Opilioacarus brignolii Araújo & Di Palma, 2018

Araújo, Marcel Santos De, Palma, Antonella Di & Feres, Reinaldo José Fazzio, 2018, A new species of Opilioacarus With, 1902 (Acari: Opilioacaridae) from Italy, and a new diagnosis of the genus, Zootaxa 4500 (1), pp. 135-145 : 138-142

Opilioacarus brignolii Araújo & Di Palma n. sp.

( Figs. 2–5 )

Material examined. Holotype ♀ 11-3, 411, ITALY, Apulia, Bari, Monopoli; coll. Brignoli, P.; 23.V.1967; paratype ♂ 11-2; paratype ♂ 11-5; paratype ♂ 11-1; paratype ♀ 11-4, same data; paratype ♂ 4-2; paratype ♀ 4-3, same data, coll. Vigna, A.; paratype ♀ 2-1, 411, ITALY, Apulia, Lecce , Santa Cesarea Terme ; coll. Brignoli, P.; 17.III.1967, paratype ♀ 2-2, paratype ♂ 2-3, 411, same data; paratype ♀ 5-1, 411, ITALY, Apulia, Taranto , Martina Franca, Bosco delle Pianelle ; coll. Brignoli, P.; 25.V.1967; paratype ♀ 6-1, 411, ITALY, Apulia, Taranto , Mottola ; coll. Brignoli, P.; 25.V.1967; paratype ♀ 3-3, 411, ITALY, Sardinia, Nuoro , Dorgali ; coll. Brignoli, P.; 5.V.1967; paratype ♀ 3-2; paratype ♂ 7-1, paratype ♂ 8-1 (used in MEV), paratype ♂ 9-1; paratype ♂ 12-1, same data; paratype ♂ 1-1 (used in MEV), same data, coll. Cottarelli, V.; paratype ♂ 10-1, 411, ITALY, Sardinia, Nuoro, Arbatax; coll. Brignoli, P.; 4.V.1967.

Etymology. Dedicated to the Italian arachnologist Paolo Marcello Brignoli, who collected most of the material.

Diagnosis. Cheliceral movable digit of adults with ventral margin bearing 4–5 denticles; palptarsus 11–16 ch, 4 foliate d1 and 1 pectinate d2 seta. Males presenting setal variation, with 0–5 stout ribbed and 0–3 acute ribbed pregenital setae; and 4–7 stout ribbed genital setae. Female with no pregenital or genital setae; 4–9 smooth eugenital setae.

Description. Based on female (N= 9) and male (N= 11).

IDIOSOMA. Coloration dark blue with violet stripes on both body and legs; sometimes with a brownish background resulting from ingested food. Distinct segmentation; integument coniculate. Dorsal segments between prodorsal shield and preanal segments without setae, but with numerous lyrifissures arranged in transverse rows. Prodorsal shield. Dorsal shield with rounded area anteriorly; with 2 pairs of dorsolateral eyes; 2 pairs of lyrifissures, one close to apical part and other smaller, close to first pair of eyes; 130–144 (female) ( Fig 2A ), 123–144 (male) ( Fig 2B ) stout ribbed setae ( Fig 4D ). Preanal region. Preanal XVI segment without dorsal and ventral setae; preanal segment XVII with more than 2 dorsal (2–6) setae and 1 pair of lateroventral setae ( Fig. 4C ). Anal valves. Each with 13–15 (female) or 11–14 (male) stout ribbed setae ( Fig. 2C, D ). Tritosternum. Each digitiform structure with 2 pairs of setae, 1 pair small at tip and 1 pair long, barbed, positioned more basally. Sternal verrucae. Each with a longer ribbed tapering seta (st1) and 3–3 (female) or 2–3 (male) acute ribbed setae; region with a pair of ventral and lateroventral lyrifissures. Female and male st2 and st3 ribbed tapering; and 4–6 (female) ( Fig. 3D ) or 4–5 (male) pairs of stout ribbed setae ( Fig. 3C ). Sternal region without p (papilliform) setae. Pregenital area. Female without setae. Male with setal shape variation, 0–5 stout ribbed and/or 0–3 acute ribbed setae. Pregenital capsules. Each with a tapering ribbed seta (st5) and 5–7 (female) or 4–6 (male) stout ribbed setae. Genital area. Female without setae. Male genital area trapezoid and with 2–7 acute ribbed setae. Ovipositor. With 4–9 smooth eugenital setae (normally with 5–7, Arbatax female with 9); ovipositor consisting of tube-shaped structure, slightly striated, without digitiform or seta-like projections. Large basal structures absent, without terminal setae. Gland-like structures absent, without accessory glands.

