Steganacarus (Rhacaplacarus) cucullus, Niedbała, 2012

Niedbała, W., 2012, An Updated Study Of Ptyctimous Mite Fauna (Acari: Oribatida) Of The Australasian Region With A Description Of Thirteen New Species, Acarologia 52 (2), pp. 183-228 : 197

Steganacarus (Rhacaplacarus) cucullus n. sp.

( Figures 4 A-I, 5A-J)

Type material — Holotype and one paratype (in NHC): ANIC-1344, Dorrigo NP, Blackbutt Trail , 8 km East of Dorrigo, 30°22’S 152°46’E, cut subtropical, closed forest Acacia and Calliconia litter, sample 1, 22 May 1993, coll. D.S. Chandler; four paratypes (two in ANIC, two in NHC): ANIC-1345, Dorrigo NP, 6 km Southeast of Dorrigo, alt. 490 m, 30°23’S 152°44’E, wet sclerophyll, Eucalyptus saligna litter, 6 Feb. 1993, coll. D.S. Chandler.

Measurements of holotype — Prodorsum: length 278, width 192, height 126, sensillum 94, setae: interlamellar and exobothridial 18, lamellar and rostral 10; notogaster: length 586, width 384, height 333, c 1, h 1 and p 1 18; genitoaggenital plate 131 × 126, anoadanal plate 197 × 131. Measurements of paratype: prodorsum: length 263, width 202, height 116; notogaster: length 566, width 434, height 313.

Description — Colour brown. Cuticle well sculptured, body covered with distinct but irregular foveae.

Prodorsum with very great, prominent median crista. Lateral carinae absent, sigillar fields not visible. Sensilla long, narrow, covered with small cilia in distal half. Setae (except filiform exobothridial) very short, swollen, rather obtuse distally.

Notogaster with prominent cowl-like structure in anterior part. Setae very short (c 1 / c 1 -d 1 = 0.1), swollen, rather obtuse distally, setae c 1-3 situated at the cowl. Lyrifissures and vestigial setae invisible.

Ventral region — Setae h of mentum slightly shorter than distance between them. Genitoaggenital plates with nine pairs of minute genital setae with arrangement: 6: 3. Anoadanal plates each with five pairs of minute setae, setae ad 3 situated near proximal border as setae ad 1 and an, setae ad 2 only slightly remote from proximal border.

Legs — Formula of setae and solenidia of complete type. Setae d of femora I slightly remote from distal end of segment.

Other localities — ANIC-1338, Dorrigo NP, 0.3 km Northwest of Visitors Centre, 770 m, 30°22’S 152°43’E, cut subtropical closed forest rotten wood litter, 20 June 1993, coll. D.S. Chandler - 1; ANIC- 1338, Dorrigo NP, 0.3 km Northwest of Visitors Centre , 770 m, 30°22’S 152°43’E, cut subtropical closed forest rotten wood litter, 20 June 1993, coll. D.S. Chandler - 1.

Etymology — The specific name cucullus is derived from Latin for "a hood" and alludes to the presence of anterior cowl on notogaster.

Comparison to related species — The new species is easily distinguishable from congeners by the shape of setae short, swollen, rather obtuse distally, prominent median crista of prodorsum, prominent anterior cowl of notogaster, minute setae of anoadanal plates. No species of Steganacarus (Rhacaplacarus) has this combination of character states.

Figures

FIGURE 4: Steganacarus (Rhacaplacarus) cucullus n. sp. (holotype): A – prodorsum, dorsal view, B – prodorsum, lateral view, C – lateral view of opisthosoma, D – dorsal view of notogaster, E – mentum of infracapitulum, F – genitoaggenital and anoadanal plates, G – trochanter and femur I, H – tibia IV; Steganacarus (Rhacaplacarus) cucullus n. sp. (paratype I): I – anoadanal plate.