Opilioacarus baeticus, Moraza & Prieto & Balanzategui, 2021

Moraza, María L., Prieto, Carlos E. & Balanzategui, Iñaki, 2021, A new species of the genusOpilioacarus With, 1902 (Acari: Opilioacarida) for the Iberian Peninsula, Acarologia 1902 (1), pp. 128-147 : 130-138

Diagnosis of Opilioacarus baeticus new species

Zoobank: 143C7A68-2830-4D27-BF59-A4882A12AA2C

Palp tarsus with five foliate setae d1, each with three lobes, and pectinate seta d2 ; sternal verrucae with st1 and four or five (females) or three or four (males) tapering ribbed setae; area between sternal and genital verrucae with two pairs of long, stout and ribbed, tapering setae (s t2–st3) similar to st1 and st5 and three to six pairs of stout and ribbed setae in both sexes; pregenital verrucae with st5 and five to seven stout and ribbed setae in both sexes; female lacks pregenital setae, and with five eugenital short, tapering and ribbed setae; males with five tapering, short and smooth pregenital setae in a trapezoidal area and five genital setae in a lobulated area. Anal valves with 12–13 stout and ribbed setae each. Cheliceral movable digit of adults with one ventral fimbriate process; female palp­tarsus with 23 ch setae, male with

16–18 ch setae, both sexes with 14 sm setae. Preanal segment with five dorsal and one pair of lateroventral stout and ribbed setae. Legs IV longer than body length; basitarsus I with a basal dorsal seta short, thick and barbed; tibia II–IV coronida present; genu II–IV with a dorsodistal sensorial seta enlarged and barbed, femur II–IV with a dorsal longitudinal row of blunt setae s,

and femur II–IV with dorsal longitudinal rows of short blunt setae.

Description

Based on female (n= 7) and male (n= 4) and female tritonymph (n=1).

Female idiosoma 2161–2445 µm long, 1000–1138 µm wide; male 1944–2000 µm long,

944–1111 µm wide; female tritonymph 1020 µm long, 510 µm wide.

Gnathosoma — Subcapitulum. All paralabial setae present ( Figure 2A–C ): pl1 conical

(19–23 µm long), obtuse, inserted near base of cb3 (69–89 µm long); pl2 (With’s organ) discoid,

marginally smooth ( Figure 11B ); pl3 (rutella) inserted dorsolaterally, 122 µm long in the male and 150 µm in the female long, with five distinct teeth in a row ( Figure 11B ); dorsal solenidia

pl4 short and blunt ( Figure 2B ); all four pairs of circumbucal setae (cb1–4) with bifurcate tips ( Figure 2D ) and similar in size and length; female with three rounded tip setae vm1, vm2,

lvm ( Figure 2A ) (53–58 µm long), eight pairs of pointed setae 33–45 µm long lm (1­2, vm3,

vp1­3, lvp, ldm setae) ( Figure 2B ); male with one rounded tip seta vm1 (50 long); eight pairs of pointed setae (vm3, lm1­2, vp1­3, lvp, ldm seta ( Figure 2 ). Female tritonymph only cb1­4,

pl1­4, lm2 and vp1 setae present. Lateral lips with distinct canals dl (1, dl2) and their orifices

(ogl1, ogl2). Hypostome with ventral and apical teeth, most basal teeth rib shape. Dorsal surface of subcapitulum with a medial and laterals coniculate areas ( Figure 2B ).

Chelicera ( Figure 2 E­G). Basal segment with one seta cht (1) in normal shape and size;

a small denticulate paraxial surface. Cheliceral fixed digit with well­developed apical hook

( Figure 2F ), and three dorsal setae, ch1 72 µm long, ch2 and ch3 shorter, 25–30 µm long; dorsal and paraxial lyrifissures present; lateral denticle absent; movable digit with well­developed apical hook, ogc present, and one ventral membranous fimbriate process ( Figure 2G ).

Palps. Female ( Figure 3A–L ). Palp­tarsus with iα and iπ lyrifissures; five setae d1 foliate

( Figure 3A, C, D ) with three acute lobules and d2 pectinate ( Figure 3E ); four setae v1 ; four v2 ;

three v3 ; three s ( Figure 3E ); 14 sm ; 23 ch setae ( Figure 3D ); tarsal claws distal, with ventral margin smooth. Pal­tibia with subequal setae: dorsal setae thin and longer than ventral setae r ;

ca. 48 setae and four setae s (two dorsal and two ventral) ( Figure 3F–H ). Genu ( Figure 3I, J )

with 41 r and 9 palmate setae p (7r+1p – 21+2p / 10+1p – 2r+5p). Femur with 12 r and 15 p

( Figure 3L ). Trochanter with 6–8 r setae ( Figure 3L ). Male palp­tarsus similar to female, with five d1 foliate with three lobules and d2 barbed; 16 ch setae. Female tritonymph palp­tarsus

( Figure 11A ) with four foliate d1, one pectinate d2, three v1, two v2, two v3, three s, 4 sm and

15 ch setae.