GNATHOSOMA. Chelicera. Basal segment with 1 seta (cht 1) in normal size; and denticulate paraxial surface. Chelicera fixed digit with 3 dorsal setae (ch 1, ch 2, ch 3); well-developed hook; 4–5 ventral denticles; lateral denticle absent; ogc present ( Fig. 2G, H ). Subcapitulum. All paralabial setae present ( Fig. 2E, F ); pl1 conical, obtuse, inserted between cb 3 and cb 4; pl2 (With's organ) discoid, marginally barbed; pl3 (rutella) inserted dorsolaterally, with distinct row of 5 teeth; pl4 tiny, conical, inserted dorsally near base of pl3; all 4 pairs of circumbuccal setae (cb) with bifurcate tips; cb 4 equal size of other cb setae; female with 2 rounded tip setae; 4–5 pairs of pointed setae (vm, lvm, vp, lvp) and 1 ldm seta; male without rounded tip setae; 3–5 pairs of pointed setae (vm, lvm, vp, lvp) and 1 ldm seta. Lateral lips with distinct canals (dl1, dl2) and their orifices (ogl1, ogl2). Palps. Female. Trochanter with 3–3 r setae. Femur with 11–12 r; 7–8 p setae. Genu with 20–28 r; 4–7 p setae. Tibia with subequal setae; 38–43 r; 3 s ( Fig. 3A ). Tarsus with iα and iπ lyrifissures; 4 d1 foliate ( Fig. 4A ) with 4–5 lobules and a d2 pectinate seta with 5 sharp lobules ( Fig. 4B ), 4–5 v1; 2–3 v2; v3 absent; 3 s; 10–11 sm1; 14–15 ch setae. Tarsus apotele distal, ventral margin smooth. Male. Trochanter with 3–4 r setae. Femur with 12–19 r; 5–9 p setae. Genu with 43–54 r; 0–1 p setae. Tibia with 43–54 r; subequal length; 3 s setae ( Fig. 3B ). Tarsus with ia and iπ lyrifissures; 4 d1 foliate with 4–5 lobules and a d2 pectinate seta with 5 lobules; 3 s; 4 v1; 2–3 v2; v3 absent; 8–12 sm1; sm3 absent; 11–14 ch setae. Apotele distal; ventral margin smooth.

LEGS. Legs thin. Papilliform setae present, longer than broad. Legs I. Longer than others. Tibia I distal long setae absent. Basitarsus I proximal long setae absent. Telotarsus I with a highly modified group of dorsal distal setae in a depression; ω1 acicular, ω2 ligulate, ω3 subulate acuminate, ω4 conical; ζ1 small with crown-like tip inserted close to sensilla group and a ζ2 filiform with bifid tip. Leg II. Acrotarsus II with a bifid seta longer than wide, without smooth dorsal setae and ωa solenidion. Leg IV. Tibia IV without coronidia. Leg I–IV. All other leg segments with 3 types of setae arranged in distal to basal lines: 1) tapering and barbed, 2) papilliform and 3) smooth setae. Tibia II–III without coronidia. Genu II–III without coronidia. Femur II–IV without ventral trichobothria. Legs II–IV. Basitarsus II–IV with coronidia. Acrotarsus II–IV with 3 ventral setae pairs v; 3 lateral setae pairs l/dl; a pair of long serrated dorsolateral setae; and a pair of distal pectinate setae lv. Pretarsi II–IV with 1 pair of well-developed sessile claws and 2 pairs of setae, 1 setal pair long and curved, other pair smaller and apically pectinate. Legs III–IV. Acrotarsi III–IV with a long dorsal serrated seta.

Measurements. Female. Idiosoma: length 910–1154; width at the level of ocelli 183–228, palp: trochanter 56–80, femur 97–151, genu 82–112, tibiotarsus 149–189; chelicera length: basal segment 124–124, fixed digit 159–159; leg I: trochanter 222–278, basifemur 41–188, telofemur 427–506, genu 247–306, tibia 472–580, basitarsus 138–181, telotarsus 179–210; leg II: trochanter 105–141, femur 173–309, genu 118–173, tibia 137–183, basitarsus 153–256, telotarsus 100–155, acrotarsus 36–48; leg III: basitrochanter 72–108, telotrochanter 67–92, femur 189–268, genu 134–165, tibia 148–184, basitarsus 164–197, telotarsus 132–162, acrotarsus 39–52; leg IV: basitrochanter 156–203, telotrochanter 123–158, femur 360–397, genu 211–261, tibia 261–295, basitarsus 229– 245, telotarsus 186–199, acrotarsus 50–57. Male. Idiosoma: length 824–1327, width at level of ocelli 181–224, palp: trochanter 58–84, femur 123–141, genu 92–113, tibiotarsus 151–181; chelicera length: basal segment 151– 173, fixed digit 53–64; leg I: trochanter 222–302, basifemur 42–55, telofemur 380–503, genu 235–304, tibia 444– 585, basitarsus 128–176, telotarsus 174–218; leg II: trochanter 89–126, femur 224–328, genu 129–170, tibia 139– 189, basitarsus 152–206, telotarsus 127–169, acrotarsus 45–53; leg III: basitrochanter 76–104, telotrochanter 73– 96, femur 197–274, genu 114–160, tibia 136–186, basitarsus 149–193, telotarsus 135–172, acrotarsus 39–62; leg IV: basitrochanter 152–190, telotrochanter 114–181, femur 305–441, genu 197–262, tibia 232–322, basitarsus 218–271, telotarsus 162–205, acrotarsus 36–60.

Figures

FIGURE 2. Opilioacarus brignolii n. sp. Prodorsal shield of (A) male and (B) female; anal area of (C) male and (D) female; gnathosoma ventral view, (E) male and (F) female); chelicera lateral view of (G) male and (H) female.

FIGURE 3. Opilioacarus brignolii n. sp. Dorsal and ventral view of (A) male palptarsi and (B) dorsal and ventral view of female palptarsi (tarsi omitted); sternitogenital view of (C) male and (D) female (with invaginated ovipositor), and detail of eugenital seta.

FIGURE 4. Opilioacarus brignolii n. sp. Phase contrast microscopy: ventral view of male palptarsi, with detail of (A) foliate d setae (d1) and (B) pectinate d setae (d2), and their semi-schematic drawing (C, D). SEM: (E) anal valve and (F) prodorsal shield stout ribbed setae.

FIGURE 5. Difference between palp tarsus setae. Opilioacarus brignolii n. sp. (A) d1 foliate and (B) d2 pectinate; foliate d types of (C) Phalangiacarus brosseti, (D) Neocarus nohbecanus, (E) Neocarus orghidani, (F) Caribeacarus armasi, (G) Neocarus coronatus, (H) Salfacarus mahafaliensis and (I) an undescribed Australian genus.