Gahniacarus tuberculatus, Beard, Jennifer J. & Ochoa, Ronald, 2011

Beard, Jennifer J. & Ochoa, Ronald, 2011, New flat mite genera (Acari: Trombidiformes: Tenuipalpidae) associated with Australian sedges (Cyperaceae), Zootaxa 2941, pp. 1-37 : 4-14

Gahniacarus tuberculatus sp. nov. Beard & Ochoa

( Figs 1 a, 2–8)

Types. Holotype. Ƥ. Australia, Queensland, Base of Mt Hedley, Home Rule, Far North Queensland, 15°44’56” S 145°17’17” E, 21.vi.2005, ex. rough saw sedge Gahnia aspera (R.Br.) Spreng. sensu lato ( Cyperaceae ) in margin of notophyll vineforest (BRI voucher PIF31002), J.J. Beard (QM, UQIC #89123). Paratypes. 22 Ƥ, 8 3, 5 deutonymphs, 3 protonymphs, larva, all same data as Holotype (QM; UQIC# 16 specimens, 14 slides: Ƥ 89108– 128 (Ƥ with long sc1 89119, 89128); Ƥ, 3, DN, PN, larva 89140; Ƥ+DN 89141; 3 89129–34; 3+DN 89142; DN 89135–36; PN 89137–38; L 89139 ).

Diagnosis. Adult female. ( Figs 1 a, 2 – 4) As per genus, in addition to: setae sc1 similar in length to other dorsal setae, inserted on large rounded tubercles; setal pairs c1–c1 and d1–d1 each inserted on single tubercle; f2 and f3 tubercles contiguous; large tubercles (not bearing setae) present between sc1–c1, laterad c1, posterad c1, posterad d1. Dorsal opisthosomal setae e3, f2, f3 present.

Immatures. ( Figs 6 – 8 ). Larva with posterior opisthosomal setae e3, f3, h1 minute, setae f2 similar to other dorsal setae. Protonymph with posterior opisthosomal setae f3, h1 minute and setae f2, e3 similar to other dorsal setae. Deutonymph with posterior opisthosomal setae h1 minute and setae f2, f3, e3 similar to other dorsal setae (f3 obviously shorter than f2, e3). Opisthosomal setae f3 migrate anteriorly with each nymphal moult, and are inserted anterior to f 2 in the adult ( Figs 2 , 6 , 7 ). Differences in how an individual mite is mounted and the direction in which setae are flattened can alter the apparent insertion point of setae f3 ( Fig. 6 ). The tubercles on which setae f2, f3 are inserted are contiguous.

Remarks. Setae f2 and f3 are inserted on contiguous tubercles on adult Gahniacarus tuberculatus , whereas setae f2 and f3 are inserted on well separated tubercles on G. gersonus ; prodorsal setae sc1 are similar in size to other dorsal setae in G. tuberculatus , whereas sc1 are elongate and tapered in G. gersonus .

Adult female. (15 measured).

Dorsum. ( Figs 1 a, 2) Body measurements: v2 –h1 210 – 237 [235] (v2 – tip of protuberance 217 – 246 [245]), sc2– sc2 74 – 80 [77], c3–c3 87 – 92 [89], f3–f3 45 – 59 [57]. All dorsal setae, except h1–h2, inserted on large tubercles: setae sc1 inserted on a pair of large rounded tubercles; setal pairs c1–c1 and d1–d1 each inserted on single tubercle; tubercles f2–f3 contiguous; additional non-seta bearing tubercles present posterad sc1, laterad c1, mesad c3 and posterad d1. Setae h1–h2 inserted beneath a tubercle-like posterior projection. Dorsal cuticle mostly smooth, with some minor transverse grooves and plicae posterior to setae c1 and some oblique plicae posterior to setae d1. Most dorsal setae thick, barbed, of subequal length; setae h1 minute; h2 elongate, barbed with minute distal club; all other dorsal setae thick, heavily barbed; barbs on prodorsal setae longer than those on opisthosoma: v2 37 – 41 [40 – 41], sc1 57 – 91 [67 – 80] (two specimens with elongate sc1, 115 – 126 (89119, 89128)), sc2 33 – 43 [39 – 42], c1 52 – 66 [59 – 60], c3 34 – 40 [35 – 40], d1 57 – 66 [61], d3 40 – 46 [45], e3 46 – 53 [47 – 48], f2 44 – 55 [49 – 54], f3 41 – 50 [49], h1 2 – 4 [3 – 4], h2 126 – 148 [141].

