Trouessartia americana Mironov and Chandler, 2020

Mironov, Sergey V. & Chandler, C. Ray, 2020, Feather mites of the genus Trouessartia (Acariformes: Trouessartiidae) from passerines (Aves: Passeriformes) in Georgia, USA, Zootaxa 4860 (1), pp. 1-54 : 23-27

Trouessartia americana Mironov and Chandler sp. n.

( Figs. 14–16 )

Type material. Holotype male ( BMOC 20-0303-005), 10 male and 15 female paratypes from Setophaga americana (Linnaeus, 1758) ( Passeriformes : Parulidae ), ( SVM 18-0530-4/2), USA, Georgia, Georgia Southern University Campus, 32°25’15”N, 81°47’22”W, 28 March 2018, coll. C. R. Chandler.

Depositories. Holotype, 5 male and 5 female paratypes— UMMZ, remaining paratypes—ZISP.

Description. MALE (holotype, ranges for 10 paratypes in parentheses) ( Figs. 14 , 16 A–D, G). Idiosoma, length × width, 430 (425–440) × 215 (210–220), length of hysterosoma 280 (275–290). Prodorsal shield: length along midline 125 (120–130), greatest width posterior to level of scapular setae 150 (145–150), anterior part at level of trochanters II not narrowed, anterolateral extensions angular, almost extending to bases of epimerites Ia, lateral margins not fused with scapular shields, posterior margin, surface without ornamentation. Internal scapular setae si spiculiform, 25 (23–25) long, separated by 65 (60–65); external scapular setae se separated by 105 (100–105). Setae c2 thin spiculiform, 40 (37–42) long, situated in anteromedian angle of humeral shields. Setae c3 narrowly lanceolate, with acute apex, 18 (17–20) long. Hysteronotal shield completely separated into prohysteronotal and lobar parts, total length 270 (265–275). Prohysteronotal shield: length along midline 175 (170–175), width at anterior margin 145 (140–145), lateral margins at level of trochanters III with incisions flanked by C-shaped heavily sclerotized patch, DHA absent, surface without ornamentation. Dorsal setae d1, d2, e2 present. Setae f2 absent. Length of lobar shield excluding terminal lamellae 97 (95–100). Opisthosoma strongly attenuate posteriorly, opisthosomal lobes fused with each other along midline forming a heavily sclerotized median septum, only apical parts of lobes posterior to level of setae h2 separated by narrow parallel-sided terminal cleft; length of cleft from anterior end to lobar apices 27 (25–28); length from anterior end to apices of terminal lamellae 35 (35–38), width 7 (7–8).

Terminal lamellae semi-ovate, with noticeably attenuate apices, with smooth margins, length from bases of setae h3 to lamellar apices 35 (35–38), greatest width 27 (25–28). Distance between dorsal setae: c2:d2 72 (72–75), d2:e2 90 (88–90), e2:h2 75 (73–75), h2:h3 25 (24–25), h2:h2 45 (42–45), h3:h3 35 (32–35), d1:d2 37 (37–40), e1: e2 40 (35–40).

Epimerites I free. Rudimentary sclerites rEpIIa small circular, with minute lacuna. Genital apparatus: length excluding basal sclerite 45 (44–45), greatest width 20 (19–20), epiandrum small ovate, latigenital sclerites absent, distal ends of parameres without denticles, aedeagus as short conoid (frustum). Anterior genital papillae larger than and situated more distant from midline than posterior ones. Postgenital plaque almost circular in shape. Setae g narrowly lanceolate (about 3 wide) with filiform apices, with bases clearly separated and surrounded by small cordiform sclerotized areas (rudiments of genital shield), not fused each other. Apophyses of adanal apodemes shaped as ridges with rounded tubercle at anterior end. Lateral margins of opisthosoma with barely distinct lateral membranes. Translobar apodeme present. Adanal shields represented by small triangular sclerites around bearing setae ps3. Adanal suckers 15 (15–17) in diameter. Inner ends of epimerites IIIa with apices extending to level of setae 4b, without denticle-like extensions on inner margins. Epimerites IVa wide, with anterior ends acute and reaching level of setae 4a. Setae 4b situated anterior to level of setae 3a; setae g posterior to level of setae 4a. Distance between ventral setae: 4b:3a 12 (10–12), 4b:g 85 (83–85), g:g 10 (9–10), g:ps3 52 (52–58), ps3: h3 95 (92–95).

