Ornithodoros guaporensis, Nava & Venzal & Terassini & Mangold & Camargo Gustavo Casás & Labruna, 2013

Nava, Santiago, Venzal, José M., Terassini, Flavio A., Mangold, Atilio J., Camargo Gustavo Casás, Luis M. A. & Labruna, Marcelo B., 2013, Ornithodoros guaporensis (Acari, Ixodida: Argasidae), a new tick species from the Guaporé River Basin in the Bolivian Amazon, Zootaxa 3666 (4), pp. 579-590 : 580-585

Description of Ornithodoros guaporensis n. sp. Nava, Venzal & Labruna

Etymology. The species is named for the Guaporé River, because its course is close to the site where the ticks were collected.

Type locality. Amazonian forest in north-eastern Bolivia (12º55’S; 62º52’W) , Beni Department, Bolivia .

Material examined. Holotype larva reared from adults, 9 paratype larvae reared from adults, 1 paratype female and 1 paratype male collected July 2010 by M. B. Labruna, J. M. Venzal, S. Nava and F. A. Terassini, deposited in the U.S National Tick Collection, Georgia Southern University, Statesboro (Holotype USNMENT 00861410; Paratypes USNMENT 00861411, 00861412, 00861413); paratypes 20 larvae, 3 males and 3 females deposited in the Coleção Nacional de Carrapatos ( CNC) of the Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil ( CNC 2305 , CNC 2306 and CNC 2307 ); paratypes 5 larvae, 3 males and 2 females deposited in the tick collection of INTA Rafaela , Santa Fe, Argentina ( INTA 2222 ); paratypes 13 larvae deposited in the Departamento de Parasitología Veterinaria , Facultad de Veterinaria , Universidad de la República , Montevideo, Uruguay ( DPVURU 804 , 805 and 806).

Larva ( Figures 1–7 ).

Body: Body outline subcircular; length including capitulum 0.850 ± 0.017 (0.823 -0.872), length without capitulum 0.447 ± 0.014 (0.421 -0.470), width 0.443 ± 0.019 (0.411 -0.470). Dorsal plate pyriform, widest posteriorly, length 0.290 ± 0.010 (0.271 -0.305), width 0.220 ± 0.008 (0.212 -0.232).

Setae of body: Dorsum with 20 pairs of setae, 16 dorsolateral (7 anterolateral and 9 posterolateral), and 4 central; anterolateral setae (Al): Al1 length 0.095 ± 0.002 (0.090 –0.097), Al2 length 0.091 ± 0.003 (0.085 –0.095), Al3 length 0.087 ± 0.004 (0.080 –0.093), Al4 length 0.086 ± 0.003 (0.078 –0.090), Al5 length 0.087 ± 0.004 (0.083 – 0.097), Al6 length 0.092 ± 0.005 (0.083 –0.100), Al7 length 0.096 ± 0.005 (0.090 –0.102); posterolateral setae (Pl): Pl1 length 0.089 ± 0.003 (0.085 –0.097), Pl2 length 0.092 ± 0.003 (0.088 –0.095), Pl3 length 0.096 ± 0.002 (0.093 – 0.0100), Pl4 length 0.095 ± 0.003 (0.090 –0.100), Pl5 length 0.088 ± 0.008 (0.075 –0.097), Pl6 length 0.084 ± 0.006 (0.075 –0.097), Pl7 length 0.090 ± 0.004 (0.085 –0.097), Pl8 length 0.088 ± 0.003 (0.085 –0.093), Pl9 length 0.091 ± 0.004 (0.085 –0.102); central setae (C): C1 length 0.094 ± 0.004 (0.083 –0.100), C2 length 0.088 ± 0.004 (0.085 – 0.093), C3 length 0.082 ± 0.005 (0.075 –0.090), C4 length 0.092 ± 0.004 (0.088 –0.097). Venter with 7 pairs of setae plus 1 pair on anal valves, and seta posteromedian present; three pairs of sternal setae (St): St1 length 0.069 ± 0.002 (0.066 –0.073), St2 length 0.055 ± 0.004 (0.049 –0.061), St3 length 0.059 ± 0.001 (0.058 –0.061); one pair of postcoxal setae (Pc) length 0.039 ± 0.004 (0.034–0.46); three pairs of circumanal setae (Ca): Ca1 length 0.052 ± 0.005 (0.044 –0.061), Ca2 length 0.071 ± 0.003 (0.066 –0.073), Ca3 length 0.101 ± 0.002 (0.097 –0.107); posteromedian setae ( PM) length 0.074 ± 0.004 (0.068 –0.080) .

