محفوظ في:
التفاصيل البيبلوغرافية
المؤلفون الرئيسيون: Gustafsson, Daniel R., Najer, Tomas, Zou, Fasheng, Bush, Sarah E.
التنسيق: Recurso digital
اللغة:
منشور في: Zenodo 2022
الموضوعات:
الوصول للمادة أونلاين:https://doi.org/10.5281/zenodo.6304095
الوسوم: إضافة وسم
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جدول المحتويات:
  • <p><b><i>Philopterus coriaceus</i> sp. nov.</b></p><p>urn:lsid:zoobank.org:act: 8D76847E-153C-4061-B476-420FEED3C483</p><p>Figs 37–42; Tables 2–4, 6</p><p><b>Diagnosis</b></p><p>Finding the closest known relative of <i>Philopterus coriaceus</i> sp. nov. is difficult. This species is set apart from almost all other known <i>Philopterus</i> complex species by the presence of a pair of setae on the anterior margin of female tergopleurite IX+X. To our knowledge, this seta is only present in some species of <i>Mayriphilopterus</i> Mey, 2004. All of the species in this genus are Neotropical, but none of them occur on passeriforms.</p><p>However, <i>P. coriaceus</i> sp. nov. does not key to <i>Mayriphilopterus</i> in the key of Mey (2004), and can be separated from this genus by the following characters: coni present in <i>P. coriaceus</i> sp. nov. (Fig. 39), but absent (possibly highly reduced) in <i>Mayriphilopterus</i>; hyaline margin with thickened setae in <i>Mayriphilopterus</i>, but without such setae in <i>P. coriaceus</i> sp. nov. (Fig. 39); area between subgenital plate and vulval margin with a large number of small setae in <i>Mayriphilopterus</i>, but without such setae in <i>P. coriaceus</i> sp. nov. (Fig. 42). It thus seems unlikely that <i>P. coriaceus</i> sp. nov. is closely related to <i>Mayriphilopterus</i>.</p><p>Only two species of <i>Philopterus</i> are previously known from icterid hosts: <i>Philopterus quiscali</i> Osborn, 1896 (ex <i>Quiscalus quiscula</i> (Linnaeus, 1758)) and <i>Philopterus agelaii</i> Osborn, 1896 (ex <i>Agelaius phoeniceus</i> (Linnaeus, 1766)). No detailed descriptions or illustrations of either of these species have been published, and both species are in need of redescription.</p><p>From Osborn’s descriptions of both species, and the illustration of <i>P. quiscali</i> (<i>P. agelaii</i> not illustrated in Osborn 1896, but said to be similar to <i>P. quiscali</i>), these two species can be separated from <i>P. coriaceus</i> sp. nov. by the following characters: preantennal head proportionately wider in <i>P. quiscali</i> than in <i>P. coriaceus</i> sp. nov. (Fig. 39); dorsal anterior plate with broad posterior extension in <i>P. quiscali,</i> but with slender posterior extension in <i>P. coriaceus</i> sp. nov. (Fig. 39); tergopleurites of <i>P. quiscali</i> extending only about halfway to midline of abdomen on each side, whereas those of <i>P. coriaceus</i> sp. nov. are much longer in both sexes, almost reaching midline in more posterior segments in male. Chaetotaxy is not given for either <i>P. quiscali</i> or <i>P. agelaii</i>, but Osborn’s illustration of <i>P. quiscali</i> has only apertures for 6 setae illustrated on each of the tergopleurites of segment II. In <i>P. coriaceus</i> sp. nov. there are 8 setae placed on each of the tergopleurites of this segment in both sexes (Figs 37–38); however, the number of setae situated median to the tergopleurites in <i>P. quiscali</i> is unknown. In specimens of <i>P. agelaii</i> deposited at the NHMUK, there are 7–8 setae on each side in females and 8–9 setae on each side in males, which overlap with the number of setae in <i>P. coriaceus</i> sp. nov.; one seta on each side is situated median to the tergopleurites in both sexes of the NHMUK specimens of <i>P. agelaii</i>. In addition, Osborn (1896: 220) mentioned “brown spots on each segment back to the eighth [= IX+X]; those on the sixth segment [= VII] form the outer portion of the genital patch.” Osborn (1896) further stated that the “lateral spots” of <i>P. agelaii</i> are “small, rather elongated, oblique”; it is not clear whether he was describing the male or the female, but his illustration is of a male. We interpret these spots as the overlap of the median section of the tergopleurites with either the lateral accessory sternal plates (in segments II–VI) or the subgenital plate (segments VII–XI+X). This overlap often shows as darker brown spots than the rest of the tergopleurite. This suggests that the central sternal plates are absent on segments II–VI in <i>P. quiscali</i> and <i>P. agelaii</i>, whereas these are present on male segments V–VII in <i>P. coriaceus</i> sp. nov. (Fig. 37).