Austrostigmaeus walteri, Fan, Qing-Hai & Beard, Jennifer J., 2006

Fan, Qing-Hai & Beard, Jennifer J., 2006, Austrostigmaeus gen. n. (Acari: Prostigmata: Stigmaeidae), with the description of a new species from Australia, Zootaxa 1211, pp. 35-51 : 38-49

Austrostigmaeus walteri sp. n.

(Figs. 1–12; Plates 1–2)

Diagnosis

Adult female. Ratio vi: vi–vi = 3.9 (3.3–3.9), ve: ve–sci = 2.2 (1.8–2.2); central area of hysterosoma striated, c1–c1: d1–d1: e1–e1: f1–f1 = 1.1: 1.1: 1.0: 1.2, c1: c1–c1 = 0.6, d1: d1–d1 = 0.2, e1: e1–e1 = 1.0; 3 pairs of aggenital setae each on a platelet; tarsi 13 + 1, 9 + 1, 7

, 7.

Adult male. Palptarsus basally angled; subcapitulum broadly expanded, nearly as wide as idiosoma; vi: vi–vi = 1.9 (1.9–2.6), ve: ve–sci = 2.0, c1–c1: d1–d1: e1–e1: f1–f1 = 1.4 (1.3–1.4): 1.2: 1.0: 1.0, c1: c1–c1 = 0.5, d1: d1–d1 = 0.2 (0.2–0.3), e1: e1–e1 = 0.8; aggenital setae situated on an undivided shield; tarsi 13 + 2, 9 + 2, 7, 7.

Material examined

Holotype adult female: Australia: Western Australia, Kimberley Region, Galvan's Gorge, 16°47'55"S, 125°50'39"E, 30 Oct 2000, J.J. Beard, small shrub with lightly pubescent leaves, 1 female on a slide.

Paratypes: 2 adult females each on 1 slide, 4 adult males on 3 slides, 2 deutonymph females each on 1 slide; same data as holotype.

Description

ADULT FEMALE (n = 3)

Yellow to dark orange in life.

Gnathosoma (Figs. 1–2). Chelicera slender, 77 (77–83) long; movable digit less than 1/2 of chelicera, 34 (33–35) long. Palp 60 (58–66) long; accessory claw seta­like; setation from palptrochanter to palptarsus: 0, 3, 1, 3 + 1 claw, 4 + 1 + 1 subterminal spine­like eupathidium + 3 basally fused eupathidia; palptarsus normal, not basally angled; setae ba, bp and lp simple, setiform; solenidion more than 1/2 of palptarsus, 10 (10–11) long. Subcapitulum normal, not broadly expanded as in adult male, subcapitular setae n 2.6 (2.1–2.6)x length of m, m = 23 (23–25), n = 60 (53–61); distance m–m about 1.4 (1.3–1.4)x distance n–n, m–m = 30 (29–31), n–n = 22 (22–23), m–n = 7 (7–9).

Idiosoma (Figs. 1–2; Plates 1–2). Oval, 293 (279–292) long, 191 (162–192) wide. Dorsal idiosomal setae sparsely barbed. Prodorsum with a small plain shield bearing 2 pairs of setae (vi and ve) and a pair of eyes; setae sci on platelets; pob not observed; sce absent; eye 7 (7–8) in diameter, ratio vi: vi–vi = 3.9 (3.3–3.9), ve: ve–sci = 2.2 (1.8–2.2); setal lengths: vi 27 (26–27), ve 48 (44–49), sci 40 (36–41); distances: vi– vi 7 (7–8), vi–ve 20 (20–21), ve–sci 22 (22–25), ve–ve 31 (31–32), sci–sci 66 (66–74). Central area of hysterosoma striated, without obvious shield; setae c1, c2, d1, d2, e1, e2 and f1 situated on small platelets, c2, d1, d2, e2 and f1 much shorter than others; ratio c1–c1: d1–d1: e1–e1: f1–f1 = 1.1: 1.1: 1.0: 1.2, c1: c1–c1 = 0.6, d1: d1–d1 = 0.2, e1: e1–e1 = 1.0 (0.9–1.0); setal lengths: c1 33 (31–33), c2 20 (20–24), d1 13 (13–14), d2 13 (13–14), e1 47 (43–47), e2 15 (14–15), f1 13 (13–14); distances: c1–c1 54 (54–56), c1–c2 62 (62–67), c1–d1 50 (45–51), d1–d1 54 (54–61), d1–d2 47 (46–47), d1– e 1 47 (45–53), e1– e 1 47 (47–50), e1– e 2 30 (30–36), e1–f1 22 (16–22), f1–f1 56 (56–64). Suranal shield entire, bearing 2 pairs of barbed setae, h1 = 32 (32–33), h2 = 24 (24–26), h1–h1 = 22 (22–25), h1–h2 = 20 (19–20). Ventral setae 4a situated posterior to coxae IV, 1a 27 (24–27), 3a 23 (22–25), 4a 21 (18–21). Aggenital area with 3 pairs of subequal setae, each on a platelet, ag3 thicker than other two pairs, ag1 13, ag2 12 (12–13), ag3 11; distances ag1–ag2 = 15 (13–16), ag2–ag3 = 15 (15–21); genital opening with a pair of setae (g), 14 long; pseudanal setae ps3 14 (14–15), ps2 14 (14–16), ps1 12 (12–13).

