Platyacarus sittasomi, Hernandes & Valim & Mironov, 2007

Hernandes, Fábio A., Valim, Michel P. & Mironov, Sergey V., 2007, Two new genera and five new species of the feather mite subfamily Proctophyllodinae (Astigmata: Proctophyllodidae) from suboscine birds in Brazil, Journal of Natural History (J. Nat. Hist.) 41 (41 - 44), pp. 2653-2681 : 2675-2679

Platyacarus sittasomi sp. n.

( Figures 41–51 )

Type material

Male holotype, and three female paratypes from the Olivaceous Woodcreeper, Sittasomus griseicapillus (Vieillot, 1818) ( Passeriformes , Dendrocolaptidae ), Fazenda Agua Limpa, Brasília, D.F., Brazil (15 ° 579S, 47 ° 569W), 25 March 2002, coll. M. F. Kanegae. Holotype and paratypes are deposited at DZSJRP; a paratype female is deposited at CAIOC.

Differential diagnosis

Platyacarus sittasomi sp. n. may be referred to the oligolaccius species group ( Kudon 1982a) by most features, except for the structure of the prodorsal shield in both sexes ( Figures 41 , 49 ) and primary spermaduct in females ( Figure 51 ). It differs from the two species previously included in this group, P. oligolaccius Kudon, 1982a and P. dontocoronius Kudon, 1982a , by the following characters: in both sexes, the lateral margins of the prodorsal shield without incision around scapular setae se; in males, the aedeagus is short (25) extending beyond genital setae g by the distal third only, and anterior margin of hysteronotal shield straight; in females, the terminal cleft is narrow (60–63×22–27), approximately three times longer than wide, and the primary spermaduct is not expanded in the proximal part. In both sexes of two formerly known species, the prodorsal shield has deep lateral incisions around setae se; in the males, the aedeagus is much longer (50 in P. oligolaccius and 41 in P. dontocoronius ), almost extending to the level of anal setae ps3, and anterior margin of hysteronotal shield is concave; in the females, the terminal cleft is approximately as long as wide (47 long in P. oligolaccius and 38 in P. dontocoronius ), and the primary spermaduct is abruptly expanded near the head of spermatheca.

Description

Male holotype ( Figures 41–48 ). Length of idiosoma 319, width 127. Prodorsal shield: 112 in length and 82 in width, surface without lacunae or pale sclerotized areas, posterior margin with blunt-angular extension, lateral margin without incision around scapular setae. Setae se 139 in length and separated by 45; si separated by 30. Setae c1 on hysteronotal shield; setae c2 on antero-medial angles of humeral shields; setae cp adjacent to humeral shield; setae c3 lanceolate, 20 in length and 5 in width. Distance between prodorsal and hysteronotal shields 20. Hysteronotal shield: 193 in length and 79 in width, anterior margin almost straight, surface with scattered small lacunae restricted to region from setae d1 to h1 ( Figures 41 , 47 ). Terminal cleft as a small inverted U, 11 in length; supranal concavity distinct, and terminal lamellae linguiform, 24 in length and 15 in width. Setae h3 about half-length of setae h2, separated by 38. Length of setae: h3 115, h2 144, ps1 5, ps2 27, ps3 8. Distance between dorsal setae: si–c1 67, c1–c2 35, c1–d1 41, d1–d2 31, d1–e1 73, d2– e1 52, e1– e2 41, e1–h1 46, e2–h1 13.

Epimerites I fused into a narrow U; rudimentary sclerite rEpIIa present; epimerites IVa barely discernible. Aedeagus dagger-shaped, 35 in length, extending by distal third beyond setae g; genital arch 19 in length, 30 in width. Genital acetabula adjacent at their bases. Distance between ventral setae: 3a–4a 39, 4a–g 39, g–ps3 33, ps3–ps3 14. Two pairs of adanal shields present, setae ps3 situated on inner pair ( Figures 42 , 48 ). Corolla of anal suckers dentate, 11 in diameter; distance between discs 14.

Seta cG of genua I and II setiform ( Figures 43, 44 ). Tarsus IV 33 in length, without apical claw-like process; button-like seta d at mid-level of this segment ( Figure 46 ).

