The ischnoceran chewing lice (Phthiraptera: Ischnocera) of bulbuls (Aves: Passeriformes: Pycnonotidae), with descriptions of 18 new species

The ischnoceran chewing lice known from bulbuls are discussed and revised, and 18 new species are described. These are: Brueelia celer sp. nov. from Pycnonotus cafer bengalensis Blyth, 1845 and Pycnonotus cafer primrosei Deignan, 1949; Brueelia colindalei sp. nov. from Hemixos castanonotus canipennis Seebohm, 1890; Brueelia doisuthepensis sp. nov. from Alophoixus ochraceus ochraceus (Moore, 1858); Brueelia galeata sp. nov. from Alophoixus pallidus henrici (Oustalet, 1896); Brueelia hermetica sp. nov. from Pycnonotus barbatus layardi Gurney, 1879; Brueelia leiae sp. nov. from Alophoixus fl aveolus burmanicus (Oates, 1899); Brueelia robertrankini sp. nov. from Pycnonotus jocosus jocosus (Linnaeus, 1758) and Pycnonotus jocosus pattani Deignan, 1948; Brueelia yunnanensis sp. nov. from Ixos mcclellandii similis (Rothschild, 1921); Guimaraesiella brunneomarginata sp. nov. from Pycnonotus goiaver samarensis Rand & Rabor, 1960 and Pycnonotus goiaver personatus Hume, 1873; Guimaraesiella caligogularis sp. nov. from Pycnonotus plumosus plumosus Blyth, 1845 and Alophoixus bres tephrogenys (Jardine & Selby, 1833); Guimaraesiella cinnamomea sp. nov. from Iole propinqua propinqua (Oustalet, 1903) and Iole viridescens cinnamomeoventris Baker, 1917; Guimaraesiella ixi sp. nov. from Ixos mcclellandii peracensis (Hartert & Butler, 1898); Guimaraesiella lorica sp. nov. from Hypsipetes leucocephalus nigerrimus Gould, 1863; Guimaraesiella mayoensis sp. nov. from Hypsipetes everetti everetti (Tweeddale, 1877); Guimaraesiella phlaoalopha sp. nov. from Alophoixus pallidus henrici (Oustalet, 1896); Philopteroides holosternus sp. nov. from Pycnonotus goiavier goiavier (Scopoli, 1786); Philopteroides longiclypeatus sp. nov. from Hypsipetes everretti samarensis Rand & Rabor, 1959; Philopteroides haerixos sp. nov. from Ixos mcclellandii holtii (Swinhoe, 1 European Journal of Taxonomy 800: 1–88 ISSN 2118-9773 https://doi.org/10.5852/ejt.2022.800.1683 www.europeanjournaloftaxonomy.eu 2022 · Gustafsson D.R. et al. This work is licensed under a Creative Commons Attribution License (CC BY 4.0). M o n o g r a p h urn:lsid:zoobank.org:pub:213B577F-867D-4ECD-AD2C-48ACA71801B5 1861) and Alophoixus pallidus henrici (Oustalet, 1896). The following new host records are provided: Hemixos castanonotus canipennis Seebohm, 1890, for Guimaraesiella fl avala (Najer & Sychra in Najer et al., 2012); Pycnonotus blanfordi conradi (Finsch in Finsch & Conrad, 1873) for Philopteroides cucphuongensis Mey, 2004. Philopterus cucphuongensis is tentatively redescribed and illustrated based on specimens from a non-type host species. The species descriptions of the following species are amended slightly, based on re-examinations of type specimens: Brueelia alophoixi Sychra in Sychra et al., 2009; Guimaraesiella cucphuongensis (Najer & Sychra in Najer et al., 2012); Guimaraesiella fl avala (Najer & Sychra in Najer et al., 2012). We propose to move Philopterus hiyodori Uchida, 1949, to the genus Craspedorrhynchus Kéler, 1938. The species Sturnidoecus acutifrons (Uchida, 1949) and Penenirmus guldum (Ansari, 1955) are considered species inquirenda. An updated checklist of ischnoceran lice known from bulbuls is provided, as well as a key to all ischnoceran species known from bulbuls.


Introduction
The bulbuls (Pycnonotidae Gray, 1840) comprise a group of about 150 species of medium-sized songbirds distributed throughout most of Africa, South Asia, and the Indo-Malayan region, with a few species occurring outside these regions (Shakya & Sheldon 2017;Clements et al. 2019). Despite the large number and broad geographical range of bulbul species, little is known about their ischnoceran lice. The most recent checklist of chewing lice of the world  lists only fi ve species of ischnoceran lice associated with three species of bulbuls. Since then, only six other species of Ischnocera Kellogg, 1896 have been described from bulbul hosts (Mey 2004;Sychra et al. 2009;Najer et al. 2012;. Our current knowledge of ischnoceran lice parasitizing bulbuls comprises 11 species from 10 host species. With few exceptions, the ischnoceran lice parasitizing bulbuls fall into three genera: Brueelia Kéler, 1936, Guimaraesiella Eichler, 1949, and Philopteroides Mey, 2004. All three genera are widely distributed on non-bulbul hosts, and no genus of lice is known to be specifi c only to bulbuls. However, the species of Brueelia and Philopteroides occurring on bulbuls belong to species groups that are known only from bulbuls see below). In contrast, the species of Guimaraesiella known from bulbuls belong to a species group that is widely distributed on a large number of passerine host families Gustafsson et al. 2019a).
Here, we review the species of ischnoceran lice known from bulbul hosts, and describe and illustrate 18 new species in the genera Brueelia, Guimaraesiella and Philopteroides. We suggest that two described species should be regarded as species inquirenda due to the inadequate original descriptions. Another species (Ph. hiyodori Uchida, 1949) is moved to the genus Craspedorrhynchus Kéler, 1938; this genus is restricted to raptors and it seems most likely that this species was described from contaminations or stragglers. We provide two new host records, and confi rm some records from non-type hosts previously published by Chu et al. (2019). We provide a tentative redescription with complete illustrations of Philopteroides cucphuongensis Mey, 2004, as well as keys to the identifi cation on all species of ischnoceran lice known from bulbuls.

Material and methods
The following abbreviations are used for morphological and setal characters. These follow the standards outlined by  and Najer et al. (2020), and are shown in Abbreviations used for measurements (all in millimeters). Standards of measurement follow Najer et al. (2020). Measurements for all species can be found in Tables 1-2

Etymology
The species name is derived from Latin 'cinnamon' for 'cinnamon', referring to the pigmentation of this species and the subspecifi c name of the host.

Material examined
Holotype (

Both sexes
Head pentagonal (Fig. 3), lateral margins of preantennal area straight to slightly convex, anterior end slightly elongated and narrowed, frons narrow, straight to slightly concave. Marginal carina narrowing markedly in anterior end, median margin almost straight to slightly irregular. Dorsal anterior plate with shallowly concave anterior margin and irregular lateral margins. Ventral anterior plate almost triangular, but with moderately concave anterior margin and blunt posterior end. Dorsal preantennal suture reaches ads, dsms, and lateral margins of head. Preantennal nodi extended medianly. Head chaetotaxy as in Fig. 3. Coni almost reach distal margins of scapes. Temples rounded. Temporal marginal carina slender, largely regular. Thoracic and abdominal segments as in Figs 1-2. Base pigmentation conspicuously cinnamon in mounted specimens, darkening in head carina and nodi, gular plate, proepimera, metepisterna, and lateral sections of tergopleurites.

Female
Thoracic and abdominal chaetotaxy as in Fig. 2. Subgenital plate with slightly convex anterior margin and wide anchor-shaped lateral submarginal extensions almost reaching lateral ends of vulval margin (Fig. 7). Vulval margin distinctly rounded, with 2-3 short, slender vms and 4-7 short, thorn-like vss on each side; 3-4 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.

Remarks
The female specimen from Iole propinqua propinqua is larger and paler than females from the type host. Head shape and other characters are similar between the females from both host species, and we tentatively consider all the specimens listed above conspecifi c.

