more narrow centrally, P-4 ventral setae inserted more closely to each other and genital field deeply indented both anteriorly and posteriorly.

Habitat.

A permanent sandy/bouldary stream, shaded by riparian vegetation (Fig. 13B).

Distribution.

Korea, only known from the locus typicus.