Pterodectes amaurochalinus Hernandes & Valim, 2006

Hernandes, Fábio A. & Valim, Michel P., 2006, Two new species of the feather mite subfamily Pterodectinae (Acari: Astigmata: Proctophyllodidae) from Brazil, Zootaxa 1235 (1), pp. 49-61 : 50-54

Pterodectes amaurochalinus Hernandes & Valim sp. n.

( Figs. 1–7 )

Type material: 1 male holotype, 6 male and 8 female paratypes from the Creamy­bellied Thrush , Turdus amaurochalinus Cabanis ( Passeriformes , Turdidae ), Belo Horizonte, Minas Gerais, Brazil, (19 S 55’–43 W 56’); 13.X.2005, coll. M.P. Valim. Holotype male and most paratypes are deposited at DZSJRP; a paratype female and male are deposited at CAIOC.

Male holotype ( Figs. 1, 2 , 5, 6 ). (range for 6 paratypes indicated in parentheses). Length of idiosoma 380 (360–380), width 160 (160–170). Prodorsal shield: 120 (120–140) in length along median line, 110 (110–120) in width at posterior margin, posterior two thirds of shield surface with numerous circular lacunae. Setae ve absent. Scapular setae si and se arranged in a transverse line. Scapular setae se 110 in length (110–140) and separated by 60 (60–70); si reduced, piliform, separated by 40 (40–50). Setae c2 on striated tegument, setae c3 lanceolate, 30 in length and 8 in width (30 x 8–10). Setae cp set off humeral shield. Distance between prodorsal and hysteronotal shields in median line 22 (19–30). Hysteronotal shield: greatest length 240 (240–250), width at level of setae cp 100 (100–110); surface of the shield with numerous circular lacunae. Dorsal shields with pale, lightly sclerotized areas, one pair on prodorsal shield and four pairs on hysteronotal shields ( Fig. 1 ). Terminal cleft U­shaped, 30 (30–30) from anterior end to lobar apices, supranal concavity indistinct. Setae h3 spiculiform, relatively short, without terminal filament, separated by 50 (40–50). Length of setae: ps1 7 (7–8), h3 30 (30), h2 198 (190–231), ps2 60 (60–90), f2 8 (7–8), ps3 40 (30–40). Distance between dorsal setae: si–c1 80 (80), c1–c2 30 (30–40), c1–d1 60 (50–60), d1–d2 40 (40–60), d1–e1 80 (80–110), d2– e1 60 (50–60), e1– e2 40 (40), e1–h1 40 (50–60), e2–h1 30 (22–27), h1–f2 20 (20–30).

Epimerites I fused as a narrow U, coxal fields I, II and III open. Sclerite (r)EpIIa present. Aedeagus reaches the level of anterior margins of anal discs, 80 in length (80–80); genital arch 40 in width (40–40). Distance between ventral setae: 3a–4a 100 (100), 4a–g 40 (40), g–ps3 100 (90–100), ps3–ps3 70 (70–80). Anal discs edentate, 15 (14–16) in diameter, and distance between centers of discs 30 (30–30). Opisthoventral shields bear seta ps3 on inner margin ( Fig. 2 ).

Solenidion σ 1 of genu I short and stubby ( Fig. 5 ), seta cG of genua I, II setiform. Tarsus IV 43 (41) in length, seta f setiform, seta e and d button­like ( Fig. 6 ).

