Crossipalpus gersoni Beard and Seeman

Beard, Jennifer J., Seeman, Owen D. & Bauchan, Gary R., 2014, Tenuipalpidae (Acari: Trombidiformes) from Casuarinaceae (Fagales), Zootaxa 3778 (1), pp. 1-157 : 36-44

Crossipalpus gersoni Beard and Seeman sp. nov.

( Figs 25–31 )

Type material examined. Holotype female ex. stems of Allocasuarina luehmannii (Casuarinaceae) , AUSTRALIA: Queensland, near Mount Slopeaway, on the old Marlborough-Sarina Road, 22°52’16” S 149°50’28” E, 19 March 2005, coll. J.J. Beard and P.I. Forster (QM). Paratypes. 14 females, 6 males, 4 deutonymphs, 3 protonymphs, and 4 larvae, same data as holotype (QM, ANIC, USNM).

Diagnosis. Dorsal setae short, broadly lanceolate, strongly barbed; dorsal setae subequal in length except c1, d1, e1, h1 obviously shorter. Palpal segments as wide as long. Genua I–II with seta d, without l′′; tarsi I–IV without seta tc′′. Solenidia of male much thicker and longer than in female.

Female (n = 15). Dorsum. ( Fig. 25 a) Body measurements: distance between setae v2 -h1 275–325 [325]; sc2- sc2 88–110 [110]; other measurements: v2-v 2 19–22 [22], sc1-sc1 69–89 [89], c1-c 1 29–37 [37], c2-c2 105–125 [125], c3-c3 125–145 [145], d1-d 1 23–28 [28], d2-d2 89–110 [110], d3-d3 105–130 [130], e1- e 1 6–17 [6], e2- e2 92–120 [120], e3- e3 83–100 [100], f3-f3 71–89 [89], h1-h 1 14–18 [17], h2-h2 49–58 [58]. Gnathosoma completely concealed beneath prodorsum ( Fig. 26 ). Anterior margin of prodorsum rounded. Seta v2 inserted dorsally, though its setal base is sometimes partially concealed by an anterior fold ( Fig. 25 a). Prodorsal shield weakly developed with papillate-rugose sculpturing laterally, longitudinal grooves medially. Opisthosomal shield weakly developed with rugose to lineate pattern, becoming weakly rugose medially between setae d1-e1. Lateral cuticle surrounding shields rugose-papillate. Most dorsal setae broadly lanceolate, barbed; medial opisthosomal setae shorter than lateral setae, palmate. Setal lengths: v 2 13–17 [17], sc 1 15–19 [19], sc 2 15–21 [21], c 1 8–11 [11], c 2 13–15 [15], c 3 15–22 [22], d1 5–9 [9], d 2 12–14 [14], d 3 13–18 [18], e1 4 –7 [7], e 2 14 –17 [17], e 3 14 –17 [17], f 3 15–18 [18], h1 5–7 [7], h 2 13–17 [17]. Palps. ( Figs 25 b, 26) Setal formula 0, 0, 0, 1, 3 (1s+2e). Tibial seta 6–8 [6] long; tarsal eupathidia 6 long, 5–6 [5] long; solenidion 5–6 [6] long. Vent er. ( Figs 26 , 27 a) Cuticle with fine transverse striae between setae 1a -3a, longitudinal between setae 3a -4a, then convex for 20–30, striae longitudinal posterior to setae 4a; fine striae become coarse lateral to genital area. Genital setae inserted in more-or-less transverse row, g1 inserted slightly posterior to level of g2. Genital shield smooth, poorly developed, ca. 15–20 [16] long, 35–40 [38] wide; anal setae ps1–2 inserted medially on anal plates in longitudinal line; seta ps3 absent. Coxal setae fine, except 2c heavily barbed; setae ag1, g1–2, ps1–2 lanceolate. Setal lengths: 1a 44–55 [44], 1b 20–26 [25], 2b 13–19 [19], 2c 14–17 [17], 3a 35–50 [50], 3b 12–22 [22], 4a 40–46 [45], 4b 13–17 [17], ag 1 9–11 [11], g 1 12–15 [15], g 2 12–14 [13], ps 1 7–11 [11], ps 2 8–10 [10]. Spermatheca. ( Fig. 27 b) Spermathecal tube long, distinctly broad near external opening, becoming narrow and convoluted distally, maximum 2 wide, ca. 100 long. Thickened part of tube 52–56 long. Spermatheca vesicle not visible. Genital opening between setae ps2. Legs. ( Fig. 28 ) Setal formula for legs I–IV (coxae to tarsi) 1-1-3-1-4-8(1), 2-1-3-1-4-8(1), 1-2-2-0-3-4, 1-1-1-0-3-4. Tarsi I and II each with 1 antiaxial solenidion ω" (7–8 [8] long) and 2 eupathidia pζ'-pζ" (6–7 [7] long, 6–8 [8] long). Leg setation as in Table 1 except: coxae I without 1c; genua I–II with d, without l ′ and l′′; tarsi I–IV without tc′′. Setae v' added to tr IV.