Female ( Figures 49–51 ) (measurements of three paratypes). Length of idiosoma 462–495, width 165–176. Prodorsal shield: 114–120 in length and 120–136 in width, surface without lacunae or pale sclerotized areas, posterior margin with shallow concavities, lateral margins concave, but without incision around scapular setae se. Setae se 133–139 in length, separated by 63–68; setae si separated by 45–46. Setae c1 on anterior hysteronotal shield; setae c2 on humeral shields; setae cp on humeral shield; setae c3 lanceolate, 22–24 in length and 5 in width. Distance between prodorsal and hysteronotal shields 22–38. Anterior hysteronotal shield: 228–245 in length and 98–103 in width; anterior margin almost straight; surface with numerous small lacunae posterior to setae d2, with a pair of pale sclerotized areas in posterior angles, postero-lateral border with oblique folds ( Figure 49 ). Lobar region: 76–87 in length and 68–90 in width. Terminal cleft as an inverted U, 60–63 in length, 22–27 in width. Supranal concavity absent. Setae h2 dagger-like with terminal filament, 98–103 in length, 4–5 in width; setae h3 relatively short, 24–30 in length and separated by 10–39. Setae h1 inserted on striated tegument between the anterior hysteronotal and lobar shields. Distance between dorsal setae: si–c1 63–82, c1–c2 41–44, c1–d1 49–54, d1–d2 38–41, d1–e1 114–117, d2–e1 76–79, e1–e2 65–68, e1–h1 72–79, e2–h1 31–34.

Epimerites I as in male, epimerites IVa barely discernible. Setae ps2 and ps3 setiform, setae ps2 approximately at mid-level of anal opening. Epigynium semicircular, 44–49 in length, 63–71 in width, tips almost extending to level of setae g. Distance between ventral setae: 1a–3a 63–68, 3a–g 24–29, 4a–ps3 114–120, g–4a 84–98, ps2–ps3 24–26, ps2–ps2 50–57, ps3–ps3 19–26. Copulatory opening terminal. Spermatheca and spermaducts as in Figure 51 . Legs I, II as in the male; legs IV extending by ambulacral disc to the level of setae h1 ( Figure 49 ).

Etymology

Specific epithet derives from the generic name of the type host and is a noun in the genitive case.

Remarks

Although Kudon (1982e) had studied bird skins from all genera of the Dendrocolaptidae , he did not find any species of Platyacarus inhabiting woodcreepers of the genus Sittasomus Swainson, 1827 . The finding of a new species of Platyacarus inhabiting this host reinforces Kudon’s hypothesis that the distribution of these mites on hosts shows that both ‘‘lower’’ and ‘‘higher’’ dendrocolaptid genera constitute the distinct family Dendrocolaptidae apart from the Furnariidae , which have never been recorded as hosts of Platyacarus . Phylogenetic relationships and monophyly of the Dendrocolaptidae are disputable; Feduccia (1973) suggested that these birds originated polyphyletically from the Furnariidae and even the lower dendrocolaptid genera ( Dendrocincla Gray G. R., 1840 , Dendronychura Cherrie, 1891, Glyphorynchus Wied-Neuwied, 1831 , and Sittasomus ) represent a polyphyletic grouping of three lineages. Thus, about half of the species (27/50) and the majority of genera (10/13) of Dendrocolaptidae sensu Dickinson (2003) are now known as the hosts of Platyacarus species , except for three monotypic genera, Drymornis Eyton, 1852 , Glyphorynchus , and Nasica Lesson, 1830 . Further sampling of these host genera is needed to determine whether they also host Platyacarus .

Figures

Figures 41, 42. Platyacarus sittasomi sp. n., male: dorsal (41) and ventral (42) views. ias, inner anal shield; oas, outer anal shield.

Figures 43–46. Platyacarus sittasomi sp. n., male legs I–IV, dorsal views.

Figures 47, 48. Platyacarus sittasomi sp. n., male: lobar region, dorsal (47) and ventral (48) views. ias, inner anal shield; oas, outer anal shield.

Figures 49–51. Platyacarus sittasomi sp. n., female. (49, 50) Dorsal and ventral views, respectively. (51) Spermatheca. pd, primary duct; sd, secondary ducts.