Amerodectes icteri, Mironov & Galloway, 2021

Mironov, Sergey V. & Galloway, Terry D., 2021, Feather mites of the subfamily Pterodectinae (Acariformes: Proctophyllodidae) from passerines and kingfishers in Canada, Zootaxa 5016 (1), pp. 1-55 : 11-15

Amerodectes icteri sp. n.

( Figs. 5–7 )

Type material. Male holotype, 17 male and 20 female paratypes from the Baltimore Oriole, Icterus galbula (Linnaeus, 1758) ( Passeriformes : Icteridae ), (NOOR/393/CEN/10, SM 2193), CANADA, Manitoba, Winnipeg, 22 May 2010, coll. T.D Galloway and C.M. Babel.

Depository. Holotype, 5 male and 5 female paratypes — CNC, remaining paratypes — WRME and ZISP.

Description. MALE (holotype, range for 10 paratypes in parentheses) ( Figs. 5 , 7A–E ). Idiosoma, length × width, 340 (320–345) × 135 (130–140), length of hysterosoma 225 (200–220). Prodorsal shield: entire, anterolateral extensions rounded, lateral margins at level of scapular setae slightly concave, posterior margin straight, posterior corners rounded, surface poorly pigmented and as colorless as striated tegument of idiosoma, length 110 (105–115), width 95 (85–95). Setae ve rudimentary, represented by alveoli. Bases of scapular setae se separated by 55 (50–55). Scapular shields narrow, not developed dorsally. Humeral shields represented by heavily sclerotized, narrow longitudinal sclerites situated dorsal to bases of setae cp and c3. Bases of setae cp and c2 situated on striated tegument. Subhumeral setae c3 lanceolate, 24 (22–25) long, 7 (6–7) wide. Hysteronotal shield: anterior margin straight, anterior corners almost rectangular, surface without ornamentation, colorless as striated tegument of idiosoma, greatest length 220 (200–225), width at anterior margin 92 (80–95). Distance between prodorsal and hysteronotal shields 15 (10–15). Opisthosomal lobes slightly shorter than wide at base; posterior margins of lobes roughly rounded, with small and blunt membranous extensions at bases of setae h2 and h3. Terminal cleft shaped as a wide U with strongly divergent branches, 25 (20–25) long. Supranal concavity semicircular. Setae f2 anterior to bases of setae ps2. Setae h1 situated at level of supranal concavity. Setae h3 spiculiform, 32 (32–40) long; setae ps2 88 (80–90) long. Setae ps1 filiform, about 5 long, situated near margins of terminal cleft slightly anterior to level of setae ps2. Distances between dorsal setae: c2:d2 82 (80–85), d2:e2 82 (70–80), e2:h3 45 (45–50), d1:d2 27 (25–28), e1: e2 25 (22–25), h1:ps2 20 (15–20), h2:h2 47 (45–50), h3:h3 32 (32–38), ps2:ps2 65 (57–65).

Epimerites I fused into a V, fused part with a pair of short and acute lateral extensions and small acute median extension. Coxal fields I, II without extensively sclerotized areas. Rudimentary sclerites rEpIIa absent. Coxal fields I–III open. Coxal fields IV without sclerotized areas at bases of trochanters IV. Epimerites IVa absent. All epimerites of coxae I-IV heavily sclerotized (dark-brown), noticeably contrasting with pale striated regiment of ventral idiosoma. Genital arch of moderate size, 22 (20–22) × 37 (35–38); aedeagus sword-shaped, 70 (68–72) long, not extending to anterior end of anal opening; basal sclerite of genital apparatus semicircular ( Fig. 7A ). Genital papillae not connected at bases. Genital and adanal shields absent. Adanal suckers 13 (12–14) in diameter, corolla with 9–10 rounded denticles, surrounding membrane with radial striae. Opisthoventral shields occupying lateral areas of opisthosoma and distal half of opisthosomal lobes; inner margins of these shields with semi-ovate extension curved anteriorly and bearing setae ps3; anterior border of shield covering opisthosomal lobes with 2-3 rounded denticlelike extensions. Setae 4b situated posterior to level of setae 3a, setae ps3 at midlevel of adanal suckers. Distance between ventral setae: 3a:4b 10 (8–12), 4b:4a 35 (30–35), 4a:g 37 (36–40), g:ps3 50 (45–50), ps3:ps3 57 (55–58), ps3:h3 32 (30–32).

Femora I, II with narrow ventral crests, other segments of legs I, II without processes ( Fig. 7B, C ). Solenidion σ of genu I half as long as this segment and situated at its midlevel. Genual setae cG I, II and mG I, II filiform. Setae d of tarsi II, III much shorter than corresponding setae f. Solenidion φ of tibia IV extending to proximal margin of ambulacral disc. Tarsus IV 25 (20–25) long, without apical process; setae d, e button-like, seta d at midlength of this segment ( Fig. 7E ). Length of solenidia: ω1 I 13 (13–15), ω1 II 9 (9–10), σ I 13 (11–14), σ III 8 (7–9), φ IV 30 (30–34).

