Ologamasus tuberculatus, Bizarro & Rode & Schussler & Costa & Ferla, 2023

Bizarro, Gabriel Lima, Rode, Priscila De Andrade, Schussler, Matheus, Costa, Tairis Da- & Ferla, Noeli Juarez, 2023, Two new species of the genus Ologamasus (Ologamasidae) from apple orchards in southern Brazil, Zootaxa 5375 (4), pp. 495-514 : 504-512

Ologamasus tuberculatus n. sp.

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Material examined. Adult females and males, protonymphs and deutonymphs collected on spontaneous plants associated with apple orchards in the municipalities of Antônio Prado (AP) and Muitos Capões (MC) Rio Grande do Sul, Brazil, as follows: Female holotype, L. multiflorum , AP, March 22, 2021; male paratype, P. australis , MC, May 31, 2021; protonymph paratype, P. australis , AP, April 12, 2021; deutonymph paratype, L. multiflorum , AP June 29, 2021; female paratype, L. multiflorum , AP, March 22, 2021; deutonymph paratype, L. multiflorum , MC, October 24, 2020. All collected by P. de A. Rode. All types are deposited at the Museu de Ciências—Univates ( MCN), University of Vale do Taquari—Univates, municipality of Lajeado, state of Rio Grande do Sul, Brazil .

Protonymph. ( Figs 18–22 ) (one specimen measured).

Dorsal idiosoma. ( Figs 18 and 36 ) Idiosoma 434 long and 282 wide. Podonotal and opisthonotal shields separate, with three pairs of small plates in between them; podonotal shield 232 long and 213 wide, shield smooth; with j1–j6, z2, z4–z5, s4 and s6 on the shield; r2, r3, r5 and r6 on the soft cuticle; five pair of lyrifissures (id1, id4– id6) inside the shield, and id2 on the soft cuticle; with a pair of large pores on a small plate on the soft cuticle (gd4) ( Fig. 37 ). Opisthonotal shield 84 long and 125 wide, smooth, with J3–J5, Z3–Z5 and S3–S4 on the shield; J1–J2, Z1–Z2, S1–S2 and R 1 on the soft cuticle. With four pair of lyrifissures (idm3–idm4 and idx) on the shield, and idm1 on the soft cuticle; with a pair of pores (gd9) posteriad to S3. All setae setiform and smooth.

Ventral idiosoma. ( Fig. 19 ) Tritosternum 81 in total length; base 46 long. Presternal plates absent; sternal shield 131 long and 89 wide, smooth, containing st1, st2 and st3 and two pairs of lyrifissures (iv1 and iv2). Setae st5 on the soft cuticle between legs IV with iv5 posteriad to it. Anal shield 64 long and 79 wide, smooth; setae JV1, JV2, JV5 and ZV2 on soft cuticle; all setae setiform and smooth.

Peritreme. Peritreme short, 35 long, reaching posterior region of coxa III.

Legs. Leg I 639; leg II 407; leg III 406; leg IV 511 and St IV 110.

Gnathosoma. Epistome ( Fig. 20 ) 81 and its base 46, with median extension bifurcated distally, and with a pair of lateral denticles; palp 193 long, with palp genu seta al1 rayed ( Fig. 21 ); movable cheliceral digit 73, with three teeth in addition to apical tooth, and fixed digit 76, with seven teeth in addition to apical tooth and setiform pilus dentilis ( Fig. 22 ); corniculi 34. Antiaxial and dorsal lyrifissures as well as dorsal setae distinct. Arthrodial process of chelicera shaped as a coronet-like fringe.

Deutonymph. ( Figs 23–26 ) (three specimens measured).