Idiosoma dorsum — Prodorsum. Prodorsal shield covered with round tubercles, pigmented around eyes and in the medial central region, with a dark blue frame, and posterior convex pigmented band ( Figure 1B ); shield with two pairs of eyes; stout, ribbed setae 16–23 µm long,

and one pair of lyrifissures antiaxial to anterior eyes; shield with rounded or slightly acuminate anteriorly margin and a convex row of nine setae at the posterior region ( Figure 1C ); male

500–597 µm long, 508–778 µm wide at eyes level; female 583–694 µm long, 805–1000 µm

wide.

Opisthonotum dark blue­violet with a sharp distinction between colored tergites and pale interarticulated membranes ( Figures 1A , 11D ); integument coniculate; nymphs may have a bright blue color ( Figure 11C ). The first two­three abdominal segments marked by distinct grooves and indistinct muscular spots, other segments only marked by distinct spots and an arrangement of lyrifissures and glands ( Figure 1A ). Except for preanal segment with a row of of digits; G – Chelicera movable digit, detail of ventral tubercle.

five dorsal setae and one pair of ventrolateral setae in both sexes ( Figure 4F, G ), other idiosomal segments lack setae, but with numerous lyrifissures and glands openings arranged in transverse rows. Four pairs of stigmata. Idiosoma venter — Tritosternum. Each sternapophysis 222–250 µm long, with two setae,

one smooth seta 31 µm long at tip and one 88–89 µm long, barbed, positioned more basally ( Figure 4A ); distal narrow region with smooth cuticle, basal region coniculate.

Sternal region. Sternal verrucae each with a slightly longer ribbed tapering seta st1 (53–57

µm long) and three to five tapering, ribbed setae in the female ( Figure 4A ) or three or four in the male ( Figure 4B ) or one in the female tritonymph (female 41–53 µm long, male 47–53

µm long, ( Figure 4C ). Setae st2 and st3 acute, stout, long, ribbed tapering (female 61–64 µm, male 44–50 µm), and two or three (female) or three (male and female tritonymph) pairs of stout ribbed setae (female 43–50 µm, male 38–45 µm long). Sternal region with three pairs of sternal lyrifissures (iv1–iv3).

Pregenital area. Adult female and female tritonymph without setae and one pair of lyrifissures (iv4) ; male with five acute short setae (13–20 µm long) in a trapezoidal area and several lyrifissures. Pregenital capsules each with tapering, ribbed seta st5 (female 55–57

µm, male 36–40 µm long) and five to seven (female) or six to seven (male) or two (female tritonymph) stout ribbed setae (female 27–36 µm, male 27–39 µm long).

Genital area. Female without setae. Male genital area lobulated area with five acute, smooth setae, 19–21 µm long, and at least three lyrifissures. Female with five acute eugenital setae

(27–36 µm long); ovipositor consisting of sack shape structure with two digitiform smooth projections ( Figure 4D ).

Preanal region. Preanal XVI segment without dorsal and ventral setae; preanal segment XVII with five dorsal setae ( Figure 4F ) and one pair of ventral setae.

Anal valves each with stout ribbed setae ( Figure 4G ), 12–13 in female and male, six or seven lyrifissures and one to six gland openings.

Legs — Legs with blue­violet stripes and different types of setae, apart from special sensilla on tarsus I ( Figure 5B, C : palmate, stout ribbed setae with barbed margin, fan­shaped setae, occasionally with a tiny terminal tip (“papillate” type “p” setae of different length) ( Figure 6G ); tapering, smooth setae “s”; tapering and barbed setae, and smooth acute setae.

Leg I–IV lengths from trochanter to base of pretarsus: I 3930 µm, II 1911 –2288 µm, III 1900 –2055 µm, IV 2766 –3044 µm. Coxae I–IV, female 3r+1p, 3r+6p, 2r+6p, 4p ( Figure 4A );

male 4r, 4r+7p, 1r+7p, 6p.

Legs I. Leg I longer than the body and longer than legs II, III and IV; leg I twice as long than the shortest leg III. Telotarsus I ( Figure 5 A­C) 336 µm long, with proximal cuticle ornate (approximately first two whorls of setae), other setae on smooth cuticle. Pretarsus with two well­developed sessile claws; Haller’s organ with two sensilla in a cavity ( Figure 5C ) and distal posterodorsal cluster of seven sensilla ( Figure 5B ): sensillum ζ1 with crown­like tip inserted close to group of sensilla; ω1 and ω2 rod­like with blunt tip, ω3 and ω4 rod­like with filiform tip, ω5 conical, and ω6 spiked maze­like; three anterodorsal sensilla ω with filiform tips at the same level than ζ1; other long telotarsal setae with blunt tips.