Legs ( Figs. 2–3 ; Plate 2). Length: leg I 146 (146–153), leg II 115(111–121), leg III 118 (114–120), leg IV 138 (138–147). Setae d of femur I and genu I sparsely barbed, 21 (21–23) and 20 (20–25) long, respectively. Leg tarsal claw absent; membranous arolium developed; empodium rod­like, arising from arolium and bearing 3 Y­shaped tenent hairs. Setae v on leg I and II, v and v” on leg III and IV very long and barbed. Counts of setae and solenidia on legs I–IV: coxae 2 + 1 elc I, 1, 2, 2; trochanters 1, 1, 1, 1; femora 5, 4, 2, 2; genua 3 + 1, 1, 0, 0; tibiae 5 + 1 p, 5 + 1 p, 5 + 1 p, 5 + 1 p; tarsi 13 + 1, 9 + 1, 7

, 7. Lengths of solenidia: I 17 (17–19), II 20 (15–20), III 10 (9–10), IV 6 (6–8).

ADULT MALE (n = 3)

Gnathosoma ( Figs. 4–5 ; Plate 2). Chelicera slender, 78 (76–81) long; movable digit less than 1/2 of chelicera, 36 (34–36) long. Palp very strong, 93 (93–105) long; accessory claw seta­like; setation from palptrochanter to palptarsus: 0, 3, 1, 3 + 1 claw, 4 + 1 + 1 subterminal spine­like eupathidium + 3 basally fused eupathidia; palptarsus basally angled as members of Summersiella ; setae ba, bp and lp simple, setiform; solenidion more than 1/2 of palptarsus, 13 long. Subcapitulum broadly expanded, nearly as wide as idiosoma, subcapitular setae n 2.3 x length of m, m = 23 (22–24), n = 53 (51–54); distance m–m about 1.6x distance n–n, m–m = 50 (44–50), n–n = 31 (31–33), m–n = 10 (10–11).

