Going Asexual: A Survey of Mites of the Genus Thyreophagus (Acari: Acaridae) Revealing a Large Number of New Parthenogenetic Species in the Holarctic Region

Abstract

Mites of the genus Thyreophagus (Acari: Acaridae) are distributed worldwide; they inhabit concealed habitats and include several beneficial and economically important species. However, species identification is difficult because many species are poorly described or delimited and their phoretic stages are unknown or uncorrelated. Furthermore, Thyreophagus is interesting because it includes entirely asexual (parthenogenetic) species. However, among the 34 described species of Thyreophagus, the asexual status is confirmed through laboratory rearing for only two species. Here, we provide detailed descriptions of five new species from North America (four) and Europe (one) based on adults and phoretic heteromorphic deutonymphs. Four of these species were asexual, while one was sexual. For most of these mites, the asexual status was confirmed and phoretic deutonymphs were obtained through rearing in the lab. We show that asexual mites retain seemingly functional copulatory and sperm storage systems, indicating that these lineages have relatively short evolutionary lifespans. One North American species, Thyreophagus ojibwe, was found in association with the native American chestnut Castanea dentata, suggesting a possibility that this mite can be used to control chestnut blight in North America. We also provide a diagnostic key to females, males, and heteromorphic deutonymphs of the Thyreophagus species in the world.

Full text

Citation: Klimov, P.B.; Kolesnikov,
V.B.; Demard, E.P.; Stinson, C.S.A.;
Merckx, J.; Duarte, M.V.A.; Pedroso,
L.G.A.; Khaustov, A.A.; Myers-
Hansen, J.L.; Wäkers, F.L.; et al.
Going Asexual: A Survey of Mites of
the Genus Thyreophagus (Acari:
Acaridae) Revealing a Large Number
of New Parthenogenetic Species in
the Holarctic Region. Life 2023,13,
2168. https://doi.org/10.3390/
life13112168
Academic Editors: Paolo Solari,
Giorgia Sollai, Roberto Massimo
Crnjar, Anita Giglio and Piero G.
Giulianini
Received: 12 October 2023
Revised: 1 November 2023
Accepted: 2 November 2023
Published: 5 November 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
life
Article
Going Asexual: A Survey of Mites of the Genus Thyreophagus
(Acari: Acaridae) Revealing a Large Number of New
Parthenogenetic Species in the Holarctic Region
Pavel B. Klimov 1, 2, *, Vasiliy B. Kolesnikov 2,3 , Emilie P. Demard 4, Clive S. A. Stinson 5, Jonas Merckx 6,7 ,
Marcus V. A. Duarte 6, Luiz Gustavo A. Pedroso 8, Alexander A. Khaustov 2, James Leslie Myers-Hansen 1,
Felix L. Wäkers 6and Dominiek Vangansbeke 6,7
1Lilly Hall of Life Sciences, Purdue University, G-225, 915 W State St, West Lafayette, IN 47907, USA;
jmyersha@purdue.edu
2X-Bio Institute, Tyumen State University, 25 Lenina St. Str., 625003 Tyumen, Russia;
jukoman@yandex.ru (V.B.K.)
3All-Russian Research Institute of Plant Protection, 396030 Voronezh, Russia
4Citrus Research and Education Center, University of Florida, 700 Experiment Road Station,
Lake Alfred, FL 33850, USA
5Beneficial Insectary Inc., Redding, CA 96003, USA; clivebugsme@outlook.com
6
Biobest Sustainable Crop Management, R&D, 2260 Westerlo, Belgium; jonas.merckx@biobestgroup.com (J.M.)
7Biodiversity Inventory for Conservation NPO (BINCO), Walmersumstraat 44, 3380 Glabbeek, Belgium
8Departamento de Zoologia, Universidade Estadual Paulista, Av. 24-A, 1515, Rio Claro 13506-900, SP, Brazil;
luizgustavopedroso@gmail.com
*Correspondence: pklimov@purdue.edu
Abstract:
Mites of the genus Thyreophagus (Acari: Acaridae) are distributed worldwide; they inhabit
concealed habitats and include several beneficial and economically important species. However,
species identification is difficult because many species are poorly described or delimited and their
phoretic stages are unknown or uncorrelated. Furthermore, Thyreophagus is interesting because it
includes entirely asexual (parthenogenetic) species. However, among the 34 described species of
Thyreophagus, the asexual status is confirmed through laboratory rearing for only two species. Here,
we provide detailed descriptions of five new species from North America (four) and Europe (one)
based on adults and phoretic heteromorphic deutonymphs. Four of these species were asexual,
while one was sexual. For most of these mites, the asexual status was confirmed and phoretic
deutonymphs were obtained through rearing in the lab. We show that asexual mites retain seemingly
functional copulatory and sperm storage systems, indicating that these lineages have relatively short
evolutionary lifespans. One North American species, Thyreophagus ojibwe, was found in association
with the native American chestnut Castanea dentata, suggesting a possibility that this mite can be used
to control chestnut blight in North America. We also provide a diagnostic key to females, males, and
heteromorphic deutonymphs of the Thyreophagus species in the world.
Keywords:
astigmatid mites; parthenogenetic species; new species; morphology; systematics; North
America; Europe; factitious food source
1. Introduction
The genus Thyreophagus (Rondani, 1874) is distributed worldwide, except in Antarc-
tica [
1
–
5
]. There are 39 nominal species and one subspecies inhabiting various envi-
ronments; however, most commonly, they are found in subcortical habitats and stored
food [
1
,
2
,
6
–
9
]. Some species of the genus are beneficial and used as a factitious food source
for the mass rearing of predacious phytoseiid mites used for biological control [
10
–
12
].
The Palearctic species, Thyreophagus corticalis (Michael, 1885) is beneficial because it is a
natural vector of a hypovirus pathogenic to the ascomycete fungus Cryphonectria parasitica
Life 2023,13, 2168. https://doi.org/10.3390/life13112168 https://www.mdpi.com/journal/life

