Unionicola (Vidrineatax) pilosa, Smit, Harry, 2008

Smit, Harry, 2008, Australian Unionicola (Acari: Hydrachnidia: Unionicolidae), with the description of two new subgenera and eight new species, Zootaxa 1674, pp. 1-26 : 21-22

Unionicola (Vidrineatax) pilosa n. sp.

( Figs. 36–41 )

Material examined. Holotype female, Hann Crossing (stagnant), Lakefield NP, Queensland, Australia, 14° 45’57.30”S 144° 04’46.60”E, 4 September 2000 (QM). Paratypes: 1 male (QM), 1 female ( ZMAN), 4 nymphs (QM, ZMAN), same data as holotype; 2 females, Geikie Gorge, western part, Geikie Gorge NP, Western Australia, Australia, 18° 7’23.92”S 125° 39’42.47”E, 28 September 1998 ( WAM).

Diagnosis. As for subgenus.

Description. Female: Idiosoma elongate, 812 (802–844) long and 535 (510–676) wide. Dorsum with two platelets in anterior half. Posterior apodemes of anterior coxal plates wide, extending beyond anterior margin of third coxal plates. Lengths of third + fourth coxal plates 381. Posterior margin of fourth coxal plates directed obliquely to lateral idiosoma margin. Posterior margins of fourth coxal plates with blunt, short extensions. Coxal plates without a reticulate pattern. Genital field terminal, with four genital plates. Each anterior plate with 5–6 (in paratypes 6–7) acetabula and two enlarged setae, each posterior plate with 9–11 acetabula and one enlarged seta; not all acetabula of posterior plates visible in ventral view. Lengths of PI-PV: 16, 118, 60, 108, 64. Palp stocky, ventral margin of PII convex. PIV with two ridges each with a short seta; ventrodistal peg-like seta of PIV blunt, on a short tubercle; PV bifurcate. Lengths of I-leg-4-6: 224, 188, 110. I-leg-6 dorsodistally with an enlarged blunt seta, I-leg-5 and -4 somewhat swollen. Lengths of IV-leg-4-6: 227, 284, 247. Fourth leg with numerous long and short setae, ventral short setae blunt. III-leg-4 with two long setae, III-leg- 5 and IV-leg-4 with three long setae, which probably act as swimming setae. Moreover, IV-leg-4 ventrally with four long setae, the two posteroventrally not illustrated because they are located at the same position as the three swimming setae. IV-leg-5 ventrally with three such long setae. Heavy setae of legs finely grooved. Claws with clawlet and without claw blade.

Male: Idiosoma 1045 long and 648 wide. Dorsum with two platelets in anterior half. Posterior apodemes of anterior coxal plates extending beyond anterior margin of third coxal plates. Lengths of third + fourth coxal plates 470. Posterior margin of fourth coxal plates directed obliquely to lateral idiosoma margin. Posterior margins of fourth coxal plates with a short extension. Coxal plates with a reticulate pattern. Genital field terminal, gonopore 112 long. Genital plates fused dorsally and ventrally. Each side with 27 acetabula, a group of nine acetabula ventrally, with one larger acetabulum, and a group of 18 acetabula dorsally. Lengths of PI-PV: 20, 176, 70, 142, 90. Palp as female, except setal tubercles of PIV: instead of two ridges two setal tubercles are present, a short, ventral tubercle and a larger, more lateral tubercle. Lengths of I-leg-4-6: 275, 211, 150. Lengths of IV-leg-4-6: 247, 324, 308. Legs as in female, but setae heavier and IV-leg-5 with four swimming setae.

Nymph: Idiosoma elongate, 446-510 long and 267-332 wide. Morphology as in adult, but legs with less setae. III-leg-4 and -5 and IV-leg-4 and -5 with two swimming setae. Provisional genital field with two pairs of acetabula.

Etymology. Named for the numerous leg setae.

Remarks. No other Australian Unionicola species has numerous acetabula. In Harvey (1998) the new species keys out on Neumania .

Figures

FIGURE 36 – 39. Unionicola pilosa n. sp., holotype female, 36, ventral view; 37, palp; 38, I-leg- 4 - 6; 39, IV-leg- 4 - 6. Scale bars = 50 µm.

FIGURE 40 – 41. Unionicola pilosa n. sp., paratype male, 40, genital field; 41, palp. Scale bars = 50 µm.