Two new feather mite species of the genus Montesauria Oudemans (Analgoidea: Proctophyllodidae) from thrushes (Passeriformes: Turdidae) in the Indian Subcontinent

Two new feather mite species of the genus Montesauria Oudemans, 1905, collected from thrushes (Turdidae) in India, are described: Montesauria hernandesi sp. n. from Turdus dissimilis Blyth, 1847 and M. caerulea sp. n. from Myophonus caeruleus (Scopoli, 1786). Both species belong to the merulae species group, being morphologically closest to other two species of the genus, previously described from birds of the family Turdidae in Asia (Japan): M. sibirica Kuroki, Nagahori and Mironov, 2006 and M. aurea Kuroki, Nagahori and Mironov, 2006, respectively. The new species most clearly differ from those described in Japan by the dorsal shield ornamentation. In both sexes of M. hernandesi sp. n., the ornamentation of the prodorsal and hysteronotal shields is represented by round and ovate lacunae, and the ornamentation of the lobar shield of females has few ovate lacunae. In both sexes of M. caerulea sp. n., the ornamentation of the hysteronotal shield is very particular, with large and almost round lacunae in the anterior half and small ovate lacunae in the posterior half.

The present paper gives descriptions of two new Montesauria species from the merulae species group found on thrushes (Turdidae) in India.