MALE (6 paratypes). Dorsum. ( Figs 29 , 30 a) Body measurements: distance between setae v2 -h1 195–225, sc2-sc2 76–81; other measurements: v2-v 2 11–13, sc1-sc1 56–63, c1-c 1 25–28, c2-c2 78–87, c3-c3 99–110, d1-d 1 10–14, d2-d2 68–71, d3-d3 79–87, e1- e1 7–8, e2- e2 67–71, e3- e3 61–65, f3-f3 52–58, h1-h 1 8–10, h2-h 2 30–40. Gnathosoma not concealed beneath prodorsum. Anterior margin of prodorsum smooth, weakly convex. Prodorsal shield weakly developed. Opisthosoma with mesonotal shield (appearing as a pair of shields) on which at least setae c1, d1 and d2 inserted, with weak rugose-lineate pattern; and pygidial shield with at least setae e1, e3, f3, h2 inserted, with oblique-longitudinal weakly lineate pattern; setae h1 often under posterior extension of pygidial shield ( Fig. 30 a); shields separated by transverse striae; cuticle laterad mesonotal shield papillate; several minute pores visible on shields. Setal lengths: v 2 13–15, sc 1 13–17, sc 2 15–18, c 1 9–11, c 2 10–12, c 3 12–17, d1 8–9, d 2 10–12, d 3 12–16, e1 5, e 2 13 –15, e 3 12 –16, f 3 13–14, h1 6–7, h 2 12–14. Palps. ( Fig. 29 ) Palps similar to female.

Tibial seta 8 long; tarsal eupathidia 5–6, 6 long; solenidion 7 long. Venter. ( Figs 30 b, c) All striae transverse, becoming coarse on opisthogaster and weak around setae ag1. Coxal setae fine, except 2c narrowly lanceolate. Setae ag1, g2 thick, barbed; g1, ps2 thin, barbed; setae ps1 modified to form thick blades (sexually dimorphic) ( Figs 29 ; 30a, b). Setal lengths: 1a 33–40, 1 b 23–25, 2 b 18–20, 2 c 10–15, 3 a 42–45, 3 b 10–12, 4 a 36–45, 4 b 10– 14, ag 1 7–10, g 1 7–10, g 2 10–11, ps 1 13–16, ps2 6. Aedeagus. ( Figs 30 c, d) Narrow, sclerotised, tapering to a point, 55–61 long. Membranous duct runs from inside aedeagus, becoming indistinguishable. Legs. ( Fig. 29 ) Setal formula same as female. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 9–10 long, ta II 9 long) and 2 eupathidia pζ'-pζ" (ta I 5–6, 6 long; ta II 6, 6 long). Solenidia much thicker and longer than in female.

DEUTONYMPH (4 paratypes). Dorsum. Body measurements: distance between setae v2 -h1 215–250, sc2-sc2 71–87; other measurements: v2-v 2 18–22, sc1-sc1 57–67, c1-c1 22, c2-c2 76–90, c3-c3 97–113, d1-d 1 15–20, d2- d2 56–68, d3-d3 77–94, e1- e 1 7–11, e2- e2 68–81, e3- e3 62–78, f3-f3 52–62, h1-h 1 11–13, h2-h2 35–39. Prodorsal shield weakly developed with oblique-longitudinal striations. Opisthosoma with setae c1, d1 and d2 on paired, weak platelets. Striae transverse, becoming convex posteriorly. Setal lengths: v 2 12–18, sc 1 16–17, sc 2 16–20, c 1 11–13, c 2 14–17, c 3 13–16, d 1 8–11, d 2 13–17, d 3 14–17, e1 5, e 2 14 –17, e 3 14 –15, f 3 13–15, h1 6–8, h 2 13–16. Palps. Palps similar to adult. Tibial seta 6 long; tarsal eupathidia 3, 4 long, solenidion 4 long. Venter. Cuticle with transverse striae anteriorly, longitudinal between setae 3a-4a, then transverse, becoming concave, to ag1, then transverse and coarse to posterior margin. Coxal setae fine, except 2c barbed; setae ag1 narrowly lanceolate, g1 barbed. Setal lengths: 1a 35–40, 1 b 12–16, 2 b 11–17, 2 c 12–14, 3 a 26–36, 3 b 10–15, 4 a 27–30, 4 b 10–15, ag 1 8– 10, g 1 8–12, ps1 6–8, ps2 6–8. Legs. Setal formula for legs I–IV (coxae to tarsi) 1-1-3-1-4-8(1), 2-1-3-1-4-8(1), 1- 2-2-0-3-4, 1-0-1-0-3-4. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 4–6 long, ta II 4–5 long) and 2 eupathidia pζ'-pζ" (5, 5–6 long). Leg setation as in adult except: tr IV without seta v ′. Setae v' added to tr I–III.

