Forficuloecus pezopori Martin, Keatley & Ash, 2024

Martin, Storm Blas, Keatley, Sarah, Wallace, Alisa, Vaughan-Higgins, Rebecca J. & Ash, Amanda, 2024, A critically co-endangered feather louse Forficuloecus pezopori n. sp. (Phthiraptera: Philopteridae) detected through conservation intervention for the western ground parrot Pezoporus flaviventris (Psittaculidae), International Journal for Parasitology: Parasites and Wildlife 24 (100931), pp. 100931-100931 : 100931-

Forficuloecus pezopori Martin, Keatley & Ash n. sp. ( Figs. 2–5 )

Classification: Phylum Arthropoda: Class Insecta: Order: Psocodea : Parvorder: Phthiraptera: Family Philopteridae : Genus Forficuloecus Conci, 1941 .

Synonyms: none.

Type-host: Pezoporus flaviventris North, 1911 ( Psittaculidae ), western ground parrot.

Type-locality: Cape Arid National Park , Western Australia .

Other localities: Perth Zoo (hosts originally from Cape Arid National Park).

Site of infection: Feathers on head and neck.

Prevalence and intensity: Detected on 2 of 8 (25%) captive birds and 3 of 7 wild birds (43%) at low intensity. It is possible a single bird might have been the original source of the infestation on the captive birds.

Material examined/deposited: Holotype ( WAM E117337 ), allotype ( WAM E117338 ), and nine paratypes ( WAM E117339–47 ).

Representative genetic sequences: Five identical replicates of COI mtDNA (GB PP524917).

ZooBank registration: LSID: https://zoobank.org/urn:lsid:zoobank.or g:act: 3A5ABCA8-537E-4738-B627-2B4152FE8B81.

Etymology: This species is named for its host Pezoporus flaviventris .

Description. Based on 2 male and 9 female specimens. Measurements in Table 1, abdominal chaetotaxy in Table 2. Body somewhat dorsoventrally flattened. Head non-circumfasciate, broadly triangular, roughly as long as wide; preantennal region with concave lateral margins, terminates in forceps-like projections extending beyond dorsal anterior plate and surrounded by substantial hyaline. Preantennal marginal carina interrupted medially and laterally; lateral interruption complete, anterior of mandibles at level of broadest part of dorsal anterior plate and midlevel of pulvinus. Dorsal anterior plate with narrow and almost straight anterior margin, becomes increasing broad posteriorly to level of lateral suture, then narrows with slightly concave lateral margins to rounded, posterior, double point which partially overlaps mandibles; ventral anterior plate narrower than and less than half the length of dorsal anterior plate. Anterior hyaline margin rounded, convex, prominent, with anteriorly recurved lateral points. Postnodal suture broad, incomplete, run posteromedially from antennae base. Pulvinus extends anteriorly to midlevel of dorsal anterior plate.

Trabecula short, broad, taper to rounded point. Antennae monomorphic, short; socket shallow, to base of trabeculum; scape short, broad, almost as wide as long, with three short, distal, marginal, spine-like setae, two dorsal and one ventral, and one dorsal and two to three ventral, minute, posteroproximal, spines; pedicel rectangular, similar in length to scape, not fused to flagellomeres, with eight setae; flagellomeres I shorter than pedicel, with six setae, flagellomere II similar in length to flagellomere I, with four setae; flagellomere III longer, with three setae and distal sensilla trichoidea.

