Olivinirmus Złotorzycka, 1964

Bush, Sarah E., 2017, Morphological revision of the hyperdiverse Brueelia - complex (Insecta: Phthiraptera: Ischnocera: Philopteridae) with new taxa, checklists and generic key, Zootaxa 4313 (1), pp. 1-443 : 199-201

Olivinirmus Złotorzycka, 1964

Nirmus Nitzsch, 1818: 291 (in partim).

Degeeriella Neumann, 1906: 60 (in partim). Brueelia Kéler, 1936a: 257 (in partim). Olivinirmus Złotorzycka, 1964a: 246 .

Type species. Nirmus glandarii Denny, 1842: 51 , by original designation.

Diagnosis. The male genitalia of Olivinirmus are variable ( Figs 334–337 ), but superficially similar to those of Corvonirmus ( Figs 323–325 ), and these two genera are similar in the setal and structural head characters ( Figs 321 , 329). In both genera parameres ( Figs 325 , 332) are long and tapering, connected to a rectangular parameral head by a distinct neck; however, the parameral neck is absent in some Olivinirmus , particularly the semiannulatus species group ( Fig. 337 ) and the meinertzhageni species group ( Fig. 335 ). The gonopore is highly modified in both genera, and there are distinct, often large, rugose areas on the ventral surface of the mesosome in both Olivinirmus ( Figs 334–337 ) and Corvonirmus ( Fig. 324 ). However, the ventral sclerite found in Corvonirmus ( Fig. 324 ) is absent in Olivinirmus ( Figs 334–337 ), and the ventral surface of the mesosome is generally simpler in Corvonirmus than in Olivinirmus . The gonopore is subterminal or terminal in Corvonirmus , but ventral in Olivinirmus , and while the exact structure of the gonopore varies between the four species groups of Olivinirmus , no pmes are ever situated on the surface of the gonopore in this genus, whereas this is the case in Corvonirmus ( Fig. 324 ). In female Olivinirmus (Fig. 333) the subgenital plate does not flare into a cross-piece or lateral submarginal extensions as in Corvonirmus ( Fig. 326 ), and the abdominal chaetotaxy of the two genera is dissimilar ( Table 2), with psps present on male tergopleurites II–III and female tergopleurite III in Corvonirmus ( Fig. 320 ), but absent on tergopleurites II–III in both sexes in Olivinirmus ( Figs 327–328 ). In all Corvonirmus asseccory sts are present on at least some segments, but this is never the case in Olivinirmus .

Description. Both sexes. Head convex- to indented-dome shaped (Fig. 329). Marginal carina uninterrupted, displaced dorsally and posteriorly at osculum. Pale dot visible in many species at dsms where marginal carina is narrowed. Dorsal preantennal suture absent. Ventral carinae sometimes continuous with marginal carina, but often diffuse anterior to pulvinus. Ventral anterior plate absent. Head setae as in Figs 329; as3 absent. Coni small, triangular. Antennae monomorphic except in the meinertzhageni and semiannulatus species groups. Temporal carinae not visible; mts 3 only macrosetae. Gular plates triangular to spade-shaped.

Prothorax ( Figs 327–328 ) rectangular. ppss on postero-lateral corner. Proepimera hook-shaped medianly, curving around coxae II. Pterothorax pentagonal; lateral margins widely divergent; posterior margin convergent to median point; mms narrowly separated medianly. Meso- and metasterna not fused; 1 seta on postero-lateral corner on each side of each plate. Metepisterna widen medianly to blunt ends. Metepimeron often broad, swollen. Leg chaetotaxy as in Fig. 25 , except fI-p2 absent.

Abdomen ( Figs 327–328 ) oval. Abdominal chaetotaxy differing slightly between species groups ( Table 9). Tergopleurites rectangular; tergopleurites II–IX+X in males and tergopleurites II–VIII in females moderately divided medianly. Tergopleurites generally translucent or weakly pigmented median to spiracle openings, and in some species median margins are hard to see. Sternal plates rectangular, not approaching pleurites; generally weakly pigmented and may be hard to see. Tergopleural plates reach to ventral side of abdomen. Pleural incrassations moderate to wide. Re-entrant heads moderate. Male subgenital plate triangular, extremely narrow at terminal end of abdomen. Female subgenital plate triangular, but in many species diffuse distally, and in some species it cannot be determined whether it reaches the vulval margin or not. Vulval margin (Figs 333) with few, long, slender vms, several thorn-like vss; vos follows lateral margins of subgenital plate; distal vos approaching or situated median to vss.