Life 2023,13, 2168 2 of 57
that causes chestnut blight, a dangerous disease of chestnuts in temperate regions in the
northern hemisphere [
13
]. The hypovirus infects C. parasitica and reduces its parasitic
growth, leading to the spontaneous recovery of infected chestnut trees, Castanea sativa, from
the disease in Europe [
14
,
15
]. When C. parasitica was inadvertently introduced to North
America, it caused the functional extinction of the American chestnut Castanea dentata [
16
].
Efforts to find remedies to alleviate the destructive attacks of this pathogen have been ongo-
ing for many decades, but no practical and widely successful solution had been discovered
to date [17].
Since most species of Thyreophagus live in concealed habitats, they have been generally
overlooked and understudied by researchers in comparison to most other acarid mite
genera. The lack of correlation of adult and deutonymphal stages for many species;
the presence of old, insufficiently described, unrecognizable taxa; the lack of types; and
unclear species boundaries are cited as being the major impediments to the systematics
of Thyreophagus [
8
]. As an example, only four species are recognizable in both adult and
deutonymphal stages: Th. Australis (Clark, 2009), Th. Corticalis,Th. Entomophagus, and Th.
Calusorum Klimov, Demard, Stinson, Duarte, Wäckers, and Vangansbeke, 2022 [
8
,
18
–
20
].
One remarkable feature of the genus Thyreophagus is the presence of both sexual and asexual
species, although only a few species from the latter group are known to date: Th. Calusorum,
Th. Plocepasseri (Klimov, Mwangi, Vangansbeke, 2020), and an unnamed species from a
wasp nest in Japan [
9
]. Asexual species have been reared in cultures for many generations
with no males detected.
Here, we provide detailed descriptions of five new species from North America (four)
and Europe (one) based on adult and phoretic heteromorphic deutonymphs. Four of
these species were asexual, while one was sexual. The asexual status for most of these
mites was confirmed through lab rearing. One North American species was found in
association with the native American chestnut Castanea dentata, thus opening avenues for
further research investigating whether the mite also can vector a hypoviruses that can
infect and control the fungal pathogen of the tree. We demonstrate that females of asexual
species retain functional structures responsible for insemination and sperm storage, with
no signs of morphological reductions observed in the spermatheca. This suggests that
these taxa are recent and probably evolutionary short-lived asexuals, thus meriting further
genomic research into the potential causes of their asexual mode of reproduction. We also
provide a diagnostic key to females, males, and heteromorphic deutonymphs for all known
Thyreophagus species in the world.
2. Materials and Methods
Fallen tree branches were collected from forest litter and processed in the lab. Feeding
stages of live mites were sampled in subcortical spaces under a Zeiss Stemi DV4 dissecting
microscope. Voucher specimens were mounted on slides, preserved in ethanol, or cultured
(room temperature, RH 85%) using bran as a food source, with the addition of baker’s yeast
(80% bran, 20% yeast by volume). The culture was harvested and subcultured several times
to obtain a large number of specimens and heteromorphic deutonymphs. The specimens
were preserved in ethanol, cleared in Nesbitt’s fluid for 1–2 days, mounted in Hoyer’s
medium, and dried at 60
◦
C for 7 days [
21
]. To control for potential environmentally
induced variations due to culturing [
22
], both original specimens collected in the wild and
cultured specimens were examined (see details below).
Images were taken using a Nikon Eclipse E800 microscope equipped with a DIC optic
and a Tucsen Discovery CH30 digital camera, and a Zeiss Axio Imager.A2 equipped with a
DIC optic and Axiocam 305 color camera. Images were taken from multiple focal planes
and assembled in Helicon Focus 7.6.4 Pro (algorithm B, rarely A) with subsequent manual
editing to add missing fine detail from the individual focal planes (retouching). Parts of the
layered images were combined in Adobe Photoshop 22.2.0. Line drawings were created in
Photoshop using microphotographs as the background.