Head chaetotaxy. First anterior seta as1 short, dorsomarginal, immediately anterior to lateral interruption of marginal carina by dorsal preantennal suture. Second anterior setae as2 long, submarginal on marginal carina at level of anterior margin of dorso-anterior plate. Third anterior setae as3 long, anterior to as2, at level of anterior hyaline margin. Dorsal submarginal seta dsms short, medial of as1, at posterior dorsomedial margin of marginal carina where lateral and medial preantennal sutures meet. Anterior dorsal setae ads short, submedial on lateral suture, postero-medial relative to dsms. Preantennal setae short pas, dorsal, at anterior base of antennae scape. Preconal setae pcs short, ventral, anterior to conus base. First anterior ventral setae avs1 long, submarginal, anterior to pcs. Second anterior ventral setae avs2 long, submarginal, anterior to avs1. Third anterior ventral setae avs3 longer than and anteromedial of avs1 and avs2, at level of dorsal preantennal lateral suture. First ventral submarginal setae vsms1 long, immediately posterior relative to as2. Second ventral submarginal setae vsms2 medial of vsms1 long, anterior of pulvinus on inner margin of forceps-like preantennal structure. Mandibular setae apparently absent, no setae on surface of pulvinus. Postnodal setae pns short, dorsal, strongly submedial, at level of eye, positioned on anterior margin of postnodal suture. Occipital setae short, lateral, on lens of eye. Marginal temple setae pairs six; mts1–3 and mts5-6 short, marginal; mts4 long, dorso-

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submarginal. Additional setae up to five each side, all minute, often with two or three on temple surface and two near to anteromedian margin of postnodal suture.

Thorax shorter and narrower than head, wider than long. Pronotum roughly rectangular, with single pair of long, posterolateral setae. Prosternum with two pairs of short, spine-like, submedial, anterior setae posterolateral of gula. Mesosternum without setae, with pair of posterolateral spiracles. Pterothorax wider than long, trapezoidal with convex lateral and posterior margins, with 9–11 pairs of long, dorsal, posteriorly submarginal setae and one pair of short posterolateral spine-like setae, sometimes with one pair of small submedial setae at midlevel. Pterothoracic sternal plate small, with single pair of sublateral setae.

Leg coxae short, broad; trochanters shorter than coxae; femurs broad, longer than coxae; tibiae narrower than femurs, similar to femurs in length in proleg and longer than femurs in metaleg and mesoleg; tarsae short. Metaleg longer than proleg. Mesoleg longest. Leg chaetotaxy of holotype: Proleg coxae with two anteroventral spines and one long posteroventral seta; trochanters with two long, ventral, distal marginal setae and one or more minute anterior spines and bosses; femurs with two long ventral setae and seven dorsal spine-like setae; tibiae with four large ventromarginal spines, one proximal and paired distal, moderately long anterior setae, three ventrolateral moderately long

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seate, four moderately long dorsal spines; tibiae with large distal claw, two pairs of smaller ventrolateral claws, and few short setae. Metaleg coxae with one anteroventral spine, two ventral and distal marginal spines, and two short posteroventral setae; trochanters with two anteroventral spines and two ventral and distal marginal setae, one short and the other long; femurs with ten spines; tibiae with paired large ventrolateral spines, four short to moderate ventrolateral setae, seven ventral setae; tarsae with large distal claw, second smaller distal claw, paired ventral claws, few setae. Mesoleg coxae with three anteroventral setae, one moderate length ventral seta, and one long posteroventral seta; trochanters with one long posteroventral seta and one short, ventral, distal marginal seta; femurs with few proximal, anterior, minute spines and bosses, two anterior spines and two short distal marginal and anterior spines, three ventral and two dorsal spines and one dorsal and distal marginal spine; tibiae with eight short to moderate setae; tarsae with large distal claw, second smaller distal claw, paired ventral claws, few setae;

Abdomen with nine apparent segments numbered II–X/XI, widest at segment V, with pair of sublateral dorsal spiracles each on III–VIII. Tergopleurites II–VIII divided in both sexes; tergocentral setae in single posteromedial row on either side (II 3–5, III 2–4, IV–VII 2, VIII 2–3), often with a second, anterior row of 1–2 on II; spiracular setae one each either side of IV–VIII, posteromedial of spiracle, stronger than and lateral to tergocentral setae; tergolateral setae one each either side on VI–VII. Sternopleurites absent from anterior sterna, greatly reduced and submedial in IV–VIII; sternocentral setae submedial, medial of sternopleurites, shorter and weaker than tergocentral setae, in single row on either side (II 1, III 2–3, IV 3–4, V–VI 2–3); sternolateral setae stronger and longer than sternocentral setae, in ventrolateral cluster (IV 1, V 3–4, VI–VIII 2, IX 1), absent on II–III.