Species Sex ps aps psps tps ss sts

Ol. glandarii M IV–VIII IV–VII IV–VIII – II–VIII II–VI F IV–VIII – IV–VII – II–VIII II–VI Ol. meinertzhageni M IV–VIII IV–VIII IV–VIII VI–VIII II–VIII II–VI F IV–VIII – IV–VIII – II–VIII II–VI Ol. nitzschi M IV–VIII IV–VII IV–VIII – II–VIII II–VI F IV–VIII – IV–VIII – II–VIII II–VI Ol. semiannulatus M IV–VIII IV–VIII III–VIII VIII II–VIII II–VI F IV–VIII – IV–VIII – II–VIII II–VI Male genitalia ( Figs 334–337 ) variable between species-groups (see below). Basal apodeme roughly rectangular, but may be constricted at mid-length ( Fig. 334 ) or widening slightly anteriorly ( Fig. 335 ). Proximal mesosome of varying shape. Gonopore (Fig. 331) open distally. Most species-groups with subparallel, flameshaped thickenings on ventral side extending into the extrusor muscles. Mesosomal lobes large, fused distally; 0–2 ames anterior to gonopore; 0–3 pmes posterior to gonopore, often 2 pmes laterally and 1 pmes just distal to gonopore. In some species both ames and pmes may be hidden in the ventral structures of the mesosome. Rugose nodi present in some species-groups. Parameral heads (Fig. 332) folded medianly, rectangular to triangular. Parameral blades elongated, tapering; pst1 sensillus, central; pst2 sensilla or microseta, central; pst1– 2 may be relatively close ( Fig. 336 ) or much separated ( Fig. 337 ).

Species-group characters. All species-groups in Olivinirmus are based primarily on the male genitalia, which are illustrated in Figs 334–337 . The phylogeny of Bush et al. (2016) did not include members of all of these groups, and the true relationships between these species-groups are unknown. Species not examined by us have been placed in species gropus based on illustrations provided with their original descriptions.

Olivinirmus glandarii species-group. Antennae monomorphic. Abdominal chaetotaxy as in Table 9; tps absent; psps absent on male tergopleurite III ( Fig. 327 ). Females with or without psps on tergopleurite VIII ( Fig. 328 ). Proximal mesosome rounded trapezoidal (Fig. 331). Mesosomal lobes not fused distally, with prominent nodi submedianly. Gonopore open distally and associated with subparallel ventral thickenings; 2 ames on each side antero-lateral to gonopore; 2 pmes on each side on lateral margin, often hard to see; 1–2 pmes on each side posterolateral to gonopore, often not visible due to rugose nodi. Rugose nodi may be present on distal mesosome. Parameral heads (Fig. 332) quadratic to rectangular; pst2 sensillus, far distal to pst1.

Olivinirmus meinertzhageni species-group. Antennae dimorphic. Abdominal chaetotaxy as in Table 9; tps present on male tergopleurites VI–VIII; psps absent on male tergopleurite III. Females without psps on tergopleurite VIII. Proximal mesosome slender ( Fig. 335 ). Mesosomal lobes fused distally, with prominent marginal thickening. Ventral surface of mesosome densely papillate proximal to gonopore. Gonopore widely open distally, and shaped as trapezoidal plate with serrated lateral margins in distal half; 2 ames on each side near anterolateral corners of gonopore; 1 pmes on each side postero-lateral to gonopore; 2 pmes on each side on lateral margins. Rugose nodi absent. Parameral heads oblique; pst2 sensillus, close to pst1.

Olivinirmus morionus species-group. Antennae monomorphic. Abdominal chaetotaxy as in Table 9; tps absent; psps absent on male tergopleurite III. Females with psps on tergopleurite VIII. Proximal mesosome slenderly trapezoidal, rounded ( Fig. 336 ). Mesosomal lobes slender, triangular, fused distally, and with prominent nodi on lateral and distal corners. Gonopore widely open distally, and extended laterally into serrated or fringed areas. Parameral heads rounded quadratic; pst2 microseta, close to pst1.

Olivinirmus semiannulatus species-group. Antennae dimorphic. Abdominal chaetotaxy as in Table 9; tps present on male tergopleurite VIII; psps present on male tergopleurite III. Females with psps on tergopleurite VIII. Proximal mesosome widely rounded ( Fig. 337 ). Mesosomal lobes large, rounded, fused distally, with extensive rugose nodi in distal half. Gonopore widely open distally. Parameral heads quadratic, but with concave median margins and serrated distal margins; pst2 microseta, far distal from pst1.

