Trouessartia petrochelidon Mironov and Galloway, 2019

Mironov, Sergey V. & Galloway, Terry D., 2019, Feather mites of the genus Trouessartia Canestrini (Acariformes: Trouessartiidae) from swallows (Passeriformes: Hirundinidae) in Canada, Zootaxa 4568 (1), pp. 1-39 : 24-31

Trouessartia petrochelidon Mironov and Galloway , sp. n.

( Figs. 13–15 )

Type material. Holotype male ( CNC 758973 ), 10 male and 10 female paratypes from Petrochelidon pyrrhonota (Vieillot, 1817) ( Passeriformes : Hirundinidae ), CANADA, Manitoba, Starbuck, La Salle River , 21 June 2001, coll. T.D. Galloway.

Depositories. Holotype, 4 male and 4 female paratypes—CNC, remaining paratypes—BMOC, WRME and ZISP.

Description. MALE (holotype, ranges for 10 paratypes in parentheses) ( Figs. 13 , 15 A–F). Length of idiosoma from anterior end to lobar apices excluding lamellae 475 (420–475), width of idiosoma at level of humeral shields 210 (175–215). Length of hysterosoma from level of sejugal furrow to lobar apices 310 (270–310). Prodorsal shield: length along midline 145 (135–150), greatest width posterior to level of scapular setae 155 (140–155), anterior part at level of trochanters II not narrowed, antero-lateral extensions fused with bases of epimerites Ia between legs I and II, lateral margins not fused with scapular shields, posterior margin almost straight, surface with barely distinct small lacunae posterior to scapular setae. Internal scapular setae si thin spiculiform, 17 (15–18) long, separated by 75 (67–75); external scapular setae se separated by 125 (110–125). Setae c2 lanceolate, with rounded apex, 15 (15–17) long, situated in antero-median angle of humeral shields. Setae c3 narrowly lanceolate, with acute apex, 17 (15–18) long. Hysteronotal shield entire, prohysteronotal and lobar parts demarcated by deep lateral incisions, total length from anterior margin to lobar apices excluding lamellae 315 (270–315). Prohysteronotal shield: length along midline 220 (195–220), width at anterior margin 155 (130–155), lateral margins straight at level of trochanters III, DHA present, central area with barely distinct pattern of small circular lacunae. Posterior margin with bottle-shaped dark patch (supranal concavity). Dorsal setae d1 present, setae d2, e2, f2 absent. Length of lobar shield excluding terminal lamellae 95 (75–95). Apical parts of opisthosomal lobes strongly approximate, separated by small parallel-sided terminal cleft with almost touching lateral margins; length of cleft from anterior end to apices of terminal lamellae 45 (35–45). Terminal lamellae semi-ovate, with inner margins straight and touching, with rounded posterior margin, length from bases of setae h3 to lamellar apices 25 (20–25). Distance between dorsal setae: h2:h3 22 (20–23), h2:h2 45 (38–45), h3:h3 27 (25–28), h1:h2 10 (7–19), ps1:h3 7.5 (6–8).

Epimerites I free. Rudimentary sclerites rEpIIa L-shaped. Genital apparatus situated between levels of trochanters III and IV, length excluding basal sclerite 45 (40–45), greatest width 40 (35–40). Epiandrum (pregenital sclerite) small. Latigenital sclerites present. Anterior genital papillae larger and noticeably distant from midline that posterior genital papillae equal. Setae g short, filiform, with bases distant from each other. Genital shield absent. Adanal apodemes heavily sclerotized, with barely distinct lateral membranes, without apophyses. Translobar apodeme absent. Adanal shields bearing setae ps3 absent. Anal suckers 11 (10–11) in diameter. Inner ends of epimerites IIIa with apices extending beyond level of setae 4b, and without extensions directed backward. Epimerites IVa long, with narrowed anterior ends fused with postero-lateral extension of intermedial sclerite. Setae 4b situated anterior to level of setae 3a; setae g anterior to level of setae 4a. Distance between ventral setae: 4b:3a 27 (25–28), 4b:g 82 (72–83), g:4a 10 (9–11), g:ps3 98 (90–98), g:g 11 (10–11), ps3: h3 82 (72–82).

Setae cG, mG of genua I, II filiform. Genual solenidia σ 1 I and σ II in basal part of corresponding genua. Trochanteral setae sR III filiform, 17 (16–18) long. Legs IV with ambulacral disc extending to midlevel between setae h2 and h3. Tarsus IV 25 (25–28) long; modified setae d barrel-shaped, with discoid cap, situated in distal one thirds of this segment; modified setae e hemispheroid, without cap, situated apically ( Fig. 15D ). Length of solenidia: σ 1 I 25 (24–25), σ II 10 (10–12), σ III 17 (15–18), φ IV 25 (23–25).

