Ptiloxenus major ( Mégnin and Trouessart, 1884 )

Lee, Sue Yeon, Yoo, Jung Sun & Kim, Seung Tae, 2017, New record of two Korean feather mites (Acari: Sarcoptiformes: Astigmata) isolated from water birds, Journal of Species Research 6, pp. 177-184 : 181-183

2. Ptiloxenus major ( Mégnin and Trouessart, 1884)

ĿḑỌHǖfflũḍϢΞή (ljḓ) ( Figs. 4, 5)

Synonyms. Pterolichus colymbi var. maior Mégnin and Trouessart, 1884: 429­430 .

Ptiloxenus major : Bedford, 1936: 71; Dubinin, 1951, p. 147 -148, fig. 15; 1956: p. 527-530, figs. 258-259;

Gaud and Atyeo, 1996, Part II, p. 419, fig. 430; Davert and Ehrnsberger, 1998, p. 151; Krantz and Walter, 2009, p. 638, fig. 16.37.

Material examined. Korea: 3♂♂, 3$$, Gwongokdong, Asan­si , Chungcheongnam­do, 36°47 ʹ 22.36 ʺ N, 127°0 ʹ 33.64 ʺ E, July 5, 2013, collected using vacuum machine from flight feathers on the wings of great crest­ ed grebe, Podiceps cristatus by Han Y.­D .

Diagnosis. Male: Length 400­415 of idiosoma from anterior end to bases of setae h3, width 220­230 at level of humeral shields ( Fig. 4A).

Gnathosoma ( Fig. 4B): Slightly widened in the posterior part, with rounded posterolateral margin, length 55­ 58 together with palps, width 48­50.

Prodorsal shield ( Fig. 4B): Covers the entire pronotum, with a dot­like pattern on the surface, length 105­ 110 along midline, width 173­178, with two internal vertical seta (vi) of filiform.

Hysteronotal shield ( Fig. 4C): Strong sclerotized on hysteronotum, anterior part with transverse line of semicircular sclerites, length 305­320 from anterior margin to base of setae h3, width 188­190 at level of setae c2. Opisthosomal lobes shot, triangle­shaped. Interlobar membranes situated from base of terminal cleft to level of setae h1. Setae h3 wide leaf­like shaped, with longitudinal line.

Sternum ( Fig. 4D, E): Epimerites I fused. Genital apparatus small, located between legs III and IV. Setae g and genital papillae situated on paragenital sclerites (ps). Paragenital sclerites band­shaped, situated on both sides of genital apparatus, anterior part not fused, extending after level of setae 4a. Setae ps3 situated on adanal sclerites. Adanal discs present. Postlobar membranes (pm) tongue­shaped, with internal extension.

Legs: Genua I and II with setae cG of hair­shape. Tarsi IV with hook­like apophyses ( Fig. 4D).

Female: length 440­445 of idiosoma from anterior end to bases of setae h3, width 200­220 at level of setae c2 ( Fig. 5A).

Gnathosoma ( Fig. 5B): length 75­83 including palps, width 60­63.

Prodorsal shield ( Fig. 5B): Shaped as in male. Length 180­183 at based of setae vi, width 113­120 at posterior part.

Hysteronotal shield ( Fig. 5C): Anterior part slightly concave, length 330­335, width 185­195 at based of setae c2. Opisthosomal lobes with shallow terminal cleft. Interlobar and lateral membranes absent.

Sternum ( Fig. 5D, E): Epigynum horseshoe­shaped, length 56­58, width 45­48. Supranal concavity circularshaped, divided from terminal cleft.

Remarks. Ptiloxenus major was originally described without illustration by Mégnin and Trouessart (1884) based on specimens collected from the great crested grebe ( Podiceps cristatus ) and red­throated diver ( Gavia stellata = Colymbus septentrionalis ) in Europe. Thereafter, this species was redescribed by several mite taxonomists with detailed morphological descriptions and illustrations ( Dubinin, 1951; 1956; Gaud and Atyeo, 1996; Krantz and Walter, 2009). Their descriptions and illustrations are very similar, except for some differences in the position of the setae on the genital area, and the shape of the paragenital sclerites. Korean specimens matched well with those of Gaud and Atyeo (1996), although some differences were found in the following characteristics in males: (1) transverse line of semi­circle located on anterior part of hysteronotal shield; and (2) genital papillae located on paragenital sclerites.

Host. Specimens were collected from the surface of flight feathers on the wings of great crested grebe, Podiceps cristatus .

Distribution. Canada ( Krantz and Walter, 2009), Europe ( Dubinin, 1951; 1956; Davert and Ehrnsberger, 1998; Gaud and Atyeo, 1996), Korea (this study).

Deposition. NIBRIV0000754047 and NIBRIV0000810 159­0000810163.

Molecular characteristics. The COI sequences with 597 bp lengths were obtained from two individuals of P. major (GenBank accession numbers: MG459420­ 459421). The sequence alignment did not contain any insertions or deletions. No frame shift was detected after amino acid conversion using the invertebrate mitochondrial genetic code.

Identifiers. Yeong­Deok Han and Gi­Sik Min.