Dorsal idiosoma. ( Fig. 23 ) Idiosoma 692 (550–773) long and 455 (390–530) wide. Podonotal and opisthonotal shields divided; podonotal shield 284 (281–304) long and 326 (268–368) wide, with concave anterolateral margin, smooth elsewhere; setae j1–j6, z1–z6, s3, s5, s6 and r3 on the shield, s2, r2 r4–r6 on the soft cuticle; with five pairs of lyrifissures (id1–id2, id4–id6) and two pair of pores (gd1 and gd4) ( Fig. 38 ). Opisthonotal shield with 20 pairs of setae, 232 (210–161) long and 285 (268–301) wide, with faint reticulation anterior to J3 and smooth elsewhere; with setae J1–J5, Z1–Z5 and S2–S5 on the shield, and S1 and R 1– R 5 on soft cuticle; with ten pairs of lyrifissures (idm1–idm6, idx, idl3–idl4 and is1), and one pair of large pores (gd9) ( Fig. 39 ). All setae smooth, reaching and exceeding the base of the subsequent setae.

Ventral idiosoma. ( Fig. 24 ) Tritosternum 173 (148–183) in total length; base 55 (49–61) long; presternal shield absent; sternal shield 234 (225–247) long and 103 (99–114) wide, with scant anterolateral margins, smooth elsewhere, with setae st1–st4 and three pair of lyrifissures (iv1–iv3). Seta st5 on soft cuticle and iv5 posteriad to coxa IV. With gd6 posteriorly in line with stigma. With four transversely alighted platelets anterior and one aside JV1, and a larger beside ZV1. Anal shield 107 (85–118) long and 129 (128–134) wide, rounded and striate; setae JV1–JV3, JV5 and ZV1–ZV2 on the soft cuticle.

Peritreme. 269 (257–282) long. Median part of peritrematic shield with an abutted plate containing ip3, ip4 and gp2.

Legs. Leg I 799 (791–885), II 517 (516–576), III 501 (489–551) and IV 689 (676–734).

Gnathosoma. Epistome ( Fig. 25 ) 100 (91–105); palp 257 (236–275) long, with palp genu seta al1 rayed and apotele trifurcate; movable cheliceral digit 95 (93–109), with three teeth in addition to apical tooth, and fixed digit 102 (96–110), with eight small teeth of different size very close to each other, one more developed teeth in addition to apical tooth, and one setiform pilus dentilis ( Fig. 26 ); corniculi 53 (50–58) long. Antiaxial and dorsal lyrifissures as well as dorsal setae distinct. Arthrodial process of chelicera shaped as a coronet-like fringe.

Adult female. ( Figs 27–31 ) (two specimens measured)

Dorsal idiosoma. ( Fig. 27 ) Idiosoma 781 (764–798) long and 780 (467–493) wide. Podonotal and opisthonotal shields fused, completely covering dorsum of idiosoma and posteriorly fused with posterior margin of ventrianal shield; with slightly concave anterolateral margin, smooth elsewhere, and faint reticulation with tiny shallow pits on opisthosoma. Podonotal region with 21 pairs of setae (s1, s4 and r1 absent), five pairs of lyrifissures (id1–id2, id4–id6), two pairs of pores (gd4 and gd5), of which gd4 is larger on a distinct protuberance projected outward ( Fig. 40 ). Opisthonotal region with 20 pairs of setae, ten pairs of lyrifissures (idm1–idm6, idx, idl3–idl4 and is1), and one pair of large pores (gd9) ( Fig. 41 ) anteriad to R 4. Measurements of setae provided in Table 2 . All setae setiform and smooth.

Ventral idiosoma. ( Fig. 28 ) Tritosternum 193 (189–197) in total length; base 68 (66–71) long; inserted between a pair of reticulate presternal platelets. Sternal shield 125 (122–128) long and 200 (187–121) wide, completely reticulated with margins more sclerotised; anterior margin straight and posterior slightly concave; with four pairs of setae (st1–st4) and three pairs of lyrifissures (iv1–iv3). Endopodal plate separate from the sternal shield and exopodal plate divided into four elongated fragments, except the one abutting the peritremal shield posteriorly which is subtriangular and have one lyrifissure on the anterior edge. Discrete metapodal platelets not distinguishable, probably incorporated to posterior end of peritrematic plate. Genital shield 150 (141–158) long and 138 (135–141) wide, with fine longitudinal striae, with setae st5 and the pair of lyrifissures iv5 posterior to coxa IV; posterior margin truncate, in line with posterior margin of coxa IV. Ventrianal shield 364 (363–363) long and 332 wide, entire imbricate, with tiny shallow pits similar to those of dorsal shield; fused posteriorly with dorsal shield only by a narrow area posterior to anus; with six pairs of setae ( JV 1– JV 3, JV5 and ZV1–ZV2) in addition to circumanal setae and three pairs of pores.

