Pentamerismus hicklingorum 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 : 104-111

Pentamerismus hicklingorum Seeman and Beard sp. nov.

( Figs 88–94 )

Type material examined. Holotype female ex. Coastal She-Oak, Casuarina equisetifolia (Casuarinaceae) , AUSTRALIA: Southeast Queensland, Beachmere, Bayside Drive, 27° 05′52′′ S, 153°05′21′′ E, 25 June 2010, coll. O.D. Seeman (QM). Paratypes. 8 females, 3 males, 2 deutonymphs, 1 protonymph, 4 larvae, same data as holotype (QM, ANIC).

Diagnosis. Dorsal opisthosomal setae f2 present. Palp setal formula 0-0-0-1-3(1), with palp tibial setae l′′PTi absent, l’PTi present. Anterior margin of prodorsal shield notched, forming 1 pair of short rounded lobes. Dorsal shields coarsely rugose with broadly rounded folds and weak reticulation; dorsal setae broadly lanceolate, barbed; lateral margins of opisthosoma coarsely papillate. Setae ag lanceolate, barbed; setae g1–2 fine, barbed; setae ps1–3 fine, ps1 barbed slightly thicker than ps2–3, ps2–3 fine, 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.

FEMALE (n = 9). Dorsum. ( Figs 88 a, 94) Body measurements: distance between setae v2 -h1 230–270 [240], sc2-sc2 105–110 [105]; other measurements: v2-v2 46 –51 [51], sc1-sc1 79–87 [83], c1-c1 51–55 [54], c2-c2 115– 120 [115], c3-c3 155–160 [155], d1-d1 37–44 [37], d2-d2 97–100 [98], d3-d3 140–145 [140], e1- e1 35–41 [36], e2-e2 135–140 [135], e3-e3 120–130 [125], f2-f2 105–120 [110], f3-f3 85–100 [87], h1-h 1 23–31 [24], h2-h2 47– 60 [56]. Anterior margin of prodorsal shield with 1 pair of small rounded lobes, forming short medial notch (internal depth 6–8). Dorsal shields coarsely rugose with broadly rounded folds and weak reticulation ( Fig. 94 ). Lateral cuticle surrounding shields coarsely papillate; cuticle between shields rugose. All dorsal setae barbed, lanceolate. Setal lengths: v 2 24–30 [25], sc 1 25–28 [25], sc 2 28–31 [31], c 1 25–31 [28], c 2 20–29 [25], c 3 22–26 [26], d 1 19–26 [24], d 2 22–24 [23], d 3 25–27 [27], e 1 18 –22 [18], e 2 20 –25 [23], e 3 18 –21 [20], f 2 18–20 [20], f 3 17–22 [18], h 1 17–19 [19], h 2 17–19 [19]. Palps. ( Fig. 88 b) Setal formula 0, 0, 0, 1, 3(1s+2e). Tibial setae, dorsal 9–10 [10] long; tarsal eupathidia 5–6 [6], 6–8 [7] long; solenidion 6 [6] long. Venter. ( Fig. 89 a) 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, weakly rugose. Setae g1 inserted in more-or-less transverse line with g2, g2 slightly anterior to g1. Genital shield mostly smooth, margins irregular, 30–33 [33] long, 41–44 [42] wide; anal setae ps1–3 inserted in longitudinal row on anal plates. Coxal setae fine, except 2c barbed; setae ag1 lanceolate, barbed; g1–2 fine, barbed; setae ps1–3 fine; ps1 barbed slightly thicker than ps2–3; ps2–3 smooth. Setal lengths: 1a 51–58 [54], 1b 25–30 [26], 2b 21–23 [21], 2c 17–18 [18], 3a 40–58 [45], 3b 13–15 [15], 4a 40–45 [45], 4b 11–15 [11], ag 1 16–21 [21], g 1 22–24 [22], g 2 19–22 [19], ps 1 13–15 [15], ps 2 13–14 [14], ps3 7–8 [7]. Spermatheca. ( Fig. 89 b) Spermathecal tube long, narrow, convoluted, <1 wide, ca. 130 long, terminating in membranous sac. Spermatheca vesicle visible in 2 specimens: 1 specimen with round spermatheca, ca. 3 diameter; second specimen with elongate spermatheca 6 long, 1–2 wide. Genital opening between anal valves and posterior margin of genital shield. Legs. ( Fig. 90 ) 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" (ta I 13–14 [14] long, ta II 13 [13] long) and 2 eupathidia pζ'-pζ" (6–7 [6–7] long). Leg setation as in Table 1 except coxae I without 1c. Setae v' added to tr IV.

