Andocaeculus beatrizrosso Porta & Pizarro-Araya & Ramírez 2021, sp. nov.
Creators: name: Porta, Andrés O.
name: Pizarro-Araya, Jaime
name: Ramírez, Martín J.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Acari
Caeculidae
Andocaeculus
Andocaeculus beatrizrosso

description: Andocaeculus beatrizrosso sp. nov.
(Figs. 31–59)
Etymology. The specific name is a noun in apposition in honor to Beatriz Rosso, researcher of Universidad Nacional de Córdoba, Argentina, in recognition of her fundamental contributions to the knowledge of water mites.
Diagnosis. Andocaeculus species of weyrauchi species group; aspidosoma with characteristic lateral constriction at level of seta Pa (Figs. 32, 34A), anterior border straight (Figs. 33, 35A) or with a medial incision in some exemplars (Figs. 32, 34A, D); palp tarsus with 3 eupathidia (Figs. 36, 47); b2 absent and d2 present (Figs. 32, 33), most setae on dorsal plates D, L and P not regressive, ellipsoidal; setae e2 and e2’ separated by ridges (Figs. 32–33). Setae of v’ series of leg I basifemur, telofemur and genu pedunculated, not pointed (Figs. 39A, 41B). Basifemur v’ (Figs. 40A, 42B), pedicelated, inserted in a long cuticular process, shorter than in other species of group, 54–60, 70–84 + long; RBaf, 0.56–0.59, RBaf +, 0.69–0.79, RTef, 0.43–0.53, RTef +, 0.61–0.78; tibia I (Figs. 40A, 43A–B) generally with 1 regressive seta in series d and tibia (Figs. 40B, 44D) II with one, solenidion φ present on tibia IV, RTi3: 3.2–4; setae l1” of tarsus II not eupathidial.
Type material. Holotype, male (MACN-Ar 41112). Argentina, Provincia de Mendoza, Departamento de Las Heras, Cerro Arcos, S32.858206°, W68.938977° (+/- 500 m), elev. 1150 masl (+/- 50 m), 24.Dec.2012, A. Porta leg., Berlese extraction of debris of xeric scrub; 6 paratypes, males (MACN-Ar 41105, 41106, 41113 to 41116), same data, cleared in lactic acid and preserved in alcohol; 7 paratypes, males (MACN-Ar 41107 to 41110, 41118 to 41119, 41121), same data, 29.Mar.2011, mounted on slides; 2 paratypes, females (MACN-Ar 41121, 41122), same data, mounted on slides; 3 paratypes, females (MACN-Ar 41137 to 41139), same data, cleared in lactic acid and preserved in alcohol; 6 paratype tritonymphs (MACN-Ar 41140-41145), same data, mounted on slides; 3 deutonymph paratypes (MACN-Ar 41147 to 41149), same data, 10.May.2013, mounted on slides; 2 larvae paratypes (MACN-Ar 41111, 41117), same data, 10.May.2013, mounted on slides; 2 paratypes, adults (MACN-Ar 41103, 41153), same data, in individual vials, preserved in alcohol; 2 paratypes, adults (CAI 4336, 4337), same data, in individual vials, preserved in alcohol 7 paratypes, 5 adults and 2 larvae, on individual stubs with exemplars mounted for SEM (MACN-Ar 41104), same data; 1 male paratype (MACN-Ar 41120) from Provincia de Mendoza, Mendoza Capital, Reserva de Flora Nativa Bosque Xerófilo, S32.891690°, W68.864855° (+/- 200 m), elev. 850 masl (+/- 5 m), 25.Dic.2012, A. Porta leg., Berlese extraction of debris of xeric scrub; 1 paratype tritonymph (MACN-Ar 41146), same data, mounted on slide; 1 paratype protonymph paratype (MACN-Ar 41150), same data, 08–10.May.2013, mounted on slide; 3 paratypes, adults (MACN-Ar 41150 to 41152), same data, preserved in alcohol; 2 paratypes, adults (MACN-Ar 41124, 41125), same data, 25.Dec.2012, preserved in alcohol.
Description
Male (n=10). Color (Fig. 31). Gnathosoma and dorsal sclerotized plates on idiosoma dark brown, membranous integument pale cream, legs also dark brown but darker than rest of body.
Gnathosoma (Figs. 32, 33, 34A, D, 35A). Covered by aspidosoma in dorsal view. Chelicerae (Fig. 36B) typical for family, 44 wide at base, 144–160 long, movable digit hook-like with 3 minute teeth; cheliceral seta ch slender (Figs. 35B–C), 6 long. Palp (Figs. 36B, 48) 4-segmented, trochanter glabrous; femorogenu with 2 clavate setae in dorsal series, d1 shorter than d; d1 and d 28–34 and 48–60 long, respectively; tibia with prominent calcar d on projecting tubercle, 26–34 long; 3 clavate setae d1, l’ and l”, 28–34, 26–36 and 32–34 long, respectively, plus one more calcar ld, 32–38 long. Palp tarsus subconical, 50–64 long, 10–16 wide at base, solenidion ω present on antiaxial face, 6–7 setae: 3 eupathidia, (u) and l ’, in addition to v, d, l” and, only in some exemplars, l1’ (Figs.36A, 48B–C). Subcapitulum (Fig. 35A) posteriorly rounded, anteriorly subconical, 156–160 long, 198–220 wide at level of palp insertion, setae m 34 long, anterior to n, 30 long, two pairs of adoral setae or 1-2 (Fig. 35B,C), 8 long.
