Meyeraepalpus delfinadae 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 : 69-80

publication ID	https://doi.org/ 10.11646/zootaxa.3778.1.1
publication LSID	lsid:zoobank.org:pub:20D5DCD9-17F5-4863-B627-42B7C349B9A7
DOI	https://doi.org/10.5281/zenodo.6137229
persistent identifier	https://treatment.plazi.org/id/194C87D0-FFA2-FF95-F387-FC0FFB91FA42
treatment provided by	Plazi
scientific name	Meyeraepalpus delfinadae Smiley, Frost and Gerson, 1996
status

Treatment

( Figs 54–66 View FIGURE 54 View FIGURE 55 View FIGURE 56 View FIGURE 57 View FIGURE 58 View FIGURE 59 View FIGURE 60 View FIGURE 61 View FIGURE 62 View FIGURE 63 View FIGURE 64 View FIGURE 65 View FIGURE 66 )

Meyeraepalpus delfinadae Smiley, Frost and Gerson, 1996: 178 , figs. 22–25. Aegyptobia delfinadae, Mesa et al. (2009) : 13.

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, 0 3 October 1995, coll. W. E. Frost ( WINC). Paratypes. 2 females, same data as holotype ( WINC; 1 slide, with 1 Crossipalpus muellerianae deutonymph); 1 male, same data as holotype ( WINC; same slide as holotype).

Non-type material examined. 8 females, 2 pharate females, 1 male, 5 deutonymphs, 3 protonymphs, 1 pharate protonymph, 1 larva, ex. Allocasuarina 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).

Diagnosis. All dorsal setae broadly lanceolate, barbed. Both dorsal shields with weak rugose sculpturing. Gnathosoma partially concealed by prodorsum. Anterior margin of prodorsum with fleshy triangular lobes, within deep anterior prodorsal concavity, anterior to setae v2. Palp setal formula 0, 0, 0, 2, 3(1). Setae ps1–3 narrow, smooth. Coxae I–IV 2-2 -1-1 (1c present on cx I); trochanters I–IV 1-1 -2-1 (seta v ′ present on tr I–IV; l ′ present on tr III); femora I–IV 3-3 -1-1 (d absent on fe III); genua I–IV 3-3 -1-0 (l ′ and l ′′ present on ge I–II; l ′ present on ge III; ge IV nude); tarsi I–IV 9 (1)-9(1)-5-5 (tc ′′ present ta I–IV). Empodia claw-like. Spermathecal tube narrow, ca. 110 long. Spermathecal vesicle elongate, 2–4 wide, 10 long. Male with swollen solenidia on palps and tarsus I–II.

FEMALE (n = 11). Dorsum. ( Figs 54 View FIGURE 54 , 55 View FIGURE 55 a, 56, 57a) Body measurements: distance between setae v2 -h1 265– 300 [290]; sc2-sc2 140–170 [145]; other measurements: v2-v 2 31–44 [31], sc1-sc1 115–135 [115], c1-c 1 30–42 [42], c2-c2 140–175 [145], c3-c3 185–235 [195], d1-d 1 18–31 [28], d2-d2 135–165 [140], d3-d3 170–205 [170], e1- e 1 18–27 [18], e2-e2 130–145 [130], e3-e3 125–155 [140], f2-f2 91–110 [94], f3-f3 96–105 [105], h1-h 1 22–31 [31], h2-h2 58–75 [68]. Gnathosoma partially concealed beneath anterior margin of prodorsum ( Fig. 56 View FIGURE 56 ). Anterior margin of prodorsum with medial notch anterior and ventral to setae v2 (internal depth 14–22 [17]), forming 1 pair of three-dimensional triangular lobes originating from within apparent depression; anterior notch often appearing slightly withdrawn into prodorsum when anterior margin of prodorsum collapsing and/or folds on itself anterior to setae v2 ( Figs 56 View FIGURE 56 , 57 View FIGURE 57 a). Prodorsal and opisthosomal shields weakly developed with sparse rugose sculpturing. Lateral cuticle surrounding shields with few irregular striae. All dorsal setae short, broadly lanceolate,

