Gamasiphis vikkiae Melo-Molina & Santos, 2021

Melo-Molina, Elsa L., Santos, Jandir C., De Moraes, Gilberto J. & Castilho, Raphael C., 2021, Gamasiphis species (Acari: Mesostigmata: Ologamasidae) from Ecuador, with description of a new species and new records, Zootaxa 5068 (3), pp. 410-418 : 411-413

Gamasiphis vikkiae Melo-Molina & Santos n. sp.

Type material. Holotype female: ECUADOR: Esmeraldas ( Coast region ): La Independencia (0°06’29.8”N 79°21’16.9”W; 164 m), from soil at the base of Piper peltatum on 26 September 2019 . Paratypes: ECUADOR: Napo (Amazon region): one female, Tena (0°53’49.4”S 77°48’08.0”W; 608 m), from soil at the base of Musa paradisiaca on 4 August 2019 ; two females, Tena (0°53’49.7”S 77°48’07.5”W; 611 m), from soil at the base of Citrus limon on 4 August 2019 ; one female, Tena (0°53’49.4”S 77°48’06.5”W; 610 m) from soil at the base of Saccharum officinarum on 4 August 2019 ; one female, Tena (0°19’36.7”S 76°53’17.5”W; 607 m) from soil at the base of Renealmia sessilifolia on 26 February 2018 . All specimens collected by C.A. Ortega-Ojeda. Holotype deposited at INABIO, three paratype at LEA-UCE and two paratypes at ESALQ / USP .

Diagnosis (adult female). Anteromedial extension of epistome aciculate; setae j2, j3, j4, j5, z3 and Z1 at least as long as distance to the base of the respective subsequent setae; with two pairs of presternal platelets; seta Zv2 as long as distance to base of Zv3; seta Jv5 about in level with anterior margin of anal opening and about four times as long as para-anal seta; post-anal seta about 4.5 times as long as para-anal setae.

Description.

Adult female (n = 6) ( Figs 1–8 ).

Gnathosoma. Fixed cheliceral digit 44 (42–47) long, with 7–8 teeth in addition to the apical hook and the aciculate pilus dentilis ( Fig. 1 ); movable cheliceral digit 47 (44–49) long, with four teeth in addition to the apical hook; chelicera with antiaxial and dorsal lyrifissures as well as dorsal seta distinct; arthrodial process shaped as a short coronet-shaped fringe. Palp apotele 3-tined. Epistome 3-tined, with an anteromedian extension longer than others, all three aciculate ( Fig. 2 ). Deutosternum with indistinct margins, with seven transverse denticulate lines ( Fig. 3 ); anteriormost shaped as an inverted “V”, first to fourth lines with very small teeth, and fifth to seventh multidenticulate; lines fourth to sixth U-shaped. Internal malae fimbriate laterally. Corniculi horn-shaped 26 (25–27) long, 16 (15–16) wide at the widest point; seta h3 directly posterior to h1 and slightly anterior and medial to h2. Measurements of setae: h1 21 (20–22), h2 18 (17–20), h3 21 (18–22), sc 18 (17–20); all setae aciculate.

Dorsal idiosoma ( Fig. 4 ). Dorsal shield 437 (419–455) long, 269 (265–276) wide (between s6 and r6), covering totally the idiosoma. Podonotal region smooth anteriad of z4, imbricate behind; with 22 pairs of setae (r1 and r2 absent; other r setae visible in ventral view); with seven pairs of lyrifissures and four pairs of pores. Opisthonotal region imbricate anteriad of J4, smooth behind; with 14 pairs of setae (J1 and all R setae absent); S2 and S 5 visible in ventral view; with nine pairs of distinguishable lyrifissures and two pairs of distinguishable pores. Measurements of setae: j1 13 (12–14), j2 34 (33–35), j3 33 (30–36), j4 34 (31–35), j5 34 (32–35), j6 34 (33–35), z1 15 (14–15), z2 30 (28–32), z3 34 (33–35), z4 35 (34–36), z5 28 (28–30), z6 37 (35–40), s1 14 (12–15), s2 14 (13–15), s3 33 (30–35), s4 36 (35–37), s5 36 (35–37), s6 33 (32–35), r3 23 (20–25), r4 12 (10–15), r5 11 (8–13), r6 28 (25–31), J2 20 (16–24), J3 19 (16–21), J4 11 (10–11), J5 7 (6–7), Z1 37 (36–40), Z2 19 (17–21), Z3 21 (20–21), Z4 10, Z5 69 (66–71), S1 7, S2 8 (7–9), S3 7, S4 11 (10–11), S5 17 (16–19); all setae aciculate.