Idiosoma (Figs. 32, 33). In dorsal view subtriangular, 822–853 long, 616–671 wide at level of coxa IV.
Aspidosoma (Fig. 34A). Subtriangular, 258–275 long, posterior margin 213–221 wide, anterior margin 60–66 wide, projecting horizontally over gnathosoma. Anterior portion with characteristic lateral constriction. Anterior margin straight (Figs. 22, 35A) or with medial incision in some exemplars (Figs. 34A, D). Seta Po (Fig. 34A, D) very long, its length 86–120, expanded distally, with anterior third setulate. Trichobothrial seta bo spatulate, 80–96 long, upturned in distal half and broadening at tip (Fig. 34D). Aspidosomal setation regressive, Pa (Fig. 34B) regressive, subcylindrical, 8 long, located on a transversal ridge; Pm regressive (Fig. 34C), cylindrical, 6 long, inserted on lateral border of aspidosoma, setae Pp absent. Lateral eye plates (Fig. 34A) separated from other plates; anterior pair of lateral eyes 14–22 diameter, posterior pair 22–24. Median eye 42–54 long, 44–50 wide.
Hysterosoma. Dorsal view. With 5 dorsal plates D, (L), M, P (Figs. 32, 33). Dorsal plate D subtrapezoidal, 260–295 long, anterior margin 197–209 long, posterior margin 274–295 long, with one longitudinal and two transversal ridges, setae a1, b1, c1, ellipsoidal, lengths: a1: 26–30, b1: 28–30, c1: 26–28; distance between setal insertions a1-a1: 98–106, b1-b1: 54–58, c1-c1: 64–74, a1-b1: 102–106, b1-c1: 108–120. Paired lateral plates L 320–336 long, 72–80 wide; a2 regressive, 9 long; b2 absent and c2 present with p=0.5; lyrifissure ia located on external side of plate, 26–30 long; lyrifissure im located on median line of plate, 12–18 long. Median plates M fused, with d1 and d2 36–38 and 29–36 long, respectively; distance between setal insertions d1-d1: 96–120, d1-d2: 130–146, d2-d2: 367–371. Posterior plates P divided by ridges, setae e1, e2 and e2’, 46–48, 38–44, and 38–44 long, respectively; in some exemplars e2 ” present, setae e2 and e2’ inserted in different sectors of plate, separated by a ridge; distance between setal insertions e1-e1: 100–126, e1-e2: 86–96. Seta hs on posterior border of idiosoma, 40–42 long.
Ventral view, podosoma and opisthosoma (Figs. 37, 38). Membranous integument striate. Coxal setation formula: 4:2–3:2–3:2, coxal setae clavate. Measurements of coxal setae, 1a: 20–26; 1b: 30–32; 1c: 32–36; 1d: 36–46; 2a: 18–22; 2b: 22–23; 2c: 16; 3a: 16–22; 3b: 16–22; 3c: 26; 4a: 20–22; 4b: 20–21; 4c: 16–22. Aggenital plates (Fig. 31B) poorly sclerotized, triangular, 72–80 long, 66–80 wide and not differentiable from integument in exemplars cleared in lactic acid. Genital opening 150–156 long, aggenital plates 34–42 wide, with 6 pairs of genital setae, 20– 24 long. Anal opening 136–146 long, adanal plates 32–34 wide, with two pairs of adanal clavate setae, 8–12 long. Pseudanal plate 164–170 long, 64–68 wide, with three pairs of setae, ps1 clavate, 34–36 long, normally developed, ps2 and ps3 regressive, ps2 10 long, ps3 8–9 long, membranous integument with 9 pairs of setae.
Internal genitalia (Fig. 39) with sclerites as in other species of the group, relatively large for Caeculidae in relation to idiosoma width, 130–140 wide at level of anterior ventral arch, 90–116 long. Ventral side (Fig. 39A) with 9 pairs of setae, 3 pairs anterior and medial, 2 pairs inserted on sclerites on each side, and 2 posterior pairs, all setae simple and unbranched, relatively long for the family in relation to the size of genital sclerite (cfr. Otto, 1993, Fig. 8; Fuangarworn & Butcher, 2015, Fig. 14; Ott & Ott, 2018, Fig. 4). Two laterodorsal apophyses clearly visible from dorsal side (Fig. 39B).
Legs (Figs. 40–47). Measurements see Table 9. Most setae inserted on big cuticular tubercles.