Idiosoma ( Figs. 4–5 ; Plate 1). Oval, 237 (228–240) long, 118 (118–120) wide. Dorsal idiosomal setae sparsely barbed. Prodorsum with a small plain shield bearing 2 pairs of setae (vi and ve) and a pair of eyes; setae sci on platelets; pob not observed; sce absent; eye 7 (7–8) in diameter, ratio vi: vi–vi = 1.9 (1.9–2.6), ve: ve–sci = 2.0; setal lengths: vi 25 (23–25), ve 44 (36–44), sci 31 (28–31); distances: vi– vi 13 (9–13), vi–ve 24 (23–25), ve–sci 22 (21–23), ve–ve 36 (35–37), sci–sci 64 (64–70). Hysterosoma with a pair of small shields between setae d2; setae c1, d1, d2, e1, e2 and f1 situated on small platelets, c2, d1, d2, e2 and f1 much shorter than others; ratio c1–c1: d1–d1: e1–e1: f1–f1 = 1.4 (1.3–1.4): 1.2: 1.0: 1.0, c1: c1–c1 = 0.5, d1: d1–d1 = 0.2 (0.2–0.3), e1: e1–e1 = 0.8; setal lengths: c1 27 (24–28), c2 22 (21–24), d1 13 (12–13), d2 13 (12–13), e1 36 (36–37), e2 13 (12–13), f1 14 (13–14); distances: c1–c1 60 (53–60), c1–c2 35 (33–38), c1–d1 40 (39–41), d1–d1 53 (48–53), d1–d2 30 (27–32), d1– e 1 30 (29–31), e1– e 1 45 (43–45), e1– e 2 21 (17–21), e1–f1 17 (16–17), f1–f1 44 (41–44). Suranal shield entire, bearing 2 pairs of barbed setae; h1 thin, much shorter than h2, h1: h2 = 0.5 (0.4–0.5); h1 = 8, h2 = 17 (17–19), h1–h1 = 10, h1–h2 = 12 (12–13). Ventral setae 4a situated posterior to coxae IV, 1a 22 (20–22), 3a 23 (20–23), 4a 20 (17–20). Aggenital area with 3 pairs of setae, all on an undivided shield, ag3 thicker than other two pairs, lengths: ag1 12 (12–13), ag2 12 (12–14), ag3 13 (13–14); distances ag1–ag2 = 15 (12–15), ag2–ag3 = 10 (10–15); genital setae absent; pseudanal setae ps1 small, 6 (5–6), ps2 12 (12–13), ps1 12.

Legs ( Figs. 5–6 ). Length: leg I 152 (139–155), leg II 108 (103–111), leg III 109 (106–109), leg IV 136 (131–141). Setae d of femur I and genu I sparsely barbed, 23 (20–23) and 16 (16–21) long, respectively. Leg tarsal claw absent; membranous arolium developed; empodium rod­like, arising from arolium and bearing 3 Y­shaped tenent hairs. Setae v on leg I and II, v and v” on leg III and IV very long and barbed. Counts of setae and solenidia on legs I–IV: coxae 2 + 1 elc I, 1, 2, 2; trochanters 1, 1, 1, 1; femora 5, 4, 2, 2; genua 3 + 1, 1, 0, 0; tibiae 5 + 1 p, 5 + 1 p, 5 + 1 p, 5 + 1 p; tarsi 13 + 2, 9 + 2, 7

, 7. Lengths of solenidia: I 1 23 (20–24), I 2 34 (33–34), II 1 28 (27–29), II 2 32 (29–33), III 12, IV 12.

DEUTONYMPH FEMALE (n = 2)

Gnathosoma ( Figs. 7–8 ). Chelicera slender, 66 (63–66) long; movable digit 27 (27–28). Palp 42 (42–44) long; accessory claw seta­like; setation from palptrochanter to PLATE 1. Austrostigmaeus walteri sp. n. (A–B, adult female; C, adult male). A, prodorsum; B, hysterosoma; C, idiosoma.

palptarsus: 0, 3, 1, 3 + 1 claw, 4 + 1 + 1 subterminal spine­like eupathidium + 3 basally fused eupathidia; palptarsus not basally angled; setae ba, bp and lp simple, setiform; solenidion more than 1/2 of palptarsus, 7 long. Subcapitulum not broadly expanded as adult male, subcapitular setae n 2.3 x length of m, m = 16 (16–18), n = 36 (33–36); distance m–m about 1.3x distance n–n, m–m = 23 (23–24), n–n = 18 (18–19), m–n = 4.

Idiosoma ( Figs. 7–8 ). Oval, 224 (218–224) long, 137 (122–137) wide. Dorsal idiosomal setae sparsely barbed. Prodorsum with a small plain shield bearing 2 pairs of setae (vi and ve) and a pair of eyes; setae sci on platelets; pob not observed; sce absent; eye PLATE 2. Austrostigmaeus walteri sp. n. (A–C, adult female; D–E, adult male). A, genito­anal area; B, leg II; C, pretarsus II; D, palpi; E, subcapitulum.

