Morphological revision of the hyperdiverse Brueelia - complex (Insecta: Phthiraptera: Ischnocera: Philopteridae) with new taxa, checklists and generic key
Author
Bush, Sarah E.
text
Zootaxa
2017
2017-08-31
4313
1
1
443
journal article
32249
10.11646/zootaxa.4313.1.1
d8cc2cd8-8410-49aa-a75d-7a41d9f52b26
1175-5326
883161
A5Fdfba5-F992-44A8-84C2-1756C943C19B
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
.
TABLE 9.
Abdominal chaetotaxy of segments II–VIII of the species groups of
Olivinirmus
. Trichoid setae of segment VIII are present in all species, and are not listed. Sets of setae differing from those of
Ol. glandarii
are highlighted in
bold
. Material examined from all species is from their respective type hosts. Abbreviations:
aps
= accessory postspiracular seta;
psps
= principal post-spiracular seta;
ps
= paratergal seta;
ss
= sutural seta;
sts
= sternal seta;
tps
= tergal posterior seta.
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
]