FEMALE (range for 10 paratypes) ( Figs. 14A, B , 15 G–H). Length of idiosoma from anterior end to apices of hyaline lobar processes 475–515, width at level of humeral shields 190–210. Length of hysterosoma from level of sejugal furrow to apices of lobar processes 325–350. Prodorsal shield: shaped as in male, 135–150 long, 145–155 wide, surface with barely distinct circular lacunae in posterior part. Setae si thin spiculiform, 15–18 long, separated by 75–78; setae se separated by 115–120. Setae c2 lanceolate with rounded apex, 15–17 long, situated in anteromedial angle of humeral shields. Setae c3 narrowly lanceolate, with acute apex, 15–17 long. Hysteronotal shield: length from anterior margin to bases of setae h3 310–335, width at anterior margin 135–155, lateral margins straight at level of trochanters III, DHA present, median area from level of setae cp to supranal concavity with numerous ovate lacunae. Dorsal setae d1 present. Setae d2, e2, f2 absent. Setae h1 short filiform, about 10–12 long, situated antero-mesal to bases of setae h2, 12–15 from corresponding lateral margins of hysteronotal shield. Width of opisthosoma at level of setae h 2 12–15. Setae ps1 positioned dorsal, approximately equidistant from outer and inner margins of opisthosomal lobes. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft from anterior margin to lobar apices 110–125, length from free margin of interlobar membrane to apices 60– 68, width of cleft at level of setae h 3 10–12. Interlobar membrane occupying anterior 1/3rd of terminal cleft. External copulatory tube absent; copulatory opening situated ventrally at free margin of interlobar membrane. Distance between dorsal setae: h2:h3 45–50, h2:h2 55–60, h3:h 3 25–28, d1:gl 45–50, h1:h 2 12–13, h1:h1 35–38, ps1:h 3 22–28.

Epimerites I free. Epigynum 35–40 long, 86–90 wide. Head of spermatheca with 5–6 rounded denticles, without collar; proximal part of primary spermaduct monotonously enlarged to head of spermatheca, distal part straight; secondary spermaducts 10–12 long ( Fig. 15H ). Posterior margins of epimerites IIIa with long narrow extension. Epimerites IVa present, long. Anal opening with adanal sclerites.

Legs I, II as in males. Trochanteral setae sR III filiform, 27–30 long. Legs IV with ambulacral disc extending to level of setae ps1 ( Fig. 15G ). Length of solenidia: σ 1 I 22–25, σ II 7–10, σ III 15–18.

Differential diagnosis. Trouessartia petrochelidon sp. n. belongs to the minutipes species group and is very similar to T. quarta Gaud and Atyeo, 1987 in having sclerites rEpIIa with acute inner ends and epimerites IVa fused with the base of the genital apparatus in males, and the distal end of the primary spermaduct straight and the external copulatory tube absent in females. Trouessartia petrochelidon differs from T. quarta by the following features: in both sexes, the posterior part of the prodorsal shield bears a faint ornamentation of small lacunae; in males, the terminal lamellae are longer (20–25 µm) and the idiosoma length is 420–475 µm ( Figs. 13A , 15E ); in females, the proximal part of the primary spermaduct is regularly enlarged toward the head of spermatheca ( Fig. 15H ). In both sexes of T. quarta , the prodorsal shield lacks any distinct ornamentation; in males, the terminal lamellae are 16–18 µm long, and the idiosomal length is 390–410 µm; in females, the primary spermaduct is enlarged unequally, its part between the head of spermathecal and secondary spermaducts is 2 times wider than the part distal to the secondary spermaducts ( Fig. 21D ).

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

Figures

FIGURE 13. Trouessartia petrochelidon sp. n., male. A—dorsal view, B—ventral view.

FIGURE 14. Trouessartia petrochelidon sp. n., female. A—dorsal view, B—ventral view.

FIGURE 15. Trouessartia petrochelidon sp. n., details. A, B—genu, tibia and tarsus I and II of male, respectively, C, D—tibia and tarsus III and IV of male, respectively, E—genital apparatus and opisthosoma of male, ventral view, F—setae si, c2, c3 and sRIII of male, G—tibia and tarsus IV of female, H—spermatheca and spermaducts. Abbreviations: ad—adanal apodeme, eaepiandrum, epIVa—epimerite IVa, bs—basal sclerite, is—intermedial sclerite, pm—paramere, tl—terminal lamella.

FIGURE 21. Trouessartia species, details of females. Trouessartia crucifera: A—dorsal hysterosoma, B—spermatheca and spermaducts; T. quarta: C—dorsal hysterosoma, D—spermatheca and spermaducts; T. ripariae: E—dorsal hysterosoma, Fspermatheca and spermaducts, G—area with distal end of primary spermaduct, ventral view. Abbreviations: co—copulatory opening, dp—distal bend of primary spermaduct, pd—primary spermaduct, vb—vertical bend of primary spermaduct.