Brachypoda milicaae, Pešić, Vladimir & Semenchenko, Ksenia, 2014

Pešić, Vladimir & Semenchenko, Ksenia, 2014, Water mites of the genus Brachypoda Lebert, 1879 (Acari: Hydrachnidia: Aturidae) from South Korea and the Russian Far East, Zootaxa 3753 (4), pp. 335-346 : 336-337

Brachypoda milicaae sp. n.

( Figs. 1A–D , 2A–B )

Material examined. Holotype male ( NIBR), dissected and slide mounted, SOUTH KOREA: CR9 Ne myeon Mt, Naebyeansan NP, stream near Naebyeansan Info Center, 35°38'25.623" N, 126°34'53.1438"E, 10.x.2012, Pešić & Choi. Paratypes ( NIBR): two males, same data as holotype, fixed in Koenike-fluid.

Diagnosis (Female unknown). Tip of Cx-I extending beyond frontal idiosoma margin; IV-L-5 dorsal margin strongly bowed, in proximal half with a group (about 10) heavy, short ventral setae; IV-L-6 with one long whip-like seta inserting at distal margin, anterior claw slightly longer than posterior claw.

Male (holotype): Idiosoma L/W 423/322; dorsal shield L/W 416/288, excretory pore and flanking glandularia on dorsal shield, near posterior margin ( Fig. 1A ). Tip of Cx-I extending beyond frontal idiosoma margin ( Fig. 1B ); distance tip Cx-I – gonopore 297; gnathosomal bay L 87; distance between IV-L insertions 146; posterior margin of Cx-IV forming a transverse ridge, in medial part with a pair of blunt tips. No ridges anterolaterally to genital field, gonopore L/W 37/38, in a deep pit surrounded in distal part by sclerotized lips and laterally flanked by acetabula arranged in a curved line, scattered fine setae surrounding the acetabular field. Gnathosoma vL 58, L with apodemes 80; chelicera ( Fig. 1D ) total L 121, basal segment L 88, claw L 39. Palp ( Fig. 1C ): total L 220, L/H, ratio L/H: P-1, 29/18–19, 1.5–1.6; P-2, 46/32, 1.44; P-3, 37/28, 1.34; P-4, 77/25, 3.0; P-5, 31/10, 3.1; P-1 with one dorsal seta; P-2 with a long, apically rounded distoventral extension; P-3 ventral margin concave; P-4 proximally narrow, in the centre, near the insertion of two setae slightly elevated to form an obtuse projection near the insertion of the stronger ventral seta, a finer seta laterally on a further blunt elevation. Legs: IV-L-4–6 as shown in Figs. 2A– B ; IV-L-4 strongly widened from base to tip, IV-L-4 L/H 65–66/51–54, ratio 1.23–1.27; IV-L-5 enlarged, dorsal margin strongly bowed, ventral margin concave, in proximal half with a group (about 10) of heavy and short setae, distal margin with several strong setae, three of these very long, whip-like, IV-L-5 L/H 130–131/56–57, ratio 2.3; IV-L-6 with a basal kink, one long whip-like seta inserting at distal margin, IV-L-6 L/H 103–107/27–28, ratio 3.7– 4.0; anterior claw slightly longer than posterior claw.

Female: Unknown.

Etymology. Named after Milica Pešić, the mother of the senior author.

Discussion. The only further known species of the subgenus Ocybrachypoda Cook, 1974 from the Palaearctic, Brachypoda celeripes K. Viets, 1910 , from northern Germany, Ireland and Poland differs from the new species in: 1) anterior margin of Cx-I on the level or slightly extending beyond the frontal idiosoma margin, 2) IV-L-5 more slender, dorsal margin equally convex, ventral setae in proximal half slender, more peg-like, 3) IV-L-6 with two long whip-like setae inserting at distal margin, anterior claw> 1.5 times longer than posterior claw, and 4) at least three long whip-like setae at the lateral margin of genital field.

Males of Brachypoda sokolowi sp. n. (see below) from the Far East of Russia resemble B. milicaae sp. n. (and differ from B. celeripes ) due to the anterior margin of Cx-I extending well beyond the frontal idiosoma margin, and IV-L-5 more enlarged, with the ventral setae in proximal half more stout. Brachypoda sokolowi sp. n. differs from B. milicaae sp. n. in: 1) IV-L-6 with two long, whip-like setae inserting at distal margin, anterior claw 1.5 times longer than posterior claw, 2) distal setae on IV-L-4 longer and more pointed, 3) three or four long curved setae at the lateral margin of genital field. Moreover, males of Brachypoda sokolowi sp. n. can be distinguished from B. celeripes and B. milicaae sp. n. in having one toothed seta inserting at distal margin of IV-L-6.

Among the North American members of the subgenus, i.e. Brachypoda oakcreekensis Habeeb, 1961 (Arizona, New Mexico, California), B. setosicaudata Habeeb, 1953 (New Brunswick, New Jersey, Maine), B. acuticaudata Habeeb, 1953 (Michigan, New Brunswick, Maryland) , B. fimbricaudata Cook, 1975 (Pennsylvania) , B. affinis Cook, 1975 (Virginia) , B. coerulea Cook, 1981 (California) , B. laversi Cook, 1981 (California) , B. ojaiensis Cook, 1981 (California) , the new species from South Korea somehow most resembles B. oakcreekensis and B. ojaiensis . The latter two species can easily be distinguished from new species in 1) anterior margin of Cx-I ending posterior to level of frontal idiosoma margin, 2) cauda slightly narrowed posteriorly, 3) IV-L-5 more slender and with dorsal margin equally convex, with scattered, longer and more peg-like, ventral setae, and 4) lateral margin of genital field with a few long setae (see Cook 1975 for B. oakcreekensis , and Cook 1981 for B. ojaiensis ).

Habitat. A permanent sandy/bouldary stream, shaded by riparian vegetation ( Fig. 9C ).

Distribution. South Korea, known only from the locus typicus.

Figures

FIGURE 1 A – D. Brachypoda milicaae sp. n., male: A = dorsal shield; B = idiosoma, ventral view; C = palp; D = chelicera. Scale bars = 100 µm.

FIGURE 2 A – B. Brachypoda milicaae sp. n., male: A = IV-L; B = IV-L- 4 – 6. Scale bar = 100 µm.

FIGURE 9 A – E. A – B Photographs of Brachypoda rubidata Kim & Chung, 1996, male: A = idiosoma, ventral view; B = idiosoma, dorsal view. C – E Photographs of sampling sites: C = CR 9 (stream in Naebyeansan NP, South Korea, locus typicus of Brachypoda milicaae sp. n.; D = CR 10 (pool near stream in Naebyeansan NP, South Korea, sampling site of Brachypoda rubidata Kim & Chung, 1996); E = Levaya Burinda River, Russia, locus typicus of Brachypoda sokolowi sp. n. and B. rossica sp. n. Photos. V. Pešić (Figs. A – D), K. Semenchenko (Fig. E).