Atractides (s. str.) asticae Petrova, 1968

Gerecke, Reinhard, 2021, The water mites of the family Hygrobatidae (Acari, Hydrachnidia) in Italy, Zootaxa 5009 (1), pp. 1-85 : 12-13

Atractides (s. str.) asticae Petrova, 1968

(Fig. 5)

Material examined: Sicilia: Madonie (PA), I 510 Int 2, Fiume Pollina upstr. Fiume Buonanotte , 50 m, UTM. VC 2704, 14.10.1986, Karaman-Chappuis dig in gravel, 1 ♀, slide .

Description: Female from Sicily: Idiosoma L/W 590/330. Integument (irregularly) striated; no lateral eye pigment visible; dorsum with four pairs of sclerites, probably representing (from anterior to posterior): (1) (Dgl- 2+postfrontale+postoculare+D-1), L 72; (2) (Dgl-3+D-2), not measured; (3) (Dgl-4+D-3), L 62; (4) (D-4 + Dgl-5, fusion in the studied specimen not clearly visible), L 42; posteroventral muscle insertions unsclerotized; diameter of glandularia not fused to muscle attachments, about 25. Vgl-1+2 fused, excretory pore on a round plate, diameter 22. Coxal plates in three groups, elongate, with a very fine porosity. Coxal field L/Cx-III W 260/250, Cx-I+II mL 112, lL 195, W 183 (mL/W ratio 0.61). Posterior margin of Cx-I+II truncate, W 26, posterior apodemes of Cx-I short and strongly curved. Posterior margin of Cx-IV nearly straight, perpendicular to body axis. Genital field elongate, L 163, with genital plates short (L/W 68/35, ratio 1.93), subtriangular, located far posterior and flanking the postgenital sclerite (triangular as well, with posteriorly-directed rounded tip, fine porose); Ac in triangular arrangement, small, maximum diameter Ac-1, 15; Ac-2, 14; Ac-3, 18; pregenital sclerite slender, slightly curved, with rounded lateral tips. I-L-4-6: Fig. 5 B. I-L-5 stout, dL/vL 115/93, ratio 1.24, dorsal and ventral margins not remarkably diverging, ventral seta inserting far proximally (distance to distoventral edge 62 % vL); HA 38, HB 38, HC 35, ratio dL/HB 3.1. L (L/W) S-1, 48 (9.5), S-2, 43 (6.8), inserted close to each other (distance 3), ratio S-1 L/distance S-1-2, 19. S-1 longer and slenderer than S-2, both with obtuse tips. I-L-6 stout and weakly curved, in the centre slightly narrowed, L 98, HA 23, HB 21, HC 25, ratio L/HB 4.6; ratio I-L-5 dL/ I-L-6 L 1.2. Mouthparts: Fig. 5 A. Gnathosoma L 100; chelicera L 205, slender, with elongate basal segment (L/H 7.5, basal segment/claw ratio 2.7). Palp total L 245; proportions of segments (L/H, ratio, % total L): P-1, 23/26, 0.9, 9; P-2, 63/48, 1.3, 26; P-3, 65/44, 1.5, 27; P-4, 68/20, 3.4, 28; P-5, 28/8, 3.7, 11; L ratio P-2/P-3, 0.96, P-2/P-4, 0.93; P-3/P-4, 0.96. P-1 with distally strongly diverging ventral and dorsal margins, P-2 ventral margin straight, at distal edge ending in a fine, acute angled tip; P-3 ventral margin straight, P-4 dorsal margin in the studied specimens crushed (H value not representative), maximum H on the level of proximoventral seta, sword seta inserting here (64 % vL from distal end); setae insertions dividing ventral margin into subequal sectors (relative length in %: 35/30/35).

Remarks: Atractides asticae has never been found again since its first description from the River Véléka basin in Bulgaria. The specimen from Sicily agrees widely with the original description, except for relatively smaller dorsal sclerites. It differs from the closely related A. longiporus Petrova, 1968 (synapomorphy: location of the ventral seta IV-L- 5 in proximal half of segment) in the slenderer P-3 and Ac in a triangular arrangement.

Habitat: Hyporheobiont.

Distribution: Bulgaria, Sicily. First record from Italy.