Iphidozercon walteri, Gwiazdowicz & Halliday, 2008

Gwiazdowicz, D. J. & Halliday, R. B., 2008, The Australian species of Iphidozercon (Acari: Ascidae), Zootaxa 1921, pp. 47-68 : 62-66

Iphidozercon walteri sp. nov.

( Figs 25–32)

Material examined. Holotype. Female. Australia, Victoria. Lerderderg River, Blackstone , 4 October 1991, streamside soil, D.E. Walter. In ANIC . Paratypes. Queensland. 2 females, Bunya Mts National Park, Barker Creek track, 21 August 2003, dry sclerophyll, soil & litter, F. Beaulieu, UQIC #93630 , 93631 ; 1 female, Gambubal Forest Station , 27º08'S, 152º09'E, 20 January 2003, sclerophyll forest, soil & litter, F. Beaulieu, UQIC #93642 ; 2 females, Brisbane Forest Park, Tenison Woods Mtn , 27º17'S, 152º45'E, 26 August 2003, dry sclerophyll, Asplenium , ground litter, F. Beaulieu, UQIC #93655 ; 1 female, Peter's Ck, north of Conondale National Park , 26º41'S, 152º36'E, 13 July 1995, rainforest litter, D.E. Walter, UQIC Reg. # 91905 ; 1 female, Miala National Park, Mt. Glorious, Greene’s Falls , 6 October 1995, leaf litter, D.E. Walter, UQIC Reg. # 91919 ; 2 females, Fraser Island , 20 August 1991, rainforest litter, D.E. Walter ; 1 female, Lamington National Park, Border Track, 1.4 km from O’Reilly's , 28º14'S, 153º09'E, 9–10 July 2003, Asplenium australasicum litter, F. Beaulieu, UQIC #93638 ; 2 females, Lamington National Park, Border Track, 1.5 km from Binna Burra ( Paweena ), 28º12'S, 153º11'E, 26–27 July 2003, ex Asplenium australasicum litter, F. Beaulieu, UQIC Reg. #93653 ; 11 females, 1 male, Lamington National Park, Daves Creek Circuit, 28º13'S, 153º12'E, 15 July 2002, rainforest/sclerophyll ecotone, soil & litter, F. Beaulieu, UQIC #93639 , 93640 , 93641 ; 3 females, Lamington National Park, Tullawalal Track ( Binna Burra ), 28º12'S, 153º11'E, 21 July 2002, beech forest, soil & litter, F. Beaulieu, UQIC #93644 , 93645 ; 4 females, 1 male, Lamington National Park, Gwongoorool Pool Track , 28º12'S, 153º11'E, 21 July 2002, wet sclerophyll, soil & litter, F. Beaulieu, UQIC #93646 ; 3 females, Lamington National Park , unnamed track, 28º12'S, 153º11'E, 24 October 2002, sclerophyll, soil, F. Beaulieu, UQIC #93650 ; 4 females, 1 male, Lamington National Park, Duck Creek Road, 28º13'S, 153º09'E, 1 June 2002, rainforest/woodland transition, sclerophyll, soil & litter, F. Beaulieu, UQIC #93651 . Tasmania. 4 females, 1 male, Warra LTER site, 43º09'S, 146º71'E, 1 October 2003, ex Eucalyptus obliqua , wet sclerophyll forest, rainforest understorey, soil & litter, F.Beaulieu; 1 female, Weldborough Pass , 41º10'S, 147º54'E, 1993, Nothofagus litter, D.E. Walter, Greenslade et al., UQIC # 91926 . Victoria. 3 females, 1 male, same data as holotype. (in UQIC) .

Description. Female. Dorsal idiosoma. Dorsal shield oval, length 360 µm, width 250 µm ( Fig. 25). Margins of shield separated from central part of shield by a line extending from setae z1 to Z5; marginal strip ornamented with transverse lines, bending around slightly onto ventral surface. Central area of shield between setae z1, j4, j5, j6, z1', j4', j5', j6' with colliculate-granulate ornamentation. Posterior of shield with tuberculate ornamentation behind setae j6, granulate ornamentation behind J2, and smooth behind J4. Setae j1, s1, s2 each 15 µm long, fine, smooth and pointed, located on ventrally curved part of shield. All other setae smooth and pointed, slightly widened at base, approximately 30 µm long, except J5 slightly shorter (20 µm), and Z5 slightly longer.

Ventral idiosoma ( Fig. 26). Tritosternum with trapezoidal base and finely pilose laciniae, length of base 20 µm, laciniae 30 µm. Sternal shield rectangular, 60 x 40 µm; setae st1-st3 smooth and pointed, length 15 µm. Metasternal setae st4 length 15 µm. Genital shield small and narrow, length 60 µm, rounded posteriorly. Genital setae st5 15 µm long. Anal shield relatively large, 55 µm long, 70 µm wide. Para-anal setae 15 µm long, post-anal seta 20 µm, cribrum distinct. Stigmata at level of coxae IV; peritrematal shields wide, with weak posterior lineate ornamentation. Opisthogastric integument behind coxae IV with one pair of oval metapodal plates. Opisthogastric setae ZV1 15 µm long, JV2 25 µm, others approximately 20 µm.

Gnathosoma . Hypostome with horn-like corniculi and four pairs of setae ( Fig. 27). Anterior setae h1 longest, 30 µm, internal seta h3 (20 µm) and palp coxal seta (25 µm) shorter, external seta h2 shortest, 10 µm. Seven transverse rows of hypostomal denticles present, number of denticles per row (anterior to posterior) 14, 15, 20, 21, 21, 18, 17. Chelicera typical for genus, fixed digit and movable digit each with three teeth ( Fig. 28), other details of chelicera not visible in available specimens. Tectum with central prong longest, its distal end club-like and denticulate, lateral prongs shorter, with denticulate outer margins ( Fig. 29). Palp tarsal claw with two unequal tines ( Fig. 31).

Legs. Length of legs: I, 225 µm, II, 200 µm, III 195 µm, IV 210 µm. Tarsus II to IV each with the dorsoproximal setae ad 2 and pd 2 short and straight ( Fig. 30). Setation of genua I-II-III-IV: 12-10-7-7; tibiae I-II-III- IV: 12-9-7-7 ( Fig. 32).

Etymology. This species is named in honour of our colleague David Evans Walter, who collected many of the specimens examined here, and who has made many other important contributions to acarology.

Notes. The peritreme, peritrematal shield, and anal shield of I. walteri are similar to those of I. gibbus , but these two species may be distinguished in several ways. The posterior half of the dorsal shield of I. walteri is not strongly ornamented, but strongly sclerotised specimens have some tuberculate and granulate sculpture. The posterior half of the dorsal shield of I. gibbus sometimes has a delicate, reticulate sculpture. The dorsal shield of I. walteri has a distinctive sculpture around the edges, while that of I. gibbus has a distinct elevation in the central section of the shield. Also, the dorsal setae in the J series in I. walteri are longer than those of I. gibbus .