Leg I (Figs. 40A, 41–43). Trochanter (Figs. 40A, 42A) with one seta in series l’ and one regressive seta in d. Basifemur (Figs. 40A, 42B) with one seta in v’, pedicelated, inserted in a long cuticular process, shorter than in other species of the group, 54–60, 70–84 + long, RBaf: 0.56–0.59, RBaf +: 0.69–0.79, setae d, l”, v” and v”1 regressive, l’ petiolate. Telofemur (Figs. 40A, 42B) with seta v’ subequal to v’ in telofemur, but more curved, 46–50, 70–76 + long, RTef: 0.43–0.53, RTef +: 0.61–0.78; setae d, l’, l” and v” regressive. Genu (Figs. 42C–D) with 3 regressive setae in series d, 1 and 3 petiolate setae in l’ and l” series, respectively, l’, 46–48, 56–70 + long, 3 petiolate setae in v’ series with v’1 medially displaced, v’, 42–44, 50–64 + long, v2’, 40–46, 56–64 + long; 2 petiolate setae in v” series. Tibia (Figs. 39A, 42D, 43A–B, E) usually with only 1 regressive seta in series d, excepting 2 exemplars asymmetrically with 2 (Fig. 40A); 4 pedunculated setae in each lateral series, 4 spinous setae with blunt tip in ventral series, (v2) medially displaced, v’, 60–64, 70–74 + long, v1’, 50–54, 60–66 + long v”, 50–52 long, solenidion φ and famulus κ” inserted laterodorsally and distally (Figs. 43B, E). Tarsus (Figs. 41, 42D, 43C–D, F–G) with each of series l’, l”, v’ and v” with 3–4, 3–4, 4, 4 setae, respectively, l1” usually eupathidial with p=11/14 (Fig. 41), with some asymmetry (Fig. 43F), solenidion ω inserted dorsally (Figs. 41, 43G) at level of l1”, simple in structure (Fig 41), famulus ε inserted in antiaxial facies (Fig. 41) at level of v1”; eupathidia: er’, (st) and, putatively, l1”, trichobothria bt 16–20 long, two claws ol’ and ol”, 10 and 28–30 long, respectively. Setal count (solenidia): 2, 6, 5, 12, 18–19(1), 19–21(1).
Leg II (Fig. 40B, 44). Trochanter (Fig. 44A) with d regressive and l’ and l” petiolate. Basifemur (Fig. 44C) with d and l” regressive, l’, v”, v1” spatulate. Telofemur (Fig. 44C) with d, l’, v and l” regressive, l’ spatulate normally developed. Genu (Fig. 44B) with 3 regressive setae in series d, 3 and 2 pedunculated setae in series l’ and l”, respectively, 2 setae in series v’, seta v” 58–60 long. Tibia (Fig.44D, F) with 1 regressive seta in series d, 4 and 3 pedunculated setae in series l’ and l”, respectively, 3 spinous setae in both ventral series, solenidion φ inserted as in tibia I (Fig. 44F). Tarsus (Fig. 44E) with 3 setae in series l’, l” and 4 in v’ and v”, solenidion ω inserted dorsally at level of l”, only er’ eupathidial; (st) absent; trichobothria bt 14–20 long. Claws ol’ and ol” length 10–12 and 30–34, respectively. Setal count (solenidia): 3, 5, 5, 11, 14(1), 17(1).
Leg III (Figs.45A, 46). No eupathidia present. Trochanter (Figs. 45A, 46A) with d regressive and l” petiolate. Basifemur (Fig. 46B) with d regressive, l’, v’, v” and v1” petiolate. Telofemur (Fig. 46B) with d, l’, v” and l” regressive and v’ petiolate. Genu (Fig. 46B) with 3–4 and 1–2 regressive setae in series d and l’, respectively, and 3 pedunculated setae in series v’ and l”, 2 setae in series v”. Tibia (Fig.46D, F) with 2–4 regressive seta in series d, 4 and 3 pedunculated setae in series l’ and l”, respectively, 5 pointed setae in both ventral series, solenidion φ inserted as in tibia I (Fig. 46G), RTi3: 3.2–4. Tarsus (Fig. 46E) with 1 and 3 setae in series l’, l”, respectively, and 3 in v’ and v”; er” present, er’ absent, trichobothria bt 100–110 long. Claws ol’ and ol”, 10 and 36–44 long, respectively. Setal count (solenidia): 2, 5, 5, 12–14, 16–18(1), 12.
Leg IV (Figs.45B and 47). Trochanter (Figs. 45A, 46A) with d and l” petiolate and v’ regressive. Basifemur (Fig. 46B) with v” regressive and l’, v’ spatulate. Telofemur (Fig. 46B) with d, l’ and v” regressive and v’ and l” spatulate. Genu (Fig. 47C) with 2 regressive setae in series d, 2 pedunculated setae in each series v’ and l”, 1 seta in series v”. Tibia (Fig.47D, F–G) with 2–3 regressive seta on tibia series d, 3 pedunculated setae in series l” and 4 pointed setae in both ventral series, solenidion φ inserted as in tibia I (Fig. 47F–G). Tarsus (Fig. 47E) with 1 and 2 setae in series l’ and l”, respectively; 3 setae in series v’ and v”, er” present, er’ absent, trichobothria bt 114–140. Claws ol’ and ol” 9–10 and 50–56 long, respectively. Setal count (solenidia): 3, 3, 5, 7, 13–14(1), 11.