barbed. Setal lengths: v 2 18–21 [19], sc 1 14–22 [17], sc 2 14–19 [17], c 1 17–23 [23], c 2 13–19 [19], c 3 13–17 [15], d 1 18–21 [20, 21], d 2 15–20 [16], d 3 14–22 [16, 18], e 1 15 –21 [19], e 2 13 –17 [13, 17], e 3 16 –20 [18, 19], f 2 15–18 [18], f 3 17–27 [20], h 1 14–17 [16], h 2 17–22 [21, 22]. Palps. ( Fig. 56 View FIGURE 56 ) Setal formula 0, 0, 0, 2, 3 (1s+2e). Tibial setae, dorsal 7–10 [8] long, ventral 9–12 [10] long; tarsal eupathidia 5–6 [6], 7–8 [8] long; solenidion 5–6 [6] long. Venter. ( Fig. 58 View FIGURE 58 a, b) Cuticle with fine longitudinal striae between 1a -1a; broadly separated transverse striae between 1a -3a; weak fine transverse striae 3a -4a; striae posterior to 4a fine transverse becoming oblique to longitudinal towards ag; ag -ag with mixed striae; broadly separated longitudinal striae surrounding genital flap; few weak longitudinal to oblique striae on genital flap. Genital setae inserted in more-or-less transverse row on genital flap. Anal setae ps1–3 fine, inserted along medial margin of anal plates in more-or-less longitudinal line. Coxal, genital and anal setae fine. Setal lengths: 1a 55–70 [64], 1b 18–33 [31], 1c 15–25 [25], 2b 20–31 [27], 2c 19–31 [24], 3a 46–77 [72], 3b 20–28 [24], 4a 45–64 [63], 4b 21–30 [25], ag 20–26 [23], g 1 22–28 [24], g 2 18–27 [23], ps 1 12–17 [15], ps 2 12–15 [14], ps 3 10–17 [13]. Spermatheca. ( Fig. 58 View FIGURE 58 c) Spermathecal tube narrow, ca. 110 long. Spermatheca elongate, 10 long, 2 wide basally and expanding to 3–4 wide. Genital opening between setae ps3. Not always clearly visible. Legs. ( Fig. 59 View FIGURE 59 ) Setal formula for legs I–IV (coxae to tarsi) 2-1-3-3-4-9(1), 2-1-3-3- 4-9(1), 1-2-1-1-3-5, 1-1-1-0-3-5. Tarsi I and II each with 1 antiaxial solenidion ω" (ta I 6–9 [8, 9] long, ta II 6–8 [8] long) and 2 eupathidia pζ'-pζ" (ta I 7–9 [8, 9] long; ta II 6–8 [7] long). Leg setation as in Table 1 except femora III without seta d. Setae v' added to tr IV.

MALE (n = 2). Dorsum. ( Fig. 55 View FIGURE 55 b) Body measurements: distance between setae v2 -h1 210–215, sc2-sc2 115– 125; other measurements: v2-v 2 25–30, sc1-sc1 93–94, c1-c 1 28–29, c2-c2 106–110, c3-c3 136–152, d1-d 1 18–19, d2-d2 92–97, d3-d3 107–113, e1- e 1 15–17, e2- e2 82–87, e3- e3 92–97, f2-f2 63–64, f3-f3 72–74, h1-h1 12, h2-h2 41–43. Gnathosoma not concealed beneath anterior margin of prodorsum ( Fig. 61 View FIGURE 61 ). Anterior margin of prodorsum similar to female, with medial notch anterior to setae v2 (internal depth 9–11) ( Figs 57 View FIGURE 57 b, 61). Prodorsal, mesonotal and pygidial shields weakly wrinkled and finely pitted; setae c1–2 and d1–2 inserted on paired mesonotal shields; setae e1, e3, f2–3, h1–2 inserted on pygidial shield. Setal lengths: v2 17, sc1 15, sc2 14, c1 17, c2 14, c3 15, d1 15, d2 14, d3 14, e1 15, e2 15, e3 16, f2 13, f3 17, h1 12, h2 17. Palps. ( Figs 60 View FIGURE 60 a, 61) Palps similar to female. Tibial setae, dorsal 10–11 long, ventral 8–9 long; tarsal eupathidia 7, 7–8 long; solenidion significantly