</p><p><b>Etymology</b></p><p>The specific name is derived from Latin ‘ <i>coriaceo</i> ’ for ‘leather-like’, referring to the colour and texture of the abdominal plates.</p><p><b>Material examined</b></p><p><b>Holotype</b> PERU • ♂ (marked with black dot on slide); Hacienda Amazonia, near Atalaya, Department of Madre de Dios; 4 Nov. 1985; S.M. Lanyon leg.; ex <i>Molothrus oryzivorus oryzivorus</i> (as <i>Scaphidura oryzivora</i>); “ 1032 ”; NHMUK.</p><p><b>Paratypes</b> PERU • 1 ♂, 2 ♀♀; same collection data as for holotype; NHMUK.</p><p><b>Type host</b></p><p><i>Molothrus oryzivorus oryzivorus</i> (Gmelin, 1788) – giant cowbird (Icteridae).</p><p><b>Description</b></p><p>Head shape and chaetotaxy as in Fig. 39, preantennal area broad. Hyaline margin broad, shallowly concave medianly, extending laterally slightly beyond marginal carina. Dorsal preantennal plate narrowing gently posteriorly, <i>ads</i> situated in transparent section. Ventral anterior plate roughly trapezoidal, anterior margin concave. Coni long, broad, pointed posteriorly. Gular plate large, irregular. Thoracic and abdominal segments as in Figs 37–38. Measurements as in Table 6.</p><p><b>Male</b></p><p>Thoracic and abdominal chaetotaxy as in Fig. 37 and Tables 2–4. Tergopleurite VIII interrupted medianly. Central sternal plates absent from segments II–IV, present but fragmented on segment V, and present on segment VI. Lateral accessory plates present on segments II–IV, present and fused to central sternal plates on segments V–VI. Subgenital plate large, lateral incisions shallow or absent, lateral accessory plate of segment IX+X fused to subgenital plate. Basal apodeme long, rectangular (Figs 40–41). Mesosomal thickening about as broad as long, laterally pointed on dorsal side, with roughly crescentshaped sclerotization in anterior end and triangular sclerotization centrally; 3 microsetae on each side of mesosome. Gonopore bilobed anteriorly, distal part as in Fig. 41. Parameres short, stocky (Figs 40–41); <i>pst1–2</i> as in Figs 40–41.</p><p><b>Female</b></p><p>Thoracic and abdominal chaetotaxy as in Fig. 38 and Tables 2–4. Tergopleurites VI–IX+X with slight to extensive reticulation median to spiracle openings. Central sternal plates absent on segments II–VI. Lateral accessory plates present on segments II–VI. Subgenital plate as in Fig. 42, reticulation prominent. Lateral sclerotizations of vulval area extended to vulval margin, chaetotaxy as in Fig. 42 and Table 3; short vulval setae thorn-like. Subvulval plates broad, roughly triangular, each with small postero-median projection.</p><p><b>Remarks</b></p><p><i>Philopterus coriaceus</i> sp. nov. is only the third species of <i>Philopterus</i> described from icterid hosts. This is surprising, as hosts in this family have been examined extensively, and many other species of ischnoceran lice are known from icterid hosts (e.g., Cicchino 1990, 2004; Cicchino & Castro 1996; Valim & Palma 2012). However, two previous studies have found comparatively low infestation rates of <i>Philopterus</i> on icterid hosts: 11.5% of examined red-winged blackbirds, <i>Agelaius phoeniceus</i> (Linnaeus, 1766) (Spory 1965) and 4.1% of brown-headed cowbirds, <i>Molothrus ater</i> (Boddaert, 1783) (Hahn <i>et al</i>. 2000).</p><p>The lack of records of <i>Philopterus</i> complex lice on icterid hosts may be related to the presence of lice of the genus <i>Bizarrifrons</i> Eichler, 1938 on some icterid hosts. This genus belongs to the <i>Brueelia</i> complex (Valim & Palma 2012; Gustafsson & Bush 2017) and is also considered to belong to the ‘head louse ecomorph’. Competition may influence the distribution of these lice, but more ecological information is needed to assess any potential interactions between these species.</p><p>Both <i>P. agelaii</i> and <i>P. quiscali</i> are in need of redescription before an adequate comparison between these species and <i>P. coriaceus</i> sp. nov. can be made. It is not clear what gender of <i>P. quiscali</i> was described by Osborn (1896); however, Emerson (1960) noted that only one female and a nymph are present in Osborn’s collection at Ohio State University, Columbus, Ohio. Emerson (1960) designated the female as the lectotype, stating that a female was illustrated. This seems incorrect, as the illustrated specimen has a rounded terminal abdomen and no medianly continuous tergopleurite, suggesting that it is a male. If so, the illustrated male is likely lost.</p>