Female
Thoracic and abdominal chaetotaxy as in Fig. 9. Subgenital plate with wide lateral submarginal extensions (Fig. 14), lateral ends of these extensions bent posteriorly. Vulval margin gently rounded with straight central part, with 3-4 short, slender vms and 6-8 short, thorn-like vss one each side; 4-7 short, slender vos on each side of subgenital plate; distal 1-2 vos median to vss. Measurements as in Table 1.

Remarks
Material from the two host subspecies differs in pigmentation patterns (see above). The male from Pycnonotus goiavier personatus has a shorter head than males from Py. g. samarensis, but the male genitalia are indistinguishable between material from the two host subspecies. We here treat all material as conspecifi c.  [15][16]; male abdominal segments VI-VII with 3 ps on each side in Gu. mayoensis sp. nov. (Fig. 15), but with only 2 ps on each side in Gu. phlaoalopha sp. nov. (Fig. 43); proximal mesosome constricted distally and with clearly concave anterior margin in Gu. phlaoalopha sp. nov. (Fig. 48), but barely or not constricted distally and with straight or slightly convex anterior margin in Gu. mayoensis sp. nov. (Fig. 20); shape of ventral sclerite of mesosome differs between species (Figs 20,48), and sclerite with proximal thickening in Gu. phlaoalopha sp. nov. (Fig. 48) that is absent in Gu. mayoensis sp. nov. (Fig. 20).

Etymology
The species name is derived from the type locality.

Material examined
Holotype (
European Journal of Taxonomy 800: 1-88 (2022) Description Both sexes Head pentagonal, short (Fig. 17), lateral margins of preantennal head slightly convex, but anterior fourth straight to concave, frons concave. Marginal carina broad, narrowing slightly in anterior end, median margins irregular, posterior end relatively narrow. Dorsal anterior plate with shallowly concave anterior margin and convex lateral margins. Ventral anterior plate pale, and often diffi cult to see, roughly triangular, but with anterior margin concave. Dorsal preantennal suture reaches ads, in some specimens extends slightly median to ads; suture reaches lateral margins of head. Preantennal nodi extended slightly medianly. Head chaetotaxy as in Fig. 17

Etymology
The species name is derived from the Latin 'loricus' for 'corselet', referring to the distinct narrowing of the mesosome.

Material examined
Holotype ( (Fig. 24), lateral margins of preantennal head straight to slightly convex, frons concave. Marginal carina moderate, narrowing slightly anteriorly, with shallowly undulating median margins. Dorsal anterior plate with shallowly concave anterior margin and slightly convex lateral margins. Ventral anterior plate roughly triangular, but with deeply concave anterior margin. Narrow dorsal preantennal suture does not reach ads in 2 examined males, and reaches ads on only one side in 2 examined females; in 2 males and 1 female suture reaches ads; suture does not reach lateral margins of head. Preantennal nodi moderate, not extended medianly. Head chaetotaxy as in Fig. 24. Coni do not reach distal margin of European Journal of Taxonomy 800: 1-88 (2022) scapes. Temples rounded, temporal marginal carina slender, of more or less constant thickness. Thoracic and abdominal segments as in Figs 22-23. Base color pale brown yellow, darkening to pale brown on marginal carina, head nodi, gular plate, proepimera, and metepisterna, and to medium brown on lateral section of tergopleurites.

Female
Thoracic and abdominal chaetotaxy as in Fig. 23. Subgenital plate broad (Fig. 28), with slender, somewhat diffuse, lateral submarginal extensions that reach slightly more than halfway to lateral ends of vulval margin. Vulval margin gently rounded (Fig. 28), with 3 short, slender vms and 6-7 short, thornlike vss on each side; 4-6 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.

Etymology
The species name is derived from the generic name of the type host.

Material examined
Holotype (

Both sexes
Head pentagonal (Fig. 31), lateral margins of preantennal head more or less straight, frons slightly concave. Marginal carina slender, gradually narrowing anteriorly, median margin only slightly undulating. Dorsal anterior plate narrowing posteriorly, with shallowly concave anterior margin and convex lateral margins. Ventral anterior plate short, bowl-shaped with slightly concave anterior margin. Dorsal preantennal suture reaches ads and lateral margins of head. Preantennal nodi extended medianly. Head chaetotaxy as in Fig. 31. Coni reach beyond distal margin of scapes. Lateral margins of postantennal head slightly convex. Temples sharply rounded. Temporal marginal carina slender, only slightly irregular. Thoracic and abdominal segments as in Figs 29-30. Base pigmentation very faint, most of body translucent, European Journal of Taxonomy 800: 1-88 (2022) except preantennal and preocular nodi, gular plate, proepimera, metepisterna and lateral sections of tergopleurites pale brown.

Etymology
The species name is derived from Latin 'caligo' for 'dark', and 'gula' for 'throat', referring to the dark gular plate.

Material examined
Holotype (

Both sexes
Head pentagonal (Fig. 38), lateral margins of preantennal head straight, frons slightly concave. Marginal carina moderate, narrowing anteriorly, median margin slightly irregular. Dorsal anterior plate roughly square-shaped, with shallowly concave anterior margin and slightly convex lateral margins. Ventral anterior plate crescent shaped. Dorsal preantennal suture reaches ads and lateral margins of head. Preantennal nodi extended medianly. Head chaetotaxy as in Fig. 38. Coni with convex margins do not reach distal margin of scapes. Temples rounded. Marginal temporal carina moderate, irregular. Thoracic and abdominal segments as in  Base pigmentation pale brown with slight reddish tint, except preantennal nodi, gular plate, proepimera, metepisterna, and lateral sections of tergopleurites a medium reddish brown. Reddish tint absent in material from Alophoixus bres tephrogenys, which is also generally paler.

Remarks
The male specimen from Al. b. tephrogenys is indistinguishable from the male from the type host in all characters except pigmentation patterns; the specimens from Al. b. tephrogenys are paler than the holotype. We consider these specimens to be conspecifi c.
A female specimen from the type host (NHML) has a distorted head, and different pigmentation patterns compared to the female from the non-type host, and can therefore not with certainty be identifi ed as Gu. caligogularis sp. nov. Illustrations of the female Gu. caligogularis sp. nov. are therefore based on the female from Al. b. tephrogenys. These two species can be separated by the following characters: abdominal segment IV with 1 ps on each side in both sexes in Gu. phlaoalopha sp. nov. , but with 2 ps on each side in Gu. mayoensis sp. nov. ; male abdominal segments VI-VII with 3 ps on each side in Gu. mayoensis sp. nov. (Fig. 14), but with only 2 ps on each side in Gu. phlaoalopha sp. nov. (Fig. 43); shape of proximal mesosome and ventral sclerite differs between species (Figs 20, 48), and sclerite with proximal thickening in Gu. phlaoalopha sp. nov. (Fig. 48) that is absent in Gu. mayoensis sp. nov. (Fig. 20).

Etymology
The species name is derived from 'phlao', Greek for 'to crush', and 'alophos', Greek for 'without a crest', referring to the host genus name.

Material examined
Holotype (

Both sexes
Head pentagonal (Fig. 45), lateral margins of preantennal head slightly convex, frons straight to slightly concave. Marginal carina gradually narrowing anteriorly, with irregular inner margin. Dorsal preantennal suture reaches ads and dsms, but does not reach lateral margin of head. Dorsal anterior plate broad, with deeply concave anterior margin and convex lateral margins. Ventral anterior plate broadly crescent shaped. Preantennal nodi extended medianly. Head chaetotaxy as in Fig. 45. Coni do not reach distal margin of scapes. Temples rounded. Temporal marginal carina slender, irregular. Thoracic and abdominal segments as in Figs 43-44. Base pigmentation pale yellow, darkening slightly on marginal carina, gular plate, proepimera, metepisterna, and lateral sections of tergopleurites.

Female
Thoracic and abdominal chaetotaxy as in Fig. 44. Subgenital plate with wide, irregular lateral submarginal extensions and broad stalk between the main and terminal part (Fig. 49). Vulval margin gently rounded, slightly fl attened medianly (Fig. 49), with 3 short, slender vms and 4-6 short, thorn-like vss on each side; 3 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.

Diagnosis
Species in the Brueelia alophoixi species group can be distinguished from other species of Brueelia by the following combination of characters: post-antennal head sensillum s4 present (Fig. 52); thumb-like projection from the ventral carina into the clypeo-labral suture anteriorly (Fig. 52); ss present on female tergopleurite VIII (Fig. 51); lateral and median folds of the distal mesosome absent (Fig. 55).

