Crossipalpus muellerianae Smiley, Frost and Gerson, 1996

Beard, Jennifer J., Seeman, Owen D. & Bauchan, Gary R., 2014, Tenuipalpidae (Acari: Trombidiformes) from Casuarinaceae (Fagales), Zootaxa 3778 (1), pp. 1-157 : 22-29

Crossipalpus muellerianae Smiley, Frost and Gerson, 1996

( Figs 13–18 )

Crossipalpus muellerianae Smiley, Frost and Gerson, 1996: 174 , figs 19–20.

Type material examined. Holotype female ex. Slaty She-Oak Allocasuarina muelleriana (Casuarinaceae) [feeding on bark of branchlets], AUSTRALIA: South Australia, Flinders Ranges, St Mary’s Peak, at 750 m, 3 October 1995, coll. W. Frost ( WINC; on same slide as 7 paratype specimens). Paratypes. 2 females, 1 pharate female, 1 deutonymph, 3 protonymphs, 1 pharate larva, and 1 larva, same data as holotype ( WINC; 2 slides, including holotype slide); deutonymph, same data as holotype, on slide with 2 females of Me. delfinadae ( WINC). Non-type material examined. 9 females, 3 pharate females, 3 deutonymphs, 1 pharate protonymph, and 1 larva ex. A. muelleriana , AUSTRALIA: South Australia, Adelaide, Athelston, Maryvale Road, Wadmore Park, 34°52’49” S 138°42’10” E, 21 April 2009, coll. J.J. Beard and C.J. Burwell (QM, USNM) ( BRI voucher BRI [AQ818802]).

Diagnosis. Dorsal setae all thinly lanceolate and weakly barbed. Prodorsal setae v2 obviously longer than setae sc1. Palpal segments elongated, thin. Genua I–II with seta l ′′ without d; tarsi I–IV with seta tc′′.

FEMALE (n = 12). Dorsum. ( Fig. 13 a) Body measurements: distance between setae v2 -h1 335–370 [345]; sc2- sc2 93–105 [105]; other measurements: v2-v 2 21–36 [29], sc1-sc1 79–89 [88], c1-c 1 14–24 [24], c2-c2 81–96 [93], c3-c3 115–130 [130], d1-d 1 19–27 [24], d2-d2 69–87 [85], d3-d3 99–115 [105], e1- e 1 13–18 [14], e2- e2 93–105 [97], e3- e3 82–94 [85], f3-f3 63–76 [72], h1-h 1 12–17 [12], h2-h2 41–52 [48]. Gnathosoma completely concealed beneath prodorsum. Anterior margin of prodorsum rounded; setae v2 often inserted ventrally on anterior margin of prodorsum ( Fig. 14 ). Prodorsal shield weakly developed with longitudinal to oblique folds and lines. Some transverse folds between dorsal shields, just anterior to c -setae. Opisthosomal shield weakly developed, mostly with oblique or longitudinal lines and weak folds; short series transverse folds across width of shield just anterior e1-e1; small areas of smooth cuticle between setae c1-c1 and d1-d1 and between d1-d2. Lateral cuticle surrounding shields mostly smooth, with few coarse striae and weak folds. Most dorsal setae thin and barbed; setae v2, sc2, e3, f2, f3, and h2 longer and thicker than other dorsal setae; setae h1 short, palmate to lanceolate. Setal lengths: v 2 21– 26 [23, 25], sc 1 8–13 [12], sc 2 11–20 [18, 19], c1 6–8 [7, 8], c 2 6–11 [9], c 3 10–16 [13, 14], d1 4–7 [5, 6], d2 6–9 [7, 9], d 3 10–15 [12, 13], e1 4 –8 [6, 7], e 2 10 –15 [14, 15], e 3 17 –22 [20], f 3 20–24 [22, 23], h 1 5–10 [7, 8], h 2 20– 24 [22, 23]. Palps. ( Figs 13 b, 14) Setal formula 0, 0, 0, 1, 3 (1s+2e). Tibial seta 9–12 [10] long; tarsal eupathidia 4– 7 [5] long (thin, tapered; could be seta), 5–8 [6, 7] long (thick, blunt); solenidion 4–6 [5, 6] long.