Basitarsus I ( Figure 5D ) slightly longer than telotarsus, 358 µm long; three basal whorls with dorsal and lateral setae serrate, smooth ventral setae, and at least three short blunt solenidia; one barbed dorsal setae shorter and thin than other dorsal setae. Three distal whorls with smooth, blunt tips setae; soft articular tegument between telo­ and basitarsus with two ventral lyrifissures.

Tibia ( Figure 6A, B ) (486 µm long, 61 µm wide at the distal region); distal whorl with 5p+1r setae; rod­like, blunt tip sensilla present in two rows (8 and 10 setae s); 44 setae r + 15 p setae

(7 dorsal, 2 anterolateral, 3 posterolateral, 3 ventral) on segment; formula 10 – 10s+11+11+8s

/ 10 +9 – 10. Pre­tibia I ( Figure 6C ) (681 µm long, 56 µm wide at the distal region): rod­like setae in two rows (12+12 s); 10 palmate setae (4 dorsal, 4 lateral, 2 ventral).

Genu ( Figure 6D ) (661 µm long, 86 µm wide at the distal region); 8 setae p on distal region (1 4 / 2 1); rod­like, blunt sensilla present in two rows (7+9 s setae); formula 12p – 7s+(6r+13p)

+ (5r+13p)+ (1r+9s) / 9r+9r – 16p.

Femur ( Figure 6E ) (854 µm long, 89 µm wide at distal region); distal whorl with 6 setae p and 1 r setae; other whorls with 6 setae; first 4 distal pairs of dorsal setae and 6 posterodorsal setae type r ; except for two setae p other ventral setae acute; formula 18p – (4r+17p) +1r+ (10r+8p) / (17r+p) + 19r+1p – 28p. Prefemur ( Figure 6F ) with one whorl of 5 setae r.

Trochanter ( Figure 6F ) 454 µm long; distal region with a whorl of 10 stout, ribbed setae and proximal region with 2 setae r; except for 7 setae r type, other setae on the segment are palmate, p setae ( Figure 6G ).

Acrotarsus II–IV have four whorls of setae (including pretarsal solenidia) and pretarsus with smooth sessile claws, two plumose setae, and two smooth setae. Acrotarsus II ( Figure 7D ) 89–91 µm long, dorsal solenidia (ωp), lateral (ωd), and dorsal bifid solenidia present; first lateral pair (lv) pectinate, and other acrotarsal setae barbed (4– 6/8–4). Acrotarsus III–IV ( Figure 7E ) 69–75 µm and 77–99 µm long to base of pretarsus; dorsal bifid solenidia absent

(4– 5/8–4).

Telotarsus II–IV ( Figure 7A–C ) 306 µm, 235 µm, 314 µm long respectively, with ibt and ibv, anterolateral, lateral, and smooth ventral setae with acute thin tips, and dorsal and posterolateral setae stout, long ribbed setae with blunt tips; only telotarsus IV with three dorsal papillate long setae. Telotarsi II–III ( Figure 7A, B ) with 7 complete whorls of setae (7– 7+7

/ 9+9 –7 and 7– 7+7 / 7+7 – 8); telotarsus IV ( Figure 7C ) with 8 whorls (8– 7+7 / 9+9 – 8),

dorsal chaetoma incomplete.

Basitarsus II–IV ( Figure 7F, G, H ), 417 µm, 314 µm, 573 µm long respectively; ibt, ibv present; distal ωd on the surface in legs II and III and in a cavity present in leg IV ( Figure 7H ) ; 5, 3 and 2 long distal solenidia between antero­ and posterolateral papillate dorsal setae; coronidia present with at least 11, 10 and 20 setae s respectively and one basal g ; all lateral setae palmate, specially enlarge in basitarsus IV ( Figure 7H ); distal pair of ventral setae r longer and stout than other; distal whorl of setae 1p– 2r/2r–1p, 1p–2p/2r–1p and 1p–3p+1s / 2r–1p respectively on legs II­IV; other basitarsal ventral setae long, smooth and acute.

Basitarsi with complex (more than six setae each) whorls of seta; chaetomic formula II–IV respectively excluding dorsal, blunt, long solenidia: 13– 8+9 / 8+9–16; 12–6+7 / 9+9–14;

13–8+7 / 9+10–10.

Genu II–IV ( Figure 8A–C ) 300 µm, 281 µm, 446 µm long respectively; lyrifissure ibv present; a dorsal longitudinal row of 6, 7 and 8 setae barbed, blunt solenidia s shorter than longer palmate setae p; other dorsal and lateral setae palmate p; 4, 8, 6 ventral setae with acute tips and other ventral setae papillate.