MALE (n = 3). Dorsum. ( Fig. 91 ) Body measurements: distance between setae v2 -h1 190–200, sc2-sc2 86–91; other measurements: v2-v2 34 –35, sc1-sc1 68–69, c1-c1 32–33, c2-c2 90–92, c3-c3 115–125, d1-d 1 22–28, d2-d2 73–81, d3-d3 100–105, e1- e1 34–40, e2- e2 90–92, e3- e3 91–96, f2-f2 80–83, f3-f3 63–65, h1-h 1 16–20, h2-h2 41– 45. Anterior margin of prodorsum with pair of small lobes forming a short medial notch (internal depth 5–6). Prodorsal, mesonotal and pygidial shields with sculpture and dorsal setae similar to female. Medial soft cuticle striated, lateral cuticle reticulated to striated. Setal lengths: v 2 21–22, sc1 17, sc2 21, c 1 18–20, c 2 17–22, c 3 16– 17, d 1 13–15, d 2 13–15, d 3 14–16, e 1 13 –15, e 2 15 –16, e 3 15 –16, f2 15, f 3 14–16, h 1 13–15, h 2 15–16. Palps. Palps similar to female. Tibial seta 8–10 long; tarsal eupathidia 5–6, 7 long; solenidion 7 long. Venter. ( Fig. 92 a) Striae entirely transverse, becoming coarse behind cx IV. Posterior opisthosoma with 2 irregular, poorly defined, striated subcircular plates, ca. 25–35 in diameter; g1–2, ps1–3 on weakly sclerotised anal valves. Coxal setae fine, except 2c barbed. Seta ag1 lanceolate, barbed; g1 barbed; g2, ps2, ps3 smooth; ps1 spine-like, thickened. Setal lengths: 1a 38–50, 1 b 22–26, 2 b 15, 2 c 15–17, 3 a 37–45, 3 b 11–15, 4 a 40–45, 4 b 15–25, ag 1 13–16, g1 6–7, g 2 14–15, ps 1 8–14, ps 2 7–10, ps3 6–8. Aedeagus. ( Fig. 92 b) Narrow, sclerotised, tapering to a point, 65–68 long; curved in 2 preparations. Membranous duct runs from inside aedeagus. Legs. Setal formula same as female. Tarsi I and II each with 1 antiaxial solenidion ω" (15–17 long) and 2 eupathidia pζ'-pζ" (6–7 long). Solenidia slightly thicker and longer than in female.

DEUTONYMPH (n = 2). Dorsum. Body measurements: distance between setae v2 -h1 185–195, sc2-sc2 90– 91; other measurements: v2-v2 30, sc1-sc1 73–75, c1-c 1 28–30, c2-c2 88–96, c3-c3 122–131, d1-d 1 23–25, d2-d2 81, d3-d3 110–114, e1- e 1 27–28, e2-e2 103–105, e3- e3 95–102, f2-f2 79–90, f3-f3 70–75, h1-h 1 21–22, h2-h2 43– 48. Anterior margin of prodorsum without medial lobes or notch. Prodorsal shield poorly defined, with fine oblique-longitudinal striations. Transverse striae between setal row C to midway between rows D and E; then opisthosomal shield region with irregular polygons arranged in oblique to longitudinal pattern. Setae v2, sc1 thickened slightly, barbed; setae sc2 narrowly lanceolate; opisthosomal setae lanceolate. Setal lengths: v 2 10–16, sc 1 15–16, sc 2 15–18, c 1 16–17, c 2 16–21, c 3 21–23, d 1 13–17, d 2 19–20, d3 27, e 1 16 –19, e 2 23 –27, e 3 20 –22, f 2 21–25, f 3 21–22, h 1 16–19, h 2 16–21. Palps. Palps similar to adult. Tibial seta 7 long; tarsal eupathidia 3, 5 long; solenidion 3 long. Venter. Striation similar to female; anal setae ps1–3 on weakly defined anal plates. Coxal setae fine, except 2c barbed; setae ag1 and ps1 with few or no barbs; other setae smooth. Setal lengths: 1a 33–35, 1 b 14– 15, 2 b 10–11, 2 c 13–14, 3 a 25–40, 3 b 8–12, 4 a 19–29, 4 b 7–10, ag 1 13–14, g 1 11–12, ps1 6, ps2 6, ps3 6. Legs. 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, 1-0-1-0-3-5. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 6–8 long, ta II 6–7 long) and 2 eupathidia pζ'-pζ" (about 5 long). Leg setation as in adult except: tr IV without seta v ′. Setae v' added to tr I–III.

