Castriidinychus tasmanicus, Dylewska & Błoszyk & Halliday, 2010

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 : 3-12

Castriidinychus tasmanicus sp. nov.

Material examined. Tasmania. Holotype. Female, Savage River, Pipeline Road , site 2, litter, 41°30'S 145°20'E, 21.iv.89, P. Greenslade and J. Diggle coll., TAS-086 (in ANIC) . Paratypes. Tasmania. 2 females, 4 males, same data as holotype ; 1 female, Savage River, Pipeline Road , site 1, moss on dead trunk, 41°30'S 145°20'E, 21.iv.89, J. Diggle and H. Mitchell coll., TAS-077 ; 1 female, 3 males, 3 DN, Savage River, Pipeline Road , site 2, moss on log, 41°30'S 145°20'E, 21.iv.89, J. Diggle and H. Mitchell coll., TAS-085 ; 1 female, Spero River , litter, 42°38'S 145°22'E, 23.ii.89, J. Marsden-Smedley coll., TAS-054 ; 2 females, Hibbs Lagoon , litter, 42°34'S 145°19'E, 27.ii.89, S. Smith coll., TAS-058 ; 1 female, Mount Horror , litter, 41°04'S 147°44'E, -.xii.88, M. Neyland coll., TAS-072 ; 2 females, 2 males, Bradshaws Road, below Mount Murchison, Loftus Hill Memorial Reserve , site 2, litter, 41°50'S 145°37'E, 21.iv.89, J. Diggle coll., TAS-101 ; 1 male, Bradshaws Road, below Mount Murchison, Loftus Hill Memorial Reserve , site 2, fungi sample, 41°50'S 145°37'E, 21.iv.89, J. Diggle and H. Mitchell coll., TAS-214 ; 1 female, Simons Road , soil cores, 41°21'S 147°31'E, 5.v.89, P. Greenslade coll., TAS-168 ; 1 female, Big Sassy Creek , 21 km NNW of Little Swanport, site 1, litter, 42°09'S 147°55'E, 12.v.89, P. Greenslade coll., TAS-193 ; 2 females, 3 males, Mount Michael , leaf litter, 148º00'E 41º10'S, 20.ix.89, H. Mitchell coll., TASII/6 ; 3 females, 4 males, Cradle Mountain , camping ground, in moss, 145º55'E 41º35'S, 18.ix.89, R . Coy coll., TASII/7 (in ANIC and AMU).

Female. Dorsal idiosoma ( Figs 1 , 2 , 3 ). Length 438–600 µm (mean 534 µm), width 261–385 µm (mean 341 µm) (n = 13). Dorsal shield oval, with small rounded vertex and characteristic ornamentation of large oval or irregular pits ( Fig. 3C ). Dorsal shield setae numerous, uniform in length and shape, smooth, basally swollen, length 32–40 µm, except one pair of vertical setae j1 long (50 µm) and distally serrated, and two posterior pairs Z4, J4 finely serrated, length 25–49 µm, inserted on small mounds ( Fig. 1 , 3B ). Marginal shield narrow, with festoons, clearly demarcated from dorsal shield. Four pairs of anterior setae on marginal shield (z1, s2, r2, r3) much longer (37–57 µm), distally serrated; lateral and posterior setae on marginal shield shorter, smooth.

Ventral idiosoma ( Figs 4 , 5A , 6 , 7A, 7B ). Tritosternum with narrow base and four forked laciniae. Sternal shield ornamented with oval-shaped pits, with four pairs of simple sternal setae, st1 shortest, inserted at anterior level of coxae II, st2-st4 lateral to epigynal shield. Epigynal shield tongue-shaped, posterior margin at level of coxae IV, central area ornamented with oval-shaped pits. Length of epigynal shield 118–137 µm (mean 126 µm) width 69–86 µm (mean 77 µm) (n = 13). Ventral opisthosoma ornamented with oval-shaped pits, with six pairs of smooth ventri-anal setae, posterior pair longest (42 µm), one postero-lateral pair minute. Anus flanked by two pairs of adanal setae, Ad1 shorter than Ad2, and long smooth post-anal seta Pa, anal opening small, oval. Submarginal ventral setae smooth, short and massive. Peritreme distinctively shaped, highly convoluted, stigmata at level of coxa II ( Figs 4 , 6C ).

Gnathosoma ( Fig. 8A ). Hypostomal setae h1 long (28 µm) and smooth, h2 slightly shorter (15 µm), simple, h3 longest (33 µm), medially serrated, h4 short (12 µm), distally serrated. Ventral setae on palp trochanter long and serrated.