Geographical distribution
Africa, and South and East Asia.

Host associations
All species except one are known from hosts in the Pycnonotidae (see below).

Remarks
Mey & Barker (2014: 79) mention a Brueelia guldum species group, which they defi ned as "narrowheaded". No other species was included in this guldum-group, which was only compared with species now placed in Guimaraesiella (see above). Not all morphological characters defi ning the Br. alophoixi species group can be seen in the illustrations of Br. guldum Ansari, 1955(Ansari 1958a, and we only tentatively include this species in the Br. alophoixi species group. For this reason, we here refer to the group of Brueelia living on bulbuls as the Br. alophoixi species group here. The specimens of the Brueelia alophoixi species group included in the phylogeny of Bush et al. (2016: fi g. 3e, clade I-2) formed a monophyletic group with good support. This included both specimens from African and Asian hosts, reinforcing the morphological similarity among Brueelia species from bulbuls in both faunal regions. Sychra in Sychra et al., 2009 Brueelia alophoixi Sychra in Sychra et al., 2009: 155.

Remarks
The original description of Br. alophoixi depicted the female without a cross-piece along the vulval margin. We have re-examined the paratypes of this species, and found that a cross-piece is present. The cross-piece and connection to the subgenital plate of Br. alophoixi is similar to that of Brueelia galatea sp. nov. (Fig. 84), but the connection is in general a bit broader, and the cross-piece somewhat narrower medianly. Ansari, 1955 Brueelia guldum Ansari, 1955: 54. Brueelia guldum -Ansari 1956: 394 (unnecessary redescription as a new species). -Ansari 1958a: 49 (unnecessary redescription as a new species).

Type locality
Pakistan, specifi c location not given.

Remarks
Ansari (1955, 1956, 1958a) published this species as new three times. None of these descriptions are very detailed, and only the 1958 description includes illustrations. In these illustrations, the thumb-like processes of the ventral carinae are not evident, and there are no ss on the female tergopleurite VIII. However, Ansari's illustrations are often incorrect and incomplete; for instance, in the illustrations for Br. guldum, there is no cross-piece along the vulval margin (Ansari 1958a: fi g. 22), no sts on abdominal segment II (ibid., fi g. 16), no dorsal head setae (Ansari 1958a: fi g. 16), and no setae in the area posterior to the vulval margin Ansari 1958a: fi g. 23). These characters are present in all species of Brueelia, and would be expected also for Br. guldum. Ansari's specimens are presumed lost (Naz et al. 2020), and new material from the type host is needed to evaluate whether or not this species belongs in the Br. alophoixi species group. Based on gross morphology and host associations, we tentatively include Br. guldum in the Br. alophoixi species group, but this needs confi rmation.

Remarks
Brueelia schoddei was originally described from Manorina melanocephala, a honeyeater (Meliphagidae Vigors, 1825) kept in captivity in Germany. As argued by Gustafsson et al. (2019b), the morphological characters of this species indicate that it belongs in the Br. alophoixi species group, suggesting that European Journal of Taxonomy 800: 1-88 (2022) the natural host of this species is a bulbul. The association of Br. schoddei with Ma. melanocephala was most likely caused by straggling from another bird kept in captivity. A second species of Brueelia belonging to the same 'Plesionirmus' group was mentioned by Mey (2017: 145) having been collected from skins of the same honeyeater species from South Australia. No bulbuls are native to Australia, but the red-whiskered bulbul, Pycnonotus jocosus (Linnaeus, 1758), has been introduced to New South Wales (Paton 1985) and is locally common in Southeast Australia (Menkhorst et al. 2017). It is possible that this specimen is a straggler from a red-whiskered bulbul, but no details were given by Mey (2017), other than the statement that this specimen was not conspecifi c with Br. schoddei.
We have examined material of the Brueelia-complex from 28 species of honeyeaters from across their range, including lice from Ma. melanocephala. None of these lice belonged to the genus Brueelia. Genera in the Brueelia-complex that naturally occur on honeyeaters are Guimaraesiella Eichler, 1949, Melibrueelia Valim & Palma, 2014, Aratricerca Gustafsson & Bush, 2017, and Melinirmus Mey, 2017 Attempts to contact Eberhard Mey to examine his specimens, or to get more information about their morphology, have not been productive. Specimens described by Mey (2017) will supposedly be deposited in the Zentralmagasin Naturwissenschaftlicher Sammlungen Halle/Saale, but they are currently not available. Ultimately, an examination of the type specimens of this species, and the specimen collected from a noisy miner in the wild, will be necessary to establish the true identity of Br. schoddei, and to establish the natural host of this species. These two species can be separated by the following characters: differences in head shape (Figs 52, 101); rugose area of mesosome covering more than half of mesosomal lobes in Br. doisuthepensis sp. nov. (Fig. 55), but covering only distal margin of mesosomal lobes in Br. yunnanensis sp. nov. (Fig. 104); gonopore more slenderly crescent shaped in Br. doisuthepensis sp. nov. (Fig. 55) than in Br. yunnanensis sp. nov. (Fig. 104); proximal part of parameres more elongated in Br. doisuthepensis sp. nov. (Fig. 54) than in Br. yunnanensis sp. nov. (Fig. 103); female subgenital plate with distinct distal 'neck' connecting plate to cross-piece in Br. doisuthepensis sp. nov. (Fig. 56), but with shorter connection in Br. yunnanensis sp. nov. (Fig. 105). Apparent differences in female vulval chaetotaxy may be due to the small number of specimens examined, and may overlap.

Etymology
The species name is derived from the type locality.

Material examined
Holotype (

Both sexes
Head fl at dome-shaped (Fig. 52), lateral margins of preantennal area convex, frons broadly fl attened. Marginal carina slender, shallowly displaced and translucent at osculum, median margin of lateral sections weakly undulated. Ventral anterior plate not pigmented and therefore not visible. Head chaetotaxy as in Fig. 52; pos located far behind eye. Lateral margins of postantennal head more or less parallel, temples European Journal of Taxonomy 800: 1-88 (2022) rounded, occiput slightly rounded. Thoracic and abdominal segments as in Figs 50-51. Pigmentation nearly uniform, pale yellow, but marginal carina, preantennal nodi, proepimera, metepisterna, and lateral sections of tergopleurites slightly darker.

Male
Thoracic and abdominal chaetotaxy as in Fig. 50; ss not visible on segments V-VII in single examined male, but may be present. Basal apodeme short and broad (Fig. 53), only slightly constricted at mid- length. Proximal mesosome roughly rectangular (Fig. 55), not visibly narrowed posteriorly. Mesosomal lobes broad, intensely rugose in medio-distal end, and with most of ventral surface scaly; 2 pmes sensilla latero-distal to gonopore. Gonopore crescent shaped, with no lateral extensions. Penile arms do not reach beyond distal margin of mesosomal lobes. Parameres elongated distally (Fig. 54); pst1-2 as in Fig. 54. Measurements as in Table 1.

Female
Abdomen of single examined female slightly distorted, and here illustrated approximately. Thoracic and abdominal chaetotaxy as in Fig. 51. Subgenital plate as in Fig. 56, with 2 short, slender vms and 4 short, thorn-like vss on each side; 4 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.

Diagnosis
Brueelia hermetica sp. nov. is one of only two species in the Br. alophoixi species group in which males lack ps on abdominal segment IV, the other being Br. robertrankini sp. nov. These two species can be separated by the following characters: male tergopleurite V with ss and aps in B. robertrankini sp. nov. (Fig. 64), but without these setae in Br. hermetica sp. nov. (Fig. 57); male tergopleurite VIII with tps in Br. hermetica sp. nov. (Fig. 57), but without tps in Br. robertrankini sp. nov. (Fig. 64); head of Br. hermetica sp. nov. fl at dome-shaped (Fig. 57), but that of Br. robertrankini sp. nov. rounded pentagonal (Fig. 66); proximal mesosome, mesosomal lobes, and gonopore of different shapes (Figs 62, 69); parameres proportionately much longer in Br. robertrankini sp. nov. (Fig. 68) than in Br. hermetica sp. nov. (Fig. 61); female abdominal segment VII with 2 ps on each side in Br. robertrankini sp. nov. (Fig. 65), but with only 1 ps on each side in Br. hermetica sp. nov. (Fig. 58); female subgenital plate and vulval margin of different shape in the two species (Figs 63, 70; note that parts of the subgenital plate of Br. hermetica sp. nov. are very poorly sclerotized in examined specimens, and here illustrated approximately).