Female (n=3). Externally similar to male except in size.
Gnathosoma. Chelicera 128–136 long. Palp 4-segmented, with chaetotaxy as in male. Subcapitulum 176–192 wide at level of palp insertion, 150–170 long, setae m anterior to n, two pairs of adoral setae or1-2.
Idiosoma. 786–924 long, 572–687 wide at level of coxa IV.
Aspidosoma. Subtrapezoidal, 258–274 long, posterior margin 213–266 wide, anterior margin 68–80 wide, projecting horizontally over gnathosoma. Seta Po 100–106 long, trichobothrial seta bo 88–120 long. Aspidosomal setation regressive, Pa and Pm minute, Pp absent; anterior pair of lateral eyes 16–20 diameter, posterior pair 18–22. Median eye 40 long, 48 wide.
Hysterosoma. Dorsal view. Dorsal plate D subtrapezoidal, 258–320 long, anterior margin 216–287 long, posterior margin 280–307 long, a1: 22–28, b1: 28–38, c1: 30–38; distance between setal insertions, a1-a1: 100–116, b1-b1: 50–72, c1-c1: 46–76, a1-b1: 102–116, b1-c1: 96–128. Paired plates L 360 long, 60–80 wide; a2 regressive 9 long; b2 and c2 absent, ia and im 30–32 and 16–20 long, respectively. Median plates M fused, with d1, d2, 36–42 and 26–30 long, respectively, distance between setal insertions, d1-d1: 90–130, d2-d2: 347–435, d1-d2: 134–158. Posterior plates P, divided by ridges, setae e1, e2, e2’ and e2 ”, 38–44, 38–46, 36–46 and 36–40 long, respectively. Setae e2’ and e2” separated by a ridge from e2, expression of e2” variable (p=0.5), distance between setal insertions, e1-e1: 110–140, e1-e2: 60–98. Seta hs on posterior border of idiosoma, 34–36 long.
Ventral view, podosoma and opisthosoma. Coxal setation formula 4:3:3:2–3. Genital opening 150–162 long, with 6 pairs of genital setae, 13–18 long. Anal opening 140–148 long, adanal plates 40–44 wide, with two pairs of adanal clavate setae, 16–18 long. Pseudanal plate 160–162 long, 56 wide, with three pairs of setae.
Legs. Measurements see table 10. Ratios, RBaf: 0.5–0.58; RBaf +: 0.77–0.83; RTef: 0.43–0.51; RTef +: 0.73–0.85.
Larva (n=3) (Figs 49–59)
Gnathosoma. Covered by aspidosoma in dorsal view (Fig. 53). Chelicera 46 long; cheliceral seta ch present. Palp (Fig. 54) 4-segmented, trochanter glabrous, femorogenu with 1 clavate seta in dorsal series, 9–10.4 long; tibia with a calcar d, 11 long, located on a projecting tubercle, 2 clavate setae l’ and l”, and 1 calcar setae ld; 8–11 long, tarsus subconical, solenidion ω present on antiaxial face, 5 setae present, setae v, l’, and d in addition to 2 eupathidia (u). Subcapitulum (Fig. 54) 90 wide at level of palp insertion, 60 long, setae m 12–13 long, anterior to n, 10 long, two pairs of adoral setae or 1-2.
Idiosoma (Figs. 49–50). 264–320 long, 184–224 wide at level of coxa III.
Aspidosoma (Figs. 51–52). Subtrapezoidal, 106–108 long, posterior margin 100–106 wide, anterior margin 32–36 wide, projecting horizontally over gnathosoma. Seta Po 38 long, trichobothrial seta bo 42 long (Figs. 51B, 52), Pa and Pm minute, Pp absent. Lateral eye plates (Figs. 49, 50A, 51A) separated from other plates; anterior pair diameter 8, posterior pair 8–10.
Hysterosoma. Dorsal view (Figs. 49, 50A). Dorsal plates poorly defined; only setae a1, b1, c1, a2, d1, e1 and hs present. Lengths of anterior hysterosomal setae, a1: 7–8; b1: 7–8; c1: 9–10; a2: 3; d1: 22–23; e2: 25–26, distance between setal insertions, a1-a1: 45–67; b1-b1: 29–30; c1-c1: 30–44, a1-b1: 38–39; b1-c1: 40–42; d1-d1: 46–53; e1-e1: 30–32.
Ventral view, podosoma and opisthosoma (Fig. 50B). Coxal setation formula 2:0:1, 16–18 long, Claparede’s organs present on anterior margin of coxae II. Anal opening 58–70 long, hs 7 long, lyrifissure ih present.