Capitulum: Capitulum large, as long as length of body; length from posterior margin of basis capituli to posthypostomal setae Ph1 0.133 ± 0.005 (0.124 –0.139), length from posterior margin of basis capituli to insertion of hypostome 0.156 ± 0.008 (0.146 –0.166), length from posterior margin of basis capituli to apex of hypostome 0.441 ± 0.006 (0.431 –0.451), width 0.179 ± 0.006 (0.173 –0.193); two pairs of posthypostomal setae: Ph1 length 0.018 ± 0.003 (0.012 –0.022), Ph2 length 0.039 ± 0.001 (0.036 –0.041), distance between Ph1 setae 0.021 ± 0.002 (0.017 –0.022), distance between Ph2 setae 0.078 ± 0.002 (0.075 –0.083); palpi total length 0.324 ± 0.007 (0.310 – 0.332), segmental length/width from I–IV: (I) 0.062 ± 0.007 (0.056 –0.083) / 0.027 ± 0.003 (0.024 –0.032), ( II) 0.129 ± 0.004 (0.122 –0.134) / 0.032 ± 0.003 (24–36), ( III) 0.107 ± 0.008 (0.085 –0.114) / 0.032 ± 0.001 (0.032 – 0.034), ( IV) 0.035 ± 0.002 (0.029 –0.039) / 0.020 ± 0.002 (0.019 –0.024); setae number on palpal articles I–IV: (I) 0, ( II) 4, ( III) 5, ( IV) 9. Hypostome: length from Ph1 to apex 0.309 ± 0.004 (0.305 –0.315) , length from insertion of hypostome in basis capituli to apex 0.276 0.007 (0.268 –0.285), length from inferior toothed portion to apex 0.256 0.007 (0.244 –0.266), width in basis portion of hypostome 0.046 0.002 (0.044 –0.049), width in medial portion of hypostome 0.044 0.001 (0.041 –0.046); hypostome pointed apically, apical dental formula 3/3, medial dental formula 2/2 and basal dental formula 2/2; row 1 with 26 to 27 denticles, row 2 with 25 to 26 denticles, and row 3 with 11 to 12 denticles.

Legs: Tarsus I without reticulations in capsule of Haller’s organ, length 0.174 ± 0.003 (0.168 –0.180), tarsus I width 0.057 ± 0.001 (0.056 –0.058); setal formula of tarsus I: one pair apical (A), one pair distomedian ( DM) fringed, 5 paracapsular (PC), 1 posteromedian (PM), 1 pair basal (B), 1 pair apicoventral (AV), 1 pair midventral (MV), 1 pair basiventral (BV), and 1 pair posterolateral (PL).

Female ( Figures 8–10, 12–13 )

Body: Body elongate, subrectangular, 4.9 ± 0.2 (4.2–5.4) long, 3.1 ± 0.2 (2.5–3.5) wide. Broadly rounded posteriorly, subparallel laterally, anteriorly converging rather abruptly to a sharp angular apex; medial dorsal-area depressed between the raised lateral margins. Dorsum: Integument covered by cell-like configuration, with mammillae larger on marginal fields and smaller on the centre of the body, many mammillae with single short seta, located peripherally. Disks very numerous, observed below the level of mammillae; size, shape, and arrangement as pictured. Lateral suture absent. Venter: Mammillae covering the ventral surface, and disks present only in postcoxal grooves. Genital area as pictured, anterior and posterior labia subequal; anus rounded, with a postanal median mammillated depression reaching the postanal groove.

Capitulum: Capitulum situated ventrally to the hood. Cheeks elongate, enfolding palps, hypostome and mouth parts. Basis capituli micromammillated, 0.28 ± 0.02 (0.2–0.4) long, 0.3 ± 0.02 (0.2–0.4) wide, with 1 pair of long posthypostomal setae, 1 pair of postpalpal setae (approximately half of the size of the posthypostomal setae), and 5 short spinelike posterolateral capitular setae. Hypostome with dental formula 2/ 2 in rows of 3 denticles in the anterior portion and then smaller denticles toward base, and small crenulations apically.

Legs: long, entirely micro-mammillated, except for coxae I–IV, which are partially covered by mammillae. Coxae I and II separated, II to IV contiguous. Tarsi narrow, lacking humps and protuberances, abruptly tapering distally. Haller´s organ with a narrow transverse slit filled with ramified setae, with 7–8 pre-halleral setae of various sizes and four medial and two lateral post-halleral setae.

