Ologamasus margaridae, 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 : 497-504

Ologamasus margaridae n. sp.

urn:lsid:zoobank.org:act:BA0D6A44-1DC5-41E2-8A47-4AA8004AA7FC

Material examined. Adult females and males, protonymphs and deutonymphs collected on spontaneous plants associated with apple orchards in the municipalities of Antônio Prado (AP), Rio Grande do Sul, and São Joaquim (SJ), Santa Catarina, Brazil, as follows: female holotype, Cantinoa mutabilis (Rich.) Harley & J.F.B. Pastore ( Lamiaceae ), AP , August 1, 2021; male paratype, Plantago australis Lam. ( Plantaginaceae ), SJ , September 10, 2021; protonymph paratype, P. australis , SJ , September 10, 2021; deutonymph paratype, P. australis , SJ , May 25, 2021; female paratype, Lolium multiflorum Lam. ( Poaceae ), AP , May 24, 2021; male paratype, Steinchisma hians Elliott Nash. ( Poaceae ), AP , May 18, 2021; protonymph paratype, C. mutabilis , AP , August 1, 2021; deutonymph paratype, C. mutabilis , AP , August 1, 2021. All specimens 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 1–2 ) (three specimens measured).

Dorsal idiosoma. ( Fig. 1 ) Idiosoma 521 (487–568) long and 367 (304–390) wide. Podonotal and opisthonotal shields separate, with scattered pairs of small asymmetric platelets between them; podonotal shield 230 (224–245) long and 258 (256–275) wide, reticulated behind j5 and s5 with rounded elements medially; j1–j6, z2, z4–z5 and s5–s6 on the shield, r2, r3 and r6 on the soft cuticle; with four pair of lyrifissures (id1, id2, id4 and id5) and one pair of pores (gd5) inside the shield, and id2 on the soft cuticle anteriad to r2; opisthonotal shield 114 (107–124) long and 208 (191–226) wide, completely reticulated, with J3–J5, Z3–Z5, S4–S5 on the shield, J1, J2, Z1, Z2, S2 and S3 on the soft cuticle; with two pair of lyrifissures (idm1 and idm3) on the soft cuticle, and two pair of lyrifissures (idx and idm4) on the shield. All setae setiform and smooth; most setae shorter than distance to the closest setae (except r3, Z3, Z4, Z5, S4 and S5 which are longer).

Ventral idiosoma. ( Fig. 2 ) Tritosternum 103 (90–108) total length; base 36 (27–36) long. Presternal plates absent; sternal shield 131 (131–148) long and 101 (101–105) wide, completely reticulated with a pointed projection posteriorly; containing st1, st2 and st3 and two pairs of lyrifissures (iv1–iv2); setae st5 on the soft cuticle. Anal shield 90 (80–104) long and 131 (121–131) wide, reticulated; opisthogastric setae JV1, JV2, JV5 and ZV2 on soft cuticle; with a pair of metapodal plates at JV1 level. All setae setiform and smooth.

Peritreme. Peritreme short, 48 (45–55) long, extending only to middle of coxa III.

Legs. Lengths: I: 564 (560–570); II: 416 (408–420); III: 412 (396–424); IV: 533 (524–547).

Gnathosoma. Epistome with a single median extension, bifurcated distally, and margins denticulate; palp 211 (178–211) length, al1 rayed; movable digit 62 (60–62) and fixed digit 67 (65–68) long; corniculi horn-like 34 (35–40).

Deutonymph. ( Figs 3–6 ) (five specimens measured).

Dorsal idiosoma. ( Fig. 3 ) Idiosoma 732 (691–789) long and 540 (509–594) wide. Podonotal and opisthonotal shields separate; podonotal shield 311 (288–320) long and 403 (397–429) wide, reticulated; j1–j6, z1–z6, s3, s5–s6 and r3 inside the shield, and z2, s2, r2, r4–r6 on the soft cuticle; five pairs of lyrifissures (id1, id2, id4, id5 and id6); two pairs of pores (gd1 and gd5); opisthonotal shield 287 (268–390) long and 376 (355–397) wide, completely reticulate; J1–J5, Z1–Z5 and S2–S5 inside the shield, and S1 and R 1– R 5 on soft cuticle; with eight pair of lyrifissures (idm1–idm5, idl3–idl4 and idx) and one pair of pores (gd8). All setae setiform and smooth; most setae shorter than distance to the closest setae (except r3, Z4, Z5, and S5 which are longer).

Ventral idiosoma. ( Fig. 4 ) Tritosternum 146 (120–163) ( Fig. 5 ), its base 41 (39–46). One pair of small presternal plates; sternal shield 224 (212–239) long and 104 (99–112) wide, completely reticulated, with setae st1–st4 and three pairs of lyrifissures (iv1–iv3). Seta st5 on soft cuticle. Anal shield 176 (164–181) long and 179 (175–194) wide, rounded, totally reticulated; setae JV1–JV5 and ZV1–ZV3 on the soft cuticle.