Gnathosoma . ( Fig. 2 ) Gnathosoma extends to genu I. Dorsal cuticle with longitudinal plicae laterally; ventral cuticle anterior to setae 1b finely papillate, longitudinal plicae between 1b–1b and 1b–1a. Ventral setae m absent. Palps three segmented; setal formula: 0, 2, 0(2); tibia with two setae (d 11 – 12; v 10 – 11); tarsus with two eupathidia (6 – 7; 5 – 6) [7; 5]. Cheliceral stylets 115 – 127.

Venter. ( Fig. 3 ) Cuticle of ventral gnathosoma finely papillate; remaining cuticle completely plicate, covered with fine, mostly transverse plicae; transverse plicae between setae 1a–g1; plicae longitudinal in coxal fields III – IV and laterad genital flap; plicae oblique on genital flap. Setae g1 inserted anterior to g2 on genital flap. All setae fine, smooth; setae 1a, 1b, 4a1, 4a2 elongate, fine (difficult to consistently determine full length). Setal measurements: 1a 69 – 119 [69], 1b 54 – 82 [67 – 82], 2b 22 – 32 [30 – 32], 2c 20 – 28 [24 – 25], 3a 30 – 37 [32 – 36], 3b 19 – 32 [20], 4a1 53 – 105 [76], 4a2 64 – 99 [99], 4b 19 – 26 [21], ag 19 – 25 [19], g 1 23 – 32 [32], g 2 21 – 31 [27 – 30], ps 1 15 – 19 [16 – 18], ps 2 15 – 18 [16].

Spermathecal apparatus. ( Fig. 3 ) Cylindrical vesicle, curled distally (27 – 32) [28].

Legs. ( Fig. 4 ) Setal formulae for legs I – IV: 1-1-3-0-5-7(1), 2-1-3-0-5-7(1), 1-1-2-0-3-3, 1-1-2-0-3-3 respectively. Tarsi I and II each with one antiaxial solenidion ω ” (5 – 6, 4 – 5 respectively) and two distal eupathidia p ζ ’- p ζ ” (7 – 8, 7 – 8; 6 – 7, 7 respectively); ta I – IV with u’-u” asymmetrically barbed. Femur I with long, barbed dorsal seta (31 – 40) [32 – 37].

Colour. This species is yellow with small black spots visible internally (presumed to be food in the gut).

Adult male. (8 measured).

Dorsum. ( Fig. 5 ) Body measurements: v2 –h1 181 – 200, sc2–sc2 68 – 72, c3–c3 70 – 75, f3–f3 45 – 46. Dorsal cuticle mostly smooth; band of weak transverse plicae anterior to setae c1. Setae sc1, c3, d3, e3, f2 inserted on large rounded tubercles; setae v2, sc2, c1, d1, f3 inserted on smaller tubercles (tubercles f2, f3 contiguous); setae h1–2 inserted under posterior tubercle-like protuberance. Setae h1 short; h2 elongate with minute distal club; all other dorsal setae thick, heavily barbed. Setal measurements: v 2 29 – 32, sc 1 27 – 30, sc 2 30 – 39, c 1 24 – 28, c 3 29 – 32, d 1 20 – 26, d 3 30 – 34, e3 36 – 40, f2 35 – 39, f3 33 – 36, h1 5 – 7, h2 114 – 148.

Gnathosoma . ( Fig. 5 ) Gnathosoma extends just past genu I. Dorsal cuticle with longitudinal plicae laterally; ventral cuticle with fine longitudinal plicae anterior to setae 1b. Ventral setae m absent. Palps three segmented; setal formula: 0, 2, 0(2); tibia with two setae (d 10 – 11, v 9); tarsus with two eupathidia (6 – 7; 4 – 6). Cheliceral stylets 89 – 92.

Venter. Cuticle completely plicate, covered with fine, mostly transverse plicae; plicae longitudinal between gnathosoma –1a, transverse between 1a–4a2; band of strong plicae and folds between coxae IV; plicae longitudinal in coxal fields III – IV; plicae oblique posterior 4a1–2, oblique to transverse ag–g1 (plicae longitudinal/oblique laterad anus, arching anteriorly to become transverse anterior g1–2). Setae ps1 modified to short thick spurs. All setae fine; setae 1a, 1b, 4a1, 4a2 elongate (difficult to consistently determine full length). Setal measurements: 1a 77 – 117, 1 b 44 – 76, 2 b 22 – 26, 2 c 19 – 24, 3 a 28 – 31, 3 b 17 – 20, 4 a1 63 – 78, 4 a2 42 – 72, 4 b 15 – 20, ag 14 – 17, g 1 13 – 19, g 2 14 – 15, ps1 6 – 7, ps 2 11 – 15.