Etymology
The species epithet is in reference to the similarity in shape between the head and the proximal mesosome, in correspondence with the Hermetic maxim 'as above, so below'. The name is ultimately derived from Hermes, the Greek herald and messenger of the gods, the namesake of Hermes Trismegistus, the thricegreatest Hermes, who is the purported author of the Emerald Tablets in which this maxim is inscribed.

Material examined
Holotype (

Both sexes
Head fl at dome-shaped (Fig. 59), lateral margins of preantennal area convex, frons rounded to slightly fl attened. Marginal carina of moderate, uneven, width, deeply displaced but not widened at osculum.

Female
Thoracic and abdominal chaetotaxy as in Fig. 58. Subgenital plate slender, probably connected to cross-piece by narrow neck, but this section poorly sclerotized in examined specimens and illustrated approximately based on what can be seen (Fig. 63). Vulval margin centrally distinctly rounded, with straight oblique lateral parts, 3-4 short, slender vms and 4-5 short, thorn-like vss on each side; 3-4 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1 . These two species can be separated by the following characters: abdominal segment IV in males without ps in Br. robertrankini sp. nov. (Fig. 64), but with ps in Br. colindalei sp. nov. (Fig. 85); male tergopleurite VIII without tps in Br. robertrankini sp. nov. (Fig. 64), but with tps in Br. colindalei sp. nov. (Fig. 85); female abdominal segment IV in Br. robertrankini sp. nov. with ps (Fig. 65 . 68) than in Br. colindalei sp. nov. (Fig. 89); female genitalia of Br. colindalei sp. nov. imperfectly known (see below), but subgenital plate appears to be broader and vulval margin more rounded in Br. robertrankini sp. nov. (Fig. 70) than in Br. colindalei sp. nov. (Fig. 91).

Etymology
The species name is in honor of the British author Robert Rankin (not to be confused with the other Robert Rankin), as a heartfelt thank-you for the many far-fetched books he has written. These have provided the fi rst author with endless joy over the last decades; moreover, it is a fact well known to those who know it well that 2021 marks the 40 th anniversary of Rankin as a published author. Thus, given the specifi c name of the host, an associated louse named Brueelia robertrankini sp. nov. seems apropos, if you know what we mean (and we are sure that you do).

Material examined
Holotype (

Both sexes
Head convex rounded pentagonal (Fig. 66), lateral margins of preantennal area convex, frons fl attened to slightly concave. Marginal carina gradually narrowing anteriorly, moderately displaced and translucent but not widened at osculum; lateral sections with distinct undulations of median margins. Ventral anterior plate fl attened oval, with brown pigmentation. Head chaetotaxy as in Fig. 66; pos located far behind eye. Temples rounded, occiput convex. Thoracic and abdominal segments as in Figs 64-65. Pigmentation generally very pale brown, except marginal and temporal marginal carinae, preantennal, preocular, and postocular nodi, proepimera, metepisterna, and lateral tergopleurites moderate brown.

Remarks
No signifi cant differences have been found between material from the two host subspecies. Diagnosis Brueelia celer sp. nov. is most similar to Br. pseudognatha , with which it shares the following characters: abdominal segments IV and VII in both sexes with 1 ps on each side (Figs 71-72); female abdominal segment VI with only 1 ps on each side (Fig. 72); male tergopleurite IV without aps, male tergopleurite VIII with tps (Fig. 71); overall shape of proximal mesosome rather broadly rounded (Fig. 76); vulval margin convergent to median point (Fig. 77). European Journal of Taxonomy 800: 1-88 (2022) These two species can be separated by the following characters: male tergopleurite VIII with 2 tps on each side in Br. pseudognatha, but with only 1 tps on each side in Br. celer sp. nov. (Fig. 71); proximal mesosome gently rounded in Br. pseudognatha, but with median bulge in Br. celer sp. nov. (Fig. 76); parameres proportionately more elongated in Br. celer sp. nov. (Fig. 75) than in Br. pseudognatha; gonopore crescent shaped in Br. celer sp. nov. (Fig. 76), but rounded in Br. pseudognatha; mesosomal lobes broader in Br. pseudognatha than in Br. celer sp. nov. (Fig. 76); differences in shape of female subgenital plate (Fig. 77).

Etymology
The species name is derived from the Latin 'celer' for 'swift', referring to the sleek, slender appearance of this species.

Both sexes
Head convex dome-shaped (Fig. 73), lateral margins of preantennal head convex, frons rounded to slightly fl attened. Marginal carina slender, moderately displaced and translucent but not widened at osculum, median margin undulating. Ventral anterior plate not visible. Head chaetotaxy as in Fig. 73; pos located near posterior margin of eye. Temples rounded, occiput slightly convex. Thoracic and abdominal segments as in Figs 71-72. Base pigmentation pale brown, darkening at median margin of marginal carina, margins of antennal socket, lateral section of postantennal head including pre-and postocular nodi and marginal temporal carina, proepimera, metepisterna, and lateral sections of tergopleurites.

Female
Thoracic and abdominal chaetotaxy as in Fig. 72. Subgenital plate long and slender (Fig. 77), with straight anteriora and lateral margins, distal connection to cross-piece broad. Vulval margin straightly convergent to rounded median point (Fig. 77), with 2-5 short, slender vms and 3-5 short, thorn-like vss on each side; 3-5 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.

Remarks
We found no signifi cant differences between specimens from the two host subspecies, and consider specimens from both host subspecies to be conspecifi c. Brueelia galeata sp. nov. can be separated from the other two species by the absence of tsp on male tergopleurite VIII in Br. galeata sp. nov. (Fig. 78); at least 1 tps on each side is present in the other two species (Fig. 71). Moreover, females of Br. galeata sp. nov. can be separated from females of the other two species by the shape of the vulval margin: gently rounded in Br. galeata sp. nov. (Fig. 84), but convergent to a median point in the other two species (Fig. 77).
Brueelia alophoixi was described from the same host species, but these two species can be separated by the following characters: preantennal area trapezoidal in Br. alophoixi, but rounded in Br. galeata sp. nov. (Fig. 80); male tergopleurite VIII with tps in Br. alophoixi, but without tps in Br. galeata sp. nov. (Fig. 78); male abdominal segment VII with 2 ps on each side in Br. alophoixi, but with 1 ps on each side in Br. galeata sp. nov. (Fig. 78); female abdominal segments VI-VII with 2 ps on each side in Br. alophoixi, but with only 1 ps each on each side in Br. galeata sp. nov. (Fig. 79); proximal mesosome rounded in Br. alophoixi, but with broadly fl attened convex anterior margin in Br. galeata sp. nov. (Fig. 83).

Etymology
The species name is derived from 'galeatus', Latin for 'helmeted'. In particular, we are here referring to the traditional Roman helmet, the 'galea', which is reminiscent of the gonopore of this species.

Both sexes
Head fl at dome-shaped (Fig. 80), lateral margins of preantennal head convex, frons rounded in male, slightly fl attened in female. Marginal carina moderate, shallowly displaced and translucent but not European Journal of Taxonomy 800: 1-88 (2022) widened at osculum; lateral sections with shallowly undulating median margins. Ventral anterior plate not visible. Head chaetotaxy as in Fig. 80; pos located far behind eye. Temples rounded, occiput more or less straight. Thoracic and abdominal segments as in Figs 78-79. Base pigmentation pale yellow-brown, except lateral sections of marginal carina, head nodi, proepimera, and lateral sections of tergopleurites slightly darker.