Ventral idiosoma ( Fig. 5 ). Base of tritosternum 19 (18–21) long and approximately 13 wide basally ( Fig. 6 ); laciniae 65 (58–73) long, pilose, separated for about 95% of their total length. With two pairs of presternal platelets. Sternal shield reticulate; 73 (70–75) long at midline and 69 (65–75) wide at median level of coxae II; with four pairs of setae (st1–st4), st3 inserted in line and medial to st2, and four pairs of lyrifissures. Genital shield scantly reticulate, 70 (68–73) long and 70 (68–72) wide at the widest level; bearing st 5, distance st5–st5 47 (46–49), anterior margin convex and posterior margin truncate. Ventrianal shield imbricate anteriorly to Zv3 and apparently smooth posteriorly; 205 (182–221) long at midline (from anterior margin to postanal seta), 176 (148–192) wide at widest point (between Jv2 and Zv2); with eight pairs of setae (Jv1–Jv5, Zv1–Zv3) in addition to circumanal setae and with four pairs of distinguishable lyrifissures. Peritreme extending to region between coxae I and II. Measurements of setae: st1 24 (23–25), st2 24 (23–27), st3 13 (13–14), st4 20 (20–21), st5 19 (18–20), Jv1 25, Jv2 25 (23–27), Jv3 26 (25–26), Jv4 33 (31–36), Jv5 46 (44–48), Zv1 32 (29–34), Zv2 35 (34–36), Zv3 25 (24–25), para-anal 13 (12–14), post-anal 53 (50–54); all setae aciculate.

Spermatheca ( Fig. 7 ). Phytoseiid-type. Spermathecal apparatus distinguishable as a membranous tubular structure, extending medially from base of coxa IV.

Legs. Lengths: I: 352 (330–364); II: 277 (250–296); III: 242 (230–247); IV: 339 (320–351). Numbers of setae on segments of legs I–IV: coxa: 2, 2, 2, 1; trochanter: 6, 5, 5, 5; femur: 13, 11, 6, 6; genu: 13, 11, 9, 8; tibia: 14, 10, 8, 9; tarsus II–IV: 18, 18, 17. Leg IV with four macrosetae: two on genu [ad2 42 (41–42) and pd1 39 (38–39)], one on tibia [pd1 42 (40–42)] and one on basitarsus [pd3 46 (44–46)] ( Fig. 8 ). All legs with pretarsi, with elongate ambulacral stalk and a pair of strongly sclerotised claws.

Etymology. The species is named in honor of the daughter of the first author, Victoria Eugenia Martinez (Vikki).

Remarks. Gamasiphis vikkiae Melo-Molina & Santos n. sp. is most similar to G. adanalis Karg, 1990 , but the latter has 20 pairs of setae on the podonotal region (s1 absent and only three pairs of r setae); 12 pairs of setae on the opisthonotal region; the dorsal setae ranging between 15-20 long; setae j2, j3, j4, j5, z3 and Z1 at most 0.6 times as long as distance to the base of the respective subsequent setae.

In the key to Gamasiphis species provided by Castilho et al. (2012b), couplet 52 (page 1993) would require the following adjustment for inclusion of this new species:

52. Dorsal and ventrianal shields mostly imbricate............................................................ 52a

- Dorsal shield smooth and ventrianal shield smooth or transversely striate anteriorly to Zv2 and smooth elsewhere....... 53

52a. Podonotal region with 20 pairs of setae (s1 absent and three pairs of r setae); opisthonotal region with 12 pairs of setae; setae j2, j3, j4, j5, z3 and Z1 at most 0.6 times as long as the distance to base of the respective subsequent setae....................................................................... Gamasiphis adanalis Karg, Lesser Antilles ( Karg 1990)

- Podonotal region with 22 pairs of setae (s1 present and four pairs of r setae); opisthonotal region with 14 pairs of setae; setae j2, j3, j4, j5, z3 and Z1 at least as long as the distance to base of the respective subsequent setae............................................................................ Gamasiphis vikkiae Melo-Molina & Santos n. sp., Ecuador

Figures

FIGURES 1–8. Gamasiphis vikkiae Melo-Molina & Santos n. sp., adult female. 1. Lateral (antiaxial) view of chelicera; 2. Epistome; 3. Hypostome; 4. Dorsal idiosoma; 5. Ventral idiosoma; 6. Tritosternum; 7. Spermatheca; 8. Leg IV. Lyrifissures and pores enlarged for improved visibility.