## Family Ixodidae Murray, 1877

**Genus** Ixodes **Latreille, 1795**

**Subgenus** Endopalpiger **Schulze, 1935**

Ixodes barkeri **Barker, 2019**

**Male**. [Based on 6 specimens, 3 measured - refer to Table 1; Figs. 2, 3, 8] Idiosoma (Fig. 2) broadly elongate-oval with broadly rounded posterior margin, widest slightly posterior to mid-length; length from apices of scapulae to posterior body margin 2.17–2.59 mm (2.42 mm), width 1.53–1.72 (1.61), ratio 1.42–1.56 (1.49). Lateral groove distinct. Conscutum (Figs. 2, 8) length 2.12–2.56 (2.38), width 1.37–1.48 (1.44), ratio 1.54–1.73 (1.65); laterally and postero-laterally with a distinct narrow non-sclerotised band; scapulae short, blunt; lateral carinae absent; cervical grooves indistinct; dense moderately large punctations evenly distributed over conscutum, except for pseudoscutum area; pseudoscutum with indistinct punctations; setae moderately dense, very short (*c.* 0.01) and indistinct (Fig. 2). Venter plate outlines as illustrated (Fig. 2); median plate: length 1.06–1.18 (1.10), width 0.74–0.84 (0.81), ratio 1.26–1.43 (1.37); adanal plate: length 0.74–0.82 (0.79), width 0.42–0.48 (0.45), ratio 1.67–1.95 (1.77); anal plate: 0.54–0.60 (0.58), width 0.32–0.36 (0.34), ratio 1.67–1.71 (1.69). All ventral plates with dense, moderately large punctations (Figs. 1, 2). Genital aperture (Fig. 2C) located at level of posterior margin of coxae II; posterior margin of genital apron deeply concave. Ventral setae (Fig. 2) moderately dense, very short, evenly distributed on all plates; length of setae on median plate *c.* 0.01. Anal groove (Fig. 2C) straight anteriorly and open posteriorly. Spiracular plate (Fig. 2A) broadly oval, longer than wide, length 0.34–0.42 (0.38), width 0.28–0.34 (0.31), ratio 1.21–1.25 (1.23).

Gnathosoma (Fig. 3, 8) length from palpal apices to cornual apices dorsally 0.45–0.48 (0.46), width between lateral projection of palpal segments I 0.43–0.48 (0.46), ratio 0.98–1.04 (1.01). Dorsal basis capituli (Fig. 3A) length from medial insertion of palpal segment I to cornual apices 0.21–0.25 (0.23), width 0.32–0.35 (0.33), ratio width to length 1.41–1.52 (1.46), subrectangular, posterior margin nearly straight; cornua long, ratio total length of basis capituli, including cornua, to cornual length 4.83–5.78 (5.39), triangular with narrowly rounded apex. Ventral basis capituli (Fig. 3C) subrectangular; lateral margins with slight constrictions at mid-length; auriculae absent; short converging ridges in auricular areas. Palpi (Fig. 3B) short, length dorsally (segments II and III) 0.23–0.24 (0.23), maximum width (in dorsolateral plane) 0.18–0.19 (0.19), ratio 1.22–1.29 (1.26), length of palpal segment I ventrally 0.16 (n = 1), maximum width ventrally 0.17 (n = 1), ratio 0.94 (n = 1); segment I greatly enlarged, greatest dimension in anteromedian-posterolateral direction; dorsally segment I subrectangular; ventrally segment I subtriangular, posterior margin with very long and narrow spur with sharply pointed apex; segments II and III fused together with indistinct suture between them, narrower proximally and abruptly widening to broadly rounded apex. Hypostome (Fig. 3C) length 0.18–0.19 (0.18), width 0.08–0.10 (0.09), ratio 1.75–2.10 (1.95); club-shaped, widening to broadly rounded apex with medial indentation; base of hypostome at level of base of palpal segment I; dental formula 3/3, basal half of hypostome without denticles, denticles sharply pointed.

Legs moderately long, slender. Coxae (Fig. 2E, 9): coxae I-IV with long and narrow external spur with narrowly rounded to sharply pointed apex; spur on coxae I-III subequal, spur on coxa IV nearly twice shorter those on coxae I-III; coxae I-IV without syncoxae. Trochanter I with long, triangular spur with sharply pointed apex; trochanters I-IV with long, narrow, with sharply pointed apex spur ventrally. Tarsus I: length 0.56–0.60 (0.58); tarsus IV length 0.53–0.58 (0.55); tarsi only slightly humped subapically.