Legs (Figs. 55–59). Measurements see table 14. Femora entire in all legs, Rf: 1–1.15; Rf +: 1.07–1.38
Leg I. (Figs. 55A, 56–57) Tr, 0; Fe, 1d*, 1l’, 1l”, 1v’, 2v”; Ge, 2d*, 1l’, 2l”, 1v’, 1v”; Ti, 1d*, 2l’, 2l”, 2v’, 2v”, κ”, φ; Ta, 3l’, 2l”, 3v’, 3v”, tb, ε (dorsal), ω, (st)ζ.
Leg II. (Figs. 55B, 58) Tr, 0; Fe, 1d*, 1l’, 1l”, 1v’, 2v”; Ge, 2d*, 1l’, 1l”, 1v’, 1v”; Ti, 1d*, 2l’, 2l”, 2v’, 2v”, φ; Ta, 3l’, 2l”, 3v’, 3v”, tb, ε (antiaxial), ω
Leg III. (Figs. 55C, 59) Tr, 0; Fe, 1d*, 1l’, 1l”, 1v’, 2v”; Ge, 1d*, 1l’, 1l”, 1v’, 1v”; Ti, 1d*, 1l’, 2l”, 2v’, 2v”, φ; Ta, 2l’, 1l”, 3v’, 2v”, tb.
Protonymph (n=1)
Gnathosoma. Chelicera 24 wide at base, 54–62 long. Palp 4-segmented, trochanter glabrous, femorogenu with 1 clavate seta in dorsal series, 24 long; tibia with 2 calcars d and ld, 17 and 15 long, respectively, and 2 clavate setae l’ and l”, 14 and 9 long, respectively; tarsus subconical, 16 long, 9 wide at base, solenidion ω present on antiaxial face, 5 setae v, l’, d in addition to 2 eupathidia (u). Subcapitulum 78 long, 102 wide at level of palp insertion, 53 long, setae m 16 long, anterior to n, two pairs of adoral setae or 1-2.
Idiosoma 416 long, 312 wide at level of coxa IV.
Aspidosoma. Subtrapezoidal 130 long, posterior margin 114 wide, anterior margin 30 wide, projecting horizontally over gnathosoma. Seta Po 49 long, trichobothrial seta bo 52 long. Aspidosomal setation regressive, Pa and Pm minute, Pp absent. Lateral eye plates separated from other plates; anterior pair of lateral eyes 7–8 diameter, posterior pair 9–10.
Hysterosoma. Dorsal view. Unpaired dorsal plate D subtrapezoidal,142 long, anterior margin 100 long, posterior margin 120 long, setae a1, b1, c1, present, lengths, a1: 16–18, b1: 16, c1: 16; distance between setal insertions, a1-a1: 50, b1-b1: 32, c1-c1: 27, a1-b1: 46–50, b1-c1: 50–54. Paired plates L 144–154 long, 36–38 wide; setae a2 regressive; b2 and c2, absent; ia and im, 16 and 10 long, respectively. Median plate M fused, seta d1: 24 long, d2 absent; distance between setal insertions d1-d1: 48. Posterior plates P with setae e1, 29 long, e2 absent, distance between setal insertions e1-e1: 44. Seta hs on posterior border of idiosoma, 17 long.
Ventral view, podosoma and opisthosoma. Coxal setation formula 3:1:1:1, coxal setae clavate. Genital opening 20 long, adanal plates 40–44 wide, with 1 pair of setae, 7 long. Anal opening 68 long, with two pairs of clavate setae. Pseudanal plate 62–64 long, 18–20 wide, with three pairs of setae, ps1, ps2 and ps3, 8–10 long.
Legs. Measurements see table 13. Femora entire in leg IV; RTfe: 0.75, RTfe +: 0.85–0.9.
Leg I. Tr, 1l’; PrFe, v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, 1l’, 1l”, 2v’, 1v”; Ti, 1d*, 2l’, 2l”, 2v’, 2v”, κ”, φ; Ta, 3l’, 2l”, 3v’, 3v”, tb, ε (antiaxial), ω, (st)ζ.
Leg II. Tr, 1l’, 1l”; PrFe, v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, 1l’, 2l”, 1v’, 1v”; Ti, 1d*, 2l’, 2l”, 2v’, 2v”, φ; Ta, 3l’, 2l”, 3v’, 3v”, tb, ε (antiaxial), ω.
Leg III. Tr, 0; PrFe, v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 1d*, l’*, 1l”, 1v’, 1v”; Ti, 1d*, 1l’*, 2l”, 2v’, 2v”, φ; Ta, 2l’, 1l”, 3v’, 2v”, tb.
Leg IV. Tr, 0; Fe, 1d*, 1v’, v”; Ge, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ti, 1d*, 1l’, 2l”, 2v’, 2v”, φ; Ta, 1l’, 1l”, 2v’, 2v”, tb.