Legs. Leg chaetotaxy as in Figure 9 . All leg setae smooth and pointed. Some dorsal and lateral setae on tarsus I, II, III thick and spine-like.

Male. Dorsal idiosoma. Length 531–615 µm (mean 570 µm), width 377–400 µm (mean 357 µm) (n = 7). Structure and chaetotaxy as for female.

Ventral idiosoma ( Fig. 10 , 7C, 7D ). Intercoxal region ornamented with a few oval-shaped pits, with five pairs of simple setae ( Fig. 7D ), st4-st5 inserted lateral to genital operculum. Genital operculum oval, smooth (45–69 x 33–39 µm), without setae, slightly displaced posteriorly to between coxae IV. Setae and sculpture of opisthosoma as for female.

Gnathosoma . Surface of hypostome smooth except for two longitudinal rows of tiny denticles ( Fig. 8B ). Hypostomal setae h1 more massive than others, 18 µm long, h2 shorter than h1 (12 µm), simple, h3 longest (20 µm), simple, h4 short (15 µm), serrated. Legs. As for female.

Deutonymph. Dorsal idiosoma ( Fig. 11A ). Length 470 µm, width 310 µm. Dorsal shield with numerous setae and characteristic ornamentation of irregular pits; marginal shield narrow.

Ventral idiosoma ( Fig. 11B ). Sternal shield elongate, strongly narrowed between coxae IV; smooth except for small oval and circular pits posterior to coxae IV; with five pairs of simple setae and two pairs of lyrifissures. Peritrematal, metapodal and pericoxal shields fused; metapodal region ornamented with circular pits. Ventri-anal shield trapezoidal, ornamented with small pits, with six pairs of ventral setae, one pair of adanal setae (Ad) and unpaired post-anal seta (Pa). Anal opening small and oval, without morphological modification for phoresy. Opisthosoma with one pair of long setae inserted on small platelets lateral to ventrianal shield. Peritreme long, slightly curved, with short post-stigmatic section, stigmata between coxae II and III.

Etymology. The name of this species name refers to its widespread occurrence in Tasmania.

Notes. Castriidinychus tasmanicus was the most widespread of the three species described here (Fig. 24), but never occurred in large numbers. Most records were in litter, moss and fungi under rainforest in western Tasmania, but it also occurred in remnants of Nothofagus forest in the northeast.

Figures

FIGURE 1. Castriidinychus tasmanicus, female, dorsal idiosoma. Scale bar 100 µm.

FIGURE 2. Castriidinychus tasmanicus, female. A, dorsal idiosoma; B, lateral habitus. Scale bar 100 µm.

FIGURE 3. Castriidinychus tasmanicus, female. A, anterolateral habitus; B, posterodorsal idiosoma; C, dorsal shield ornamentation; D, antero-marginal setae.

FIGURE 4. Castriidinychus tasmanicus, female, ventral idiosoma. Scale bar 100 µm. Inset, peritreme, enlarged.

FIGURE 5. Castriidinychus spp., females, intercoxal area and genital shield. A, C. tasmanicus; B, C. longisetosus; C, C. robynae. Scale bar 100 µm.

FIGURE 6. Castriidinychus tasmanicus, female. A, ventral idiosoma; B, coxae I and camerostome; C, peritreme.

FIGURE 7. Castriidinychus tasmanicus. A. female, intercoxal region and genital shield; B, female, postero-ventral idiosoma; C, male, ventral idiosoma; D, male, intercoxal region.

FIGURE 8. Castriidinychus spp., hypostome. A. C. tasmanicus female; B. C. tasmanicus male; D, C. longisetosus female; D, C. longisetosus male; E, C. robynae female. Scale bar 50 µm.

FIGURE 9. Castriidinychus tasmanicus, female, A. leg I, B. leg II, C. leg III, D. leg IV. Black setae are visible when the specimen is examined ventrally, with the legs in their natural folded position. Scale bar 100 µm.

FIGURE 10. Castriidinychus tasmanicus, male, ventral idiosoma. Scale bar 100 µm.

FIGURE 11. Castriidinychus spp., deutonymph. A, C. tasmanicus, dorsal idiosoma; B. C. tasmanicus, ventral idiosoma; C, C. longisetosus, dorsal idiosoma; D, C. longisetosus, ventral idiosoma. Scale bar 100 µm.