Venter. ( Figs 14 , 15 a) Ventral cuticle of anterior prodorsal margin with coarse striae forming triangular pattern ( Fig. 14 ); cuticle between setae 1a -3a with broadly separated transverse striae; fine longitudinal striae between setae 3a to just posterior setae 4a; narrow band of transverse striae ca. 10 wide posterior 4a, then fine longitudinal striae to ag; oblique striae between ag -ag forming inverted “v” shape; coarse striae laterad genital region, longitudinal to oblique. Genital setae widely separated, inserted on posterior corners of genital flap in more-or-less transverse row, g1 inserted slightly posterior to level of g2. Genital shield weakly developed, cuticle on genital flap between g setae with mixed oblique striae (g1-g1 33–36) anal setae ps1–2 inserted in longitudinal line along inner edge of anal plates; seta ps3 absent ( Fig. 15 a). Coxal, genital and anal setae fine, except 2c thicker, weakly barbed; setae 1a, 3a, 4a long, finely tapered, often broken and difficult to determine full length. Setal lengths: 1a 48–82 [48, 57], 1b 19–32 [22, 23], 2b 17–29 [21, 26], 2c 18–24 [18, 19], 3a 38–81 [38], 3b 17–25 [22], 4a 40–78 [54], 4b 17–28 [25, 28], ag 1 10–16 [11], g 1 19–26 [24], g 2 18–25 [23], ps 1 9–14 [14], ps 2 9–14 [13]. Spermatheca. ( Fig. 15 b) Spermathecal tube long, distinctly broad near external opening, becoming narrow and convoluted distally, maximum 2 wide, ca. 110 long. Spermatheca vesicle 10–13 long, 2–3 wide proximally, 3–5 wide distally. Genital opening between setae ps2 and posterior margin of genital flap. Legs. ( Fig. 16 ) Setal formula for legs I–IV (coxae to tarsi) 1-1-3-1-4-9(1), 2-1-3-1-4-9(1), 1-2-2-0-3-5, 1-1-1-0-3-5. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 5–7 [6] long, ta II 4–6 [6] long) and 2 eupathidia pζ'-pζ" (6–7 [6] long). Leg setation as in Table 1 except: coxae I without 1c; genua I–II with l", without d; tarsi I–IV with tc". Setae v' added to tr IV.

MALE. Unknown.

DEUTONYMPH (n = 3). Dorsum. ( Fig. 17 ) Body measurements: distance between setae v2 -h1 285–305, sc2- sc2 83–91; other measurements: v2-v 2 18–21, sc1-sc1 66–75, c1-c 1 14–16, c2-c2 72–89, c3-c3 107–109, d1-d 1 16–18, d2-d2 64–78, d3-d3 86–99, e1- e 1 8–11, e2- e2 72–92, e3- e3 71–78, f3-f3 59–62, h1-h 1 12–15, h2-h2 42–46. Prodorsal shield similar to female, but with fewer folds, with central longitudinal folds and sublateral oblique folds. Opisthosoma with widely separated transverse folds between c1 and e1, and distinct oblique folds between c2-c3; paired minute pores present between c1-c2, d1-d2 and laterad e1. Setal lengths: v 2 29–35, sc 1 6–10, sc 2 13–20, c1 3–7, c2 4–7, c 3 8–12, d1 3–5, d2 4–7, d 3 9–11, e1 3 –6, e 2 9 –15, e 3 20 –24, f 3 22–26, h1 4–6, h 2 22–25. Palps. Palps same as adult. Tibial seta 8–9 long; tarsal eupathidia 3–5 long (thin, blunt), 5–6 long (thick, blunt); solenidion 3–5 long. Venter. Cuticle with striae similar to adult female. Coxal, genital and anal setae fine. Setal lengths: 1a 35–49, 1 b 16–19, 2 b 12–18, 2 c 17–20, 3 a 34–40, 3 b 13–20, 4 a 35–41, 4 b 14–17, ag 1 8–11, g 1 10–17, ps1 7–8, ps 2 7–10. Legs. Setal formula for legs I–IV (coxae to tarsi) same as adult female except tr IV nude: 1-1-3- 1-4-9(1), 2-1-3-1-4-9(1), 1-2-2-0-3-5, 1-0-1-0-3-5. Tarsi I and II each with 1 bulbous antiaxial solenidion ω" (3-4 long) and 2 eupathidia pζ'-pζ" (5–6 long). Leg setation as in adult except: tr IV without seta v ′. Setae v' added to tr I–III.