Female
Thoracic and abdominal chaetotaxy as in Fig. 79. Subgenital plate long and slender, widening anteriorly (Fig. 84), distal connection to cross-piece broad, cross-piece broad. Vulval margin rounded (Fig. 84), with 3 short, slender vms and 5 short, thorn-like vss on each side; 3 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements as in Table 1.  (Fig. 87); male abdominal segment IV with 1 ps on each side and segment VII with 2 ps on each side (Fig. 85); male tergopleurite IV without aps (Fig. 85); male tergopleurite VIII with 2 tps on each side (Fig. 85); short and broad male basal apodeme, constricted at mid-length and with rounded anterior margin (Fig. 88); female abdominal segment VI with 2 ps on each side (Fig. 86); head shape pentagonal (Fig. 87).
These two species can be separated by the following characters: lateral margins of preantennal head more or less straight in Br. alophoixi, but convex in Br. colindalei sp. nov. (Fig. 87); head proportionately broader in Br. alophoixi than in Br. colindalei sp. nov. (Fig. 87); female abdominal segment IV with ps in Br. alophoixi, but without ps in Br. colindalei sp. nov. (Fig. 86); differences in shape of proximal mesosome (Fig. 90); distal mesosome more rounded in Br. colindalei sp. nov. (Fig. 90) than in Br. alophoixi.

Etymology
The species name is in honor of our friend and colleague Dr Colin Dale (University of Utah, Salt Lake City, Utah, USA), in recognition of his research elucidating interactions between lice and their endosymbiontic bacteria.

Material examined
Holotype (

Female
Thoracic and abdominal chaetotaxy as in Fig. 86. Subgenital plate roughly rectangular, in some specimens broader than illustrated, with broad connection to cross-piece. Vulval margin seemingly fl attened medianly (Fig. 91), with at least 3-5 slender vms and 3-5 short, thorn-like vss on each side; 4 slender vos on each side of subgenital plate, 1 vos near vms. Measurements as in Table 1.

Remarks
Specimens from Guangdong are slightly larger than specimens from Guangxi; however, given that so few specimens were examined from each place, we do not consider this signifi cant, and have presented all measurements under one heading in Table 1.
Brueelia colindalei sp. nov. was included in the phylogeny of Bush et al. (2016), represented by four specimens from different host species, all from South China. It is possible that, at least locally, Br. colindalei sp. nov. occurs naturally on all these hosts (Ixos mcclellandii, Spizixos semitorques, Emberiza godlewskii Taczanowski, 1874). However, other specimens examined from Ixos mcclellandii are not conspecifi c with Br. colindaeli, and one of the hosts in Bush et al. (2016) is an emberizid. We prefer not to count these bird species as hosts of Br. colindalei sp. nov. until this has been confi rmed.  (Fig. 92), but this is absent in the other two species (Figs 50, 99).

Etymology
The specifi c epithet is in honor of Ms Lujia Lei, formerly a student of DRG's at the Guangdong Institute for Zoology, as a small compensation for her hard work in the fi eld and in the lab, braving torrential rain, GUSTAFSSON D.R. et al., New species of Ischnocera (Psocodea, Phthiraptera) from bulbuls sleepless mountain nights, hundreds of brown shrikes, terrestrial leeches and the possibility of snakes. Reliable, diligent, and all-round great students like her are rare.

Material examined
Holotype (

Both sexes
Head fl at dome-shaped (Fig. 94), lateral margins of preantennal area convex, frons fl attened to slightly concave. Marginal carina broad, moderately displaced and widened at osculum; width more or less even throughout except for near frons. Ventral anterior plate small, somewhat rectangular. Head chaetotaxy

Remarks
One examined female has an aps on one side of tergopleurite VII, but this is absent on the other side and on both sides in the other female; we have not illustrated this seta, as aps are usually absent in females of Brueelia spp., and is here presumably an aberration. These two species can be separated by the following characters: differences in head shape (Figs 52,101), with Br. yunnanensis sp. nov. having proportionately wider temples, with a blunter angle at mts3 than in Br. doisuthepensis sp. nov.; the portion of the temple margin between mts3-5 is more fl attened in Br. yunnanensis sp. nov., making the head look somewhat angular; lateral margins of preantennal head are more straight in Br. yunnanensis sp. nov. (Fig. 101) than in Br. doisuthepensis sp. nov. (Fig. 52); rugose area of mesosome covering more than half of mesosomal lobes in Br. doisuthepensis sp. nov. (Fig. 55), but covering only distal margin of mesosomal lobes in Br. yunnanensis sp. nov. (Fig. 104); posterior cutout of the gonopore larger in Br. doisuthepensis sp. nov. (Fig. 55) than in Br. yunnanensis sp. nov. (Fig. 104); parameres more elongated in Br. doisuthepensis sp. nov. (Fig. 54) than in Br. yunnanensis sp. nov. (Fig. 103); female subgenital plate with distinct distal 'neck' connecting plate to cross-piece in Br. doisuthepensis sp. nov. (Fig. 56), but with shorter connection in Br. yunnanensis sp. nov. (Fig. 105). Apparent differences in female vulval chaetotaxy may be due to the small number of specimens examined, and may overlap.

Both sexes
Head rounded pentagonal (Fig. 101), frons narrow and fl attened, lateral margins of preantennal area slightly convex. Marginal carina broad, of irregular width, narrowing at frons, and moderately displaced but not much widened at osculum. Head chaetotaxy as in Fig. 101; pos situated far behind eye. Temples somewhat angular, with area between mts3-5 fl attened; occiput convex. Thoracic and abdominal segments as in Figs 99-100. Pigmentation yellowish brown, only markedly darker at head nodi, proepimera, metepisterna, and lateral margins of tergopleurites.

Remarks
The species of Philopteroides parasitizing bulbuls appear to form a homogenous group within the Philopteroides mitsusui species group sensu Valim & Palma (2013). In particular, the species known GUSTAFSSON D.R. et al., New species of Ischnocera (Psocodea, Phthiraptera) from bulbuls from bulbuls are united by the following characters: Mesosome covers central ⅓ of distal margin of basal apodeme (Figs 109, 115); parameres curved medianly (115)(116); at least some of sternal plates III-VI reduced in female, with accessory lateral sternal plates (if visible) clearly separated from central sternal plates in at least some segments (Figs 107, 113). In males of most species, at least sternal plate III is reduced in the same way (Fig. 106), but in Ph. cucphoungensis the central sternal plate may be connected to the accessory lateral sternal plates (Mey 2004: fi g. 23d), and in Ph. holosternus sp. nov. male sternite III is entire (Fig. 112).

Remarks
Bitrabeculus kayanobori was placed in Philopteroides by Mey (2004), without justifi cation. The original description and illustration of this species was based on a single male and single female (Uchida 1948), and fi ts with the description of the genus Philopteroides, except that the illustration indicates three temporal macrosetae on each side, whereas other species of Philopteroides only have two temporal macrosetae on each side. If correct, this character separates Ph. kayanobori from all other known species of Philopteroides.
We examined two female Philopteroides from the mainland host subspecies Spizixos semitorques semitorques Swinhoe, 1861. These specimens were reported as Po. kayanobori by Chu et al. (2019); however, these specimens do not have ps on abdominal segment III, as in the original illustrations of this species. Moreover, both specimens have only two temporal macrosetae on each side. As Uchida (1948) only illustrated the male, and both our specimens are female, we cannot presently confi rm whether these specimens are conspecifi c with Po. kayanobori. Najer & Sychra in Najer et al., 2012 Philopteroides fl avala Najer & Sychra in Najer et al., 2012: 39.

Remarks
Specimens from Alophoixus fl aveolus burmanicus and A. pallidus henrici examined by us are indistinguishable from the illustrations of Najer et al. (2012), and we agree with Chu et al. (2019) that these specimens represent Po. fl avala. Chu et al. (2019) also reported this species from Hypsipetes leucocephalus (Gmelin, 1789), but the male on which this report was based was misidentifi ed (see below). Mey, 2004 Figs 106-111

Type locality
Cuc Phuong National park, Vietnam.