Female ( Figs. 3, 4 , 5 ). (measurements of 8 paratypes). Length of idiosoma excluding terminal appendages 510–550, width 180–210. Prodorsal shield: 140–160 in length along median line, 130–140 in width at posterior margin, posterior 2/3–3/4 of shield with numerous small circular lacunae. Setae ve absent. Scapular setae si and se arranged in transverse line. Setae se 120–150 in length and separated by 80; pair si reduced, piliform, separated by 50–60. Setae c2 on striated tegument; setae c3 lanceolate, 30–40 in length and 9–10 in width. Setae cp set off humeral shield. Distance between prodorsal and hysteronotal shields in median line 22–33. Anterior hysteronotal shield: greatest length 260–270, width at level of setae cp 120–130; surface with numerous small circular lacunae. Dorsal shields with pale, lightly sclerotised areas, one pair on prodorsal shield and four pairs on hysteronotal shields ( Fig. 3 ). Length of lobar region excluding terminal appendages 90–100, greatest width 80–90. Supranal concavity distinct, circular. Setae h2 thickened, with very short terminal filament, 80–90 in length, 6–8 in width. Setae h1 inserted on anterior third of lobar shield. Setae h1 and f 2 in trapezoidal arrangement. Distance between dorsal setae: si–c1 80–100, c1–c2 40–60, c1–d1 60–80, d1–d2 50–60, d1–e1 110–130, d2–e1 70–90, e1– e2 40–50, e1–h1 90–100, e2–h1 54 (52–54), h1–f2 20–40, f2–h2 10–20.

Epimerites I fused as a narrow U, coxal fields I, II and III open. Setae ps2 and ps3 button­like set in nearly rectangular arrangement. Terminal cleft as an inverted V, its length 54–63 from anterior end to lobar apices. Distance between ventral setae: 1a–3a 70–80, 3a–g 20–40, 4a–ps3 90–100, g–4a 120–130, ps2–ps3 12–14, ps2–ps2 35–39, ps3–ps3 28–31. Spermatheca and spermaducts as in Fig. 7 . Legs I, II as in the male; legs IV extending by ambulacral disc to the level of setae f2.

Etymology The epithet is derived from specific name of the type host, Turdus amaurochalinus . Differential diagnosis

Pterodectes amaurochalinus n. sp. differs from other species of Pterodectes described on Turdus spp. ( P.turdinus Berla, 1959 and P. fissuratus Hernandes & Valim, 2005 ) by the following characters: (1) epimerites I and II not connected; (2) dorsal shields without median longitudinal fissure; (3) pronounced pale, lightly sclerotised areas present on dorsal shields, visible as lighter areas on lateral parts of these shields; and (4) female setae ps2–ps3 button like. The new species resembles P. fissuratus by the structure of epimerites I, which are fused as a narrow U and not connected to epimerites II in both sexes, by relative length of aedeagus, by button­like setae ps2, ps3 and setae h2 with terminal filament in female. However, in P. amaurochalinus there is no suture on dorsal shields, and the lacunae are circular rather than of irregular shape as in P. fissuratus . Pterodectes amaurochalinus sp. n. can be easily separated from P. turdinus by the conformation of epimerites I and II in males, not connected and U shaped. In females of the new species, these epimerites are U shaped as well, whereas in P. turdinus there is a weak lateral projection towards epimerites II. In the latter species female setae ps2–ps3 are setiform. Females of these three species can also be separated by the shape of spermathecae.

Remarks

Park & Atyeo (1971) proposed two main species groups (rutilus and gracilis) in the genus Pterodectes . The new species should be referred to the gracilis group sensu Park & Atyeo (1971), because it has setae c2 inserted off the hysteronotal shield, and has a narrow genital arch. However, in contrast to the characteristic of the gracilis group regarding the structure of setae h 2 in female, P. amaurochalinus n. sp. has setae h2 with a clear terminal filament as in two other species associated with the hosts of genus Turdus ( P. fissuratus and P. turdinus ). The discovery of several species displaying characteristics of different species groups shows that the current definition of species groups in Pterodectes should be revised.

Figures

FIGURE 1–2. Pterodectes amaurochalinus n.sp. Male: dorsal (1) and ventral (2) views. Scale in µm.

FIGURE 3–4. Pterodectes amaurochalinus n.sp. Female: dorsal (3) and ventral (4) views. Scale in µm.

FIGURE 5–7. Pterodectes amaurochalinus n.sp. Dorsal view of male legs I (5) and IV (6); female spermatheca (7). Scales in µm.