PROTONYMPH (n = 1). Dorsum. Body measurements: distance between setae v2 -h1 145, sc2-sc2 80; other measurements: v2-v2 27, sc1-sc1 66, c1-c1 20, c2-c2 83, c3-c3 110, d1-d1 19, d2-d2 71, d3-d3 92, e1- e1 18, e2- e2 78, e3- e3 70, f2-f2 48, f3-f3 45, h1 missing on left hand side, h2-h2 23. Anterior margin of prodorsum without medial notch. Dorsal cuticle similar to deutonymph, except opisthosoma with coarse irregular striae only. Setae similar in length to those of adult; narrowly lanceolate, barbed. Setal lengths: v2 19, sc1 14, sc2 15, c1 19, c2 19, c3 20, d1 17, d2 23, d3 23, e1 23, e2 25, e3 20, f2 24, f3 23, h1 23, h2 18. Palps. Palps similar to adult. Tibial seta 6 long; tarsal eupathidia 3, 5 long; solenidion 3 long. Venter. Cuticle same as deutonymph. Anal setae ps1–3 on weakly defined anal plates. Coxal and anal setae fine, except 2a with few barbs. Setal lengths: 1a 33, 1 b 8, 2 b 10, 3a 35, 3 b 10, ag1 9, ps1 5, ps2 5, ps3 5. Legs. Setal formula for legs I–IV (coxae to tarsi) 1-0-3-1-4-9(1), 1-0-3-1- 4-9(1), 1-1-2-1-3-5, 0-0-1-0-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (4 long) and 2 eupathidia pζ'-pζ" (3-4 long). Leg setation as in deutonymph except: seta 2c absent; seta 4b absent; tr I–III without seta v ′; ge I–II without seta d, l′′; ta IV without setae tc ′, tc′′. Setae l' added to tr III.

LARVA (n = 4). Dorsum. ( Fig. 93 ) Body measurements: distance between setae v2 -h1 110–125, sc2-sc2 56– 59; other measurements: v2-v 2 23–27, sc1-sc1 48–51, c1-c 1 14–17, c2-c2 57–63, c3-c3 81–87, d1-d 1 9–11, d2-d2 51–58, d3-d3 68–74, e1- e1 7, e2- e2 52–57, e3- e3 41–46, f2-f 2 30–35, f3-f 3 22–28, h1-h 1 9–10, h2-h 2 13–14.

Anterior margin of prodorsum without medial notch. Prodorsal shield absent, with longitudinal striations. Opisthosomal shield absent; coarse, irregular transverse striae, becoming oblique posteriorly. Setae similar in length to those of adult; setae narrowly lanceolate to thickened, barbed; setae d1 and e1 broadest; setae h2 narrowest. Setal lengths: v 2 14–18, sc 1 12–15, sc 2 14–16, c 1 15–19, c2 15, c 3 11–14, d1 20, d 2 14–16, d 3 13–16, e 1 18 –22, e 2 14 –17, e 3 15 –16, f2 15, f 3 15–16, h 1 14–16, h 2 16–18. Palps. ( Fig. 93 ) Palps similar to adult. Tibial seta 6–7 long; tarsal eupathidia both 5 long; solenidion 3 long. Venter. Cuticle with transverse striae to setae 3a, longitudinal to anal area, slightly coarser around anal area. Anal setae ps1–3 on weakly defined anal plates. Coxal setae fine. Setal lengths: 1a 28–37, 1 b 13–19, 3 a 32–40, ps1 4–5, ps2 4–5, ps3 4–5. Legs. ( Fig. 93 ) 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" (4 long) and 2 eupathidia pζ'-pζ" (4–5 long). Leg setation as in protonymph except: seta 2b absent; seta 3b absent; tr I–III nude; ta I–III without seta tc ′, tc′′.

Etymology. It is with great pleasure that the manuscript’s second author names this species for his mother’s family, the Hicklings.

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

Individual adults were found in close association with their cast nymphal skins ( Fig. 94 ), and often still within the deutonymphal and/or protonymphal skins.

Figures

FIGURE 88. Pentamerismus hicklingorum Seeman and Beard, adult female, a. dorsum; b. detail of palp (scale bar for palp = 25 Μm).

FIGURE 89. Pentamerismus hicklingorum Seeman and Beard, adult female, a. posterior venter; b. detail of spermatheca.

FIGURE 90. Pentamerismus hicklingorum Seeman and Beard, adult female, legs (legs I – II left side, ventral aspect; legs III – IV right side, ventral aspect); solenidion ω " and eupathidia (pζ ′ - pζ ′′) not labelled on legs I – II.

FIGURE 91. Pentamerismus hicklingorum Seeman and Beard, adult male, dorsum.

FIGURE 92. Pentamerismus hicklingorum Seeman and Beard, adult male, a. posterior venter; b. aedeagus.

FIGURE 93. Pentamerismus hicklingorum Seeman and Beard, larva, dorsum with details of legs I – II and palps.

FIGURE 94. Pentamerismus hicklingorum Seeman and Beard, adult female, moulting in close association with deutonymphal and protonymphal skins.