Dubininia nestori, Mironov, Sergey V., Ehrnsberger, Rainer & Dabert, Jacek, 2017

Mironov, Sergey V., Ehrnsberger, Rainer & Dabert, Jacek, 2017, Feather mites of the genera Dubininia and Cacatualges (Acari: Xolalgidae) associated with parrots (Aves: Psittaciformes) of the Old World, Zootaxa 4272 (4), pp. 451-490 : 470-473

Dubininia nestori sp. n.

( Figs. 14–16 )

Type material. Male holotype, 1 male and 2 female paratypes ( MNHN 34G8) from Nestor notabilis Gould (Strigopidae) , New Zealand, no other data.

Depository. MNHN.

Description. Male (holotype, size for 1 paratype in parentheses). Idiosoma, length × width, 450 (420) × 300 (270), length of hysterosoma 320 (290). Prodorsal shield: narrowly oval, with posterolateral extensions bearing scapular setae se, si, with pair of median ridges, length along midline 112 (110), greatest width 70 (65) ( Fig. 14 A). Setae se separated by 57 (55). Hysteronotal shield completely fused with humeral shields, anterior margin shaped as recurve bow, greatest length from anterior margin to level of setae h3 300 (275), surface with a pair of longitudinally striated patches mesal to area of humeral shields. Setae c2 situated on anterior margin of hysteronotal shield. Outer margins of opisthosomal lobes slightly concave, width of opisthosoma at level of setae f2 150 (135). Opisthosomal lobes long, slightly divergent; terminal cleft deep triangular, interlobar septa almost extending to level of setae e2, length of cleft from anterior end to bases of h3 85 (70), length of cleft including septa 125 (120). Interlobar membrane well-developed, incision in this membrane triangular, with acute anterior end, 52 (40) long; terminal extensions of this membrane poorly developed, with widely rounded posterior margins, length of extensions 20 (16); lateral membranes with smooth lateral margins. Setae d2 (broken in holotype) extending to anterior end of interlobars septa (in paratype), setae e2 extending beyond lobar apices. Setae h2, h3 and f2 situated on lobar apices, their bases arranged in oblique row, setae ps1 situated at level of setae f2. Setae f2 filiform, extending beyond tips of tarsi IV. Setae ps2 situated on posterolateral margins of interlobar membrane. Distance between dorsal setae: c2:d2 78 (73), d2:e2 98 (88), e2:h3 125 (128), h2:h2 130 (125), h3: h3 110 (105), ps1:ps1 85 (80), ps1:h3 10 (10), h3:ps2 10 (7).

Epimerites I fused as a Y, sternum long, more than 1/2 of the total length of epimerites, area between anterior parts not sclerotized ( Fig. 14 B). Rudimentary sclerites of epimerites IIa present. Epimerites IIIa long, their sclerotized areas large, with a pair of acute extensions. Coxal fields IV closed. Genital apparatus enlarged posteriorly, 23 (24) × 16 (17); paragenital apodemes absent; genital shield absent, setae g situated on soft tegument. Adanal shield entire, bow-shaped, bearing setae ps3, with tips not extending to level of adanal suckers. Adanal suckers circular, with diameter 21 (19). Setae 4b situated anterior to level of setae 3a. Setae 1a represented by macrosetae extending to level of adanal suckers; setae 4b reaching the level of setae g; setae 3a as macrosetae, extending beyond lobar apices. Distance between ventral setae: 4b:g 38 (36), g:ps3 62 (55), ps3:h3 138 (130).

Tarsus I with ventral setae la, ra, and wa filiform, seta s slightly thickened basally ( Fig. 15 A). Genual solenidia: σ 1 I 90 (80), σ III 50 (40) long. Tarsus II with long tongue-like ventral extensions, seta s lanceolate at base, setae wa whip-shaped with membraneous enlargement in medial part ( Fig. 15 B). Ambulacral disc I normally developed, oval with long triangular central sclerite; ambulacral disc II much smaller, about 1/3 the length of disc I, central sclerite triangular; ambulacral discs III and IV strongly reduced. Legs III with tarsus extending beyond lobar apices. Tibia III without spine-like apical extension, 105 (95) long, seta kT not extending to midlevel of tarsus III ( Fig. 14 ). Tarsus III 104 (98) long, with small spine-like apical process; setae w half as long as this segment; bases of setae e, f close each other and situated approximately at midlevel of this segment, seta f 1.5 times longer than seta e. Tibia IV 78 (71) long, without dorsal ridge; tarsus IV 78 (71) long, with truncate apical process ( Fig. 15 D). Length of ambulacral discs: I—23 (25), II—10 (11), III and IV—less than 5.

