Iphidozercon australis, Gwiazdowicz & Halliday, 2008

Gwiazdowicz, D. J. & Halliday, R. B., 2008, The Australian species of Iphidozercon (Acari: Ascidae), Zootaxa 1921, pp. 47-68 : 49-53

Iphidozercon australis sp. nov.

( Figs 1–8)

Material examined. Holotype. Female. Australia, Queensland. Lab-reared 24 April 1995. Origin of culture Gadgarra Cedar, Atherton, 7 April 1995, ex fungal sporocarp, D.E. Walter coll., QM S83796 , in QM, formerly in UQIC (Reg. # 91915) . Paratypes. Queensland. 10 females, same data as holotype but reared 5 May 1995, UQIC Reg. #91910-91916 ; 2 females, 2 males, lab reared 17 December 1995, origin of culture Wright’s Creek, Lake Eacham National Park , 17º17'S, 145º37'E, 2 December 1995, ex fungi on log, D.E. Walter coll., UQIC Reg. # 91900-91902 ; 2 females, Cape Tribulation, Oliver Creek , 16º08'30"S 145º26'30"E, 27 June 1995, ex Asplenium nidus litter, D. Rodgers coll., UQIC # 93621 , 93622 ; 1 female, Wongabel State Forest , 13–16 April 1994, Asplenium litter, C. Thebaud coll. (in UQIC) .

Description. Female. Dorsal idiosoma ( Fig. 1). Dorsal shield oval, length 400 µm, width 220 µm, with distinct colliculate ornamentation throughout. All setae fine, smooth and pointed, length of setae 30 µm except j1 and three antero-lateral pairs shorter, ca. 10 µm.

Ventral idiosoma ( Fig. 2). Tritosternum with trapezoidal base and finely pilose laciniae, length of base 30 µm, laciniae 50 µm. Sternal shield rectangular, 80 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, spatulate posteriorly. Genital setae st5 15 µm long. Anal shield obovate, length 70 µm, width 60 µm. Para-anal setae 20 µm long, postanal seta 25 µm, cribrum distinct. Stigmata located at level of coxae IV, peritremes extending anterior to coxae I, projecting for a short distance behind stigmata. Opisthogastric skin posterior to coxae IV with a pair of oval metapodal shields, a pair of smaller plates near posterior end of peritrematal shields, several pairs of very small platelets bearing pores, and 11 pairs of opisthogastric setae in addition to the R-series setae.

Gnathosoma . Hypostome with robust horn-like corniculi and four pairs of setae ( Fig. 3). Anterior seta h1 and palp coxal seta longest, 35 µm, internal seta h3 shorter, 25 µm, external seta h2 shortest, 20 µm. Seven transverse rows of hypostomal denticles present, number of denticles per row (anterior to posterior) 16, 10, 12, 9, 15, 15, 5. Chelicera typical for genus, fixed digit and movable digit each with three teeth ( Fig. 4), other details of chelicera not visible in available specimens. Tectum with a central elongated prong ending in three denticles, lateral prongs shorter, with denticulate outer margins ( Fig. 5). Palp tarsal claw with two unequal tines ( Fig. 7).

Legs. Lengths I 320 µm, II 260 µm, III 250 µm, IV 310 µm. Tarsus II to IV each with dorsoproximal setae ad 2 and pd 2 short and straight ( Fig. 6). Setation of genua I-II-III-IV: 12-9-7-7, av 1 absent from genu II; tibiae I-II-III-IV: 12-9-7-7 ( Fig. 8).

Etymology. The name of this species reflects the fact that it was collected in Australia.

Notes. Iphidozercon australis is similar to I. corticalis , which was described by Evans (1958) from Europe, but these two species may distinguished in several ways. The dorsal shield of I. australis is sculptured over its whole surface, while that of I. corticalis is sculptured only in the anterior half. Posterodorsal setae J, Z and S in I. australis are long, and almost reach the bases of the next posterior setae, whereas in I. corticalis they reach only half the distance to the next seta. Iphidozercon australis has two pairs of metapodal plates where I. corticalis has only one, and I. australis has a short section of peritreme behind the stigma, whereas this section of peritreme in I. corticalis is much longer. Genu II in I. australis carries nine setae, whereas in I. corticalis and the remainder of the genus there are ten setae on this segment.