Both sexes
Head shape as in Fig. 108, lateral margins of preantennal area concave, frons deeply concave, with central sclerotization divided medianly. Dorsal anterior plate with deeply concave anterior margin, convex lateral margins in anterior end, and slender posterior elongation that reaches posterior to mandibles. European Journal of Taxonomy 800: 1-88 (2022) Ventral anterior plate crescent shaped, with deeply concave anterior margin. Lobes of ventral carinae transparent and hard to see in many specimens. Head chaetotaxy as in Fig. 108. Thoracic and abdominal segments as in Figs 106-107. Tergopleurites III-VIII with translucent fenestrae around spiracular opening; plates only barely reaching ventral surface. Base pigmentation pale brown, darker on dorsal and ventral anterior plates, preantennal nodi, temporal carinae, and proepimera, very dark brown on marginal carinae anterior to lobes of ventral carinae.

Male
Thoracic and abdominal chaetotaxy as in Fig. 106. Metanotum with 7-9 mms on each side. Sternal plate II very small and may be divided medianly; sternal plate III with accessory lateral plate; sternites IV-VI wide, with no separation between central and lateral plates. Subgenital plate with large, oblong lateral plate on segment IX+X. Basal apodeme long, widening gently in distal end (Fig. 109). Dorsal thickening of mesosome slender, mitre-shaped. Gonopore wide, inverse U-shaped, with small triangular process on anterior margin and median thickening (Fig. 110). Distal processes of mesosome broad with rugose median margins. Parameres simple; 2 sensilla on lateral margin of basal paramere, and 2 sensilla on lateral margin in distal half of each paramere. Measurements as in Tables 1-2.

Female
Thoracic and abdominal chaetotaxy as in Fig. 107. Metanotum with 9-11 setae on each side. Sternal plate II very small, divided medianly or absent; sternal plates III-V with accessory lateral plates; sternal plate VI wide, with narrow connection to accessory lateral plate. Lateral ends of subgenital plate bending posteriorly, median section with distinct bulge. Vulval margin more or less straight with a sublateral bulge on each side (Fig. 111), with 5 short and 3 long setae on each side. Subvulval plates broad, with blunt distal ends. Measurements as in Tables 1-2.

Remarks
No type specimens of Po. cucphuongensis or specimens from the type host of this species were examined. The specimens examined are largely indistinguishable from the original description of Po. cucphoungensis, with the following exceptions: female abdominal segment VII with 3 ps on each side in our specimens (Fig. 107), but with 2 ps on each side in specimens from type host; mts1 signifi cantly shorter than mts3 in our specimens (Fig. 108), but of similar length in specimens from type host; male central sternal plate III clearly separated from accessory lateral sternal plates in our specimens (Fig. 106), but closer together and in some cases fused in specimens from the type host. The preantennal head is also slightly narrower in specimens from the type host than in our specimens (Fig. 108), but the shape is similar. Measurements are largely overlapping between specimens from the two hosts (Table 1).
We consider these differences to be insuffi cient to separate these specimens from Po. cucphuongensis, and consider Pycnonotus blanfordi conradi to be a new host record for this species; moreover, this is the fi rst record of Po. cucphuongensis from Thailand. However, the original illustrations of Po. cucphuongensis are only partial, and e.g., the male genitalia are illustrated with dorsal and ventral features mixed. It is possible that more detailed comparisons of the male genitalia and other characters will necessitate the separation of these specimens as a separate species. We here provide a description and illustrations of our specimens, to complement those of Mey (2004).

Diagnosis
Philopteroides holosternus sp. nov. does not appear particularly close to any other species of Philopteroides known from bulbuls. It can be separated from all other species in the genus known from bulbuls by the following characters: male sternal plates III-VI entire, with no lateral accessory sternal plates present (Fig. 112); dorsal sclerite of mesosome with elongated, bifi d proximal end (Fig. 115); distal basal apodeme with central ridge that appears to lie dorsal to dorsal sclerite and bear one sensillum on each side (Fig. 115); gonoporal complex unique among species known from bulbuls (Fig. 116).

Etymology
The species name is derived from the Greek words 'holos' for 'whole', and 'sternon' for 'chest', referring to the broad sternal plates and uninterrupted sternal plate of male abdominal segment III.

Material examined
Holotype (

Male
Thoracic and abdominal chaetotaxy as in Fig. 112. Metanotum with 8-9 setae on each side. Base pigmentation light brown, except posterior elongation of dorsal anterior plate, temporal carinae, and proepimera medium brown. Sternal plate II medianly continuous; sternal plates III-VI broad, long, not divided into central and accessory plates. Subgenital plate large, with small irregular accessory plate on segment IX+X. Basal apodeme broad (Fig. 115), narrowing markedly in anterior end, with slightly convex anterior margin. Distal end of basal apodeme with arched, medianly convergent dorsal ridges (Fig. 115). Dorsal thickening of mesosome with bifi d anterior extension. Gonopore wide, crescent shaped, distally with wide, blunt nodes (Fig. 116); 1 sensillum on each lobe. Parameres simple (Fig. 116), 2 sensilla on lateral margin of basal paramere, and 2 sensilla on lateral margin in distal half of each paramere. Measurements as in Tables 1-2.

Etymology
The species name is derived from the Latin words 'longus' for 'long' and 'clypeus' for 'shield', referring to the long dorsal anterior plate.  Fig. 120, anterior end narrow and elongated, lateral margins of preantennal head slightly concave, frons deeply concave, with central sclerotization medianly continuous. Dorsal anterior plate with moderately concave anterior margin, convex lateral margins in anterior end, and slender posterior elongation that does not reach beyond mandibles. Ventral anterior plate elongated triangular, with concave anterior margin. Lobes of ventral carinae roughly rectangular. Head chaetotaxy as in Fig. 120 European Journal of Taxonomy 800: 1-88 (2022) around spiracular openings; plates barely reaching ventral surface. Base pigmentation moderate yellow, only mandibles and parts of preantennal nodi and marginal carina darker.

Male
Thoracic and abdominal chaetotaxy as in Fig. 118. Metanotum with 6-7 setae on each side. Sternal plate II very small, divided medianly; sternal plate III with lateral accessory plate on each side; sternal plates IV-VI wide, without accessory plates. Subgenital plate large, with small, irregular lateral accessory plate on segment IX+X. Basal apodeme long, slender (Fig. 121), widening distally. Dorsal thickening of mesosome diffuse but broad, roughly triangular (Fig. 121). Gonopore wide, anterior margin with blunt median point (Fig. 122), distally with bilobed median processes on each side. Parameres simple (Fig. 121); 2 sensilla on lateral margin of basal paramere, and 2 sensilla on lateral margin in distal half of each paramere. Measurements as in Tables 1-2.

Female
Thoracic and abdominal chaetotaxy as in Fig. 119. Metanotum with 6-7 setae on each side. Sternal plate II small, divided medianly; sternal plates III-VI small, in some specimens with median part much narrowed, each with small accessory plate on each side, in more posterior segments often oblong. Subgenital plate as in Fig. 123, lateral sections with slender posterior extensions, detached from subgenital plate in some specimens; median section with wide, often angular, posterior bulge. Surface between subgenital plate and vulval margin densely reticulated. Vulval margin slightly concave, with 4 long and 3 short setae on each side. Subvulval plates small, oval. Measurements as in Tables 1-2.

Remarks
Abdominal size is variable among female specimens examined. We have illustrated a female with a proportionately small abdomen, but note that other specimens have proportionately larger abdomens, similar to those of other species treated here. Structurally, there are no differences between the abdomens of these females, and we do not consider these differences meaningful. We illustrate the smaller-bodied specimens here to highlight the possible variation in body shapes among specimens of Philopteroides.  (Fig. 126), but slender elongated in Po. longiclypeatus sp. nov. (Fig. 120); sternal plate II absent in both sexes in Po. haerixos sp. nov. (Figs 124-125), but present in Po. longiclypeatus sp. nov. (Figs 118-119); male basal apodeme in all its length more or less equally wide in Po. haerixos sp. nov. (Figs 127-128), but narrowing anteriorly in Po. longiclypeatus sp. nov. (Figs 121-122); gonoporal complex of different structure (Figs 122, 128); female subgenital plate with elongated, slender postero-lateral extensions in Po. longiclypeatus sp. nov. (Fig. 123), but without such extensions in Po. haerixos sp. nov. (Fig. 129) Fig. 126, lateral margins of preantennal head concave, frons deeply concave, with central sclerotization medianly continuous. Dorsal anterior plate with deeply concave anterior margin, convex lateral margins, and moderate posterior extension reaching beyond mandibles. The posterior extension continually outgoing from the rest of the plate, without clear angle or separation. Ventral anterior plate trapezoidal, with deeply concave anterior margin. Lobes of ventral carinae rectangular, bulging slightly posteriorly in median section. Head chaetotaxy as in Fig. 126. Thoracic and abdominal chaetotaxy as in Figs 124-125. Base pigmentation yellowish brown, except marginal carina, preantennal nodi, and proepimera slightly darker. Male sternal and subgenital plates brown with slight reddish tint; female sternal and subgenital plates the same yellowish color as tergopleurites.