Aedeagus. ( Fig. 5 ) Sclerotised elongate, narrow arrow-head shaped aedeagus (28 – 33), with long, narrow membranous tube (up to 85), indistinguishable distally.

Legs. ( Fig. 5 ) Setal formulae same as adult female except ω ’ present on ta I – IV: 1-1-3-0-5-8(2), 2-1-3-0-5- 8(2), 1-1-2-0-3-4(1), 1-1-2-0-3-4(1) respectively. Tarsi I and II each with two solenidion (ta I paraxial ω ’ 8 – 9, antiaxial ω ” 7 – 8; ta II paraxial ω ’ 8, antiaxial ω ” 6 – 7) and two distal eupathidia p ζ ’-p ζ ” (7 – 8, 8 – 9; 8, 6 – 7 respectively); tarsi III and IV each with one paraxial solenidion ω ’ (8, 8 – 9 respectively); ta I – IV u’-u” asymmetrically barbed. Femur I with long, barbed dorsal seta (27 – 32).

Deutonymph. (5 measured).

Dorsum. ( Fig. 6 ) Body measurements: v2 –h1 170 – 228, sc2–sc2 64 – 73, c3–c3 70 – 82, f3–f 3 31 – 43. Cuticle mostly smooth with some transverse plicae mesally sc2–d1. Setae sc1, c1, c3, d1, d3, e3, f2 inserted on rounded tubercles (tubercles f2, f3 contiguous); additional tubercles between setae sc1, anterior c3, on posterior margin of opisthosoma. Setae h1–2 inserted under posterior tubercle-like protuberance. Setae f3 short; h1 minute; setae h2 elongate, barbed, with minute club; all other setae thick, heavily barbed. Setal measurements: v 2 30 – 35, sc 1 31 – 47, sc 2 24 – 31, c 1 24 – 34, c 3 28 – 30, d 1 23 – 35, d 3 27 – 32, e 3 29 – 36, f 2 27 – 32, f 3 13 – 18 (one specimen 6), h1 1 – 2, h2 112 – 126.

Gnathosoma . Gnathosoma extends to genu I. Ventral cuticle anterior to setae 1b finely papillate; cuticle with longitudinal plicae between setae 1b–1b and 1b–1a. Ventral setae m absent. Palp with three segments; setal formula: 0, 2, 0(2); tibia with two setae (d 10, v 8); tarsus with two eupathidia (6, 5). Cheliceral stylets 97 – 103.

Venter. Cuticle completely plicate, covered mostly with transverse plicae; plicae longitudinal from gnathosoma to setae 1a; plicae transverse between 1a–g1; plicae oblique laterad ps1–2. All ventral setae fine; setae 1a, 1b, 4a1, 4a2 elongate (difficult to determine full length). Setal measurements: 1a 63 – 104, 1 b 37 – 56, 2 b 15 – 20, 2 c 16 – 20, 3 a 13 – 23, 3 b 13 – 20, 4 a1 38 – 53, 4 b 10 – 12, ag 7 – 11, g 1 5 – 12, ps1 6 – 7, ps2 6.

Legs. Setal formulae same as adult female except tr IV nude: 1-1-3-0-5-7(1), 2-1-3-0-5-7(1), 1-1-2-0-3-3, 1-0- 2-0-3-3 respectively. Tarsi I and II each with one antiaxial solenidion ω ” (4 – 5; 4 respectively) and two distal eupathidia p ζ ’-p ζ ” (6, 6; 6, 6 respectively); ta I – IV u’-u” asymmetrically barbed. Femur I with long, barbed dorsal seta (25 – 34).

Protonymph. (3 measured).

Dorsum. ( Fig. 7 ) Body measurements: v2 –h1 161, sc2–sc2 65, c3–c3 66, f3–f3 29. Cuticle with smooth area anteriorly on prodorsum and posteriorly between setae d1–h1; transverse plicae between setae sc2–d1. Setae sc1, c1, d3, e3, f2 inserted on rounded tubercles (tubercles e3, f2 contiguous); additional tubercles between setae sc1, laterad c1, posterior margin of opisthosoma. Setae h1, h2 inserted under posterior tubercle-like projection. Setae f3, h1 minute; h2 elongate, barbed, with minute club; all other setae thick, strongly barbed: v 2 28 – 31, sc1 34 – 35, sc 2 31 – 32, c 1 25 – 29, c 3 26 – 27, d 1 22 – 23, d 3 27 – 28, e 3 24 – 28, f 2 20 – 21, f3 1 – 2, h1 1, h2 95.