PROTONYMPH (n = 3). Dorsum. Body measurements: distance between setae v2 -h1 195–200, sc2-sc2 73– 75; other measurements: v2-v 2 18–19, sc1-sc1 57–60, c1-c 1 11–13, c2-c2 62–64, c3-c3 93–100, d1-d 1 12–14, d2- d2 56–58, d3-d3 74–77, e1- e1 6–8, e2- e2 65–68, e3- e3 51–55, f3-f3 41–43, h1-h 1 9–11, h2-h 2 23–25. Prodorsal shield similar to female, but with fewer and much weaker folds. Setal lengths: v 2 24–25, sc1 6–7, sc 2 11–14, c 1 11–13, c2 5–7, c 3 9–11, d1 4–5, d2 5–6, d 3 7–10, e1 2 –4, e 2 10 –12, e 3 14 –17, f 3 16–18, h1 4–5, h 2 18–21. Palps. Palps same as adult. Tibial seta 8 long; tarsal eupathidia both blunt 4, 5; solenidion 3–4 long. Venter. Cuticle with striae similar to adult. Coxal, genital and anal setae fine. Setal lengths: 1a 28–39, 1 b 16–18, 2 b 15–16, 3 a 17–26, 3 b 11–14, ag1 8, ps1 6–7, ps2 7–8. Legs. Setal formula for legs I–IV (coxae to tarsi) 1-0-3-0-4-9(1), 1-0-3-0-4- 9(1), 1-1-2-0-3-5, 0-0-1-0-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 3–4 long, ta II 3 long) and 2 eupathidia pζ'-pζ" (5 long). Leg setation as in deutonymph except: seta 2c absent; seta 4b absent; tr I–II without seta v ′; ge I–II without seta l′′; ta IV without setae tc ′, tc′′. Setae l' added to tr III.

LARVA (n = 2). Dorsum. ( Fig. 18 ) Body measurements: distance between setae v2 -h1 140–160, sc2-sc2 61– 71; other measurements: v2-v 2 11–15, sc1-sc1 47–55, c1-c 1 10–11, c2-c2 55–58, c3-c3 82–90, d1-d 1 13–15, d2-d2 43–49, d3-d3 59–61, e1- e1 7–9, e2- e2 49–57, e3- e3 36–50, f3-f 3 21–28, h1-h1 5–9, h2-h 2 10–15. Prodorsum with central area smooth to finely striate; lateral cuticle with coarse longitudinal to oblique striae. Opisthosomal cuticle with mostly transverse striae, with some longitudinal striae posteriorly. Setal lengths: v 2 15–24, sc1 5–7, sc 2 9–13, c1 4–5, c2 4–6, c3 7–8, d1 3–5, d2 4–8, d3 6–7, e1 3 –4, e2 6 –8, e 3 10 –13, f 3 11–13, h1 4–5, h 2 15–17. Palps. ( Fig. 18 ) Palps same as adult. Tibial seta length 6–8; tarsal eupathidia 3–4 long (blunt), 4–5 long (blunt); solenidion 2–3 long. Venter. Striae transverse to anal area, becoming longitudinal and coarse around anal area. All setae fine. Setal lengths: 1a 21–37, 1 b 10–18, 3 a 22–33, ps1 6–7, ps2 5–8. Legs. ( Fig. 18 ) 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 bulbous antiaxial solenidion ω" (2–3 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′′.

Remarks. Smiley et al. (1996) remarked that this species was unique with the adult female having tarsi I–IV 6 (1)-6(1)-6-5. This is incorrect and the true count is 9(1)-9(1)-5-5. Individuals were found wedged within pits and crevices on the bark of stems of the host ( Fig. 17 ).

This species is very similar to Cr. verticillatae but can be readily distinguished from it by the presence of setae tc'' on tarsi I–IV (absent in Cr. verticillatae ), the finer palpal segments (stout in Cr. verticillatae ), palmate setae h1 (lanceolate setae h 1 in Cr. verticillatae ), and irregular dorsal reticulation (linear in Cr. verticillatae ).

Figures

FIGURE 13. Crossipalpus muellerianae Smiley, Frost and Gerson, adult female, a. dorsum; b. detail of palp (scale bar for palp = 25 Μm).

FIGURE 14. Crossipalpus muellerianae Smiley, Frost and Gerson, adult female, ventral view of anterior margin of prodorsum, with detail of palps.

FIGURE 15. Crossipalpus muellerianae Smiley, Frost and Gerson, adult female, a. posterior venter; b. spermatheca.

FIGURE 16. Crossipalpus muellerianae Smiley, Frost and Gerson, adult female, legs (left side, ventral view), eupathidia (pζ ′ - pζ ′′) not labelled on legs I – II.

FIGURE 17. Crossipalpus muellerianae Smiley, Frost and Gerson, a. deutonymph in habitat; b. detail deutonymph dorsum.

FIGURE 18. Crossipalpus muellerianae Smiley, Frost and Gerson, larva, dorsum with detail of legs and palp.