Trouessartia niltavae Constantinescu

Constantinescu, Ioana Cristina, Popa, Oana Paula, Popa, Luis Ovidiu, Cobzaru, Ioana, B., Mukhim D. Khlur & Adam, Costică, 2018, A new feather mite species of the genus Trouessartia Canestrini, 1899 (Acarina, Trouessartiidae) - an integrative description (morphology and DNA barcoding data), ZooKeys 789, pp. 19-35 : 21-26

Trouessartia niltavae Constantinescu sp. n. Figs 1, 2, 3, 4, 5, 6

Type material.

Male holotype (ANA663), 5 male (ANA661, ANA662, ANA664, ANA665, ANA838) and 8 female (ANA666, ANA667, ANA668, ANA669, ANA670, ANA839, ANA840) paratypes, 27.01.2014, from the Large Niltava Niltava grandis grandis (Blyth) ( Passeriformes , Muscicapidae ); INDIA: Meghalaya, Jaintia Hills, Shnongrim village, (25°21 ’12.36” N, 92°31 ’3.06” E); 1151 m; subtropical forest; collector D. K. B. Mukhim.

Description.

Male (Figs 1; 2; 3 A–E; holotype, range for four paratypes in parentheses): length of idiosoma from anterior end to bases of setae h3 384 (404-424), greatest width at level of humeral shields 182 (194-202). Length of hysterosoma from sejugal furrow to bases of setae h3 250 (260-272). Prodorsal shield: length along midline 130 (130-142), greatest width in posterior part 144 (142-148), lateral margins not fused with scapular shields, antero-lateral extensions almost extending to bases of epimerites Ia between legs I and II, surface without ornamentation (Fig. 1). Internal scapular setae si spiculiform, 32 (30-32) long, separated by 48 (42-46); external scapular setae se situated on prodorsal shield, separated by 80 (88-93). Vertical setae ve represented by alveoli. Humeral shield with setae c2 spiculiform, 44 (42-46) long. Setae c3 narrowly lanceolate with acute apex, 23 (20-25) long. Dorsal hysterosoma with prohysteronotal shield and lobar shield connected, delimited from each other by lateral incisions immediately posterior to setae e2. Prohysteronotal shield: length 162 (156-162), width at anterior margin 133 (126-132), lateral margins, each with two shallow incisions at level of trochanters III, dorsal hysterosomal apertures (DHA) absent. Dorsal setae d1, d2 present, minute. Length of lobar shield excluding lamellae 90 (90-102). Opisthosomal lobes approximate, separated by narrow parallel-sided terminal cleft; length of this cleft from anterior end to apices of lamellae 42 (44-46), width in anterior part 6 (6-8). Lamellae smooth, slightly attenuate apically, length from bases of setae h3 to lamellar apices 28 (30-32). Setae h1 anterior to setae h2. Distance between dorsal setae: c2-d2 80 (80-82), d2-e2 82 (84-87), e2-h2 70 (70-76), h2-h3 22 (20-22), h2-h2 36 (34-38), h3-h3 29 (26-28), d1-d2 30 (24-30), e1-e2 38 (38-44).

Epimerites I free. Rudimentary sclerites rEpIIa present, roughly rounded. Genital apparatus situated between levels of trochanters III and IV, length excluding basal sclerite 38 (37-40), greatest width 14 (10-14) (Fig. 2). Epiandrum present, setae g long and filiform, contiguous at bases, postgenital plaque present. Adanal apodemes heavily sclerotised, with narrow lateral membrane and a pair of apophysis. Translobar apodeme present. Adanal shields very small, teardrop-shaped, bearing setae ps3. Anal suckers 12 (12-13) in diameter. Anterior ends of epimerites IV extending beyond level of setae 4b; epimerites IVa short, not extending to level of genital apparatus. Setae 4b situated anterior to level of setae 3a, setae g situated posterior to level of setae 4a. Distance between ventral setae: 4b-3a 31 (30-36), 4b-g 72 (74-80), g-ps3 48 (44-50), ps3-h3 86 (86-94). Setae sR of trochanters III narrowly lanceolate, with acute apex 20 (19-24) long, setae cG and mG of genua I, II filiform, not thickened basally. Tarsus IV 36 (34-36) long; seta d barrel-shaped, with discoid cap; seta e with hemispheroid base and stick-shaped apical part, situated subapically (Fig. 3D). Legs IV with ambulacral disc extending to level of setae h3.

