Tycherobius acicula, Fan, Qing-Hai & Walter, David E., 2006

Fan, Qing-Hai & Walter, David E., 2006, A review of the genus Tycherobius (Acari: Camerobiidae), with descriptions of four new species from Australia, Zootaxa 1121, pp. 1-52 : 40-45

Tycherobius acicula sp. n.

(Plate 4; Figs. 25–28 , 33 )

Material examined

Holotype: adult female, from litter in African Mahogany plantation, 12°40'S, 141°57'E, Far North Queensland, Queensland, Australia, coll. G. Gordh, 30 Sept 1997. In QM.

Diagnosis

Adult female. Peritremes with two loops; palptarsus with 2 + 1 eupathidium + 1; dorsum with a single pdx; idiosomal setae lanceolate, c1, d1 and e1 much longer than others; c1: c2 = 4.0, d1: d2 = 7.7, e1: e2 = 3.8, f1: f2 = 2.2, c1: d1: e1: f1 = 2.8: 2.8: 1.7: 1.3; femora I–IV with 4, 3, 3, 2; tarsi I–II with 10 + 1, 8 + 1.

Description

ADULT FEMALE (Plate 4; Figs. 25–28 )

Gnathosoma . Stylophore stumpy, 43; movable digits 23; peritremes with two loops. Palp 50; counts of setae and solenidia from trochanter to tarsus: 0, 2, 1, 3 + 1 claw, 2 + 1 eupathidia + 1 solenidion (). Subcapitular setae m 23, distance m–m, 25.

Idiosoma. Nearly circular in shape, 232 long, 192 wide. Prodorsum bearing one pair of eyes, 7 in diameter, one pair of postocular bodies, 10 in diameter, and five pairs of lanceolate setae, c1, d1, e1 and f1 obviously longer than other setae, vi 60, ve 20, sci 20, sce 15, pdx (single) 15; ratio vi: ve =3.0; distances: vi– vi 32, vi–ve 30, vi–pdx 25, ve–sci 22, sci–sce 50. Hysterosoma bearing ten pairs of setae, c1 153, c2 38, d1 153, d2 20, e1 95, e2 25, f1 55, f2 25, h1 16, h2 15; ratios c1: c2 = 4.0, d1: d2 = 7.7, e1: e2 = 3.8, f1: f2 = 2.2, c1: d1: e1: f1 = 2.8: 2.8: 1.7: 1.3; distances: c1–c1 15, c1–c2 77, c1–d1 52, d1–d1 20, d1–d2 55, d1– e 1 42, e1– e 1 20, e1– e 2 50, e1–f1 37, f1–f1 17, f1–f2 33, f1–h1 27, h1–h1 15, h1–h2 17. Venter with three pairs of setae, 1a 23, 3a 25, 4a 20; coxal setae 1c about 1.3x of 1b, 1b 30, 1c 40. Aggenital setae small, ag 15. Genito­anal valves with one pair of genital setae, g 13, and three pairs of pseudanal setae, ps3 13, ps2 13, ps1 13.

Legs. Length (from base of trochanter to tip of tarsus): leg I 533, leg II 438, leg III 507, leg IV 555. Setae on genua lanceolate, IV> III> II> I, length: I 26, II 32, III 57, IV 75. Tibiae I–IV each with one solenidion: I 20, II 13, III 10, IV 10. Tarsi I–II each with one solenidion: I 7, II 5. Counts of setae and solenidia on legs I–IV: coxae 1a + 2, 1, 2, 2; trochanters 1, 1, 1, 1; femora 4, 3, 3, 2; genua 1 + 1, 1 + 1, 1, 1; tibiae 9 + 1, 8 + 1, 7 + 1, 7 + 1; tarsi 10 + 1, 8 + 1, 7, 7.

Remarks

Adult females of this species are similar to that of T. virginiensis McGregor, 1950 in having a single pdx, but can be readly separated from the latter by having idiosomal setae c1, d1 and e1 prominently long, extending beyonged bases of setae in next row (vs: c1, d1 and e1 minute, peg­like), palptarsus with 2 setae (vs: 1 seta).

Figures

FIGURE 25. Tycherobius acicula sp. n. (adult female). Dorsal view of idiosoma.

FIGURE 26. Tycherobius acicula sp. n. (adult female). Ventral view of idiosoma.

FIGURE 27. Tycherobius acicula sp. n. (adult female). A, chelicerae; B, palp; C, genito­anal area.

FIGURE 28. Tycherobius acicula sp. n. (adult female). A, leg I; B, leg II; C, leg III; D, leg IV.

FIGURE 33. Geographic distribution of Tycherobius stipula sp. n., T. australis sp. n., T. acicula sp. n., T. variegata sp. n. and T. elongata sp. n.