Peritreme. 270 (253–286) long, reaching coxa I.

Legs. Leg I 734 (682–751); leg II 539 (489–578); leg III 536 (470–547); leg IV 688 (578–719).

Gnathosoma. Epistome with median extension bifurcated distally, and margins dentate; fixed cheliceral digit 84 (69–97) with setiform pilus dentilis and three teeth in addition to apical tooth, movable digit 77 (61–93) long, with four teeth in addition to apical tooth ( Fig. 6 ); palp 279 (239–295) long, apotele 3–tined; all setae setiform, except al1 of palp genus which is rayed; subcapitulum with four pairs of setae, deutosternum with five visible segments divided by transverse denticulate lines, corniculi horn-like 44 (40–46).

Adult female. ( Figs 7–12 ) (three specimens measured).

Dorsal idiosoma. ( Fig. 7 ) Idiosoma 861 (851–879) long and 585 (556–614) wide. Podonotal and opisthonotal shields fused, completely covering dorsum of idiosoma and extending ventrolaterally, fused only with the posterior margin of ventrianal shield, completely reticulated; with tiny shallow pits in the imbrication connection posterior to J1. Podonotal region with 21 pairs of setae (s1, s4 and r1 absent). With five pairs of distinguishable lyrifissures (id1–id2, id4–id6) and two pair of pores (gd1 and gd5). Opisthonotal region with 20 pairs of setae, nine pair of lyrifissures (idm1–idm5, idx, is1 and idl3–idl4) and only one pair of pores (gd8). Measurements of setae provided in Table 1 . All setae setiform and smooth; most setae shorter than distance to the closest setae (except j3, z5, r3, and Z5, and S5 which are longer).

Ventral idiosoma. ( Fig. 8 ) Sternal, genital and ventrianal shield completely reticulated. Tritosternum 124 (100–129) of total length; base 45 (39–58) long ( Fig. 9 ), inserted between a pair of reticulate presternal platelets. Sternal shield 138 (134–140) long and 195 (180–197) wide; anterior and posterior margin concave; with four pairs of setae (st1–st4) and three pairs of lyrifissures (iv1–iv3). Genital shield 150 (125–157) long 175 (168–175) wide, reticulated, with setae st5 and a pair of lyrifissures iv5; posterior margin truncate, in line with posterior margin of coxa IV. Ventrianal shield 441 (439–451) long and 419 (407–419) wide, entirely imbricate, with tiny shallow pits in the imbrication connection, similar to the opisthonotal region; fused posteriorly with dorsal shield only by a narrow area posterior to anus; with seven pairs of setae ( JV 1– JV 4 and ZV1–ZV3) in addition to circumanal setae and one pair of lyrifissure. Endopodal plate incorporated into the sternal shield and exopodal plate divided into five fragments, most of which elongated, except between coxae II–III, subtriangular. Discrete metapodal platelets not distinguishable, probably incorporated to posterior end of peritrematic plate.

Peritreme. 383 (360–386) long, extending anteriorly to the median region of coxa I (level of seta s2). Peritrematic plate fused anteriorly with dorsal shield and abutting ventrianal shield posteriorly; with two pairs of lyrifissures (ip3–ip4), one posterior to stigma and another on the lateral margin and a pore (gp2) in between them.

Spermathecal apparatus. Not visible.

Legs. Lengths: I 857 (840–911), II 631 (618–697), III 622 (584–661) and IV: 874 (800–888). 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; pretarsus I about half as long as other pretarsi. 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/ 2 1, femur 1 2/1, 2/0 0, genu 2 2/1, 2/1 1, tibia 2 1/1, 2/1 1; 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; tarsi II–IV: 18 setae each.

Gnathosoma. Epistome ( Fig. 10 ) with anteromedian extension bifurcate distally, laterally denticulate; fixed cheliceral digit 116 (103–118) long, with pillus dentilis and three teeth, and movable digit 100 (90–108) long with two teeth ( Fig. 11 ); arthrodial process of chelicera shaped as a small coronet-like fringe. Palp 279 (252–291) long, apotele 3–tined and setae setiform, except al1 of palp genus which is rayed ( Fig. 12 ); corniculi horn-like 54 (54–56) long.

