Neocarus platensis Silvestri 1905

Araújo, Marcel Santos De, Palma, Antonella Di, Feres, Reinaldo José Fazzio & Penteado-Dias, Angelica Maria, 2023, Redescription of Neocarus platensis Silvestri, 1905 (Acari: Opilioacaridae) and a new species from the syntype series, Zootaxa 5230 (2), pp. 209-224 : 212-216

Neocarus platensis Silvestri 1905

( Figures 3–5 )

Material examined. Lectotype F ( UNINA), ARGENTINA, Misiones, Posadas, coll. F. Silvestri, ex. under stones, 27.MAY.1899. There is no information about the coordinates or specific location.

Paralectotypes. Same data as for the lectotype: F ( UNINA), M ( UNINA) .

Remarks. The type material was evaluated by Araújo et al. (2020) as syntypes: 5 M, TN/M (UNINA). URUGUAY, Salto, Salto, La Sierra, 27.MAY.1899, coll. F. Silvestri, under stones; 3 F (UNINA), M (UNINA), ARGENTINA, Misiones, Posadas, same data and collector.

Diagnosis. Male pregenital area with 6 stout ribbed setae and genital area with 5 acute smooth setae. Female with no pregenital and genital setae. Female ovipositor with no projections, 4–10 smooth eugenital setae. Male palp tarsus with 17–18 ch and female with 22–25 ch setae; adults with 5–6 d setae.

Description

Based on female (N = 2) and male (N = 1).

IDIOSOMA. Distinct segmentation; integument corniculate; dorsal segments between prodorsal shield and preanal segments without setae, but with numerous lyrifissures arranged in transverse rows; with four pairs of dorsal stigmata without peritremes; anus positioned terminally. Prodorsal shield ( Figure 3A ). With rounded area anteriorly; without dense patch; with 2 pairs of dorsolateral eyes; 2 pairs of lyrifissures, one close to apical part and other smaller close to first pair of eyes; female with 140–142 and male with>100 (not clearly distinguishable) stout ribbed setae. Preanal region ( Figures 3D, E ). Segment XVI without setae; preanal segment XVII with a single dorsal and a pair of lateroventral stout ribbed setae. Anal valves ( Figures 3D, E ). Each with 12–14 (female) and 11–12 (male) stout ribbed setae. Tritosternum. Each digitiform structure with 2 pairs of setae, 1 small at tip and 1 long, barbed positioned more basally. Sternitogenital area ( Figures 3B, C ). Sternal verrucae. In both adults, each with a longer ribbed smooth tapering seta (st1); female with 3–5 and male with 2 acute ribbed setae. Sternal region. With a pair of ventral and lateroventral lyrifissures. Adults with st2 and st3 ribbed tapering; female with 5–7 and male 4–5 pairs of stout ribbed setae. Sternal region without p setae. Pregenital area. Female without setae. Male with 6 stout ribbed setae. Each pregenital capsules in both adults with a ribbed, smooth tapering setae (st5); female with 4–6 and male with 5 stout ribbed setae. Genital area. Female without setae, but with 4–10 smooth eugenital setae. Male genital area trapezoid with 5 acute smooth setae; Ovipositor. Consisting of a tube-shaped structure; slightly striated; without digitiform or seta-like projections; large basal structures; terminal setae; gland-like structures or accessory glands. Male glands. 2 pairs of glands, one larger and one smaller, without reel-like structures.

GNATHOSOMA. Chelicera ( Figures 4B, D ). Both adults presenting chelicera basal segment with 1 seta (cht 1); normal size; and denticulate paraxial surface; fixed digit with 3 dorsal setae (ch 1, ch 2, ch 3) and id and iα lyrifissures; well-developed hook; movable digit with 1 ventral denticle; lateral denticle absent; ogc present. Subcapitulum ( Figures 4A, C ). Both adults with paralabial setae present; pl1 conical, obtuse, inserted between cb 2 and cb 3; 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; lateral lips with distinct canals (dl1, dl2) and their orifices (ogl1, ogl2). Female with 2 rounded tip setae; 5–7 pairs of pointed setae (vm, lvm, vp, lvp) and 1 ldm seta; male with 1 rounded tip seta; 5 pairs of pointed setae (vm, lvm, vp, lvp) and 1 ldm seta.

