Pentamerismus wardo Seeman and Beard

Beard, Jennifer J., Seeman, Owen D. & Bauchan, Gary R., 2014, Tenuipalpidae (Acari: Trombidiformes) from Casuarinaceae (Fagales), Zootaxa 3778 (1), pp. 1-157 : 97-104

Pentamerismus wardo Seeman and Beard sp. nov.

( Figs 82–87 )

Type material examined. Holotype female ex. Allocasuarina scleroclada (Casuarinaceae) , AUSTRALIA: Western Australia, approx. 3 km N Coomberdale, along Moora-Watheroo Road, 30°24’17” S 116°02’29” E, 15 April 2009, coll. J.J. Beard ( WAM) ( BRI voucher, BRI [AQ814925]). Paratypes. 6 females, 3 pharate females, 2 males, 2 pharate males, 4 larvae, same data as holotype ( WAM, QM, ANIC, USNM).

Diagnosis. Dorsal opisthosomal setae f2 present. Palp setal formula 0-0-0-2-3(1), with palp tibial setae l’PTi and l′′PTi both present. Anterior margin of prodorsal shield with short notch. Dorsal shields with irregular weakly reticulate to rugose mosaic sculpturing; dorsal setae broadly lanceolate, barbed; lateral margins of opisthosoma with transverse to oblique folds or striae. Posterior ventral setae ag fine, barbed; setae g1–2 fine, barbed; setae ps1– 3 fine, ps1 slightly thicker than ps2–3, ps1–2 barbed, ps3 smooth. Seta 1c absent. Setae d on femora and genua I–II lanceolate; seta ev ′ on femora III fine, smooth; setae v ′, v′′ on tibiae III fine, smooth to weakly barbed.

FEMALE (n = 7). Dorsum. ( Fig. 82 a) Body measurements: distance between setae v2 -h1 220–260 [260], sc2- sc2 105–120 [110]; other measurements: v2-v2 40 –46 [45], sc1-sc1 77–86 [86], c1-c1 49–72 [51], c2-c2 110–135 [110], c3-c3 160–180 [160], d1-d1 33–38 [38], d2-d2 90–115 [98], d3-d3 130–150 [135], e1- e1 36–43 [41], e2-e2 120–140 [130], e3-e3 110–125 [115], f2-f2 96–110 [100], f3-f3 77–89 [80], h1-h 1 24–29 [24], h2-h2 54–63 [54].

Anterior margin of prodorsal shield with 1 pair of small lobes forming short medial notch (internal depth 9–12). Prodorsal shield with irregular weakly reticulate to rugose mosaic of polygonal cells medially, with cells elongate anteriorly and laterally. Opisthosomal shield with similar pattern to prodorsal shield, except pattern less complete, especially laterally. Lateral cuticle surrounding prodorsal shield smooth to weakly rugose medially, with some weak folds posteriorly; lateral cuticle surrounding opisthosoma with transverse to oblique folds and striae. All dorsal setae barbed, lanceolate, becoming broader posteriorly. Setal lengths: v 2 22–27 [22], sc 1 24–27 [24], sc 2 26–31 [26], c 1 22–26 [22], c 2 25–26 [25], c 3 20–23 [20], d 1 16–17 [not measurable], d 2 16–20 [16], d 3 18–20 [18], e 1 15 –17 [not measurable], e 2 17 –19 [17], e 3 19 –21 [19], f 2 17–19 [17], f 3 17–19 [17], h 1 17–18 [17], h 2 18– 20 [18]. Palps. ( Fig. 82 b) Setal formula 0, 0, 0, 2, 3(1s+2e). Tibial setae, dorsal 5–6 [6] long, ventral 7–9 [7] long; tarsal eupathidia 3–4 [3] long, 5 [5] long; solenidion 5–6 [5] long. Venter. ( Fig. 83 ) Cuticle with transverse striae, becoming longitudinal just anterior to setae ag, becoming coarse around genital area. Circular thickening present in metapodal region, ca. 25 diameter, rugose. Setae g1 inserted in more-or-less transverse line with g2, g2 slightly anterior to g1. Genital shield punctate, margins irregular, 30–32 [32] long, 40–45 [43] wide; anal setae ps1–3 inserted in longitudinal row on anal plates. Coxal setae fine, except 2c thickened, barbed; setae ag1 fine, barbed; g1–2, ps1–2 fine, barbed; ps3 fine, smooth. Setal lengths: 1a 47–52 [47], 1b 18–31 [17], 2b 20–25 [20], 2c 16–20 [17], 3a 49–58 [49], 3b 15–19 [19], 4a 46–55 [46], 4b 11–17 [15], ag 1 12–20 [19], g 1 18–24 [20], g 2 15–22 [15], ps 1 13–15 [13], ps 2 13–14 [13], ps3 7–8 [17]. Spermatheca. Spermathecal tube long, narrow, convoluted, <1 wide,> 70 long. Spermatheca vesicle obscured in all specimens. Genital opening between anal valves and posterior margin of genital shield. Legs. ( Fig. 84 ) Setal formula for legs I–IV (coxae to tarsi) 1-1-3-3-4-9(1), 2-1-3-3-4-9(1), 1-2-2-1-3-5, 1-1-1-0-3-5. Tarsi I and II each with 1 antiaxial solenidion ω" (9–10 [9] long) and 2 eupathidia pζ'-pζ" (6–7 [7] long). Leg setation as in Table 1 except coxae I without 1c.