Adult male. ( Figs 13–17 ) (three specimens measured)

Dorsal idiosoma. ( Fig. 13 ) Idiosoma 787 (785–800) long and 538 (530–545) wide. Podonotal and opisthonotal shields fused, completely covering dorsum of idiosoma and extending ventrolaterally, fused with ventrianal shield; shield completely reticulated imbricate; tiny shallow pits posterior to J2 as in female. Podonotal region with 21 pairs of setae (s1, s4 and r1 absent) and five pairs of distinguishable large lyrifissures (id1–id2, id4–id6) and two pair of pores (gd1 and gd5). Opisthonotal region with 20 pairs of setae, nine pair of lyrifissures (idm1–idm5, idx, is1 and idl3–idl4) and only one pair of pores (gd8). All setae setiform and smooth; most setae shorter than distance to the closest setae (except j4, j5, z5, r3, and Z5, and S5 which are longer).

Ventral idiosoma. ( Fig. 14 ). Tritosternum as in female, 162 (156–208) total length; base 42 (39–51) long, inserted between a pair of reticulate presternal platelets. Sternogenital shield reticulate, 260 (253–264) long at midline and 202 (177–206) wide between coxae II and III; with five pairs of setae (st1–st5) and three pairs of lyrifissures (iv1–iv3); posterior margin truncate in line to posterior margin of coxa IV. Ventrianal shield imbricate, with tiny shallow pits as in adult female, 299 (384–395) long and 497 (495–508) wide at widest point, abbuting with peritrematic plate and posterolaterally with dorsal shield, with fusion line at ZV2 level; with eight pairs of setae ( JV 1– JV 5 and ZV1–ZV3) in addition to circumanal setae and five pairs of lyrifissures in addition to iv5 on the anterior margin of the shield and one pair of pores.

Peritreme. Extending anteriorly almost to median region of coxa I (level of seta s2). Peritrematic plate abutting anterolaterally to dorsal shield and posteriorly to ventrianal shield; with a single pair of lyrifissures posterior to stigma (ip3). Exopodal plate divided into four fragments, most of which elongated, except between coxae II–III, subtriangular. Fragment posterior to coxa IV apparently incorporated to the anterolateral edge of ventrianal shield.

Legs. Leg I 878 (730–889), II 639 (577–677), III 618 (581–643) and IV 806 (804–884). Femur II with a saddle-like big spur, curved and enlarged distally with a thorn-like seta posteriad it 21 (20–22) long; genu II with a small horn-like spur; tibia with one spur at the middle and two sharp spurs of different sizes at the anterior edge. Tarsus has a markedly different structure, with a whitish coloration and appears to be projecting outward, possibly serving the same function as the spurs in other segments: attachment to the female for copulation ( Figs 15 and 36 ).

Gnathosoma. Epistome as in female 102 (98–107) long; fixed cheliceral digit 95 (95–101) with a pilus dentilis and no teeth, and movable digit 89 (80–93) long and with a single tooth at mid-point; arthrodial process of chelicera shaped as in female. Spermodactyl dagger-like 80 (80–81) long ( Fig. 16 ), curved at its tip. Palp ( Fig. 17 ) 297 (240– 321) long, with a small rounded spur on palpfemur; number of setae on palp (trochanter to tarsus): 2-5-6-14-15 all setiform except al1 which is rayed as in female; apotele 3–tined; corniculi horn-like, 53 (51–58) long.

Etymology. The specific name margaridae is in memory of P.A.Rode’s maternal grandmother who affectionately dedicated her life to caring for and protecting her entire family.

Remarks. Following the key proposed by Santos et al. (2015), the new species is closest to Ologamasus brevisetosus Karg & Schorlemmer, 2009 by having most dorsal setae aciculate and smooth, dorsal shield J setae at most 0.8 times as long as the distance between their bases and bases of subsequent J setae and ventrianal shield fused with dorsal shield only by a narrow area posterior to anus. However, it can be easily distinguished from O. brevisetosus by having the epistome with a bifurcate median projection with denticles at the base instead of a single pointed branch. The new species has a striate genital shield while O. brevisetosus has a single pointed branch on the epistome; also, the new species has the peritreme extending to coxa I level, while in O. brevisetosus it extends only to coxa II level.

Figures

FIGURES 1–2. Ologamasus margaridae n. sp. Protonymph. 1. Dorsal idiosoma; 2. Ventral idiosoma.

FIGURES 3–6. Ologamasus margaridae n. sp. Deutonymph. 3. Dorsal idiosoma; 4. Ventral idiosoma; 5. Tritosternum; 6. Chelicera.

FIGURES 7–12. Ologamasus margaridae n. sp. Adult female. 7. Dorsal idiosoma; 8. Ventral idiosoma; 9. Tritosternum; 10. Epistome; 11. Chelicera; 12. Palp.

FIGURES 13–17. Ologamasus margaridae n. sp. Adult male. 13. Dorsal idiosoma; 14. Ventral idiosoma; 15. Leg II; 16. Chelicera; 17. Ventral view of palp.

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.