Castriidinychus Hirschmann, 1973

Dylewska, M., Błoszyk, J. & Halliday, R. B., 2010, Three new species of mites in the genus Castriidinychus Hirschmann from Tasmania (Acari: Uropodidae), Zootaxa 2546 (1), pp. 1-30 : 2

Genus Castriidinychus Hirschmann

Castriidinychus Hirschmann, 1973b: 158 .

Type species Uroobovella castrii Hirschmann, 1972: 11 , by original designation.

Diagnosis. Mites of average size, idiosoma of female 450–800 µm long x 320–690 µm wide, male 560–710 µm long x 400–510 µm wide, oval-shaped and well sclerotised, colour brown. Base of tritosternum covered by coxae I. Pedofossal grooves distinct and characteristically shaped. Epigynum of female large, anterior margin oval-shaped, posterior margin straight, located in central part of intercoxal region between coxae II – IV. Genital shield of male oval-shaped, located between coxae IV. Female with four pairs of sternal setae, male and deutonymph with five pairs. Peritreme with a characteristic convoluted shape, with short poststigmatal section. Opisthosoma with five or six pairs of ventral setae, one clearly longer than the others. Anus flanked by two pairs of adanal setae Ad 1, Ad 2 and an unpaired post-anal seta Pa. Tarsus I with long claw. Fixed digit of chelicera one-third longer than movable digit, distally expanded and blunt; movable digit with one strong tooth. Hypostomal setae h1 distinctly longer than h2 and h4; h2 short, distally serrated; h3 long, serrated in the central one-third; h4 short, serrated. Hypostomal seta h 1 in male massive, sometimes divided. Hypostomal groove wide, with few denticles arranged in two longitudinal rows (oligodentic type). Corniculi robust, horn-like, internal malae plumose .

Notes on the genus. Various species of Castriidinychus have sometimes been placed in the related genus Uroobovella (sensu Hirschmann 1961) . These two genera are distinguished by a number of characters of both the female and male, especially by the presence of modified setae on the anterior margins of the dorsal idiosoma of Castriidinychus (absent in Uroobovella ) and the presence of only four pairs of sternal setae in the female and five in the male of Castriidinychus (eight in Uroobovella ). These and other characters that separate these two genera are summarised in Table 1.