Trouessartia mniotilta 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 : 32-36

Trouessartia mniotilta Mironov and Chandler sp. n.

( Figs. 20–22 )

Type material. Holotype male ( BMOC 20-0303 - 007 ), 9 male and 10 female paratypes from Mniotilta varia (Linnaeus, 1766) ( Passeriformes : Parulidae ) ( SVM 15-1012 - 2 /2), USA, Georgia, Statesboro, Georgia Southern University Campus , 32°25’15”N, 81°47’22”W, 4 May 2015, coll. C. R. Chandler.

Depositories. Holotype, 4 male and 5 female paratypes— UMMZ, remaining paratypes—ZISP.

Additional material. 8 males and 5 females from M. varia ( Passeriformes : Parulidae ), ( SVM 18-0615 - 1 /2), USA, Florida, Monroe Co, Vaca Key , 1 May 2015, coll. L.J. Hribar.

Description. MALE (holotype, ranges for 9 paratypes in parentheses) ( Figs. 20 , 22 A–D, G). Idiosoma, length × width, 425 (410–440) × 215 (210–220), length of hysterosoma 275 (260–280). Prodorsal shield: length along midline 125 (120–130), greatest width posterior to level of scapular setae 140 (130–150), anterior part at level of trochanters II not narrowed, anterolateral extensions angular, extending to epimerites Ia but not fused with them, lateral margins not fused with scapular shields, posterior margin straight, surface without ornamentation. Internal scapular setae si thin spiculiform, 27 (25–30) long, separated by 52 (47–55); external scapular setae se separated by 95 (87–100). Setae c2 long spiculiform, 45 (40–45) long, situated in anteromedian angle of humeral shields. Setae c3 narrowly lanceolate, with weakly bidentate or truncate apex, 23 (22–24) long. Hysteronotal shield completely separated into prohysteronotal and lobar parts, total length 260 (255–275). Prohysteronotal shield: length along midline 175 (160–180), width at anterior margin 135 (130–145), anterior margin slightly convex medially, lateral margins at level of trochanters III with incision flanked by bean-shaped heavily sclerotized patch, DHA absent, surface without ornamentation. Dorsal setae d2, e2 present. Setae d1, f2 absent. Length of lobar shield excluding terminal lamellae 95 (87–98).

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 25 (22–25); length from anterior end to apices of terminal lamellae 50 (50–55), width 10 (8–10). Terminal lamellae narrow semi-ovate, with smooth margins, length from bases of setae h3 to lamellar apices 25 (25–30), greatest width 25 (24–28). Distance between dorsal setae: c2:d2 67 (62–68), d2:e2 95 (85–98), e2:h2 75 (72–80), h2:h3 25 (23–25), h2:h2 43 (38–48), h3:h3 33 (32–35), e1: e2 44 (40–45).

Epimerites I free. Rudimentary sclerites rEpIIa small roughly circular. Genital apparatus: length excluding basal sclerite 52 (47–52), greatest width 25 (24–26), epiandrum small ovate, latigenital sclerites absent, distal ends of parameres without denticles, aedeagus shaped as thick conoid (fustum). Anterior and posterior genital papillae approximately equal in size, anterior papillae more distant from midline than posterior ones. Postgenital plaque small trapezoidal. Setae g long filiform, exceeding half-distance between levels of setae 4a and ps3, bases of setae g separated and surrounded by small sclerotized areas weakly connected to each other. Adanal apodemes with apophyses shaped as narrow 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 or teardrop-shaped sclerites bearing setae ps3. Adanal suckers 13 (12–14) in diameter. Inner ends of epimerites IIIa with tips slightly extending beyond level of setae 4b, and with blunt-angular extension on inner margins. Epimerites IVa wide and short, with anterior ends not reaching level of basal sclerite of genital apparatus. Setae 4b situated anterior to level of setae 3a; setae g posterior to level of setae 4a. Distance between ventral setae: 4b:3a 10 (8–12), 4b:g 80 (73–80), g:g 5 (5–6), g:ps3 55 (50–55), ps3: h3 90 (85–97).

Setae cG, mG of genua I, II filiform. Genual solenidia σ I and σ II situated at midlength of corresponding genu ( Fig. 22A, B ). Trochanteral setae sR III narrowly lanceolate, with truncate apex or with poorly distinct bidentation, 16 (15–18) long. Legs IV with ambulacral disc extending to level of setae h3. Tarsus IV 35 (30–35) 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. 22C ). Length of solenidia: σ I 52 (48–55), σ II 15 (12–15), σ III 30 (25–30), φ IV 37 (35–38).