swollen 8–9 long ( Fig. 61 View FIGURE 61 ). Venter. ( Fig. 60 View FIGURE 60 b) Cuticle with fine longitudinal striae between 1a -1a; broadly separated transverse striae between 1a -3a; weak fine transverse striae 3a -4a; broadly separated transverse striae and folds between 4a and posterior margin of body. Coxal setae fine and finely barbed. Setae ag1, g1, g2, ps2, ps3 fine; setae ps1 modified to form thick spines ( Fig. 60 View FIGURE 60 b). Setal lengths: 1a 59–66, 1 b 26–30, 2 b 25–29, 2 c 21–24, 3 a 43–61, 3 b 23–26, 4 a 40–49, 4 b 24–28, ag 1 17–19, g 1 15–18, g 2 17–18, ps 1 13–15, ps 2 11–14, ps 3 13–15. Aedeagus. ( Fig. 60 View FIGURE 60 c) Narrow, sclerotised, tapering to a blunt point, 60–61 long. Legs. ( Figs 62 View FIGURE 62 , 63 View FIGURE 63 ) Setal formula same as female. Tarsi I and II each with 1 antiaxial solenidion ω", significantly swollen (ta I 12–14 long; ta II 8–12 long) and 2 eupathidia pζ'-pζ" (7–8 long). Solenidia significantly broader and longer than those of female ( Fig. 63 View FIGURE 63 ).