7 in diameter, ratio vi: vi–vi = 3.3, ve: ve–sci = 1.8; setal lengths: vi 23 (23–30), ve 42 (42–43), sci 28 (27–28); distances: vi– vi 7, vi–ve 18, ve–sci 23 (21–23), ve–ve 30 (30–32), sci–sci 66 (66–67). Central area of hysterosoma faintly straited; setae c1, c2, d1, d2, e1, e2 and f1 situated on separate small platelets, c2, d1, d2, e2 and f1 much shorter than others; ratio c1–c1: d1–d1: e1–e1: f1–f1 = 1.3 (1.2–1.3): 1.3 (1.2–1.3): 1.0: 1.2, c1: c1–c1 = 0.6 (0.5–0.6), d1: d1–d1 = 0.2, e1: e1–e1 = 1.0; setal lengths: c1 24 (23–24), c2 27 (25–27), d1 9, d2 10, e1 38 (37–38), e2 10, f1 10; distances: c1–c1 53 (44–53), c1–c2 59, c1–d1 40 (36–40), d1–d1 50 (43–50), d1–d2 37 (34–37), d1– e 1 37 (37–39), e1– e 1 40 (37–40), e1– e 2 28 (27–28), e1–f1 17 (12–17), f1–f1 46 (45–46). Suranal shield entire, bearing 2 pairs of barbed setae, h1 = 23 (23–24), h2 = 16 (16–18), h1–h1 = 18 (15–18), h1–h2 = 11 (10–11). Ventral setae 1a 18 (18–19), 3a 19 (18–19), 4a 13 (13–15). Aggenital area with 3 pairs of subequal setae, each on a separate platelet, ag3 thicker than other two pairs, ag1 10, ag2 10, ag3 11; distances ag1–ag2 =12 (12–14), ag2–ag3 = 8 (7–8); genital setae absent; pseudanal setae ps3 12 (11–12), ps2 12 (10–12), ps1 10.

Legs ( Fig. 9 ). Length: leg I 105 (105–114), leg II 76 (76–80), leg III 78 (78–86), leg IV 91 (91–95). Setae d of femur I and genu I sparsely barbed, 11 (11–13) and 13 (13–14) long, respectively. Leg tarsal claw absent; membranous arolium developed; empodium rod­like, arising from arolium and bearing 3 Y­shaped tenent hairs. Setae v on leg I and II, v and v” on leg III and IV very long and barbed. Counts of setae and solenidia on legs I–IV: coxae 2 + 1 elc I, 1, 2, 2; trochanters 1, 1, 1, 0; femora 5, 4, 2, 2; genua 3 + 1, 1, 0, 0; tibiae 5 + 1 p, 5 + 1 p, 5 + 1 p, 5 + 1 p; tarsi 13 + 1, 9 + 1, 7, 7. Lengths of solenidia: I 14 (13–14), II 16 (14–16), III 7 (6–7), IV 6 (5–6).

Etymology

The species is named after Dr David Evans Walter (University of Alberta, Canada) who has broadened our knowledge of acarology.

Figures

FIGURE 2. Austrostigmaeus walteri sp. n. (adult female). A, ventral view of idiosoma; B, subcapitulum; C, genito­anal area; D, pretarsus II.

FIGURE 3. Austrostigmaeus walteri sp. n. (adult female). A, leg I; B, leg II; C, leg III; D, leg IV.

FIGURE 4. Austrostigmaeus walteri sp. n. (adult male). A, dorsal view of idiosoma; B, chelicerae; C, palp; D, palpal tarsus; E, dorsal view of opisthosoma; F, dorsal idiosomal setae.

FIGURE 5. Austrostigmaeus walteri sp. n. (adult male). A, ventral view of idiosoma; B, subcapitulum; C, genito­anal area; D, pretarsus III.

FIGURE 6. Austrostigmaeus walteri sp. n. (adult male). A, leg I; B, leg II; C, leg III; D, leg IV.

FIGURE 7. Austrostigmaeus walteri sp. n. (deutonymph female). A, dorsal view of idiosoma; B, chelicerae; C, palp.

FIGURE 8. Austrostigmaeus walteri sp. n. (deutonymph female). A, ventral view of idiosoma; B, subcapitulum; C, genito­anal area.

FIGURE 9. Austrostigmaeus walteri sp. n. (deutonymph female). A, leg I; B, leg II; C, leg III; D, leg IV.