Atractides loricatus Piersig, 1898

Gerecke, Reinhard, 2014, The water mites of the genus Atractides Koch, 1837 (Acari, Hydrachnidia: Hygrobatidae) in Corsica and Sardinia, Zoosystema 36 (4), pp. 735-759 : 753

Atractides loricatus Piersig, 1898

MATERIAL EXAMINED. — Sardinia. I 361, 1 ♀ ; I 364b, 1 ♂, 2 ♀♀; I 1159, 9 ♀♀; I 1161, 7 ♀♀ ( Coll. RG). First records from the area covered .

DISTRIBUTION. — Central and Southern Europe, from the Pyrenees to the Carpathians. First records from the area covered.

HABITAT. — Crenobiont. In the area covered only in the upper Gennargentu mountains of Sardinia, in rheohelocrenic springs from 1000 to 1550 m.

REMARKS

All specimens agree in idiosoma sclerotization and setation of appendages with specimens from continental Europe ( Gerecke 2003), but differ in measurements and proportions of I-L-5/6 (both segments longer, L ratio I-L-5/6> 4.3, setae S-1/-2 longer and more distanced, and P-3/-4 (more slender). Furthermore, the female genital plates are more elongate, with acetabula arranged in a weakly curved line while they are triangular in central European specimens. Before weighting the genetical significance of these differences, more information is necessary on variability in the still understudied central European populations. In the following, I give a survey of measurements of the Sardinian specimens.

Males

Idiosoma L/W 480/350, coxal field L/W 280; further coxae measurements impossible due to damage. I-L-5 dL/vL 145/115, ratio 1.26; HA 36, HB 43, HC 48, ratio dL/HB 3.4; S-1 L/W 71/7, ratio 10,5; S-2 L/W 63/10, ratio 6.6; distance S-1-2, 10, L ratio S-1/-2, 1.1; I-L-6 dL 103, HA 26, HB 18, HC 24; ratio dL/HB 4.6; dL ratio I-L-5/6, 1.41. Genital field L/W 105/110. Palp total L 290; L/H (ratio, rel. L [%]) P-1, 28/23 (1.2, 9); P-2, 61/48 (1.3, 21); P-3, 69/38 (1.8, 24); P-4, 100/32 (3.1, 34); P-5, 23/13 (2.9, 11); L ratio P-2/P-4, 0.61; P-3/P-4, 0.69.

Females

Idiosoma L/W 590-650/400-530, coxal field L/W 280-320/330-370; Cx-I+II medial L 100-115, lateral L 195-225, W 275-295. I-L-5 dL/vL 163- 175/125-138, ratio 1.3; HA 38-43, HB 48-53, HC 53-58, ratio dL/HB 3.3-3.5; S-1 L/W 79-85/7-8, ratio 11.0-12.1; S-2 L/W 70-78/9-10, ratio 7.0-8.9; distance S-1-2, 10-13, L ratio S-1/-2, 1.1-1.2; I-L-6 dL 108-118, HA 29-30, HB 24-25, HC 23-26; ratio dL/HB 4.5-4.7; dL ratio I-L-5/6, 1.42-1.53. Genital field L/W 165-180/160-170, genital plates L/W 100-110/30-40. Palp total L 313-340; L/H (ratio, rel. L [%]) P-1, 28-33/24-25 (1.1-1.3, 9-10); P-2, 66-73/45-50 (1.4-1.5, 21-22); P-3, 80-88/36- 41 (2.1-2.2, 25-26); P-4, 105-113/26-29 (3.8-4.0, 33-34); P-5, 31-35/11-12 (2.7-2.9, 10); L ratio P-2/P-4, 0.63-0.64; P-3/P-4, 0.76-0.80.