Wuria milloti, Gerecke, 2004

Gerecke, Reinhard, 2004, The water mites of Madagascar (Acari, Hydrachnidia): a revised list completed by original material conserved at the Muséum national d’Histoire naturelle, Paris, Zoosystema 26 (3), pp. 393-418 : 406

Wuria milloti n. sp.

( Figs 7-9 )

TYPE MATERIAL. — Holotype, mounted in glycerine jelly together with one paratype, northwest, Ankarana, IX.1946, J. Millot (A 20 J); further paratypes: northwest, Ankarana (marais), IX.1946, J. Millot, 2, 1 (A 01 D).

ETYMOLOGY. — Named in honour of J. Millot, the collector of a large part of the water mites dealt with in this paper.

DIAGNOSIS. — Coxae with fine porosity, but a stripe of idiosoma surface with large pores separating the medial margins of cx-3/4 as well as the facing margins of cx-2 and cx-3; distinct, nose-shaped projections associated with the insertions of IV-L; palpus robust, with very stout setae; P-4 curved (dorsal margin convex, ventral margin concave); IV-L showing sexual dimorphism.

DISTRIBUTION. — Northwest Madagascar.

DESCRIPTION

Both sexes

Surface of coxae and appendages with a fine, regular porosity, surface of idiosoma shields ( Fig. 7A ) covered by groups of these pores, each joined to a larger subcutaneous cavern by fine channels; a stripe of idiosoma surface with large pores extending between the medial margins of cx-3/4 as well as the facing margins of cx-2 and cx-3; legs with pointed distal extensions at distal margins of segments 2-5; III- and IV-L (see Figs 8B ; 9 ) bearing numerous swimming hairs; genital field completely lacking surface porosity, but many acetabula in the genital field linked in a similar manner as the idiosomal pores in groups of two to four each to a subcutaneous cavern, gnathosoma ( Fig. 8A ) flattened and enlarged rostrally, with a robust chelicera bearing a strongly hooked claw; palp with eight stout setae scattered on the medial surface of P-2 and one remarkably strong seta inserted at the base of the ventrodistal extension of P-4; P-5 curved and directed medially.

Male

Idiosoma L/W 630-650/520-550; dorsal furrow incomplete (dorsal shield posteriorly fused with ventral shield), maximum W 400-410; distance between projections near insertion IV-L 500- 545; IV-L ( Fig. 9 ) with long and stout setae at distal margins of segments 3-5; IV-L-2-5 dorsal L 95, 115, 125, 160; genital field L/W 180- 200/310-315; gonopore short and narrow, flanked by a group of fine setae (see Fig. 7A ), L/W 50-55/25-32 (gnathosoma not measured due to unsuitable position in preparations).

Female

Idiosoma L/W 800/710; dorsal furrow complete, dorsal shield L/W 710-720/570-590; distance between projections near insertion IV-L 630; setae on distal margins of IV-L-3-5 distinctly shorter than in males ( Fig. 8B ); IV-L-2-6 dorsal L 110, 110, 155, 175, 180; genital field L/W 300-310/430-510; gonopore large, flanked by a line of fine setae ( Fig. 7B ), L/W 125-140/100- 140; gnathosoma L 140-160; chelicera basal segment 100, claw 55, maximum H 55; palp segments L/H P-1 25/50, P-2 65/60, P-3 50/52, P-4 80/43, P-5 30/18.

DISCUSSION

W. milloti n. sp. differs from W. falciseta K. Viets, 1916 , from continental Africa, in the presence of a stripe of sclerite surface with larger pores extending between the medial margins of cx-3+4 and the facing margins of cx-2/3, and in the distinctly thicker palpal setae. W. sumatrensis K. Viets, 1935 , a species known from the female sex only, is similar to W. milloti n. sp. in the presence of sclerite stripes with larger pores between coxal plates, but has a more slender palp. W. boutit Harvey, 1989 from Australia differs in having the acetabula arranged in more narrow rows. The characters of W. expansipalpis Smit, 2002 from New Caledonia differ greatly from all other species of the genus – from many points of view the described female resembles Arrenurus . As previously no attention has been paid to details of leg shape and setation in the genus, it is still unclear if the sexual leg dimorphism in W. milloti n. sp. is limited to this species.

Figures

FIG. 7. — Wuria milloti n. sp.; A,, ventral view; B,, genital field. Scale bar: 100 µm.

FIG. 8. — Wuria milloti n. sp.,; A, gnathosoma, chelicera and palp in medial view; B, fourth leg. Scale bar: 100 µm.

FIG. 9. — Wuria milloti n. sp.,