Setae cG, mG of genua I, II filiform. Genual solenidia σ I and σ II situated at midlength of corresponding genua ( Fig. 16A, B ). Trochanteral setae sR III narrowly lanceolate, with blunt apex, 14 (14–15) long. Legs IV with ambulacral disc extending to level of setae h3. Tarsus IV 33 (33–35) long; modified setae d barrel-shaped, with discoid cap, situated in distal one third of this segment; modified setae e button-like, without cap, situated apically ( Fig. 16C ). Length of solenidia: σ I 50 (50–54), σ II 10 (10–13), σ III 23 (23–25), φ IV 35 (35–38).

FEMALE (range for 10 paratypes) ( Figs. 15 , 16E, F ). Idiosoma, length × width, 490–530 × 205–230, length of hysterosoma 350–370. Prodorsal shield: shaped as in male, 135–140 long, 150–160 wide, surface without ornamentation. Setae si thin spiculiform, 25–30 long, separated by 62–68; setae se separated by 100–105. Setae c2 spiculiform, 35–47 long, situated in anteromedial angle of humeral shields. Setae c3 narrowly lanceolate, with blunt apex, 20–23 long. Hysteronotal shield: length from anterior margin to posterior tips 320–330, width at anterior margin 145–155, lateral margins at level of trochanters III with incision flanked by C-shaped heavily sclerotized patch, DHA absent, median area from level of setae cp to setae e1 with poorly distinct narrowly ovate lacunae, area between levels of trochanters IV and setae h1 with well pronounced small ovate lacunae. Dorsal setae d1, d2, e2 present. Setae h1 narrowly lanceolate, 32–38 long, situated anteromesal to bases of setae h2, 20–23 from corresponding lateral margins of hysteronotal shield, with tips extending beyond free margin of interlobar membrane. Width of opisthosoma at level of setae h2 100–105. Setae ps1 situated dorsally, equidistant from margins of opisthosomal lobes. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft from anterior end of supranal concavity to lobar apices 135–155, length from free margin of interlobar membrane to lobar apices 105–120, greatest width of cleft 42–45. Interlobar membrane occupying anterior 1/8th of terminal cleft. External copulatory tube straight stylet-like with acute apex, situated on free margin of interlobar membrane, 25–30 long; basal guides of copulatory tube well developed, primary spermaduct guide in supranal concavity present. Distance between dorsal setae: c2:d2 75–78, d2:e2 87–90, e2:h2 55–60, h2:h3 70–75, h2:h2 80–84, h3:h3 55–60, d1:d2 40–45, e1: e2 25–30, h1:h2 15–20, h1:h1 47–50, ps1:h3 13–18.

Epimerites I free. Epigynum 45–50 long, 87–98 wide. Inner margins of epimerites IIIa small denticle-like extension. Epimerites IVa short and wide. Anal opening with small adanal sclerites. Setae f2, ps2 present. Head of spermatheca with semi-ovate peak; primary spermaduct without enlargement and with S-shaped bend before entering into external copulatory tube; secondary spermaducts 30–33 long ( Fig. 16E ).

Legs I, II as in males ( Fig. 14A, B ). Trochanteral setae sR III narrowly lanceolate, with blunt apex, 13–20 long. Legs IV with ambulacral disc extending to midlenth between levels of setae h2 and h3. Length of solenidia: σ I 47–53, σ II 13–15, σ III 24–25.

Differential diagnosis. Among previously described species of the capensis group, the new species, Trouessartia americana sp. n., is most similar to T. basileuteri Hernandes, 2014 in having, in males, the postgenital plaque almost circular in shape, setae g narrowly lanceolate and sclerites rEpIIa small ovate, and, in females, the external copulatory tube acute and stylet-like. Trouessartia americana sp. n. differs from the latter species by the following features: in males, the small sclerotized areas around the bases of setae g are cordiform, and the anterior genital papillae are more distant from the midline than the posterior papillae; in females, setae h1 extend distinctly beyond the free margin of the interlobar membrane, and the distal end of the primary spermaduct has a S-shaped bend. In males of T. basileuteri , the small sclerotized areas around the bases of setae g are absent, and the anterior and posterior genital papillae are equidistant from the midline; in females, setae h1 do not extend beyond the free margin of the interlobar membrane, and the distal end of the primary spermaduct is straight.

Etymology. The specific epithet is taken from the specific name of the type host.

Figures

FIGURE 14. Trouessartia americana sp. n., male. A—dorsal view, B—ventral view.

FIGURE 15. Trouessartia americana sp. n., female. A—dorsal view, B—ventral view.

FIGURE 16. Trouessartia americana sp. n., details.A, B—genu, tibia and tarsus I, II of male, respectively, C—tibia and tarsus IV of male, D—setae si, c2, c3 and sRIII of male, E—spermatheca and spermaducts, F—opisthosoma of female, dorsal view, G—opisthosoma and genital apparatus of male, ventral view.