Host distribution. Most species occur on members of the Corvidae , but not on the genus Corvus . No comprehensive phylogeny of the Corvidae is known to us, but based on the phylogeny of Ericson et al. (2005) the distribution of Olivinirmus on corvid hosts appears to be discontinuous. Outside the Corvidae , Olivinirmus is only know from the Cracticidae , where it occurs on all genera, and possibly all species.

Geographical range. Almost global, not known from Africa south of the Sahara. Corvid hosts not belonging to Corvus from this area are parasitised by species of Brueelia s. str.

Remarks. In the phylogeny of Bush et al. (2016), Olivinirmus was placed as a sister group to Sturnidoecus with high support, but few morphological similarities exist between these two genera. The “head louse” ecomorph has evolved independently several times within the Brueelia -complex, and the evolution of the head louse morphology in Sturnidoecus may have obscured similarities between the ancestors of these two genera. Alternatively, the placement of Olivinirmus as sister to Sturnidoecus is marginally nonsignificant (0.93 Bayesian Posterior Probability) and the data set in Bush et al. (2016) may not be sufficient to indicate the true sister relationship between these two genera.

Both Toon & Hughes (2008) and Bush et al. (2016) found considerable geographical structure in Olivinirmus from Australian cractids. Interestingly, Bush et al. ’s (2016) study showed that several host species in the same geographic region were parasitised by the same lineage of Olivinirmus . The collection of fresh, sequenceable, material from more host species and more geographic regions is needed to understand the diversity and host specificity within Olivinirmus .

Included species

Olivinirmus glandarii species-group

* Olivinirmus glandarii ( Denny, 1842: 51) [in Nirmus ] Nirmus affinis Nitzsch [in Giebel], 1874: 132 nec Nirmus affinis Children, 1836 [1]

* Olivinirmus husaini ( Ansari, 1956b: 383) n. comb. [in Brueelia ]

* Olivinirmus olivaceus ( Burmeister, 1838: 431) [in Nirmus ]

* Olivinirmus perisoreus ( Ansari, 1956b: 374) [in Brueelia ]

Figures

FIGURES 25. Dorso-ventral views of coxae I – III, trochanters I – III, and femora I – III, showing terminology of the leg setae used here. Other parts of the thorax removed for clarity. Setae situated marginally are illustrated and named on both dorsal (lefthand) and ventral (right-hand) sides. Terminology for individual seta as used in the text obtained by combining the leg segment (larger font) and the setal name (smaller font). Abbreviations: a 1 – 5, anterior setae 1 – 5; cI – III, coxae I – III; d 1 – 3, dorsal setae 1 – 3; dm 1 – 4, distal marginal setae 1 – 4; fI – III, femur I – III; p 1 – 3, posterior setae 1 – 3; s 1 – 6, sensilla 1 – 6; tI – III, trochanter I – III; v 1 – 4, ventral setae 1 – 4.

FIGURES 334 – 337. Ventral views of male genitalia representing species groups of Olivinirmus: 334, Olivinirmus glandarii (Denny, 1842) (O. glandarii group); 335, Olivinirmus meinertzhageni (Ansari, 1956 d) n. comb. (O. meinertzhageni group); 336, Olivinirmus cyaneus (Carriker, 1963) n. comb. (O. morionus group); 337, Olivinirmus semiannulatus (Piaget, 1883) n. comb. (O. semiannulatus group).

FIGURES 321 – 326. Corvonirmus uncinosus (Burmeister, 1838) ex Corvus cornix cornix: 321, male head, dorsal and ventral views. 322, female antenna, ventral view. 323, male genitalia, dorsal view. 324, male mesosome, ventral view. 325, male paramere, dorsal view. 326, female subgenital plate and vulval margin, ventral view.

FIGURES 319 – 320. Corvonirmus uncinosus (Burmeister, 1838) ex Corvus cornix cornix: 319 male habitus, dorsal and ventral views. 320 female habitus, dorsal and ventral views.

FIGURES 327 – 328. Olivinirmus glandarii (Denny, 1842) ex Garrulus glandarius atricapillus: 327, male habitus, dorsal and ventral views. 328, female habitus, dorsal and ventral views.