Multidentorhodacarus triramulus (Karg)

Rueda-Ramirez, Diana, Castilho, Raphael C. & De Moraes, Gilberto J., 2013, Mites of the superfamily Rhodacaroidea (Acari: Mesostigmata) from Colombia, with a key for the world species of Desectophis Karg (Ologamasidae), Zootaxa 3734 (5), pp. 521-535 : 531-534

Multidentorhodacarus triramulus (Karg)

Rhodacarus (Multidentrhodacarus) [sic] triramulus Karg, 1998: 187 . Multidentorhodacarus triramulus .—Karg, 2000b: 145.

Diagnosis (adult female). Epistome with an anteromedian extension wider at the base and distally denticulate, flanked by a pair of shorter, denticulate anterolateral extensions; podonotal shield with a lateral punctate band between s 1 and s3, with 22 pairs of setae (including r 2, r 3, r 5 and r 6; r1 absent; r 4 on unsclerotised cuticle); opisthonotal shield with 18 pairs of setae (including R 1, R 3 and R 4; R 2 and R 5 on unsclerotised cuticle); without accessory shields anterolaterad of podonotal shield; with a slim punctate band along medial region of anterior margin of opisthonotal shield; Z 3 about 0.8 to 1.2 times as long as Z 4; S 1 almost reaching base of S 2; Zv 1 on unsclerotised cuticle next to anterior margin of ventri-anal shield.

Adult female ( Figs. 17–21 , based on Colombian specimens) – Two Colombian specimens considered, in addition to holotype.

Gnathosoma. Fixed digit of chelicera 56–60 (broken in holotype) long, with 11–12 teeth in addition to apical tooth and setiform pilus dentilis ( Fig. 17 ); movable digit of chelicera 50–55 (broken) long, with five teeth in addition to apical tooth; antiaxial and dorsal lyrifissures as well as dorsal seta distinct, the latter capitate. Numbers of setae on palp trochanter – tarsus: 2-5-6-14 -15. Epistome with an anteromedian extension wider at the base and distally denticulate, flanked by a pair of shorter, denticulate anterolateral extensions; some specimens with a pair of small, round and denticulate more lateral lobes ( Fig. 18 ). Deutosternum with eight roughly transverse lines of about uniform lengths, each with 13–15 denticles ( Fig. 19 ). Internal malae totally separated from each other, each bifurcate; outer branch of each internal mala fimbriate and inner branch smooth. Corniculus horn-like, about 4.1 times as long as its basal width. Setae h 1 - sc about in longitudinal line. Measurements of setae: h 1 20 (broken in holotype), h 2 11 (broken in holotype), h 3 13 (broken in holotype), sc 14 (broken in holotype); all aciculate and smooth.

Dorsal idiosoma ( Fig. 20 ). Idiosoma 278–300 (292) long and 142–165 (164) wide at widest level. Podonotal and opisthonotal shields separated. Podonotal shield smooth, except for a lateral punctate band between s 1 and s 3 and a punctate band along posterior margin; with V-shaped line posterior to setae j 4 and s 2; 141–148 (147) long and 135–164 (164) wide at widest level; with 22 pairs of setae (including r 2, r 3, r 5 and r 6; r 1 absent) and seven pairs of distinguishable lyrifissures (laterad of and about in transverse line with j 2, anterolaterad of z 2, anterior to and about in longitudinal line with j 4, anterior to and about in longitudinal line with z 4, laterad of and about in transverse line with j 5, anteromesad of z 5, mesad of and about in transverse line with z 6); with three small scleronoduli between j 5 and j 6. Unsclerotised cuticle laterad of podonotal shield with a pair of setae (r 4); without accessory shields anterolaterad of podonotal shield. Opisthonotal shield smooth, except for a narrow punctate band along medial region of anterior margin; 136–152 (145) long and 103–110 (114) wide at widest level; with 18 pairs of setae (including R 1, R 3 and R 4) and nine pairs of distinguishable lyrifissures (three at anterior corner of the shield, mesad of and about in transverse line with J 1, posteromesad of J 2, posterolaterad of J 3, posterolaterad of J 4, posteromesad of S 3, posterior to and about in longitudinal line with R 1). Unsclerotised cuticle laterad of opisthonotal shield with two pairs of setae (R 2 and R 5). Measurements of setae: j 1 16 (15), j 2 17 (broken), j 3 21 (19), j 4 20 (21), j 5 18 (19), j 6 18 (broken), z 1 10–11 (11), z 2 14 (15), z 3 21 (21), z 4 19 (21), z 5 18 (22), z 6 23 (24), s 1 8 (8), s 2 20 (24), s 3 20 (18), s 4 27 (24), s 5 22 (24), s 6 23 (24), r 2 22–23 (22), r 3 32–35 (30), r 4 15–16 (19), r 5 15–17 (20), r 6 24 (26), J 1 19–20 (21), J 2 19–20 (21), J 3 21 (22), J 4 19 (23), J 5 15–16 (18), Z 1 22 (25), Z 2 20–21 (24), Z 3 22–24 (25), Z 4 21–25 (21), Z 5 38–40 (43), S 1 20 (22), S 2 20 –21 (23), S 3 19 –21 (24), S 4 19 –20 (23), S 5 27 –30 (27), R 1 16 (15), R 2 10–11 (15), R 3 10–12 (13), R 4 16–18 (16), R 5 26–28 (32). All dorsal idiosomal setae aciculate and smooth.

