Fedrizzia strandi (Oudemans)

Seeman, Owen D., 2007, Revision of the Fedrizziidae (Acari: Mesostigmata: Fedrizzioidea), Zootaxa 1480, pp. 1-55 : 31-32

Fedrizzia strandi (Oudemans)

Toxopeusia strandi Oudemans, 1927: 227 . Fedrizzia strandi -- Womersley, 1959: 28.

Type specimens. Holotype, F, INDONESIA: Buru: Station 12, Buru (“Boeroe” on slide), 4–7.ii.1922 (slide number 3562, registration P 1088). Paratype, Wai Eno tot Wai Temoln, Buru (“Boeroe” on slide), 3.ii.1922 (slide number 3562, without registration number). In Mus. Leiden.

Diagnosis. Both sexes: with 4–6 large dorsal pores; ventral shield lineate-reticulate laterally, smooth medially; exopodal patterning between CxII–III spotted; pedofossae III absent; CxIV-marginal suture absent; femur III and IV without lamellae; femur IV not enlarged. Female: 850–857 long, 630 wide, setae st2 32–35 long, barbed, st 3-4 13–20 long; sternogynial shield lineate-reticulate, flanked by 3 pairs of pores and 3 pairs of setae; seta h1 unmodified. Male: smaller, idiosoma 730–760 long, 590 wide; sternoventral shield with weak suture behind genital opening; seta h1 with slightly bulbous base, seta h3 level with position of h2.

Redescription. Female: Idiosoma 850 long, 630 wide, with 4–6 large pores medially; anterior hyaline projection with 1 pair barbed setae ca. 40 long. Marginal setae 5 long. Tritosternum base obscured. Tetartosternum and sternal shield smooth; tetartosternum sub-rectangular; st1 barbed, 45–48; st2 barbed, 32–35, st3-4 barbed, 13–20; posterolateral margin of sternal shield acutely pointed, st3-4 5 from posterior margin, pore stp x level with stp2. Sternogynial shield 130 long, 170 wide, densely lineate-reticulate, with 6 pores and 6 setae flanking shield. Ventral shield lineate laterally, smooth medially, with a large pore between CxIII–IV, 2 pairs of large pores (8–12 diameter) posteromedial and posterior of CxIV, 2–3 pairs of small round pores, and 6–7 pairs of setae, the most posterior and lateral are 8 long. Ventrianal shield 183 long, 450 wide, smooth, paranal setae 45–50 long, other setae 12–15 long; anterolateral corner of ventrianal shield not fused with ventral shield. Marginal shields partially obscured, probably smooth.

Legs. TrI with seta pv1 smooth of with very few barbs, not thicker than seta av1. FeI with seta pv3 similar to seta pv1 and pv2. FeII with small lamella distal to seta pv1, seta ad1 with very few barbs, thickened. FeIII without lamella, seta pv1 not spine-like. FeIV not significantly enlarged, 110–120 long, 88 wide at distal end, without lamella, seta pv1 not spine-like, seta pd2 just proximal to seta ad2. TaII with seta av2 spine-like, subequal in length to av3; TaIII with seta av2 spine-like, subequal to seta av3. Legs II–IV with setiform ad and pd setae.

Gnathosoma . Seta h1 smooth, straight, 63 long, distance between h1–h1 30; h2 with few minute barbs, 53 long; h3 12 long, posterolaterad h2; palpcoxal seta 10 long. Corniculi on small tubercles 8 long. Palp, seta av1 on trochanter with 7 branches, seta av2 barbed, spur with two blunt processes and accessory spine. Chelicera, fixed digit 168 long, movable digit 45 long; fixed digit with 2 large and 2 minute teeth; excrescences arise from an enlarged base of digit and consist of a large brush-like process, a ca. 75 long ribbon-like process with a serrate edge and a toothed edge, other process not seen, probably obscured.

Male: Idiosoma 760 long, 590 wide. Tetartosternum 30 long at midline, 105 wide; st1 smooth, 30 long; st2 smooth, 23 long; st3 smooth, 20 long. Genital opening 43 long, 53 wide. A weak suture lies behind the genital opening, demarking an anterior smooth region from a weakly reticulate posterior region. Ventral shield with network of reticulation medially, lineate reticulation laterally; ventrianal and marginal shields smooth. Gnathosoma . Seta h1 55, smooth, with slightly bulbous base; seta h3 8 long, lateral to and in line with h2. Palpcoxal seta 8 long.

Remarks. The male may not be the same species because the female idiosoma is about 100 µm longer than the male, and sexes of Fedrizziidae are usually of similar size ( Womersley 1959; pers. obs.). Furthermore, the male and female were collected from different sites. However, apart from the size differences, no other feature discounts the supposition that they represent the same species. Linking the sexes, both have relatively long sternal setae in comparison with the similar species F. c a r a b i, which has female and male specimens with setae st2-3 <10 long.

Oudemans (1927) originally reported “eye-like organs”, but these represent internal sclerotisation anterior of CxI on the ventral surface of the dorsal shield present in all Fedrizziidae . He also illustrated a pair of setae in the anterolateral corners of the tetartosternum, but these are not present; setae st1 are placed either side of the tritosternal base, their usual position in Fedrizzia . Additionally, the original description showed that the CxIV-marginal suture could be present, but it is not.