Male ( Figure 11 )

Similar to the female except in the genital area. Body 3.95 ± 0.12 (3.20–4.50) long, wide 2.5 ± 0.14 (1.90– 2.91). Basis capituli 0.25 ± 0.06 (0.21–0.34) long, 0.27 ± 0.09 (0.22–0.36) wide. Genital area as a rounded flap surrounded by smaller mammillae.

Analysis of mitochondrial 16S rDNA. DNA from both adult and larval specimens yielded identical 16S rDNA sequences, which have been submitted to Genbank under the accession number KC493652 . The ML tree inferred from the 16S rDNA sequences of Neotropical soft ticks is shown in Figure 14 . Ornithodoros guaporensis is grouped with O. puertoricensis , O. rioplatensis and O. hasei (bootstrap support 82%). The pairwise differences of O. guaporensis with O. puertoricensis , O. rioplatensis and O. hasei were 12.6%, 13.2% and 14.1%, respectively. The differences with the remaining species included in the analysis were larger than 14.9%.

Morphological comparisons. Larvae of O. guaporensis are morphologically closely related to O. rioplatensis , O. puertoricensis and O. talaje . Larvae of O. guaporensis and O. rioplatensis can be separated from O. puertoricensis and O. talaje by the number of pairs of dorsal setae: 20 in O. guaporensis and O. rioplatensis , 18 in O. puertoricensis and 17 in O. talaje . There are two discrete characters that can be used to differentiate between larval O. guaporensis and larvae of O. rioplatensis : medial dental formula is 2/ 2 in O. guaporensis and 3/ 3 in O. rioplatensis , and the apex of the hypostome is more pointed in O. rioplatensis than in O. guaporensis ( Fig. 15 ). The PCA performed with larval morphometric characters showed a clear separation between O. guaporensis , O. rioplatensis , O. puertoricensis and O. talaje ( Fig. 16 and Table 1). The first principal component (explaining 42.12% of total variance) is mainly loaded with body length (a), circumanal setae, length of basis capituli (e), palpal length, length of palpal article II, and hypostome length, while the second component (explaining 28.96% of total variance) is loaded most heavily by width of basis capituli, length of basis capituli, denticles in hypostomal row 3, and length of dorsal plate. Finally, the ML tree showed that O. hasei , a tick species not previously associated with the O. talaje complex ( Camicas et al. 1998; Venzal et al. 2008), is phylogenetically related to O. guaporensis , O. rioplatensis and O. puertoricensis . Larvae of O. hasei can easily be distinguished from larvae of O. guaporensis , O. rioplatensis and O. puertoricensis by the number of denticles in hypostomal rows 1 and 2; O. hasei has 16–18 in row 1 and 15–18 in row 2, while O. guaporensis , O. rioplatensis and O. puertoricensis have more than 20 in both rows (Table 1).

No significant morphological differences were found among adults of O. guaporensis , O. rioplatensis , O. puertoricensis and O. talaje . This fact coincides with the conclusion of Venzal et al. (2008), who stated that morphological characters of the adults of these species are inadequate for taxonomic determination.

Figures

FIGURE 14. Maximum-likelihood tree based on 16S rDNA partial sequences. Numbers represent bootstrap support generated from 1,000 replications. GenBank accession numbers are also indicated. An., Antricola; O., Ornithodoros; N., Nothoaspis; Ot., Otobius; Ar., Argas.

FIGURE 15. Optical micrographs of the hypostomes of the larvae of Ornithodoros guaporensis (A), Ornithodoros puertoricensis (B), and Ornithodoros rioplatensis (C). Arrows indicate denticles in hypostomal row 3.

FIGURE 16. Principal components analysis of the body and setal measurements of the larvae of Ornithodoros guaporensis (G1–G10), Ornithodoros rioplatensis (R1–R10), Ornithodoros puertoricensis (P1–P10) and Ornithodoros talaje (T1–T5), using the features detailed in Table 1. Each point constitutes the position of each measured specimen on the reduced space.

FIGURES 1–3. Larva of Ornithodoros guaporensis. 1. Dorsal idiosoma. 2. Ventral idiosoma. 3. Tarsus 1.

FIGURES 4–7. Larva of Ornithodoros guaporensis. 4. Dorsal idiosoma. 5. Dorsal plate. 6. Hypostome. 7. Capitulum, ventral view.

FIGURES 8–13. Adults of Ornithodoros guaporensis. 8. Female, dorsal idiosoma. 9. Female, ventral idiosoma. 10. Female, capitulum, ventral view. 11. Male, ventral idiosoma. 12. Female, hypostome. 13. Female, capsule of Haller’s organ. Note: Male is similar to the female except for the genital area (see figure 11).