Palps ( Figure 5 ). Female. Trochanter with 3–4 r setae. Femur with 8–19 r; 9–10 p setae; spike-like setae absent. Genu with 28–41 r; 4–6 p setae. Tibia with subequal setae; 47–60 r; 3 s. Tarsus with iα and iπ lyrifissures; 5–6 d1 foliate stout pointed setae; 4–5 v1; 4–6 v2; v3 absent; 3 s; 9–11 sm1; 22–25 ch setae. Tarsus apotele distal; ventral margin smooth. Male. Trochanter with 3 r setae. Femur setation was not possible to count due the angle and condition of the material assemble. Genu with 23 r; 0 p setae. Tibia with 42–44 r; subequal length; 3 s setae; tarsus with ia and iπ lyrifissures; 6 d1; foliate stout pointed setae with 4–5 lobules; 3 s; 2–3 v1; 3–4 v2; v3 absent; 9–10 sm1; sm3 absent; 17–18 ch setae; apotele distal; ventral margin smooth.

LEGS. Papilliform setae longer than broad. Legs I–IV thin. Legs I. 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; ω1 conical, ω2 ligulate, ω3 subulate acuminate, ω4 acicular; ζ1 small with crown-like tip inserted close to sensilla group and a ζ2 filiform with bifid tip. Legs II. Acrotarsus II with a bifid seta longer than wide. And a smooth dorsal seta and ωa solenidion. Legs 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. Legs II–IV. Femora II–IV without ventral trichobothria. Genua and tibiae II–IV without coronidia. Basitarsi II–IV with coronidia. Acrotarsi 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 bifid setae lv; lightly bifid. 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; ambulacrum rounded and smooth; with a pair of well-developed sessile claws. Legs III–IV. Acrotarsi III–IV with a long dorsal serrated seta.

Measurements. Female. Idiosoma: length 1947–2141; width at level of ocelli 331–363, palp: trochanter 105– 119, femur 246–247, genu 183–186, tibiotarsus 295–313; chelicera length: basal segment 250–250, fixed digit 281– 281; leg I: trochanter 493–540, basifemur 93–95, telofemur 922–1055, genu 684–732, tibia 976–1105, basitarsus 311–342, telotarsus 435–488; leg II: trochanter 250–287, femur 579–615, genu 322–323, tibia 340–368, basitarsus 405–407, telotarsus 334–334, acrotarsus 98–98; leg III: basitrochanter 211–238, telotrochanter 180–226, femur 481–527, genu 351–365, tibia 362–382, basitarsus 417–417, telotarsus 321–321, acrotarsus 104–104; leg IV: basitrochanter 376–388, telotrochanter 347–369, femur 837–853, genu 505–524, tibia 629–652, basitarsus 579–589, telotarsus 397–406, acrotarsus 123–155. Male. Idiosoma: length 1755–2283, width at level of ocelli 303–355; palp: trochanter 83–121, femur 181–233, genu 120–198, tibiotarsus 246–284; chelicera length: basal segment 169, fixed digit 266; leg I: trochanter 438, basifemur 83, telofemur 883, genu 605, basitibia 444, telotibia 475, basitarsus 327, telotarsus 376; leg II: trochanter 230, femur 491, genu 287, tibia 254, basitarsus 292, telotarsus 256, acrotarsus 90; leg III: basitrochanter 185, telotrochanter 151, femur 442, genu 269, tibia 294, basitarsus 341, telotarsus 287, acrotarsus 82; leg IV: basitrochanter 306, telotrochanter 279, femur 698, genu 451, tibia 492, basitarsus 456, telotarsus 358, acrotarsus 107.

Figures

FIGURE 3. Neocarus platensis. (A) Female dorsal shield, (B) female sternitogenital region and ovipositor, (C) male sternitogenital region; anal regions, (D) female, (E) male. Abbreviations: oc = ocelli; sv = sternal verrucae, pgc = pregenital capsule, pg = pregenital area; g = genital area; eug = eugenital setae; ov = ovipositor; ogc = orifice of cheliceral gland.

FIGURE 4. Neocarus platensis. Female. (A) Ventral view of subcapitulum and (B) chelicera (dorsal view of basal segment, and lateral view of fixed digit, twisted due the assemblage); male (C) ventral view of subcapitulum and (D) dorsal view of chelicera.

FIGURE 5. Neocarus platensis. Palp (dorsal and ventral view). Female, (A) trochanter to tibia, (B) detail of the tarsus; male, (C) genu and tibia, (D) detail of the tarsus.