DEUTONYMPH (n = 5). Dorsum. ( Figs 57 View FIGURE 57 c, 64) Body measurements: distance between setae v2 -h1 260–275, sc2-sc2 120; other measurements: v2-v2 34, sc1-sc1 109, c1-c 1 26–28, c2-c2 122, c3-c3 150, d1-d1 21, d2-d2 108– 110, d3-d3 150–165, e1- e 1 18–20, e2-e2 100–102, e3- e3 90–100, f2-f2 80–95, f3-f3 66–67, h1-h 1 19–20, h2-h2 41–50. Anterior margin of prodorsal shield without notch ( Fig. 57 View FIGURE 57 c). Prodorsal shield smooth with few irregular creases. Opisthosoma with irregular transverse striae and some patches of smooth cuticle, including setae c1. Lateral cuticle smooth with weak irregular striae. Dorsal setae broadly lanceolate, except narrowly lanceolate setae f3 and h2. Setal lengths: v 2 17–19, sc 1 14–15, sc 2 13–14, c 1 17–18, c 2 12–17, c3 11, d 1 16–17, d 2 12–14, d 3 15– 17, e1 15, e 2 11 –13, e 3 14 –16, f2 11, f3 19, h 1 9–10, h 2 15–20. Palps. Palps similar to adult. Tibial setae, dorsal 6– 7 long, ventral 8–9 long; tarsal eupathidia 4–5, 5–6 long, solenidion 3–4 long. Venter. Cuticle with fine transverse striae to anterior of ag, longitudinal striae becoming coarse around anal region. Coxal, genital and anal setae fine. Setal lengths: 1a 40–48, 1 b 16–20, 2 b 14–19, 2 c 18–20, 3 a 30–40, 3 b 15–17, 4 a 25–28, 4 b 14–17, ag1 15, g1 16, ps1 8, ps 2 8–10, ps3 8. Legs. Setal formula for legs I–IV (coxae to tarsi) 2-1-3-3-4-9(1), 2-1-3-3-4-9(1), 1-2-1-1-3- 5, 1-0-1-0-3-5. Tarsi I and II each with 1 antiaxial solenidion ω" (4 long) and 2 eupathidia pζ'-pζ" (6–7, 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, sc2-sc2 100; other measurements: v2-v2 30, sc1-sc1 89, c1-c1 23, c2-c2 104, c3-c3 140, d1-d1 16, d2-d2 93, d3-d3 130, e1- e1 16, e2- e2 83, e3- e3 80, f2-f2 60, f3-f3 40, h1-h1 11, h2-h2 23. Anterior margin of prodorsal shield without notch. Prodorsal shield smooth with few irregular creases. Opisthosoma with irregular transverse striae. Lateral cuticle smooth with weak irregular striae. Dorsal setae broadly lanceolate. Setal lengths: v2 15, sc1 11, sc2 12, c1 16, c2 9, c3 13, d1 11, d2 12, d3 12, e1 11, e2 8, e3 11, f2 10, f3 19, h1 7, h2 17. Palps. Palps similar to adult. Tibial setae about 5 long; tarsal eupathidia 4, 5 long, solenidion 3 long. Venter. Striation same as deutonymph. Coxal, genital and anal setae fine. Setal lengths: 1a 40, 1 b 15, 1 c 12, 2 b 14, 3a 40, 3 b 13, ag1 7, ps1 6, ps2 4, ps3 3. Legs. Setal formula for legs I–IV (coxae to tarsi) 2-0-3-1-4-9(1), 1-0-3-1-4-9(1), 1-1-1-1-3-5, 0-0-1-0-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (3 long) and 2 eupathidia pζ'-pζ" (ta I 4–5, 4 long; ta II both 4 long). Leg setation as in deutonymph except: seta 2c absent; seta 4b absent; tr I–III without v ′; ge I–II without setae l ′ and d; ta IV without setae tc ′, tc′′. Setae l' added to tr III.

LARVA (n = 1). Dorsum. ( Fig. 65 View FIGURE 65 ) Body measurements: distance between setae v2 -h1 165, sc2-sc2 91; other measurements: v2-v2 29, sc1-sc1 74, c1-c1 21, c2-c2 88, c3-c3 125, d1-d1 15, d2-d2 74, d3-d3 93, e1- e1 15, e2- e2 67, e3- e3 63, f2-f2 45, f3-f3 44, h1-h1 9, h2-h2 24. Anterior margin of prodorsal shield without notch. Prodorsal shield smooth with few irregular creases. Opisthosoma with few irregular striae, especially mid-dorsally. Setal lengths: v 2 12–13, sc 1 12–13, sc 2 14–15, c1 15, c 2 13–15, c 3 10–13, d 1 10–11, d 2 12–13, d 3 12–14, e1 6 –7, e 2 13 –15, e3 15, f 2 13–15, f 3 14–17, h 1 8–11, h 2 15–16. Dorsal setae lanceolate except setae f2-f3, h1-h2 thickened, barbed. Palps. Palps similar to adult. Tibial setae, dorsal 5 long, ventral 6 long; tarsal eupathidia 5, 6 long, solenidion 3 long. Venter. Striation same as deutonymph. Coxal and anal setae fine. Setal lengths: 1a ca. 30, 1 b 11, 3 a ca. 25, ps1 5, ps2 3, ps3 5. Legs. ( Fig. 65 View FIGURE 65 ) Setal formula for legs I–III (coxae to tarsi) 1-0-3-1-4-7(1), 0-0-3-1-4- 7(1), 0-0-1-1-3-3. Tarsi I and II each with 1 antiaxial solenidion ω" (2 long) and 2 eupathidia pζ'-pζ" (3 long). Leg setation as in protonymph, except: seta 2b absent; seta 3b absent; tr III without l ′; ta I–III without setae tc ′, tc′′.