MALE (n = 2). Dorsum. ( Fig. 85 ) Body measurements: distance between setae v2 -h1 185–190, sc2-sc2 85–88; other measurements: v2-v 2 26–30, sc1-sc1 63–67, c1-c1 39–41, c2-c2 89–93, c3-c3 120–125, d1-d 1 20–22, d2-d2 70–74, d3-d3 93–97, e1- e 1 29–34, e2- e2 89–93, e3- e3 17, f2-f2 76–77, f3-f3 61–63, h1-h 1 13–14, h2-h2 15. Anterior margin of prodorsum with pair of small lobes forming a short medial notch (internal depth 3–4). Prodorsal, mesonotal and pygidial shields with sculpture and dorsal setae similar to female. Medial soft cuticle striated, lateral cuticle smooth, becoming festo1d posteriorly. Setal lengths: v 2 20–22, sc1 21, sc 2 21–22, c1 18, c 2 19–21, c3 17, d 1 11–13, d2 15, d 3 15–16, e1 12, e2 16, e3 17, f2 16, f 3 16–17, h 1 13–14, h2 15. Palps. ( Fig. 85 ) Palps similar to female. Tibial setae, dorsal 6 long, ventral 7–8 long; tarsal eupathidia 3, 5–6 long; solenidion 4–5 long. Venter. ( Fig. 86 ) Striae entirely transverse, becoming coarse behind cx IV. Posterior opisthosoma with 2 irregular, poorly defined, striated subcircular plates, ca. 30 in diameter; g1–2, ps1–3 on weakly sclerotised anal valves; ps1 modified, thickened. Coxal setae fine, except 2c thickened, barbed. Seta ag1 narrowly lanceolate, barbed; g1 lanceolate; g2, ps2, ps3 smooth; ps1 spine-like, thickened. Setal lengths: 1a 38–48, 1 b 26, 2 b 26, 2 c 13, 3a 30–37, 3 b 18–19, 4 a 47, 4 b 20, ag1 13, g1 11, g 2 11–13, ps 1 11–14, ps2 7, ps3 6–7. Aedeagus. Narrow, sclerotised, tapering to a point, 66 long, curved. Membranous duct runs from inside aedeagus. Legs. ( Fig. 85 ) Setal formula same as female. Tarsi I and II each with 1 antiaxial solenidion ω" (9–10 long) and 2 eupathidia pζ'-pζ" (about 6 long).

LARVA (n = 2). Dorsum. ( Fig. 87 ) Body measurements: distance between setae v2 -h1 130–140, sc2-sc2 54– 59; other measurements: v2-v 2 20–22, sc1-sc1 44–48, c1-c 1 17–20, c2-c2 61, c3-c3 87–89, d1-d1 13, d2-d2 51–52, d3-d3 72–76, e1- e 1 8–10, e2- e2 56–61, e3- e3 50–53, f2-f2 36–38, f3-f 3 24–31, h1-h1 4–6, h2-h 2 11–16. Anterior margin of prodorsum without medial notch. Prodorsal shield 54–57 long, 64 wide, defined by numerous longitudinal striations. Opisthosomal shield absent; coarse, irregular transverse striae, becoming obsolete between d1-e1. Setae similar in length to those of adult; setae narrowly lanceolate to thickened, barbed; setae d1 and e1 broadest; setae v2, sc1, sc2, h2 narrowest. Setal lengths: v 2 14–19, sc 1 13–15, sc 2 14–17, c 1 19–20, c2 14, c 3 14– 15, d 1 19–20, d 2 17–18, d 3 17–20, e 1 21 –22, e 2 20 –21, e 3 20 –23, f2 20, f 3 24–26, h 1 24–25, h2 20. Palps. ( Fig. 87 ) Palps similar to adult. Tibial setae, dorsal 4 long, ventral 5 long; tarsal eupathidia 3, 4 long; solenidion 3 long. Vent er. Cuticle with transverse striae to setae 3a, oblique posterior to 3a, transverse to midway between 3a and ps3, then longitudinal anal area, slightly coarser around anal area. Anal setae ps1–3 on weakly defined anal plates. Coxal setae fine. Setal lengths: 1a 25–30, 1 b 15, 3a 35–38, ps1 3–4, ps2 4–5, ps3 4–5. Legs. ( Fig. 87 ) Setal formula for legs I–III (coxae to tarsi) 1-0-3-1-4-7(1), 0-0-3-1-4-7(1), 0-0-2-1-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 5 long, ta II 4 long) and 2 eupathidia pζ'-pζ" (about 4 long). Leg setation as in Table 1.

Etymology. The specific name, wardo , is an Australian indigenous word meaning “a little bird” referring specifically to the Willy Wagtail ( Rhipidura leucophrys Latham ( Rhipiduridae )), and is the source of the town name Watheroo, near which this mite was collected.

Remarks. Pentamerismus wardo is similar to P. hicklingorum , but can be separated by having two setae on the palp tibia (one seta on the palp tibia of P. hicklingorum ) and the dorsal cuticle being weakly reticulate (with broadly rounded folds on P. hicklingorum ).

Individuals were found buried in the thick pubescence present on the tips of the needle-like stems and branchlets of the host.

Figures

FIGURE 82. Pentamerismus wardo Seeman and Beard, adult female, a. dorsum; b. detail of palp (scale bar for palp = 25 Μm).

FIGURE 83. Pentamerismus wardo Seeman and Beard, adult female, posterior venter.

FIGURE 84. Pentamerismus wardo Seeman and Beard, adult female, legs (right side), eupathidia (pζ ′ - pζ ′′) and unguinal setae (u ′ - u ′′) not labelled on legs I – II.

FIGURE 85. Pentamerismus wardo Seeman and Beard, adult male, dorsum with details of legs and palps.

FIGURE 86. Pentamerismus wardo Seeman and Beard, adult male, posterior venter.

FIGURE 87. Pentamerismus wardo Seeman and Beard, larva, dorsum with detail of legs and palps.