Male. Abdomen shorter and rounder relative to female; posterior extremity protuberant and bluntly rounded. VII–VIII without sternocentral setae. IX–XI difficult to interpret in available specimens; IX seemingly with tergopleurites divided with 2–3 tergocentral setae and one sternolateral seta either side; X/XI seemingly with tergopleurites fused with two, minute setae along anterior margin, four dorsal and posteroterminal setae, and four ventral and posteroterminal setae, either side. Ventral subgenital plate difficult to trace, seemingly spans segments VII–X. Male genitalia elongate; basal apodome extends anteriorly to segment VII, rounded proximally, sclerotised dorsolaterally along most of length, distal margin strongly sclerotised ventrally and weakly so dorsally; parameres long, with almost straight external margin to

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level of end of penis then sharply curved inward, with prominent hooked or recurved distal tip and single subterminal seta; endomeres ventral to and about half length of parameres, stout, directed posteromedially, with hooked distal tip, apparently without setae or tubercles; telomeres short, blunt-ended, immediately submedial, directed posteriorly, ventral to but largely not overlapping endomeres; mesosomal plate ventral to telomeres, with nearly circular medial aperture arising from incomplete posterior margin, anterior sclerotised margin narrow and separated from posterior sclerotised margin of basal apodeme, posterior margin strongly sclerotised with two to three submarginal tubercles; penis elongate, tapers gently distally.

Female. Abdomen ovate; posterior extremity bluntly rounded. IX with tergopleurites entire, prominent with two, long medioposterior setae and two anterolateral setae, one short and one long, either side; sternopleurites fused with those of X to form subvulvular sclerites, with one sternolateral seta either side. X/XI with tergopleurites separate, reduced, slightly submedial, with two short, dorsal, submedial setae flanking genital opening, a cluster of 5–6 longer, posterolateral setae, and two short, spine-like, terminal setae, one dorsal and one ventral, either side. Ventral subgenital plate clamshell shape, spans roughly half abdomen width on VI–VIII, with two pairs of minute, submedial spines. Subgenital fold on VIII between subgenital plate and subvulvular sclerites, with 9–11 short setae either side with one row of 4–5 along margin of fold, a cluster of 3–4 anterolateral to that row, and a single, smaller seta submedial and just posterior to the subgenital plate.

3.3.1. Remarks

Price et al. (2008) divided species of Forficuloecus into two species groups, the F. forficula species group and the F. meinertzhageni Guimar˜aes, 1974 group. Forficuloecus pezopori is consistent with the F. forficula group, defined for species in which both sexes have one (vs two) long seta on each lateral temple margin, the male has a conspicuously elongate and tapered penis, and the subgenital plate of the female has few setae grouped around inwardly pointed sclerites. This group includes: F. forficula , F. banksi Price, Johnson & Palma, 2008 , F. greeni Guimar˜aes, 1985 , F. josephi , F. palmai and F. wilsoni . Forficuloecus pezopori is among the smallest species in this group together with F. greeni and F. josephi . It is most similar to those species, and keys to F. josephi using Price et al. (2008).