Male
Thoracic and abdominal chaetotaxy as in Fig. 124. Metanotum with 6-7 setae on each side. Sternal plate II absent but small, rounded lateral accessory plate present; sternal plate III with lateral accessory plate; sternal plates IV-VI wide, without accessory plates. Subgenital plate large, with small kidney-shaped accessory plate on segment IX+X. Basal apodeme long (Fig. 127), only slightly more narrow proximally than distally. Dorsal thickening of mesosome rounded triangular (Fig. 127). Gonopore deeply crescent shaped (Fig. 128), with rounded anterior margin, distally with blunt, lobe-like median extensions. Parameres simple (Fig. 127); 2 sensilla on lateral margin of basal paramere, and 2 sensilla on lateral margin in distal half of each paramere. Measurements as in Tables 1-2.

Female
Thoracic and abdominal chaetotaxy as in Fig. 125. Metanotum with 6-7 setae on each side. Sternal plate II absent or very small at base of median-most setae; sternal plates III-VI small with small, often irregularly shaped, lateral accessory plates. Subgenital plate as in Fig. 128, lateral sections only slightly extended posteriorly. Surface between subgenital plate and vulval margin with some reticulation in postero-median section. Vulval margin more or less straight, with 4-5 long and 3-4 short setae on each side. Subvulval plates large, distal ends pointed and curving slightly medianly. Measurements as in Tables 1-2

Remarks
We have re-examined the male Philopteroides reported from H. l. ambiens by Chu et al. (2019) in light of the new descriptions and the key constructed for this manuscript. This specimen has male genitalia that are similar to those of Po. longiclypeatus sp. nov., but with a larger and more semi-circular gonopore. Moreover, on segments III-IV the lateral accessory sternal plates are connected to the central sternal plate by a slightly narrowed "isthmus". Unfortunately, the male is poorly cleared, and cannot be European Journal of Taxonomy 800: 1-88 (2022) described. However, as we do not consider it conspecifi c with Po. fl avala, we hereby remove this record from the list of hosts from which this species is known.

Remarks
In light of these new descriptions, we re-examined the specimen of Philopteroides reported by Chu et al. (2019) from H. c. canipennis. The specimen is poorly cleared, and many characters used in our key cannot be seen; in our key, it is impossible to get beyond couplet 9 for this specimen. Overall, there seem to be no characters that directly contradict the statement that this specimen represents Po. fl avala, but we prefer to consider this specimen to be unidentifi ed, as the identity cannot be established with certainty. We therefore hereby remove H. c. canipennis from the host list of Po. fl avala.

Remarks
The combination of characters illustrated by Uchida (1949) are incompatible with all known genera in the Philopterus-complex sensu Mey (2004). Hopkins & Clay (1952: 91) placed this species in Craspedorrhynchus "with some doubt", but did not expand on this placement. Indeed, the characters in the original illustration and description of this species agree well with those of most species of Craspedorrhynchus. Uchida (1949: 546) also stated that this species belonged to "Piaget's group Delatatoclypeati infesting the birds of prey", further supporting the removal of this species to Craspedorrhynchus.
Specifi cally, the hyaline margin of Philopterus hiyodori is without median sclerotization, emarginate medially, and extends lateral to the marginal carina. The dorsal anterior plate is elongate and tongue-like, GUSTAFSSON D.R. et al., New species of Ischnocera (Psocodea, Phthiraptera) from bulbuls without lateral extensions near ads. At least some preantennal setae appear to be dorsal, and the two anterior-most of these appear to be elongated and thickened compared to the other illustrated preantennal setae. The eyes are extended posteriorly. Apart from the os, three temporal setae on each side are illustrated as macrosetae; the identity of these is not clear, but they appear to be mts1-3. In the illustration, there is a dotted line along the median pterothorax, which is described as "separated by a narrow, uncoloured, mesal linear space" in the text; this suggests that the pterothorax is divided by a median suture. All these characters are found in Craspedorrhynchus (see Gállego et al. 1987;Mey 2001), except that posteriorly extended eyes are limited to a few species in this genus (e.g., Mey 2001: fi g. 14). Mey (2001) treated this species as a member of Tritrabeculus Uchida, 1948, but gave no details. Later, Mey (2004) did not include Ph. hiyodori in Tritrabeculus, limiting this genus to two species known from cuckoo-shrikes. The following characters mentioned or illustrated by Uchida (1949) separate Ph. hiyodori from Tritrabeculus: frons hyaline throughout in Ph. hiyodori, but medianly sclerotized in Tritrabeculus; Ph. hiyodori with four temporal macrosetae, but Tritrabeculus with only two temporal macrosetae; at least two preantennal setae on each side situated on the hyaline frons in Ph. hiyodori, but no setae situated in hyaline section in Tritrabeculus.
We hereby move Philopterus hiyodori to the genus Craspedorrhynchus, where it was previously placed by Hopkins & Clay (1952). As this genus is otherwise only found on raptors, it seems probable that Cr. hiyodori was described from stragglers. In the same publication, Uchida (1949) (Nitzsch, 1818) [= Craspedorrhynchus haematopus (Scopoli, 1763)], but none of his material is from the same locality as his specimens of Cr. hiyodori. A detailed study of the type specimens, if they remain, will be needed to establish whether Cr. hiyodori is synonymous with any of the other species of Craspedorrhynchus known from Japan. (Ansari, 1955) Sturnidoecus guldum Ansari, 1955: 59. Sturnidoecus guldum -Ansari 19561958b: 78. Penenirmus guldum -Gustafsson & Bush 2017: 321.

Type locality
Pakistan, specifi c locality not provided. Ansari (1955Ansari ( , 1956Ansari ( , 1958b described this species as new three times, but only Ansari (1958b) included enough details to be able to place this species accurately. As argued by , this species belongs in Penenirmus Clay & Meinertzhagen, 1938, rather than Sturnidoecus Eichler, 1944. The type specimens of this species are presumed to be lost (Naz et al. 2020), and it has never been described or illustrated in suffi cient detail. It should be considered a species inquirenda. No other species of Penenirmus have been described from any species of bulbul, but the genus is widely distributed across a large range of hosts , and is generally poorly known, so species parasitizing bulbuls may have been overlooked. It is also possible that Ansari's specimens constituted stragglers or contaminations. Until more red-vented bulbuls have been examined, and it has been established whether or not Pe. guldum naturally occurs on this host species, Pe. guldum should be considered a species inquirenda.

Remarks
Philopterus acutifrons was based on a single female, which was never illustrated or described in detail. It was separated from Philopterus sturni [= Sturnidoecus sturni (Schrank, 1776)] based on differences in measurements, the shape of the frons, and the lack of setae on posterior corners of the prothorax. In Philopteroides, the pronotal setae are situated more medianly, which may be interpreted as an 'absence' of setae on the pronotum. Similarly, the frons of Philopteroides on bulbuls is generally narrower and more deeply emarginated than in Sturnidoecus sturni (cf. Fig. 108 with : fi g. 379). However, as at least some of Uchida's species appear to be described from stragglers or contaminations (see above), it is possible that his specimen of P. acutifrons is a straggler that could belong to any head louse ecomorph genus occurring in Japan. Without examining specimens it is impossible to know what genus this belongs to; the species is in need of redescription, and should presently be considered a species inquirenda. If the type specimen is lost, it may be best to consider this name a nomen dubium, as it cannot reliably be placed in any genus.