Deutonymph (n=2)
Gnathosoma. Chelicera 76–88 long. Palp 4-segmented, trochanter glabrous, femorogenu with 2 clavate setae in dorsal series, d and d1, 32–36 and 20–22 long, respectively; tibia with 2 calcars d and ld, 20 long, and 2 clavate setae l’ and l”, 18–22; tarsus subconical, 28–30 long, 12–15 wide, solenidion ω present on antiaxial face, 5 setae v, l’, d in addition to 2 eupathidia (u). Subcapitulum 126–140 wide at level of palp insertion, 90–96 long, setae m anterior to n, and two pairs of adoral setae or 1-2.
Idiosoma. 537–640 long, 379–482 wide at level of coxa IV.
Aspidosoma. 168–184 long, posterior margin 150–160 wide, anterior margin 50–52 wide, projecting horizontally over gnathosoma. Seta Po 62–64 long, trichobothrial seta bo 60–68 long. Aspidosomal setation regressive, Pa and Pm minute, Pp absent. Lateral eye plates separated from other plates; anterior pair of lateral eyes 12 diameter, posterior pair 14–18.
Hysterosoma. Dorsal view. Unpaired dorsal plate D subtrapezoidal, 172–201 long, anterior margin 143–151 long, posterior margin 176–180 long, lengths, a1: 20–24, b1: 22–27, c1: 22; distance between setal insertions, a1-a1: 60, b1-b1: 34, c1-c1: 30–42, a1-b1: 70–74, b1-c1: 68–72. Paired plates L 213–230 long, 50–58 wide; a2 regressive 9 long; b2 and c2, absent; ia and im, 20–26 and 10–16 long, respectively. Median plate M fused d1 24–28 long, d2 absent; distance between setal insertions d1-d1: 60–66. Posterior plates P with setae e1 and e2 30 –32 and 26–28 long, respectively; distance between setal insertions, e1-e1: 54–60, e1-e2: 52–58, e2-e2: 128–140. Seta hs on posterior border of idiosoma, 28 long.
Ventral view, podosoma and opisthosoma. Coxal setation formula 4:1–2:2–3:2. Genital opening 36 long, aggenital plates 13–14 wide, with one pair of genital setae, 10 long. Anal opening 100–104 long, adanal plate 30–32 wide, with two pairs of adanal clavate setae.
Legs. Measurements see table 12. Ratios: RBaf: 0.79–0.87; RBaf +: 0.96–1.04; RTef: 0.62–0.8; RTef +: 0.85– 0.96
Leg I. Tr, 1d*, 1l’; PrFe, 1d*, 1l’, 1l”*, 1v’, 2v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, 1l’, 2l”, 2v’, 2v”; Ti, 1d*, 2l’, 2l”, 3v’, 3v”, κ”, φ; Ta, 3l’(l” ζ, p=1/4), 2l”, 3v’, 3v”, tb, ε, ω, (st)ζ, present in only 1 individual: er’ζ and er”.
Leg II. Tr, 1l’, 1l”; PrFe, (0–1)d*, l”*, 1v’, 2v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, 1l’, 2l”, 2v’, 1v”; Ti, 1d*, 2l’, 2l”, 2v’, 2v”, φ; Ta, 3l’, 2-3l”, 3v’, 3v”, tb, ε, ω.
Leg III. Tr, 1l”, 1v’; PrFe, 1v’, 1v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, (0-1)l’*, 2l”, 2v’, 1–2v”; Ti, 2d*, 2l”, 3v’, 3v”, φ; Ta, 2l’, 1l”, 3v’, 3v”, er”, tb.
Leg IV. Tr, 0; PrFe, 0–1v’; TeFe, 0-1d*, 1l’*, 1l”, 1v’, 1v”; Ge, 1d*, 1l’*, 1l”, 2v’, 1v”; Ti, 2d*, 2l”, 2v’, 2v”, φ; Ta, 1l’, 1l”, 3v’, 2v”, er”, tb.
Tritonymph (n=8)
Gnathosoma. Chelicerae 90–110 long. Palp 4-segmented, trochanter glabrous, femorogenu with 2 clavate setae in dorsal series, d and d1, 36–42 and 26–30 long, respectively; tibia with 2 calcars d and ld, 24–28 and 26–30 long, respectively, and 3 clavate setae d1, l’ and l”, 18–28 long; tarsus subconical, 38–42 long, 14–18 wide at base, solenidion ω present on antiaxial face, 6 setae v, l” and d in addition to 3 eupathidia, (u) and l’. Subcapitulum 116–120 long, 148–180 wide at level of palp insertion, long, setae m anterior to n, long, two pairs of adoral setae or 1-2.
Idiosoma. 734–790 long, 490–592 wide at level of coxa IV.
Aspidosoma. Subtrapezoidal, 206–221 long, posterior margin 186–206 wide, anterior margin 50–60 wide, projecting horizontally over gnathosoma. Seta Po 76–88 long, trichobothrial seta bo, 72–84 long. Aspidosomal setation regressive, Pa and Pm minute, Pp absent. Lateral eye plates separated from other plates; anterior pair of lateral eyes 13–14 diameter, posterior pair 16–22.