The abdominal chaetotaxy is useful for distinguishing F. pezopori . Price et al. (2008) distinguished F. josephi from all other species of the group by fewer tergocentral setae, with at most two setae medial of the spiracles on each side of abdominal segments V–VIII; F. greeni always has more than four tergocentral setae total on each of these segments ( Guimar˜aes, 1985; Price et al., 2008). In addition to these tergocentral setae, F. pezopori , F. josephi and F. greeni have a stronger dorsal seta associated with the spiracle on some abdominal segments, as well as a tergolateral (= paratergal) seta. In F. josephi and F. greeni , the spiracular setae are posterolateral relative to the spiracles such that Price et al. (2008) did not include these in their count of tergal setae. However, in F. pezopori , the spiracular setae are posteromedial relative to the spiracles and so would be included as tergocentral using the definition in Price et al. (2008), despite seemingly being homologous with setae otherwise treated as tergolateral. Thus, excluding the spiracular setae, F. pezopori has only two pairs of tergocentral setae on abdominal segments V–VII, like in F. josephi , although there are two or three (vs two) pairs on VIII. Forficuloecus pezopori has a spiracular seta on either side of IV–VIII and a tergolateral seta either side on VI–VII, whereas, as far as we can determine from the figures in Price et al. (2008) and Guimar˜aes (1985), F. josephi lacks spiracular (and tergolateral) setae on IV and has both spiracular and tergolateral setae on V, and both F. josephi and F. greeni have both spiracular and tergolateral setae on VIII. Forficuloecus pezopori has up to nine tergocentral setae on II, with three to five either side, vs up to six with two to three either side in F. josephi and up to seven with two to four either side in F. greeni , plus usually an additional pair of submedial setae on II anterior to the row of tergocentral setae and not reported for F. josephi or F. greeni . Forficuloecus pezopori has more sternocentral setae on III–V than F. josephi , and more sternolateral setae on V–VIII than F. greeni (see Table 2). Chaetotaxy of the terminal abdominal segments appears to be similar for all three species, in both sexes, although the illustration of Price et al. (2008) suggests the female may have only about five pairs of setae on the subgential fold vs about nine in both F. pezopori and F. greeni .

The male terminal genitalia of F. pezopori is similar to that of both F. josephi and F. greeni . In F. pezopori , the parameres appear to be straighter and narrower relative to both species, the penis appears to be relatively straighter than in F. josephi and more similar to that of F. greeni , the endomeres are perhaps narrower than in either species and lack the minute setae depicted for F. greeni , and the shape of the posterior margin of the basal apodeme is more similar to that of F. josephi . The tergopleurites of IX in the male appear to divided in F. pezopori and F. josephi vs complete in F. greeni .

Figures

Fig. 2. Forficuloecus pezopori Martin, Keatley & Ash n. sp. habitus, female allotype, dorsal (left) and ventral perspective. Some variably absent setae added from reference to paratypes. Tergites and sternites labelled with Roman numerals. Abreviations: ms, mesosternum; pn, pronotum; ps, prosternum; pt, pterothorax; ss, spiracular seta; sgp, subgenital plate. Scale bar: 250 μm.

Fig. 3. Forficuloecus pezopori Martin, Keatley & Ash n. sp. head, female paratype, dorsal (left) and ventral perspective. Abbreviations: ads, anterodorsal seta; as, anterior seta; avs, anteroventral seta; dsms, dorsal submarginal seta; mts, marginal temple seta; os, ocular seta; pas, preantennal seta; pcs, preconal seta; pns, postnodal seta; pts, posterior temple seta; vsms, ventral submarginal seta. Scale bar: 200 μm.

Fig. 4. Forficuloecus pezopori Martin, Keatley & Ash n. sp. male holotype, ventral perspective, A. proleg, B. metaleg, C. mesoleg. Scale bar: 200 μm.

Fig. 5. Forficuloecus pezopori Martin, Keatley & Ash n. sp., dorsal (left) and ventral perspective, A. female allotype posterior terminus with egg, B. female alloptype anterior dorsal plate, C. male holotype posterior terminus, D. male holotype terminal genitalia. Tergopleurites and sternopleurites labelled with Roman numerals. Abbreviations: a, basal apodeme; e, endomere; m, mesosomal plate; p, paramere; sgp, subgenital plate; svs, subvulvular sclerite; t, telomere. Scale bars: 200 μm.