Remarks. Specimens for this redescription were collected from the type host in the type locality. Individuals were collected from fine branches of the host ( Fig. 66 View FIGURE 66 ).

We are resurrecting the original generic placement of this species, Meyeraepalpus delfinadae , despite its recent placement within Aegyptobia by Mesa et al. (2009). This species would be unusual among Aegyptobia as it would be the only species we know that lacks seta d on femur III ( Seeman & Beard 2011), has the gnathosoma partially concealed by the prodorsum, prodorsal lobes in a deep anterior concavity, and has a male with greatly swollen solenidia. The loss of seta d on femur III is unique among all species studied here, but the male with swollen solenidia also occurs in Crossipalpus , Magdalenapalpus and Palpipalpus . The concealed gnathosoma occurs in other tegopalpine mites, being partially concealed in Magdalenapalpus and Palpipalpus , and completely concealed in Australopalpus , Chaudhripalpus , Crossipalpus , Philippipalpus and Tegopalpus . Meyeraepalpus delfinadae also has two coxal setae, i.e. seta both 1b and 1c are present, and while this is unique for tegopalpine species, it is common for Aegyptobia ( Seeman & Beard 2011) .

Meyeraepalpus delfinadae is substantially different to the three genera with which it shares the character of swollen solenidion in the male, i.e., Crossipalpus , Magdalenapalpus and Palpipalpus . Meyeraepalpus delfinadae is different to Crossipalpus , which has four palpal segments, no prodorsal projections of any type, seta f2 absent, no seta 1c, two pairs of pseudanal (ps) setae, genual setal counts of 1-1-0-0, and its gnathosoma is completely concealed by the prodorsum; and is different to Palpipalpus which has a pair of rounded prodorsal lobes anterior to v2, two pairs of ps setae, coxae without 1c, and genua with 2-2-0-0. Meyeraepalpus delfinadae bears a greater resemblance to the third genus, Magdalenapalpus (especially Ma. strandtmanni , with setae f2 present), where it was originally placed by Smiley et al. (1996). Mesa et al. (2009) moved the species to Aegyptobia because it “has a rostral shield and the anterior margin of the prodorsum is not invaginated”. However, adult Me. delfinadae do indeed have an invaginated anterior margin, formed by distinct lobes on the anterior margin of the prodorsum, that are often slightly retracted into the prodorsum, forming a shallow cavity anteroventral to setae v2 ( Figs 56 View FIGURE 56 , 57 View FIGURE 57 a, b). These lobes are not present on the immature life stages ( Fig. 57 View FIGURE 57 c). The anterior lobes of Me. delfinadae are unlike any other found in Aegyptobia , which are formed by a simple notch in the prodorsal shield (e.g. Fig. 124a) or a forked extension of the prodorsal shield (e.g. Aegyptobia bromi Khanjani et al., 2012a ). Likewise the lobes on Meyeraepalpus delfinadae do not appear homologous with those of Magdalenapalpus ( Figs 42 View FIGURE 42 , 43 View FIGURE 43 ), but instead, they appear similar to those of Chaudhripalpus ( Figs 1 View FIGURE 1 , 2 View FIGURE 2 , 8 View FIGURE 8 a) and Tegopalpus ( Fig. 107 View FIGURE 107 a, 108, 110a, b, 111a), which originate from below the level of the dorsal surface of the prodorsum. Furthermore, Me. delfinadae does not share the same leg setation with species of Magdalenapalpus which all lack seta 1c on cx I, v ′ on tr I–IV, l ′ and l′′ on ge I–III, and tc′′ on ta I–IV, all of which are present in Me. delfinadae .

It is for the above mentioned differences, and not those listed by Mesa et al. (2009) that we exclude Me. delfinadae from Aegyptobia and Magdalenapalpus . Further evidence is presented in our cladistic analysis, which places Me. delfinadae as a unique species and sister group to all other tegopalpine mites.