**Female.** [Based on 1 to 5 specimens - refer to Table 1; Figs. 4, 5, 9] Idiosoma (Fig. 4A, 9) length from scapular apices to posterior body margin in moderately engorged specimen 4.1 (n = 1), width in moderately engorged 2.5 (n = 1), ratio 0.16 (n = 1), broadly suboval, widest approximately at mid-length. Scutum (Fig. 4, 9) length 1.05–1.18 (1.13; n = 4), width 1.40–1.58 (1.49; n = 4), ratio 0.73–0.79 (0.75; n = 4); lateral margins diverging for approximately 2/3 of scutum length, broadly rounded posteriorly; lateral carinae lacking; cervical grooves shallow; dense, small punctations evenly distributed throughout scutum; setae (Fig. 4) relatively sparse, very short (*c.* 0.005), indistinct and nearly equal to those on alloscutum, distributed as figured. Alloscutum (Fig. 4) as illustrated; setae of alloscutum (Fig. 4C) numerous, evenly distributed, very short, length of setae in central field *c.* 0.01, indistinct. Venter (Fig. 4E) as illustrated; genital aperture (Fig. 4E) medial to coxae III; genital groove (Fig. 4E) well developed; anal groove (Fig. 4E) oval with open posterior margin; ventral setae numerous, length of preanal setae *c.* 0.01, evenly distributed. Spiracular plates (Fig. 5A) length 0.27–0.32 (0.30; n = 4), width 0.39–0.47 (0.44; n = 4), ratio 0.68–0.70 (0.69; n = 4); broadly oval; marginal row of perforations in groove anteriorly.

Gnathosoma (Fig. 5B) length from palpal apices to cornual apices dorsally 0.60–0.70 (0.65; n = 4), width between lateral projection of palpal segments I 0.66–0.74 (0.71; n = 4), ratio 0.89–0.95 (0.92; n = 4). Dorsal basis capituli (Fig. 5B) length from medial insertion of palpal segment I to cornual apices 0.22–0.25 (0.24; n = 4), width 0.51–0.55 (0.54; n = 4), ratio width to length 2.20–2.32 (2.26; n = 4), subrectangular, posterior margin nearly straight; cornua short, ratio of total length of basis capituli (including cornua) to cornual length 17.50–20.00 (19.12; n = 4), triangular with broadly rounded apex; subcircular porose areas poorly distinct, not indented, separated by distance nearly equal to their own width, several openings arranged in discrete punctations. Ventral basis capituli (Fig. 5C) subrectangular; lateral margins with slight constrictions at mid-length; auriculae absent; short converging ridges in auricular areas. Palpi (Fig. 5B) short, length dorsally (segments II and III) 0.41–0.50 (0.46; n = 4), maximum width (in dorsolateral plane) 0.21–0.25 (0.23; n = 4), ratio 1.85–2.10 (1.95; n = 4), length of palpal segment I ventrally 0.31–0.36 (0.34; n = 4), maximum width ventrally 0.19–0.20 (0.20; n = 4), ratio 1.64–1.75 (1.68; n = 4); segment I greatly enlarged, greatest dimension in anteromedian-posterolateral direction; dorsally segment I subrectangular with convex medial margin; ventrally segment I subtriangular, posterior margin with long moderately narrow spur with narrowly rounded apex; segments II and III fused together with indistinct suture between them, narrower proximally and abruptly widening to broadly rounded apex. Hypostome (Fig. 5C) length 0.36–0.40 (0.38; n = 4), width 0.12–0.16 (0.14; n = 4), ratio 2.46–2.85 (2.68; n = 4); club-shaped, widening to broadly rounded apex with medial indentation; base of hypostome approximately at level of base of palpal segment II; dental formula 4/4 (few rows may be 3/3), basal half of hypostome without denticles, denticles sharply pointed.

Legs moderately long, slender. Coxae (Figs. 5E, 9): coxae I-IV with moderately long and narrow external spur with narrowly rounded apex; spur on coxae I-III subequal, spur on coxa IV nearly twice shorter those on coxae I-III; coxae I-IV without syncoxae. Trochanter I with moderately long, triangular spur with sharply pointed apex; trochanters I-IV without spur ventrally. Tarsus I: length 0.66–0.76 (0.73; n = 4); tarsus IV length 0.57–0.66 (0.63; n = 4); tarsi only slightly humped subapically.

**Nymph.** [Based on 34 specimens - refer to Table ; Fig. 6] Scutum (Fig. 6A) length 515–520 (518; n = 2), width 690–700 (695; n = 2), ratio 0.74–0.75 (0.75; n = 2); lateral margins diverging for approximately half of scutum length, broadly rounded posteriorly; posterolateral margin with slight indentations; lateral carinae lacking; cervical grooves shallow; moderately dense, small punctations evenly distributed throughout scutum; setae (Fig. 6A) relatively sparse, very short: length in central field of scutum 10 (n = 2), indistinct and nearly equal to those on alloscutum, distributed as figured. Setae of alloscutum numerous, evenly distributed, very short, length of setae in central field 10–13 (11; n = 2), indistinct. Anal groove oval with open posterior margin; ventral setae numerous, evenly distributed. Spiracular plates (Fig. 6B) broadly oval; marginal row of perforations in groove anteriorly.