Ventral idiosoma ( Fig. 21 ). Base of tritosternum 15–16 (broken in holotype) long and 9 wide proximally; laciniae 55, separated for about 90% of their total length, slightly pilose. Sternal shield smooth, anterior margin indistinct; region anterior to the first pair of sternal setae (st 1) lightly sclerotised and punctate; posterior margin with short central rounded projection; approximately 101 (106) long, from anterior margin of lightly sclerotised and punctate region to tip of medial projection of posterior margin, 63 (68) wide at widest level; with four pairs of setae and three pairs of lyrifissures. Genital shield smooth, with a punctate band along convex posterior margin; longer than wide; extending posteriorly well behind coxae IV; distance between st 5– st 5 32 (35). Lyrifissure iv 5 on unsclerotised cuticle, posterolaterad of st5. Ventri-anal shield smooth, with a narrow punctate band along anterior margin; 102–106 (102) long and 83–89 (82) wide at widest level, not fused with dorsal shield; with four pairs of setae (Jv 1– Jv 3 and Zv2) in addition to circum-anal setae, without distinguishable lyrifissures. Unsclerotised cuticle around margins of ventri-anal shield with three pairs of setae (Jv 5, Zv 1 and Zv3). Peritreme extending anteriorly to level of anterior margin of coxa III (region between r 3 and r 4). Peritrematic shield narrow, fused anteriorly to dorsal shield anterior to r 3 and extending posteriorly as a narrow and diagonal strip to level of posterior margin of coxa IV; with a pair of lyrifissures posterior and close to stigma. A pair of elongate metapodal platelets present well behind insertion of coxa IV, at level of anterolateral corners of ventri-anal shield. Measurements of setae: st 1 17 (18), st 2 18 (18), st 3 18 (17), st 4 17–18 (17), st 5 14–15 (broken), Jv 1 16–17 (17), Jv 2 17 (broken), Jv 3 21–23 (23), Jv 5 19–20 (20), Zv 1 14–16 (15), Zv 2 15–16 (17), Zv 3 10 (12), para-anal 24–25 (27), post-anal 45–47 (48). All ventral idiosomal setae aciculate and smooth.

Spermatheca. Not visible.

Legs. Lengths: I: 247–276 (268); II: 185–199 (215); III: 150 (174); IV: 215 (242). Numbers of setae on legs I– IV: coxae: 2, 2, 2, 1; trochanters: 6, 5, 5, 5; femora: 13, 11, 6, 6; genua: 13, 11, 9, 10; tibiae: 14, 10, 8, 10; tarsi II– IV: 18, 18, 17. Chaetotaxy as reported by Evans (1963) for “ Rhodacarus -group” of Rhodacaridae , except tarsus IV with one less seta, pl 4. Seta ad 1 of tibia IV (26–28) distinctly longer than other dorsal setae of the same segment (15–17); all dorsal setae of femur and genu of leg IV and of femur, genu and tibia of other legs similar to each other in lengths (15–21). Seta pd 2 of tarsus IV (30–37) erect, slightly longer than other dorsal setae on the same segment (17–27). Pretarsus I absent; pretarsi II–IV similar in shape and length, each consisting of an elongate ambulacral stalk, a pair of strongly sclerotised claws and three rounded pulvillar lobes.