Hysterosoma. Dorsal view. Dorsal plate D subtrapezoidal, 230–279 long, anterior margin 160–176 long, posterior margin 200–234 long, a1: 22–30, b1: 22–26, c1: 24–26; distance between setal insertions, a1-a1: 84, b1-b1: 40–50, c1-c1: 50–55, a1-b1: 90–94, b1-c1: 90–96. Paired plates L 279–320 long, 60–66 wide; a2 regressive 9 long; b2 and c2 absent; ia and im 22–30 and 17–20 long, respectively. Median plates M fused, with d1 and d2, 28–34 and 22–26 long, respectively, distance between setal insertions, d1-d1: 86–90, d2-d2: 316, d1-d2: 120–124. Posterior plates P, divided by ridges, setae e1 and e2, 34 –40 and 32–34 long, respectively. Setae e2’ separated by ridge from e2, distance between setal insertions, e1-e1: 90–96, e1-e2: 84–86. Seta hs on posterior border of idiosoma, 26 long.
Ventral view, podosoma and opisthosoma. Coxal setation formula 3–4:2:3:2. Genital opening 62–70 long, aggenital plates 18–20 wide, with 3 pairs of genital setae, 11–14 long. Anal opening 118–134 long, adanal plate 34–42 wide, with two pairs of adanal clavate setae, 10–12 long. Pseudanal plate 128–143 long, 50–52 wide, with three pairs of setae.
Legs. measurement see table 11. Ratios, RBaf: 0.58–0.67; RBaf +: 0.86–0.97; RTef: 0.5–0.57; RTef +: 0.75– 0.89.
Leg I. Tr, 1d*, 1l’; PrFe, 1d*, 1l’, 1l”*, v’, 2v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2-3d*, 1l’, 2l”, 3v’, 2-3v”; Ti, 1d*, 3l’, 2-3l”, 3v’, 3v”, κ”, φ; Ta, 3l’, 3l”, 3v’, 3-4v”, tb, ε, ω, (st)ζ, er’ζ, er”.
Leg II. Tr, 1d*, 1l’, 1l”; PrFe, 1d*, 1l’*, 1v’,2v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 2d*, 1l’, 2l”, 3v’, 1v”; Ti, 1d*, 3l’, 3l”, 3v’, 2-3v”, φ; Ta, 2-3l’, 2-3l”, 3v’, 3v”, tb, ε, ω,, er’ζ, er”.
Leg III. Tr, 1d*, 1l”, 1v’; PrFe, 1d*, 1l”, 1v’, 2v”; TeFe, 1d*, 1l’*, 1l”*, 1v’, 1v”; Ge, 3d*,0-1l’*, 2l”, 2v’, 2v”; Ti, 2-3d*, 3l”, 4v’, 3-4v”, φ; Ta, 2-3l’, 1l”, 3v’, 3v”, er”, tb.
Leg IV. Tr, 1d*, 1l”, 0-1v’; PrFe, 0-1d*, 1l”, 1v’; TeFe, 1d*, 1l’*, 1l”, 1v’, 1v”; Ge, 1-2d*, 0-1l’*, 2l”, 2v’, 1-2v”; Ti, 2d*, 1-2l”, 3v’, 3v”, φ; Ta, 1-2l’, 1l”, 2-3v’, 2-3v”, er”, tb.
Phylogenetic analysis
The Bayesian analysis was fully compatible with the maximum likelihood tree used to select the best fitting model. The best fit models for each codon were SYM+G4 for COI1, GTR+F+G4 for COI2, and HKY+F+G4 for COI3. In the resulting tree (Fig. 60) the family, the genus Andocaeculus and the A. weyrauchi species group (only A. weyrauchi and A. burmeisteri sp. nov.) were recovered as monophyletic with high posterior probabilities (p=1, 0.99 and 1, respectively). In contrast to our previously published morphological phylogeny for the family (Porta et al., 2019), Neocaeculus did not occupy a derived position with respect to the clade [Caeculus + Andocaeculus]. These results are, however, preliminary and will be tested using more terminals in the following part of the revision of the genus. The five exemplars assigned, on the basis of their morphology, to the species A. weyrauchi were recovered as a monophyletic group, which allows us to study the variation of morphological characters at the intraspecific level.
Remarks
On the d series setae of the legs and other characters of the A. weyrauchi species group
Under the optical microscope, leg setae of the series d in the A. weyrauchi species group resemble eupathidia by their shape and size. However, under inspection with SEM, the tarsal eupathidia present the typical ‘baguette de tambour’ shape (see for example Figs. 9I, 15, 43G), which clearly differ both in shape and size to the setae of the d series on other leg segments. In contrast, some setae on the larval stages (see Figs. 55–58) are similar, both in shape and size, to the d series setae on legs of the adults. Moreover, in the ontogeny of A. beatrizrosso sp. nov. and A. weyrauchi, some of these leg setae with typical regressive morphology become, in later stages, normal shaped setae (e.g. l’ on basifemur I), precluding any possibility that these setae were originally eupathidial. These facts reveal that these setae are regressive in the adult stage as consequence of a neotenic processes present in the group. A similar regressive process has been described for some setae of the same series for Microcaeculus hispanicus (Coineau, 1974a).