Female (Figs 4; 5; 6 A–E; range for five paratypes): length of idiosoma from anterior end to apices of lamellar lobar processes 452-468, greatest width 148-200. Length of hysterosoma from sejugal furrow to apices of lamellar lobar processes 308-324. Prodorsal shield shaped as in male, 130-140 in length, 144-152 in width, surface without ornamentation. Setae si spiculiform, 29-34 long, separated by 44-48; external scapular setae se situated on prodorsal shield, separated by 90-94. Humeral shields with setae c2 spiculiform, 42-44 long. Setae c3 narrowly lanceolate, with acute apex, 22-24 in length. Hysteronotal shield: length from anterior margin to bases of setae h3 270-300, width at anterior margin 128-132, lateral margins with shallow concavity at level of trochanters III, bottom of these concavities with dark sclerotisation, DHA absent. Posterior half of hysteronotal shield with distinct ornamentation: with large ovate lacunae in median area and few small elliptical lacunae arranged marginally (Fig. 4). Dorsal setae d1 and d2 present. Setae h1 thick, lanceolate, surrounded by small ovoid area of unsclerotised tegument, 24-28 long, situated antero-mesal to bases of setae h2, 20-24 from each lateral margin of hysteronotal shield. Setae ps1 positioned dorsally on opisthosomal lobes, equidistant from outer and inner margins of lobe, close to bases of setae h3. Distance from bases of setae h3 to membranous apices of lobes 29-32. Setae f2 present. Supranal concavity open posteriorly into terminal cleft. Length of terminal cleft together with supranal concavity 102-120, width of cleft at level of setae h3 38-48. Interlobar membrane occupying anterior 1/3 of terminal cleft, distance from free margin of interlobar membrane to membranous lobar apices 78-88. External copulatory tube minute, 1-2 long, situated on free margin of interlobar membrane. Spermatheca with short collar, primary spermaduct without enlargements, secondary spermaducts with small verrucosities in distal half, length 26-30 (Fig. 6E). Distance between dorsal setae: c2-d2 76-80, d2-e2 82-92, e2-h2 50-56, h2-h3 58-64, h2-h2 68-80, h3-h3 50-60, d1-d2 29-34, e1-e2 45-52, h1-h2 18-21, h1-h1 38-46, ps1-h3 9-10.

Epimerites I free. Epigynum 36-38 in length, 76-80 in width (Fig. 5). Epimerites IVa present, short. Setae sR of trochanters III narrowly lanceolate, with acute apex, 18-21 long, setae cG and mG of genua I, II filiform, not thickened basally. Legs IV with ambulacral disc extending to midlevel between setae h2 and h3.

Etymology.

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

Remarks.

Trouessartia niltavae sp. n. is morphologically close to T. bulligera Gaud, 1968 from Clytorhynchus hamlini (Mayr) ( Passeriformes : Monarchidae ), shar ing in males a unique character within the genus: setae e on tarsi IV are hemispheroid with stick-like apex. Additionally, in both sexes of these species, setae d1 are present, setae c2 and sRIII are narrowly lanceolate, with acute apex and the dorsal hysterosomal apertures (DHA) is absent. Both sexes of T. niltavae differ from those of T. bulligera by the shape of setae c2, which are spiculiform in the first species ver sus needle-like in the second. Males of both species have the prohysteronotal shield without ornamentation, the lamellae of opisthosomal lobes are attenuate apically and with entire margins, the translobar apodeme is present, setae g are contiguous at bases and situated on postgenital plaque. In males of T. niltavae , the prodorsal shield is without ornamentation, the prohysteronotal shield and lobar shield have wide median connection, the terminal cleft is parallel-sided and 44-46 μm long, and terminal lobes are separated by 6-8 μm. In males of T. bulligera , the prodorsal shield has ornamentation with faint, interconnecting network of irregular lines, the prohysteronotal shield is completely separated from the lobar shield, the terminal cleft is divergent in posterior half and 75 μm in length, and terminal lobes are separated by 12 μm. In females of both species, setae h1 are lanceolate, the external copulatory tube is present, the supranal concavity is open posteriorly into terminal cleft, and the interlobar membrane occupies the anterior 1/3 of terminal cleft. In females of T. niltavae setae f2 are present, the posterior half of the hysteronotal shield is ornamented with large ovate lacunae in the central area and small elliptical lacunae marginally arranged. In females of T. bulligera setae f2 are absent, the posterior half of the hysteronotal shield has ornamentation with small elliptical lacunae in the central area and large ovate lacunae marginally arranged.

DNA barcode. Representative DNA sequences: molecular voucher specimens ANA838 male (GenBank accession number MH094247), ANA839 female (Gen Bank accession number MH094248), ANA840 female (GenBank accession number MH094249).

We sequenced a 586-pb fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene for two females and one male paratypes. All three sequences belong to a single haplotype. The calculated intra-specific genetic distances (K2P) for other species of Trouessartia was as follows: Trouessartia rosterii 0,8%, T. reguli 1,4%, T. kratochvili 1%, T. rubecula 0,5%, T. simillima 0.4%, T. ripariae 0,4%, T. microcaudata 0,7%, T. tenuipillata 0,6%, T. jedliczkai 1,6%, T. trouessarti 1.4%, T. motacillae 1.1%, T. bifurcata 11,5%.

The best-fit base substitution model for the analyzed data was determined to be TN93+G+I. The NJ and ML trees exhibited similar topologies and branching structures (see Figures 7 and 8). In both trees our new species was grouped with Trouessartia rubecula and T. simillima , also described from the Muscicapidae family. Our analysis resolved well the analysed Trouessartia species with the exception of T. motacillae and T. jedliczkai , which were poorly resolved in both analyses. Another noticeable feature of our analysis refers to the species T. bifurcata , identified on two avian families: Sylviidae and Acrocephalidae . The two sequences of T. bifurcata introduced in our analysis exhibit a high intraspecific diversity which can be a signal of two cryptic species presently identified as T. bifurcata .