Gnathosoma . Gnathosoma extends beyond genu I. Ventral cuticle anterior setae 1b finely papillate; cuticle with longitudinal plicae between setae 1b–1b and 1b–1a. Ventral setae m absent. Palps with three segments; setal formula: 0, 2, 0(2); tibia with two setae (d 8 – 9, v 7); tarsus with two eupathidia (6, 4). Cheliceral stylets 88.

Venter. Cuticle completely plicate, mostly covered with transverse striae; plicae longitudinal from gnathosoma to 1a; plicae transverse 1a–ag; plicae oblique laterad ps1–2. Setae fine; setae 1a, 1b elongate (difficult to determine full length). Setal measurements: 1a 57 – 61, 1 b 43, 2 c 7 – 10, 3 a 30, 3 b 8, ag 4, ps1 4, ps2 4.

Legs. Setal formulae for legs I – IV: 1-0-3-0-5-7(1), 1-0-3-0-5-7(1), 1-0-2-0-3-3, 0-0-2-0-3-3 respectively. Tarsi I and II each with one antiaxial solenidion ω ” (4; 3 respectively) and two distal eupathidia p ζ ’-p ζ ” (6, 6; 5, 5 respectively); ta I – IV u’-u” asymmetrically barbed. Femur I with long, barbed dorsal seta (24 – 25). Larva. (3 measured)

Dorsum. ( Fig. 8 ) Body measurements: v2 –h1 132, sc2–sc2 63, c3–c3 70, f3–f3 26. Cuticle almost entirely plicate with mostly transverse plicae between setae sc2–d1; central prodorsum and posterior opisthosoma with smooth cuticle. Dorsum with large rounded tubercle anterior to setae c1. Most opisthosomal setae set on small tubercles, except e3, f3, h1. Most dorsal setae of subequal length, thick, strongly barbed, except setae e3, f3, h1 minute; h2 elongate, lightly barbed basally: v2 23, sc 1 29 – 31, sc 2 28 – 29, c 1 22 – 23, c 3 25 – 26, d 1 26 – 29, d 3 26 – 27, e3 2, f 2 26 – 27, f3 1 – 2, h1 1 – 2, h2 98 – 100.

Gnathosoma . ( Fig. 8 ) Gnathosoma extends beyond tibia I. Ventral cuticle longitudinal; ventral setae m absent. Palps with three segmented; 0, 2, 0(2); tarsus with two eupathidia (6; 2); tarsus with two setae (d 7 – 9, v 6 – 7). Cheliceral stylets 80.

Venter. Plicae on cuticle fine, difficult to see, mostly transverse with longitudinal plicae between setae 1b–1a; transverse plicae between setae 1a–ps2, oblique laterad ps1–2. Setal measurements: 1a 79 – 94, 1 b 32, 3 a 25, ps1 2, ps2 3.

Legs. ( Fig. 8 ) Setal formulae for legs I – IV: 1-0-3-0-5-6(1), 0-0-3-0-5-6(1), 0-0-2-0-3-3 respectively. Tarsi I and II each with one antiaxial solenidion ω ” (3, 3 respectively) and two distal eupathidia p ζ ’-p ζ ” (5, 6; 5, 5 respectively); ta I – IV u’-u” asymmetrically barbed. Femur I with long, barbed dorsal seta (17 – 18).

Host. Rough saw sedge, Gahnia aspera sensu lato ( Cyperaceae ) growing along margin of notophyll vineforest.

Distribution. Mt Hedley, Far North Queensland.

Remarks. Live individuals of this species are yellow in colour and live within grooves on the ventral surface of the leaf blade of its sedge host plant.

Etymology. This species is named for the tubercles present over the dorsum. The Latin word “tuber” means swelling.

Figures

FIGURE 1. DIC image of adult female dorsum. a. Gahniacarus tuberculatus sp. nov.; b. Gahniacarus gersonus sp. nov.; c. Cyperacarus naomae sp. nov. (scale bar = 50 μm).

FIGURE 2. Gahniacarus tuberculatus sp. nov. adult female—dorsum, with detail of seta h 2.

FIGURE 3. Gahniacarus tuberculatus sp. nov. adult female—posterior venter; with details of variation in spermatheca.

FIGURE 4. Gahniacarus tuberculatus sp. nov. adult female—legs I – IV (legs I – II dorsal-paraxial view; legs III – IV dorsalantiaxial view).

FIGURE 5. Gahniacarus tuberculatus sp. nov. adult male—dorsum, with detail of legs; detail of aedeagus.

FIGURE 6. Gahniacarus tuberculatus sp. nov. deutonymph—dorsal opisthosoma.

FIGURE 7. Gahniacarus tuberculatus sp. nov. protonymph—dorsal opisthosoma.

FIGURE 8. Gahniacarus tuberculatus sp. nov. larva—dorsum, with detail of legs.