Female (range for 2 specimens). Idiosoma length, length × width, 360–365 × 200–210, length of hysterosoma 210–225. Prodorsal shield narrowly oval, strongly narrowed in anterior part, without posterolateral extensions, with a pair of median ridges, median area with larger dots than in lateral areas, posterior margin slightly extending beyond level of setae se, length along midline 95–100, greatest width 44–50 ( Fig. 16 A). Scapular setae se situated on small oval plates, setal bases separated by 65–74. Opisthosoma bluntly rounded. Hysteronotal shield absent. Distance between dorsal setae c2:d2 80–85, d2:e2 95–98, e2:h3 42–45, h2:h2 68–70, h3:h3 48–50. Setae c2, d2, e2 filiform, 30–35 long.

Epimerites I fused into a Y with very short sternum, area between free parts of epimerites not sclerotized ( Fig. 16 B). Epigynum bow-shaped, 10–11 × 42–44, tips not extending to level of genital papillae, setae 4b situated on tips of epigynum. Apodemes of oviporus long, extending to midlevel between trochanters III and IV. Epimerites IIIa, IVa present, small. Setae 1a filiform, reaching the epigynum. Setae 3a 55–60 long, 4a 90–110, 4b 34–36 long, g about 25–30 long. Setae g situated slightly posterior to level of setae 3a. Distance between ventral setae: 4b:g 35– 40, g:4a 65–70.

Legs I, II as in male. Genual solenidia: σ 1 I 50–58, σ III 15–18 long. Length of leg segments: tibia III 38 –40, tarsus III 50 –53, tibia IV 43 –45, tarsus IV 66 –68. Tarsi III, IV without ventral extensions. Setae sR III filiform, about 32–35 long; setae kT III filiform, shorter than corresponding tibiae; length of tibial solenidia: φ III 25–30, φ IV 18–20. Setae w III, w IV, r IV thickened basally, with filiform apex; remaining setae of tarsi III, IV filiform. Ambulacral discs: I—18–20, II—10–11, III and IV—7–9 long. Ambulacral stalks of tarsi III, IV nearly 3 times longer than corresponding discs. Setae d of tarsi III, IV longer than corresponding tarsi.

Differential diagnosis. The new species, Dubininia nestori sp. n., is very close to D. psittacina from Strigops harboptilus (Strigopidae) in having, in both sexes, the ambulacral discs of legs I about 3 times longer than those on tarsi II, and, in males, the epimerites IIIa with a pair of acute extensions, the ventral extension of tarsi II noticeably protruding, and tibia III without the dorso-apical spine. Dubininia nestori is distinguished from the latter species by the following characters: in males, the terminal cleft is triangular, setae se, si are situated on the posterolateral extensions of the prodorsal shield, and the anterior margin of the hysteronotal shield between setae c2 is shaped as a recurved bow; in females, setae e2 are short filiform (20–25 µm) and do not extend to the level of seta h2 bases, bases of setae w and r of tarsus IV divide this segment into three approximately equal parts. In males of D. psittacina , the terminal cleft is semi-oval, setae se, si are on teardrop-like sclerites separated from the main body of the prodorsal shield, and the anterior margin of the hysteronotal shield between setae c2 is slightly convex; in females, setae e2 are longer (30–40 µm) and extending to level of seta h2 bases, and seta w of tarsus IV is situated approximately at the midlevel of this segment.

Etymology. The specific epithet is derived from the generic name of the type host and is a noun in the genitive case.

Figures

FIGURE 14. Dubininia nestori sp. n., male. A—dorsal view, B—ventral view.

FIGURE 15. Dubininia nestori sp. n., legs of male. A – D—tibiae and tarsi I – IV, respectively.

FIGURE 16. Dubininia nestori sp. n., female. A—dorsal view, B—ventral view.