Adult male. Not found.

Material examined. Two females from soil in a grassland ( pH 5.0–6.0; organic matter 26–37%; humidity 70– 75%) at “Setor San José” (04°39’ N 73°51’ W), “Vereda Mundo Nuevo”, municipality of “La Calera”, Departamento de Cundinamarca, Colombia, February and December 2010. All specimens collected by D. Rueda– Ramirez and deposited at Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Universidade de São Paulo (USP, Piracicaba, State of São Paulo, Brazil). The holotype female was collected by A. Zicsi and I. Loksa from moss on litter of a vertical bank of the river Rio Guajalito (alt. 1850 m), Las Palmeras, Pichincha Province, Ecuador, 18 April 1989. Deposited at Arachnologischen Sammlung des Museums für Naturkunde, Berlin, Germany.

Remarks. This species was described on the basis of the adult female holotype and 18 adult female paratypes. The following characteristics mentioned or shown in the original description and illustrations of the species do not agree with our observations of the holotype and of the specimens collected from Colombia: podonotal shield without a lateral punctate band between s 1 and s 3, and with 20 pairs of setae; unsclerotised cuticle laterad of podonotal shield with three pairs of setae (s 3, r 2 and r 3); opisthonotal shield with 16 pairs of setae; unsclerotised cuticle laterad of opisthonotal shield with three pairs of setae (R 2– R 4); seta R 5 absent. Karg (1998) provided no information about the hypostome, tritosternum, lyrifissures and leg setal counts. The only measurements provided in the original description are the length (260–300) and width (120–150) of the idiosoma, lengths of setae j 1 (cited as i 1) (16), z 1 (cited as r 1) (8), s 1 (cited as r 2) (8), J 5 (cited as I 5) (16), Z5 (40), other dorsal idiosomal setae (22– 25), post-anal (cited as Ps) (45), other ventral idiosomal setae (16–22), lengths of legs I (290), II (190), III (150) and IV (220).

In addition to the characteristics mentioned in the diagnosis of Multidentorhodacarus by Castilho et al. (2012a, 2012b), other morphological features found in M. triramulus and M. colombianus could also correspond to characteristics common for the genus. These are: fixed digit of chelicera with setiform pilus dentilis [also shown in M. paulista Castilho & Moraes, 2010 ; M. ruwenzoriensis (Loots, 1969) ; M. saboorii Castilho, Jalaeian & Moraes, 2012 ; M. sogdianus (Shcherbak, 1980) , M. squamosus Karg, 2000 b, M. sublapideus (Ryke, 1962) ; M. tertius (Karg, 1996) , and M. thysi (Jordaan, Loots & Theron, 1988) ]; chelicera with antiaxial lyrifissure (not shown in other species), with dorsal lyrifissure and dorsal seta (both of the latter two structures also shown in M. thysi ). In contrast to what was observed in M. triramulus and M. colombianus , the dorsal cheliceral seta of M. thysi was illustrated as setiform.

Acknowledgements

We thank the Brazilian CNPq (National Council for Scientific and Technological Development) for the scholarship to the first author. We are also grateful to FAPESP (São Paulo Foundation Research) for the postdoctoral fellowship to Raphael de Campos Castilho (Process # 2011/18971-7).

Figures

FIGURES 17 – 21. Multidentorhodacarus triramulus (Karg, 1998). Female (based on Colombian specimens). 17. Chelicera; 18. Epistome; 19. Hypostome and basal palp segments; 20. Dorsal idiosomal shields; 21. Ventral idiosoma. Lyrifissures are represented by circles or ovals enclosing a dot. Lyrifissures enlarged for improved visibility.