Materials and methods
The material used in the present paper was collected in the neighborhood of Shnongrim (Meghalaya, India) in January 2014.The birds were captured using mist-nets, identified and visually checked for the presence of mites and after collecting of mites released back to the wild.Mite specimens were collected manually with a needle and placed in tubes with 96% ethanol.Then, in laboratory conditions, mite specimens were cleared in 90% lactic acid for 24 hours and mounted on microscope slides in Hoyer's medium.Drawings were made using an Olympus CX21 microscope with a camera lucida drawing device.The bird specimens were identified according to Rasmussen and Anderton (2012) and Grimmett et al. (2011), and the taxonomy of birds follows Clements et al. (2017).The body setation of mites follows that of Griffiths et al. (1990) with the modifications by Norton (1998) concerning coxal setae, while the setation of legs follows Gaud and Atyeo (1996).The description of the new species of Montesauria is given according to the current format used for species of pterodectine mites (Mironov and Fain 2003, Mironov 2006, Valim and Hernandes 2006, Mironov et al. 2008, 2010, 2012, Mironov and Tolstenikov 2013, Hernandes and OConnor 2017) and the measuring techniques of particular structures used were described by Mironov and Proctor (2009).
We give the full set of measurements for a holotype (male) and a range of measurements for corresponding paratypes.All measurements are in micrometers (μm).The holotype and paratypes of both new species are deposited in the Acarological Collection of the "Grigore Antipa" National Museum of Natural History, Bucharest, Romania (MGAB).Inventory numbers are given in brackets for all type specimens.
Six paratype specimens of Montesauria hernandesi sp.n. (three males ANA1442 C1, ANA1443 C2, ANA1444 C3, and three females ANA1445 C4, ANA 1446 C5, ANA1447 C6) and three paratype specimens of M. caerulea sp.n. (two males ANA1436 B1, ANA1438 B3, and one female ANA1441 B5) were used to isolate DNA using DNAeasy Tissue Kit (Qiagen).All specimens used for molecular analyses were mounted and kept as reference vouchers for morphological examination.The specimens preserved in ethanol 96% were transferred in 180μl ATL Buffer with 20 μl of Proteinase K and incubated overnight at 56 °C on a shaking thermoblock.After 24 h, 5 μL of Proteinase K were added and incubation was continued until 72h.For the rest of the protocol we followed the manufacturer specifications and the modification suggested by Dabert et al. (2008).
Sequence electrophoregrams were edited and assembled with CodonCode Aligner version 3.7.1.Pairwise distances between sequences were computed with MEGA version 7 (Kumar et al. 2016) using K2P distance model (Kimura 1980).DnaSP v5 was used to obtain data about the genetic polymorphism in the studied specimens (Librado and Rozas 2009).
Differential diagnosis -The new species, Montesauria hernandesi sp.n., belongs to merulae species group and is most similar to M. sibirica Kuroki, Nagahori and Mironov, 2006 described from the Siberian thrush Geokichla sibirica davisoni (Hume, 1877) (Passeriformes, Turdidae) (Kuroki et al. 2006).In males of both species, the posterior margin of opisthosomal lobes is notched, the opisthoventral shields have a triangular form, and the inner angles of these shields are slightly posterior to the level of anal suckers, the anterior end of terminal cleft is surrounded by small sclerotized plate, setae h1 are situated at the level of anterior margin of supranal concavity, the genua IV have an ovate ventral apophysis, setae d and e of tarsus IV are ovate, the diameter of seta e is twice as short as that in seta d; in females, the primary spermaduct has a bulb-shaped enlargement, and setae h3 are about 1/3 the length of terminal appendages.Montesauria hernandesi sp.n. clearly differs from M. sibirica by the following features (corresponding character states of M. sibirica in parentheses): in both sexes, the ornamentation of prodorsal and hysteronotal shields is represented by ovate lacunae (vs.small pit-like lacunae), in males, tarsus IV has a bidentate apex (vs.with apical claw-like process); in females, the lobar shield bears a few ovate lacunae in the anterior part (vs.without ornamentation), epimerites I are fused into a Y (vs.fused into a V), the secondary spermaducts are longer than the distance between the large bulb-shaped enlargement of primary spermaduct and the small bulge near the head of spermatheca (vs.shorter than this distance).
Etymology -The species epithet is taken from the species name of the type host and is an adjective.
Differential diagnosis -Montesauria caerulea sp.n. belongs to merulae species group and is most similar to M. aurea Kuroki, Nagahori and Mironov, 2006 described from White's thrush Zoothera aurea toratugumi (Momiyama, 1940) (Passeriformes, Turdidae) in Japan (Kuroki et al. 2006).Males of the both species have a similar shape of opisthosomal lobes, which are short, with apices slightly narrowed, and with notched distal margins, the aedeagus does not reach the level of anterior margin of anal suckers, the genua IV have semi-round ventral apophysis, the setae h1 are situated anterior to the level of the supranal concavity; females have setae h3 about 1/2 the length of terminal appendages.Montesauria caerulea sp.n. clearly differs from M. aurea by the following features (corresponding character states of M. aurea in parentheses): in both sexes, the ornamentation of hysteronotal shield is represented by big and almost circular lacunae in the anterior half and small ovate lacunae in the posterior half (vs.small pit-like lacunae), in males, epimerites I and II are connected (vs.disconnected), the basal sclerite of the genital apparatus is shaped like an inverted trapezium (vs.crescent-shaped), the opisthoventral shields are almost trapezoidal in shape and located at the level of anal suckers (vs.almost triangular and located slightly anterior to the level of anal suckers), tarsus IV has bidentate apex (vs.apical claw-like process).In females of the new species, the humeral shields are present (vs.humeral shields absent), the epimerites I are fused into a Y (vs.fused into a V), the posterior margin of the hysteronotal shield is convex in median part (vs.concave), the secondary spermaducts are shorter than the distance between the large bulb-shaped enlargement of the primary spermaduct and the small bulge near the head of spermatheca (vs.longer than that distance).
In the resulted alignment of 482-pb fragment of the mitochondrial cytochrome C oxidase subunit I (COI) gene, we identified 5 polymorphic sites (three with singleton variable sites and two parsimony informative ones).Three haplotypes were identified: H1 (ANA1442 C1 male, ANA1446 C5 female), H2 (ANA1443 C2 male), H3 (ANA1444 C3 male, ANA1445 C4 female, ANA1447 C6 female).Intraspecific genetic distances between the analyzed specimens using K2P model is 0.5%.Also, all observed nucleotide substitutions were synonymous and did not have differences in the amino acid sequence.
In the resulted alignment of 482-pb fragment of the mitochondrial cytochrome C oxidase subunit I (COI) gene, we identified 4 singleton variable sites.Three haplotypes were identified: H1 (ANA1436 B1 male), H2 (ANA1438 B3 male) and H3 (ANA1441 B5 female).Intraspecific genetic distances between the analyzed specimens using K2P model is 0,6%.All observed nucleotide substitutions were synonymous and did not have differences in amino acid sequence.
The reported intraspecific genetic distances for the two species of Montesauria described in the present study are comparable with genetic distances found in other related mites like Proterothrix chachulae (0.8%) (Constantinescu et al. 2017) also belonging to the subfamily Pterodectinae and distributed the Oriental Region.

Figure 6
Figure 6 Montesauria caerulea sp.n., Male: A -D -details of legs, dorsal view: A -leg I, B -leg II, C -leg III, D -leg IV; E -details of opisthosoma.