Other neotenic processes present in this group are the morphology of aspidosomal setae, the presence of only one seta on the palpal femur and the presence of only 3 eupathidia on the palp tarsus of A. beatrizrosso sp. nov. In contrast, the low count of eupathidia on the legs could be the result of other process that have a wider occurrence within the genus (Ott & Ott, 2014, AOP pers. obs.).
On the absence of (st) pair on tarsus II
About the (st) pair of setae on tarsus II, Coineau (1974a: 204) stated: “ Celles-ci [p’ p” setae] existent aux tarses I et II des Caeculidae (nous les notons st’ st”) et aux trois premiers tarses chez Anystis Granjean (1947 c, p. 88) alors qu’elles ne subsistente généralement qu’aux tarses I de la plupart des Acariens actinochitineux ”. [“These [p’ p” setae] exist on tarsi I and II of the Caeculidae (we denote them st’ st”) and on the first three tarsi in Anystis Grandjean (1947 c, p. 88) whereas they generally only subsist on the tarsi I of most actinochitinous mites”]. In contraposition to the Coineau statement, our examination of species of the genus Andocaeculus (all the described and several undescribed species) revealed that they all lack the (st) pair on tarsi II in all life stages. As this characteristic is not shared by other genera of caeculids, our preliminary phylogenetic analysis suggests that this is a synapomorphy of the genus Andocaeculus.
On the presence of solenidion φ on leg IV on A. weyrauchi.
The presence of a solenidion on tibia IV of species of the genus Neocaeculus from Oceania and South Africa has was used by Coineau (1967, 1974b) and Coineau & Enns (1969) to support the genus Neocaeculus, which occurs in Oceania and South Africa. Outside Neocaeculus, it has only been registered in Microcaeculus (?) pica Otto, 1997 and, as a variation, on left tibia IV of the holotype of Microcaeculus sabulicola Franz, 1952 (Coineau, 1969). As consequence of our phylogenetic analysis the presence of a solenidion on tibia IV of A. weyrauchi (Fig. 60, filled circles) is a primitive condition for the family Caeculidae, that was lost in the clade Caeculus + Andocaeculus (empty circles), and re-gained in A. weyrauchi. It is possible that the presence of the same derived condition in A. beatrizrosso sp. nov. could be conditioned by the psammophylous habits of both species, and, in consequence, further studies could bring some light on the function of these solenidia.
On the high variability of some characters on A. weyrauchi
Although our sampling of A. weyrauchi is restricted to type locality, we found remarkable variability in morphological characters in adults that are conserved in other species of the group: in dorsal chaetotaxy, the idiosomal setae b2 and c2 may be present or absent with almost equal probability; and some exemplars exhibit presence of neotrichy on the d2 sector. Likewise, some morphometric characters, such as the idiosomal and segment dimensions (Table 2), exhibit relatively high variability in their ranges. This variability can be illustrated using the quotient of the length of interval of the range over the midpoint of that interval. For example, in females of A. weyrauchi, for idiosomal length, where the range is 840–1110, this quotient is of 27.69%; and, for length of tibia III, where the range is 142–230, the quotient is 47.31%. In contraposition for females of A. burmeisteri these quotients values are of the order of 5 and 7%, for the lengths of the idiosoma and the tibia III, respectively. Variabilities of these characters, both idiosomal chaetotaxy and linear measures, have been used to distinguish species in another genus of the family (see keys for Caeculus on McDaniel & Boe (1990), Bernard et al. (2020) and discussion on Porta & Vazquez (2020)). In A. weyrauchi these characters are correlated in such a way that bigger females have, in general, more idiosomal setae that smaller ones. With the objective to study at least the variability of dorsal chaetotaxy we sequenced five exemplars showing different combinations of absence/presence of b2 and c2 setae and of neotrichy on the d2 sector, and incorporated their sequences in the phylogenetic analyses. The resulting tree (Fig. 60) as well as the intraindividual variation of gene sequences (intraspecific distance in A. weyrauchi max 5.18%, mean 2.17%; interspecific distance in Andocaeculu s min 12.1%; mean 22.09%) are consistent with the hypothesis that morphological variability could be assigned to intraspecific variability.
description: Published as part of Porta, Andrés O., Pizarro-Araya, Jaime & Ramírez, Martín J., 2021, Revision and phylogeny of the genus Andocaeculus (Acari: Caeculidae) I: the A. weyrauchi species group, pp. 1-78 in Zootaxa 4945 (1) on pages 42-76, DOI: 10.11646/zootaxa.4945.1.1, http://zenodo.org/record/4614242