FEMALE (range for 10 paratypes) ( Figs. 21 , 22E, F ). Idiosoma, length × width, 500–535 × 210–225, length of hysterosoma 345–365. Prodorsal shield: shaped as in male, 130–135 long, 145–150 wide, surface without ornamentation. Setae si thin spiculiform, 28–32 long, separated by 52–55; setae se separated by 95–100. Setae c2 long spiculiform, 42–45 long, situated in anteromedial angle of humeral shields. Setae c3 narrowly lanceolate, with truncate apex, 22–24 long. Hysteronotal shield: length from anterior margin to posterior tips 320–335, width at anterior margin 135–150, lateral margins at level of trochanters III with incision flanked by bean-shaped heavily sclerotized patch, DHA absent, anterior part (at level of humeral shields) with poorly expressed ovate lacunae, central area between trochanters III and IV with well outlined ovate lacunae, area between trochanters IV and setae h2 with small ovate and circular lacunae. Dorsal setae d2, e2 present. Setae d1 absent. Setae h1 narrowly lanceolate, 28–30 long, not extending to free margin of interlobar membrane, situated anteromesal to bases of setae h2, 22–24 from corresponding lateral margins of hysteronotal shield. Width of opisthosoma at level of setae h2 95–100. Setae ps1 situated dorsally, equidistant from margins of opisthosomal lobes. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft from supranal concavity to lobar apices 145–155, length from free margin of interlobar membrane to apices 100–105, width of cleft at level of setae h3 40–45. Interlobar membrane occupying anterior 1/6th of terminal cleft. External copulatory tube straight finger like with bluntly rounded apex, situated on free margin of interlobar membrane, 25–32 long; basal guide of copulatory tube distinctly sclerotized, primary spermaduct guide in supranal concavity well developed. Distance between dorsal setae: c2:d2 70–75, d2:e2 85–100, e2:h2 62–65, h2:h3 68–72, h2:h2 78–80, h3:h3 56–60, e1: e2 37–47, h1:h2 16–18, h1:h1 40–42, ps1:h3 15–18.

Epimerites I free. Epigynum 38–40 long, 88–95 wide. Inner margins of epimerites IIIa with blunt-angular 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, secondary spermaducts 25–27 long ( Fig. 22E ).

Legs I, II as in males ( Fig. 22A, B ). Trochanteral setae sR III narrowly lanceolate, with blunt apex, 18–20 long. Legs IV with ambulacral disc extending to midlength between setae h2 and h3. Length of solenidia: σ I 45–50, σ II 12–13, σ III 24–26.

Differential diagnosis. The new species, Trouessartia mniotilta sp. n., clearly differs from all previously described species of the capensis group and five new species described above by the absence of dorsal setae d 1 in both sexes. In having this character, T. mniotilta is similar to the four species described below. Among previously described species of the capensis group, T. mniotilta is most similar to T. basileuteri Hernandes, 2014 in having setae h 1 in females relatively short and not extending beyond the free margin of the interlobar membrane. In addition to the absence of setae d 1 in both sexes of T. mniotilta , this species differs from T. basileuteri by the following features: in males, setae g are long filiform, the bases of these setae are surrounded by small sclerotized and weakly connected areas, the postgenital plaque is small and trapezoidal with a slightly concave posterior margin; in females, the central part of the hysteronotal shield bears large circular and ovate lacunae, and the external copulatory tube is thick with a rounded tip. In males of T. basileuteri , setae g are distinctly thickened in their basal 2/3rd, the bases of these setae are not surrounded by sclerotized areas, and the postgenital plaque is large and semicircular; in females, the central part of the hysteronotal shield bears small and poorly distinct ovate lacunae, and the external copulatory tube is stylet-like with an acute apex.

Etymology. The specific epithet is taken from the generic name of the type host and is a noun in apposition.

Figures

FIGURE 20. Trouessartia mniotilta sp. n., male. A—dorsal view, B—ventral view.

FIGURE 21. Trouessartia mniotilta sp. n., female. A—dorsal view, B—ventral view.

FIGURE 22. Trouessartia mniotilta 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.