Peritreme. 354 (344–365) long, extending anteriorly to the median region of coxa I (level of seta s2). Peritrematic plate abutting laterally with a subtriangular exopodal subfragment; with two lyrifissures (ip3 and ip4) and one pore (gp2) posteriorly. Spermathecal apparatus. Not visible.

Legs. Lengths: I: 986 (977–995), II: 641 (621–661), III: 608 (597–618); IV: 859 (832–886). Setae are setiform and smooth. All legs with pretarsi; median section of pulvilli of legs I–IV rounded, with an elongate ambulacral stalk and a pair of prominent claws; coxa I and femur IV with distal pointed projections; trochantera III and IV each with an anterodistal apophysis. Chaetotaxy: I: coxa 0 0/2, 0/0 0, trochanter 1 0/1, 1/2 1, femur 2 5/4 2, genu 2 3/2, 3/1 2, tibia 2 3/2, 3/2 2; II: coxa 0 0/1, 0/1 0, trochanter 1 0/3 1, femur 2 3/1, 2/2 1, genu 2 3/1, 2/1 2, tibia 2 2/1, 2/1 2; III: coxa 0 0/1, 0/1 0, trochanter 1 1/1, 0/0 1, femur 1 2/1, 1/0 0, genu 2 2/1, 2/1 1, tibia 2 1/1, 2/1 2; IV: coxa 0 0/1, 0/0 0, trochanter 1 1/2, 0/1 0, femur 2 1/ 0, 1/0 2, genu 2 2/1, 2/1 2, tibia 2 1/1, 3/1 2.

Gnathosoma. Epistome ( Fig. 29 ) similar to protonymph and deutonymph, 174 (168–187); movable cheliceral digit ( Fig. 30 ) 117 (113–122), with four teeth in addition to apical tooth, and fixed digit 136 (136–137), with two large teeth separated by a series of 6–9 small teeth next to the setiform pilus dentilis; antiaxial, dorsal lyrifissures and arthrodial process as in deutonymph; palp 290 (283–298) long, with palp genu seta al1 rayed and apotele trifurcate ( Fig. 31 ); corniculi 58 (55–60).

Adult male. ( Figs 32–35 ) (two specimens measured)

Dorsal idiosoma. ( Fig. 32 ) Idiosoma 767 (753–781) long and 495 (457–534) wide. Podonotal and opisthonotal shields fused, completely covering dorsum of idiosoma and extending ventrolaterally, fused with posterior part of ventrianal shield. Podonotal region with 21 pairs of setae (s1, s4 and r1 absent); five pairs of lyrifissures (id1–id2, id4–id6), two pairs of pores (gd4 and gd5), of which gd4 is larger on a distinct protuberance projected outward. Opisthonotal region with 20 pairs of setae, ten pairs of lyrifissures (idm1–idm6, idx, idl3–idl4 and is1), and one pair of large pores (gd9) anteriad to R 4.

Ventral idiosoma. ( Fig. 33 ) Tritosternum 153 (150–156) in total length; base 34 (27–40) long, inserted between a pair of reticulate presternal platelets. Sternogenital shield with longitudinal striae, 260 (256–264) long and 190 (188–191) wide between coxae II and III; with five pairs of setae (st1–st5) and three pairs of lyrifissures (iv1–iv3); posterior margin truncate close to anterior margin of ventrianal shield. Ventrianal shield 369 (363–375) long and 342 (341–344) wide at widest point, fused with peritrematic plate only by a fine strip, anteriorly imbricate and smooth elsewhere with tiny pits as in adult female; iv5 on the anterior edge posteriad to coxa IV; with six pairs of setae ( JV 1– JV 3, JV5 and ZV1–ZV2) in addition to circumanal setae and two pairs of pores. Peritreme extends anteriorly nearly to the median region of coxa I (level of seta s2). Peritrematic plate fused anterolaterally to dorsal shield and posteriorly to ventrianal shield by a fine strip, with two pairs of lyrifissures (ip3 and ip4) and one pair of pores (gp2); exopodal plate divided into three elongated fragments.

