Arrenurus (Megaluracarus) chutteri longipes, Smit, 2012

Smit, H., 2012, New records of the water mite family Arrenuridae from the Afrotropical region, with the description of 11 new species and two new subspecies (Acari: Hydrachnidia), Zootaxa 3187, pp. 1-31 : 11

Arrenurus (Megaluracarus) chutteri longipes n. subsp.

( Figs. 25–29)

Material examined. Holotype male, ditch along Okavango Swamp at Drotsky’s Camp, S of Shakawe, Botswana, 18° 25’ 24,20 S 21° 53’ 28.17 E, 23-vii-1996 ( RMNH) . Paratypes: four males, two females (one young), same data as holotype ; one male, one female, tributary of Okavango River near Drotsky’s Camp, south of Shakawe, Botswana, 23-vii-1996 ( RMNH) .

Diagnosis. IV-leg-6 long; genital plates of male widened laterally and extending well onto dorsum; median cleft of cauda wide. Genital plates of female wing-shaped, widened laterally.

Description. Male: Idiosoma brownish, 887 (859–915) long and 518 (502–526) wide, lateral margin swollen anterior of genital plates. Anterior idiosoma margin straight to slightly concave. Dorsal furrow incomplete, passing onto cauda. Dorsal shield 348 (340–365) wide. Cauda distinct, with distinct posterolateral corners. Cauda posteriorly with a wide medial cleft; in anterior part of this cleft the so-called rudimentary petiole and two small setae. Cleft posteroventrally with two rounded extensions. D4 lying in an area with irregular lineation. Anterior coxal plates not reaching anterior idiosoma margin. Gonopore 50 long. Genital field long, extending onto dorsum and there widened. Lengths of PI-PV: 30, 66, 42, 64, 32; PII medially with three setae near anterior margin. Lengths of I-leg-4-6: 120, 110, 104. Lengths of IV-leg-4-6: 190, 210, 186 (till tip of segment). IV-leg-4 with a spur, IV-leg-6 slightly bowed.

Female: Idiosoma brownish, 761 (794) long and 632 (688) wide, anterior margin convex; idiosoma truncated posteriorly. Dorsal shield complete, 575 (583) long and 462 (478) wide. Anterior coxal plates not reaching anterior idiosoma margin. Medial margin of fourth coxal plates longer than medial margin of third coxal plates. Medial distance of fourth coxal plates slightly smaller than width of one gonopore valve. Gonopore 112 long and 140 wide. Genital plates long, extending to lateral idiosoma margin, wing-shaped and widened laterally. Lengths of PI–PV: 30, 66, 50, 65, 32; palp as in male. Lengths of I-leg-4-6: 116, 100, 90. Lengths of IV-leg-4-6: 164, 154, 130.

Etymology. Named for the relatively long fourth legs segment of the male.

Remarks. The new subspecies is larger than the nominate taxon, the latter being 760–852 in length. Moreover, the leg segments of the new subspecies are longer: IV-leg-6 of A. chutteri chutteri is 155–167 long and IV-leg-5 160–174 (K.O. Viets 1966). The posterior cleft is much narrower in A. chutteri chutteri , and the genital field is not extending onto the dorsum. Arrenurus iniquiformis Lundblad, 1949 is very similar to the new subspecies, but the cleft is differently shaped. The presence of the characteristic lineated area near D4 and the presence of a rudimentary petiole are not mentioned by Lundblad (1949). Arrenurus iniquiformes has swollen genital plates, but Lundblad does not say whether they extend onto the dorsum or not. The female differs much from the female of A. chutteri chutteri , the latter having more or less straight genital plates.