Femur II–IV ( Figure 8D–F ) elongate and flattened with basal lyrifissures present; 589 µm, 465 µm, 731 µm long respectively; two dorsal longitudinal rows of acute, thin setae, shorter or as long as papillate setae present (4+7, 6+10, 4+11 respectively), other setae palmate of different size, those in the lateral surfaces smaller.

Prefemur ( Figure 9D, E ). Leg II prefemur absent; prefemur III 173 µm and IV 296 µm long. Except for three (leg III) or two (IV) setae r, other dorsal, lateral and ventral setae palmate.

Trochanters II–IV ( Figure 10 A­C) 223 µm, 181 µm, 335 µm long respectively, with a dorsal lobulated protuberance; all ventral setae palmate; trochanter II with 4 laterodorsal blunt, barbed, ribbed setae increasing in length toward lateral side, and a longitudinal more lateral row of 3 setae r ( Figure 10A ); leg III with 1 pair of dorsodistal setae and 2 r basal setae ( Figure 10B ), and leg IV with 1 pair of dorsal barbed, ribbed setae r ( Figure 10C ).

Figures

Figure 1 Opilioacarus baeticus n. sp.: A – Idiosoma, dorsal view (specimen photographed by E. Mateos in December 2019); B –Detail of prodorsum (specimen in alcohol); C – Detail of prodorsal shield.

Figure 2 Opilioacarus baeticus n. sp.: A – Subcapitulum, female, ventral view; B – Subcapitulum, female, dorsal view; C – Subcapitulum, male, ventral view; D – Detail of notate subcapitular setae; E – Chelicera, female, antiaxial view; F – Chelicera, female, detail of distal region

Figure 3 Opilioacarus baeticus n. sp.: A – Palp­tarsus, female, dorsal view; B – Palptarsus, female, ventral view; C – Palp­tarsus, female, anterolateral view; D – Palp­tarsus, female, posterolateral view; E – Detail of notate palp tarsal setae; F – Palp­tibia, female, lateral view; G –Ventral view; H –Palp­tibia, dorsal view; I – Palp­genua, dorsal view; J – Palp­genua, ventral view; K – Detail of palmate seta (p) in different views and serrate setae (r) on palps; L – Palp­trochanter and femur, lateral view. Black circles refer to setae inserted on posterior side of the segment.

Figure 4 Opilioacarus baeticus n. sp.: A – Female, sternigenital region; B – Male, sternigenital region; C – Detal of sternal and genital setae; D – Detail of ovipositor; E – Detail of no palmate coxal setae; F – Preanal segment and anal valves, dorsal view; G – Preanal segment and anal valves, ventral view.

Figure 5 Opilioacarus baeticus n. sp.: A– Telotarsus I, posterolateral view; B – Detail of basitarsal group of sensilla; C – Detail of Haller’s organ; D – Basitarsus I, posterolateral view.

Figure 6 Opilioacarus baeticus n. sp.: A – Tibia I, posterolateral view; B – Tibia I, anterolateral view; C – Pretibia I, posterolateral view; D – Genua I, dorsolateral view; E – Femur I, dorsal view; F – Trochanter and prefemur I, posterolateral view; G – Detail of papillate setae.

Figure 7 Opilioacarus baeticus n. sp., female, right legs: A – Telotarsus II, posterolateral view; B – Telotarsus III, posterolateral view; C – Telotarsus IV, posterolateral view; D – Acrotarsus II, posterolateral view; E – Acrotarsus IV, posterolateral view; F – Basitarsus II, posterolateral view; G – Basitarsus III, posterolateral view; H – Basitarsus IV, dorsal view.(A–C, F,G, H, same scale).

Figure 8 Opilioacarus baeticus n. sp., female, right legs: A Tibia II, posterolateral view; B – Tibia III, posterolateral view; C – Tibia IV, dorsallateral view; D – Genua II, dorsolateral view; E – Genua III, posterolateral view; F – Genu IV, dorsal view.

Figure 9 Opilioacarus baeticus n. sp., female, right legs: A – Femur II, posterolateral view; B – Femur III, posterolateral view; C – Femur IV, dorsallateral view; D – Prefemur III, posterolateral view; E – Prefemur IV, posterolateral view.

Figure 10 Opilioacarus baeticus n. sp., female, right legs: A – Trocahnter II, posterolateral view; B – Trochanter III, posterolateral view; C – Trochanter IV, dorsolateral view.

Figure 11 Habitus photos ofOpilioacarus baeticus n. sp.: A – female tritonymph, palptarsus, lateral view: B– female tritonymph, detail of several ganthosomal structures; C – Nymph from Murcia, J. Carrillo (December 8, 2011); D – Adult female from Almería, E. Mateos (December,