FEMALE (range for 10 paratypes ( Figs. 6 , 7F, G ). Idiosoma, length × width, 455–485 × 155–170, length of hysterosoma 325–340. Prodorsal shield: entire; anterolateral extension short, with poorly distinct margin, pointed or rounded; lateral margins with concavities extending to bases of setae se; posterior margin convex; posterior corners rounded; surface without ornamentation, weakly sclerotized as in the male; 120–125 × 105–120. Setae ve rudimentary, represented by alveoli. Bases of setae se separated by 67–75. Scapular shields not developed dorsally. Humeral shields represented by small longitudinal heavily sclerotized sclerites situated ventrolaterally. Setae cp on ventral margins of humeral shields, c2 on striated tegument. Setae c3 lanceolate, 22–25 long, 7–8 wide. Distance between prodorsal and hysteronotal shields, 10–20. Anterior and lobar parts of hysteronotal shield separated dorsally by narrow transverse band of soft tegument and connected ventrolaterally. Anterior hysteronotal shield: nearly rectangular in shape, anterior margin straight or slightly convex, anterior corners rounded, median area of posterior half with minute circular lacunae, lateral margins of posterior half with heavily sclerotized (dark-brown) bands, remaining surface of this shield poorly sclerotized, as pale as the striated tegument of idiosoma, greatest length 245–255, width at anterior margin 110–115 ( Fig. 6A ). Length of lobar region 82–95, greatest width 80–85. Terminal cleft narrow, roughly V-shaped, margins of anterior half almost touching each other, 60–70 long, 12–15 wide posteriorly. Lobar shield split longitudinally by narrow band of soft tegument, anterior margins of these pieces straight, surface without ornamentation. Supranal concavity absent. Setae h1 distant from anterior margins of lobar shields; setae h1 and f 2 in trapezoidal arrangement. Setae h2 spindle-like, 42–50 × 7.5–8. Setae ps1 situated on inner margins of opisthosomal lobes, near to lobar apices. Setae h3 18–20 long, 1/6–1/5th the length of terminal appendages. Distances between dorsal setae: c2:d2 100–110, d2:e2 105–115, e2:h2 56–60, h2:h3 38–40, d1:d2 38–45, e1: e2 33–42, h1:h2 30–35, h1:h1 28–30, h2:h2 65–70, h2:ps1 20–22.

Epimerites I fused into a V, fused part with narrow median extension ( Fig. 6B ). Lateral parts of coxal fields I, II without extensive sclerotized areas. Epimerites IVa absent.

Translobar apodemes of opisthosomal lobes narrow and not fused to each other anterior to terminal cleft. Epigynum without lateral extension, greatest width 60–70; apodemes of oviporus fused with epimerites IIIa. Pseudanal setae filiform, setae ps2 situated at level of posterior end of anal opening and widely separated from each other; distance between pseudanal setae: ps2:ps2 40–45, ps3:ps3 19–22, ps2:ps3 20–25. Head of spermatheca narrowly conical; primary spermaduct without enlargements; secondary spermaducts 10–12 long ( Fig. 7G ).

Legs I, II as in male. Solenidion σ of genu I half as long as this segment and situated at its midlevel. Genual setae cG I, II, mG I, II as in male. Seta d of tarsi II–III much shorter than corresponding setae f. Genu IV dorsally inflated, with narrow dorsal crest. Lengths of solenidia: ω1 I 15–18, ω1 II 10–12, σ I 13–15, σ III 7–10, φ III 32–35, φIV 8–10.

Differential diagnosis. The new species, Amerodectes icteri sp. n., is most similar to A. passerinae Mironov & Chandler, 2017 in having the following: in both sexes, the humeral shields shaped as small longitudinal sclerites and touching bases of setae cp; in males, setae h3 long spiculiform; and in females, the lobar shield completely split longitudinally. Amerodectes icteri differs from A. passerinae in having the following features: in males, the aedeagus does not extend to the anterior end of anal opening, the corolla of adanal suckers bears 9–11 denticles, the anterior margin of ventral sclerotized area of opisthosomal lobes with 3 rounded denticles, and tarsus IV lacks an apical claw-like process; in females, the posterior margin of the prodorsal shield is distinctly convex, the anterior hysteronotal shield bears small circular lacunae in the posterior half, and the lobar shield lacks any lacunae. In males of A. passerinae , the aedeagus extends to the anterior end of anal opening, the corolla of adanal suckers is smooth, the anterior margin of ventral sclerotized area of lobes with one heavily sclerotized denticle, and tarsus IV has a small, claw-like apical process; in females, the posterior margin of the prodorsal shield is slightly sinuous, the entire surface of the anterior hysteronotal shield is covered with small circular lacunae, and each piece of the lobar shield bears 2–3 small circular lacunae. Additionally, A. icteri is readily distinguished from all presently known Amerodectes species in having epimerites of all coxal fields (I–IV) heavily sclerotized and colored dark-brown in both sexes.

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

Figures

FIGURE 5. Amerodectes icteri sp. n., male. A—dorsal view, B—ventral view.

FIGURE 6. Amerodectes icteri sp. n., female. A—dorsal view, B—ventral view.

FIGURE 7. Amerodectes icteri sp. n., details. A—opisthosoma of male, ventral view, B, C—legs I, II of male, respectively, D, E—tibiae and tarsi III, IV of male, respectively, F—tibia and tarsus IV of female, G—spermatheca and spermaducts.