Guimaraesiella from bulbuls
The genus Guimaraesiella is widely distributed across both of the major bulbul clades (Table 3). To date, Guimaraesiella has not been described from African bulbul genera, but undescribed species have been reported by Bush et al. (2016), Light et al. (2016), and Gajdosova et al. (2020). In the phylogeny of Bush et al. (2016), Guimaraesiella parasitizing bulbuls were placed in two different groups: lice collected from four Asian bulbul species were placed in a clade with Guimaraesiella from other passerines, mainly from the Indo-Malayan and Australasian regions (Bush et al. 2016: fi g. 3, clade A1), and lice from ten African bulbul species were nested in another clade containing Guimaraesiella from other Africa passerines (Bush et al. 2016: fi g. 3, clade A2). The Asian bulbul Guimaraesiella in clade A1 are all part of the "core group" of Guimaraesiella (Gustafsson et al. 2019a), whereas the African species in clade A2 are not. The morphological variation among species in clade A2 is largely unexplored, and several species groups appear to be involved (DRG, unpublished data). As no African Guimaraesiella were studied in detail here, we cannot presently assess their phylogenetic relationships.

Brueelia from bulbuls
In contrast to Guimaraesiella, the Brueelia known from bulbuls all parasitize hosts belonging to the Asian clades in the phylogeny of Shakya & Sheldon (2017). Two species of Brueelia are known from African hosts, but these are found on bulbuls in the genus Pycnonotus, which is an Asian radiation of bulbuls that colonized Africa secondarily. To date, no species of Brueelia are known from bulbul genera endemic to Africa. In the phylogeny of Bush et al. (2016: fi g. 3e, clade I-2), the species of Brueelia from bulbuls formed a single well-supported clade.
With the exception of Br. guldum, all species of Brueelia from bulbuls fall into a single morphological group, here called the Br. alophoixi species group. This group is characterized by a combination of characters that are either rare among other species of Brueelia, or found only in this group. Notably, almost all Brueelia species included in the phylogeny of Bush et al. (2016) were almost genetically identical; most of their samples are conspecifi c with the species here described as Brueelia colindalei sp. nov. Additional sampling is needed to understand the relationship between Br. guldum and other species of Brueelia known from bulbuls.

Philopteroides on bulbuls
With the species described here, only six species of Philopteroides are known from bulbuls, of which one (Po. kayanobori) is inadequately described and poorly known. The described species are all from hosts belonging to the Asian bulbul clade in the phylogeny of Shakya & Sheldon (2017). However, undescribed species have been reported from African hosts belonging to the African clade of bulbuls (Light et al. 2016). Notably, nearly every host sampled by Light et al. (2016) appears to be parasitized by a genetically distinct lineage of Philopteroides. This suggests that Philopteroides may be widely distributed across bulbuls, and that bulbuls may harbor a large, relatively unstudied, radiation of lice.

Host and geographic specifi city
The family Pycnonotidae is quite diverse; it includes about 150 species in 26 genera. We are just beginning to understand the diversity of lice on these hosts; ischnoceran lice are known from just 24 bulbul species, which is ~16% of bulbul diversity. Thus, it is premature for in-depth analyses of the specifi city of these lice. However, a few general patterns are beginning to emerge. All three of these genera of lice found on bulbuls are quite widely distributed on other passerines (Mey 2004;Valim & Palma 2013;Bush et al. 2016).
Published reports of undescribed species are only included in those cases where no described species are known from a given host genus. As specimens reported by McClure et al. (1973) were not identifi ed to species level, have not been described since, and were not examined by us, we have not been able to include these records in this table. References are given only to unidentifi ed species; for references to reports of identifi ed species, see the text. The non-type hosts of Brueelia colindalei sp. nov. reported by Bush et al. (2016) are not included here, until these host associations can be confi rmed. Among the few known species of lice from bulbuls, a considerable amount of variation in specifi city is apparent. Species of Brueelia found on bulbuls are quite host specifi c, with most species being associated with only a single host species, or in a few cases, two host species in a single host genus. Similarly, Philopteroides spp. on bulbuls tend to be restricted to a single host species (Valim & Palma 2013); however, based on the few known species of Philopteroides from bulbuls, it is clear that this genus can be much less specifi c. For example, Po. fl ava is known from four host species (Najer et al. 2012;Chu et al. 2019;this paper). Guimaraesiella spp. on bulbuls are more catholic, and often parasitize several bulbul species, and even different host genera (Table 4). At the other side of this spectrum, the grey-eyed bulbul (Io. propinqua) is parasitized by different species of Guimaraesiella in different parts of its range ( Table 5). This is not to say, however, that these lice are extremely host specifi c, because both of these species of lice also parasitize other species of bulbuls.

Host genus
The distribution of lice on bulbuls appears to be heavily infl uenced by geography. At a gross level, the relationships between groups of Guimaraesiella from bulbuls appear to mirror the biogeography of their hosts. At a smaller geographic scale, lice seem to be moving among sympatric hosts. For example, Gu. cucphuongensis is found on three different species of bulbuls that all occur in the same region of Vietnam. Geography also appears to be important in the host associations of Brueelia on bulbuls. For example, the louse Brueelia colindalei sp. nov. is found on Hemixos castanonotus, and appears (based on sequence similarity, Bush et al. 2016) to be found on three other bulbul species and a sparrow in the same geographic region (Ixos mcclellandii, Spizixos semitorques, Pycnonotus xanthorrhous and Emberiza godlewskii). Yet, Ixos mcclellandii in Yunnan, China, is parasitized by a different species of Brueelia, Br. leiae sp. nov. Among the few Philopteroides known from bulbuls, at least two are known from multiple host species that live in the same region. In all, it seems that geography infl uences host associations for lice in Brueelia, Guimaraesiella, and Philopteroides. Additional sampling of bulbuls and other passerines from the same regions is necessary to understand how specifi c these parasites are, and to understand how transmission among related and unrelated hosts infl uences the distribution of diversity of these groups.
Abiotic factors may also play a role in the distribution of these lice. As a general rule, Brueelia appears to occur mainly on hosts living in drier environments, whereas Guimaraesiella occurs on species living in more humid environments. This is seen among lice on 'babblers' (Timaliidae s. lat.): species of Guimaraesiella are widely distributed across babblers that occur in rainforests (Gustafsson et al. 2019c), whereas babblers in drier environments are parasitized by species of Brueelia . Similarly, Takano et al. (2019) found species of Brueelia on different hosts throughout dry sampling localities in South Africa, but only found Guimaraesiella in the most humid locality. In the humid Congo Basin, Light et al. (2016) found only Guimaraesiella (identifi ed as Brueelia in their phylogeny). As most of the bulbuls in the African clade are rainforest birds, this may explain the lack of records of Brueelia from bulbul genera endemic to Africa. Additional sampling of more birds, especially in the drier regions of Africa, is sorely needed (as stressed by Gustafsson et al. 2019d).
The amblyceran genus Myrsidea Waterston, 1915, forms an interesting parallel case to the genera treated here. Lice in this genus known from bulbuls also include species occurring on several host species in the same region as well as lice restricted to single host subspecies. Moreover, lice in the genus Myrsidea appear to occur throughout the Pycnonotidae, though they are better known from Asian hosts than from African hosts Johnson & Price 2006). Notably, none of the species groups of Myrsidea erected by     Bush et al. (2016) are not included here, until these host associations can be confi rmed. Table 5. Host-louse list of the ischnoceran lice known from bulbuls. As the natural host of Brueelia schoddei (Mey, 2017) is unknown, this species is not listed here. Species marked with an asterisk (*) are dubious; see text for details. The non-type hosts of Brueelia colindalei sp. nov. reported by Bush et al. (2016) are not included here, until these host associations can be confi rmed.

Summary
With these descriptions, the number of ischnoceran chewing lice known from bulbul hosts has increased from 7 to 25 (not including dubious records). The majority of ischnoceran species parasitizing bulbuls are known from Southeast Asia, though many unidentifi ed species have been reported from Africa. With the descriptions and key provided here, we hope to facilitate further research into the ischnoceran lice of bulbuls. The potential co-occurrence of all three genera of lice on most or all species of bulbuls would make them ideal for studies of intraspecifi c competition among lice, and the range in geographic and host specifi city provides interesting opportunities to study co-evolutionary and ecological factors (e.g., mixed-species fl ocks or abiotic factors) governing the diversifi cation and distribution of lice.