PROTONYMPH (3 paratypes). Dorsum. Body measurements: distance between setae v2 -h1 158–181, sc2-sc2 64–70; other measurements: v2-v 2 16–19, sc1-sc1 52–57, c1-c 1 16–24, c2-c2 63–76, c3-c3 97–99, d1-d 1 16–17, d2-d2 49–51, d3-d3 67–73, e1- e1 6, e2- e2 64–67, e3- e3 57–61, f3-f3 43–44, h1-h 1 22–24, h2-h2 7–9. Prodorsal shield weakly developed. Opisthosoma with setae c1, d1 and d2 on paired, weak platelets. Striae of idiosoma similar to deutonymph. Setal lengths: v 2 13–15, sc 1 14–15, sc 2 14–15, c 1 12–13, c 2 14–16, c 3 13–14, d1 11, d 2 13–14, d3 14, e1 4 –5, e2 12, e 3 14 –15, f 3 9–13, h1 4–5, h 2 9–15. Palps. Palps similar to deutonymph except solenidion 3 long. Venter. Same as deutonymph. Coxal setae fine, except 2b, ag1 barbed. Setal lengths: 1a 36, 1 b 11–13, 2 b 13–16, 3 a 30, 3 b 9, ag1 7, ps1 5, ps2 5–6. Setae 2c, 4a, 4b, g1, g2 absent. Legs. Setal formula for legs I– IV (coxae to tarsi) 1-0-3-0-4-8(1), 1-0-3-0-4-8(1), 1-1-2-0-3-4, 0-0-1-0-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (4 long) and 2 eupathidia pζ'-pζ" (5, 4–5 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; ta IV without setae tc ′. Setae l' added to tr III.

LARVA (4 paratypes). Dorsum. ( Fig. 31 ) Body measurements: distance between setae v2 -h1 130–150, sc2-sc2 55–60; other measurements: v2-v 2 13–15, sc1-sc1 43–49, c1-c 1 12–16, c2-c2 51–55, c3-c3 84–85, d1-d 1 13–15, e1- e1 4–5, e2- e2 57–62, e3- e3 38–44, f3-f 3 11–13, h1-h1 5–7, h2-h 2 10–13. Prodorsal shield weakly formed, 58– 60 long, 61–66 wide, with few irregular striations. Opisthosomal shields absent; coarse, irregular transverse striae becoming oblique posteriorly. Setal lengths: v 2 11–14, sc 1 12–13, sc 2 14–15, c1 10, c 2 12–14, c3 11, d 1 9–11, d 2 11–14, d 3 11–13, e1 3 –4, e 2 11 –15, e 3 11 –12, f 3 11–13, h1 4–5, h 2 11–14. Palps. ( Fig. 31 a) Palps same as deutonymph. Tibial seta 5–6 long; tarsal eupathidia 2, 3 long, solenidion 2–3 long. Venter. ( Fig. 31 b) Striation same as deutonymph. All setae fine. Setal lengths: 1a 17–27, 1 b 9–13, 3 a 25–33, ps1 4–5, ps2 4–5. Legs. ( Fig. 31 c) Setal formula for legs I–III (coxae to tarsi) 1-0-3-0-4-7(1), 0-0-3-0-4-7(1), 0-0-2-0-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (3 long) and 2 eupathidia pζ'-pζ" (ta I 4, 4 long; ta II 5, 5 long). Leg setation as in protonymph except: seta 2b absent; seta 3b absent; tr I–III nude; ta I–III without seta tc ′.

Etymology. It is with great pleasure that we name this species for our colleague and friend Prof. Uri Gerson, in recognition of his acarological works, especially those on the Tegopalpinae.

Remarks. Crossipalpus gersoni sp. nov. was found on Bull-Oak Allocasuarina luehmannii in Eucalyptus fibrosa woodland on red soil, with vine thicket in small patches.

This species is similar to Cr. raveni sp. nov., as they both have seta d present on ge I–II, but Cr. gersoni has spatulate setae d on femora and genua I–II (lanceolate in Cr. raveni ), and posterior ventral setae are thick, broadly lanceolate and strongly barbed (thin, setiform and weakly barbed in Cr. raveni ).

Figures

FIGURE 25. Crossipalpus gersoni Beard and Seeman, adult female, a. dorsum; b. detail of palp; c. detail of tips of combined stylets. Scale bar for b. and c. = 25 Μm.

FIGURE 26. Crossipalpus gersoni Beard and Seeman, adult female, ventral view of anterior margin of prodorsum, with detail of palps.

FIGURE 27. Crossipalpus gersoni Beard and Seeman, adult female, a. posterior venter; b. spermatheca.

FIGURE 28. Crossipalpus gersoni Beard and Seeman, adult female, legs (right side), solenidion ω " and eupathidia (pζ ′ - pζ ′′) not labelled on leg I.

FIGURE 29. Crossipalpus gersoni Beard and Seeman, adult male, dorsum, with details of legs and palp.

FIGURE 30. Crossipalpus gersoni Beard and Seeman, adult male, a. posterior dorsal opisthosoma with expanded genital opening; b. posterior venter with expanded genital opening (same individual as a.); c. posterior venter with retracted genital opening, and details of aedeagus; d. aedeagus.

FIGURE 31. Crossipalpus gersoni Beard and Seeman, larva, a. dorsum, with details of palps; b. posterior venter; c. legs (right side).