Gnathosoma (Fig. 6C) length from palpal apices to cornual apices dorsally 285 (n = 2), width between lateral projection of palpal segments I 375–380 (378; n = 2), ratio 0.75–0.76 (0.76; n = 2). Dorsal basis capituli (Fig. 6C) length from medial insertion of palpal segment I to cornual apices 108 (n = 2), width 238–240 (239; n = 2), ratio width to length 2.21–2.23 (2.22; n = 2), subrectangular, posterior margin nearly straight; cornua moderately long, triangular with narrowly rounded apex. Ventral basis capituli (Fig. 6D) subrectangular; lateral margins with slight constrictions at mid-length; auriculae absent; short converging ridges in auricular areas. Palpi (Fig. 6C) short, length dorsally (segments II and III) 190–193 (191; n = 2), width 73–85 (79; n = 2), ratio 2.24–2.66 (2.45; n = 2), length of palpal segment I ventrally 140–150 (145; n = 2), maximum width ventrally 125–130 (128; n = 2), ratio 1.12–1.15 (1.14; n = 2); segment I greatly enlarged, greatest dimension in anteromedian-posterolateral direction; dorsally segment I subrectangular with convex medial margin; ventrally segment I subtriangular, posterior margin with long moderately broad spur with narrowly rounded apex; segments II and III fused together with indistinct suture between them, narrower proximally and abruptly widening to broadly rounded apex. Hypostome (Fig. 6D) length 150 (n = 1), width 73 (n = 1), ratio 2.07 (n = 1); club-shaped, widening to broadly rounded apex with medial indentation; base of hypostome approximately at level of base of palpal segment II; dental formula 3/3 (few basal rows 2/2), basal half of hypostome without denticles, denticles sharply pointed.

Legs moderately long, slender. Coxae (Fig. 6F): coxae I-IV with external spur; spur on coxae I-III moderately long, nearly subequal; spur on coxa I with broadly rounded apex, spur on coxae II and III with narrowly rounded to sharply pointed apex; spur on coxa IV very short; coxae I-IV with syncoxae occupying approximately 1/3, 1/4, 1/5 and 1/6 respectively of coxal width. Trochanters I-IV without spur ventrally. Tarsus I: length 320–335 (328; n = 2); tarsus IV length 298–310 (304; n = 2); tarsi only slightly humped subapically.

**Larva.** [Based on 2 specimens - refer to Table 1; Figs. 7, 10] Scutum (Fig. 7A) length 238 (n = 1), width 360 (n = 1), ratio 0.66 (n = 1); lateral margins diverging for approximately half of scutum length, broadly rounded posteriorly; posterolateral margin with slight indentations; lateral carinae lacking; cervical grooves shallow; setae 3 pairs, length of Sc1 11 (n = 1); length of Sc4 14 (n = 1). Dorsal setae of alloscutum undetermined in number since we only had larvae that were engorged to examine: it was impossible to confidently count and associate setae of the idiosoma dorsally and ventrally. Length of Cd1 17 (n = 1), length of Md1 23 (n = 1). Ventral setae undetermined number; 1 pair on anal valves; 3 pairs of sternals, length of St1 19 (n = 1); 2 pairs of preanals, length of Pa1 22 (n = 1), length of Pa2 32 (n = 1).

Gnathosoma (Fig. 7B, 7C, 7D) length from palpal apices to cornual apices dorsally 123 (n = 1), width between lateral projection of palpal segments I 155 (n = 1), ratio 0.79 (n = 1). Dorsal basis capituli (Fig. 7B) width 135 (n = 1), subrectangular, posterior margin nearly straight; cornua practically indistinct. Ventral basis capituli (Fig. 7C) subrectangular; lateral margins with slight constrictions at mid-length; auriculae absent. Post-hypostomal setae 2 pairs, length of Ph1 4 (n = 1), length of Ph2 4 (n = 1); distance between Ph1 37 (n = 1), distance between Ph2 27 (n = 1). Palpi (Fig. 7B) short, length dorsally (segments II and III) 77 (n = 1), maximum width (in dorsolateral plane) 42 (n = 1), ratio 1.83 (n = 1), maximum width of palpal segment I ventrally 50 (n = 1); segment I greatly enlarged, greatest dimension in anteromedian-posterolateral direction; dorsally segment I subrectangular with convex medial margin; ventrally segment I subtriangular, posterior margin with long moderately broad spur with narrowly rounded apex; segments II and III fused together with indistinct suture between them, narrower proximally and abruptly widening to broadly rounded apex; segment I lacking setae, segments II and III combined with 9 dorsal and 3 ventral setae. Hypostome (Fig. 7C) length 83 (n = 1), width 34 (n = 1), ratio 2.44 (n = 1); club-shaped, widening to broadly rounded apex with medial indentation; base of hypostome approximately at level of mid-length of palpal segment I; dental formula 2/2, approximately 5 denticles in files; basal half of hypostome without denticles, denticles sharply pointed.

Legs moderately long, slender. Coxae (Fig. 7E): coxae I-III with external spur; spur on coxa I moderately long, on coxa II and III short to very short; spur on coxae I-III with broadly rounded apex; coxae I-III with syncoxae occupying approximately 1/3, 1/4 and 1/5 respectively posteromedian portion of coxal width. Trochanters I-IV without spur ventrally. Tarsus I: length 183 (n = 1); tarsus III length 166 (n = 1); tarsi only slightly humped subapically.