Legs. Leg I 998 (965–1030), II 751 (701–801), III 646 (636–657) and IV 880 (850–909). Femur II large with a saddle-like spur, curved and enlarged distally, with a clubbed-like seta posteriad to it 26 (25–27); genu II with an inner outward projection; tibia with one conical spur ( Fig. 34 ).

Gnathosoma. Epistome as in female 142 (141–142); movable digit 102 (99–108) long, without visible teeth, fixed digit 121 (111–131) with a pilus dentilis and three developed teeth and apical tooth, spermodactyl dagger-like 102 (100–103); arthrodial process of chelicera as in female ( Fig. 35 ). Palp 320 (310–330) long, without spur; number of setae on palp (trochanter to tarsus): 2–5–6–14–15; apotele 3–tined; corniculi horn-like 70 (65–75) long.

Etymology. The specific name tuberculatus is derived from Latin, combining ' tuberculum ' (referring to a protuberance) and the suffix '- atus ' (indicating possession or presence), and refers to the presence of a pore in an atypical protuberance on the dorsal shield.

Remarks. Following the key proposed by Santos et al. (2015), the new species is close to Ologamasus striolatus ( Berlese, 1916) and Ologamasus striolatosimilis Karg, 1976 by having dorsal shield J setae at least as long as distance between their bases and bases of subsequent J setae, ventrianal shield fused with dorsal shield only by a narrow area posterior to anus, ventrianal shield with six pairs of setae and 20 pairs of setae on opisthonotal region (R1–R5 present); Despite all those similarities, O. striolatus has the ventrianal shield smooth while in the new species it is imbricate. Ologamasus striolatosimilis also has the ventrianal shield imbricate, however, the new species has a large distinctive pore on a protuberance on the podonotal shield, while this characteristic is absent in O. striolatosimilis and O. striolatus . When compared to the original description by Karg (1976), the new species has a longer idiosoma (798μm) while O. striolatosimilis only up to 600μm. Seta on femur II of O. striolatosimilis male is spine-like, while in the new species it is club-like.

Figures

FIGURES 18–22. Ologamasus tuberculatus n. sp. Protonymph. 18. Dorsal idiosoma; 19. Ventral idiosoma; 20. Epistome; 21. Palp genu; 22. Chelicera.

FIGURES 36–41. Ologamasus spp., microphotographs. 36. Ologamasus margaridae, adult male, leg II, tibial spur and similar structure on tarsus; 37. Ologamasus tuberculatus, protonymph, dorsal pore gd4; 38. Ologamasus tuberculatus, deutonymph, podonotal shield and pore gd4; 39. Ologamasus tuberculatus, deutonymph, opisthonotal shield and pore gd9; 40. Ologamasus tuberculatus, adult female, dorsal pore gd4 pore; 41. Ologamasus tuberculatus, adult female, dorsal pore gd9.

FIGURES 23–26. Ologamasus tuberculatus n. sp. Deutonymph. 23. Dorsal idiosoma; 24. Ventral idiosoma; 25. Epistome; 26. Chelicera.

FIGURES 27–31. Ologamasus tuberculatus n. sp. Adult female. 27. Dorsal idiosoma; 28. Ventral idiosoma; 29. Epistome; 30. Chelicera; 31. Palp.

FIGURES 32–35. Ologamasus tuberculatus n. sp. Adult male. 32. Dorsal idiosoma; 33. Ventral idiosoma; 34. Lateral view of leg II; 35. Chelicera.