Life 2023,13, 2168 3 of 57
The idiosomal chaetotaxy followed Griffiths et al. [
23
]; the terminology of coxisternal
setae followed Norton [
24
]; for appendages, the chaetotaxy and solenidiotaxy followed
Grandjean for palps [
25
] and legs [
26
]. Designations of tarsal dorsoapical setae on legs
III–IV followed Klimov et al. [7]. All measurements are presented in micrometers (µm).
3. Descriptions of New Species
Thyreophagus ais Klimov, Kolesnikov, Demard, Vangansbeke sp. n.
(Figures 1–8).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Life 2023, 13, x FOR PEER REVIEW 3 of 62
the layered images were combined in Adobe Photoshop 22.2.0. Line drawings were cre-
ated in Photoshop using microphotographs as the background.
The idiosomal chaetotaxy followed Griffiths et al. [23]; the terminology of coxisternal
setae followed Norton [24]; for appendages, the chaetotaxy and solenidiotaxy followed
Grandjean for palps [25] and legs [26]. Designations of tarsal dorsoapical setae on legs III–
IV followed Klimov et al. [7]. All measurements are presented in micrometers (µm).
3. Descriptions of New Species
Thyreophagus ais Klimov, Kolesnikov, Demard, Vangansbeke sp. n.
(Figures 1–8).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Figure 1.
Thyreophagus ais sp. n., female (holotype): (
A
)—dorsal view; (
B
)—ventral view. Scale bar:
100 µm.

Life 2023,13, 2168 4 of 57
1
Figure 2.
Thyreophagus ais sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsolateral view; F—tarsus III,
ventrolateral view; G—leg IV, dorsolateral view; H—tarsus IV, ventrolateral view; I—spermatheca;
J—supracoxal sclerite and Grandjean’s organ. Scale bar: 50 µm.

Life 2023,13, 2168 5 of 57
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Figure 3.
Thyreophagus ais sp. n., female (holotype), DIC images: (
A
)—dorsal view; (
B
)—ventral view;
(C)—coxal fields I–II; (D)—coxal fields III–IV; (E)—ovipore and coxal fields III–IV. Scale bar: 50 µm.

Life 2023,13, 2168 6 of 57
Life 2023, 13, x FOR PEER REVIEW 6 of 62
Figure 3. Thyreophagus ais sp. n., female (holotype), DIC images: (A)—dorsal view; (B)—ventral
view; (C)—coxal fields I–II; (D)—coxal fields III–IV; (E)—ovipore and coxal fields III–IV. Scale bar:
50 µm.
Figure 4. Thyreophagus ais sp. n., female (holotype), DIC images: (A)—prodorsal shield; (B)—su-
pracoxal sclerite and Grandjean’s organ; (C)—leg I and gnathosoma (part), dorsal view; (D)—leg I
and gnathosoma (part), ventral view; (E)—leg I, ventral view; (F)—tarsus I, dorsal view; (G)—leg I,
Figure 4.
Thyreophagus ais sp. n., female (holotype), DIC images: (
A
)—prodorsal shield; (
B
)—
supracoxal sclerite and Grandjean’s organ; (
C
)—leg I and gnathosoma (part), dorsal view; (
D
)—leg I
and gnathosoma (part), ventral view; (
E
)—leg I, ventral view; (
F
)—tarsus I, dorsal view; (
G
)—leg
I, dorsal view; (
H
)—leg II, dorsal view; (
I
,
J
)—leg II, ventral view; tarsus II, ventral view. Scale bar:
50 µm.

Life 2023,13, 2168 7 of 57
Life 2023, 13, x FOR PEER REVIEW 7 of 62
dorsal view; (H)—leg II, dorsal view; (I,J)—leg II, ventral view; tarsus II, ventral view. Scale bar: 50
µm.
Figure 5.
Thyreophagus ais sp. n., female (holotype (
A
–
G
) and paratypes (
H
–
J
)), DIC images: (
A
)—
legs III–IV, dorsolateral view; (
B
)—legs III–IV, ventrolateral view; (
C
)—leg III, dorsolateral view;
(
D
)—leg III, ventrolateral view; (
E
)—leg IV, dorsolateral view; (
F
)—leg IV, ventrolateral view; (
G
–
J
)—
spermatheca. Scale bar: 50 µm.

Life 2023,13, 2168 8 of 57
Life 2023, 13, x FOR PEER REVIEW 8 of 62
Figure 5. Thyreophagus ais sp. n., female (holotype (A–G) and paratypes (H–J)), DIC images: (A)—
legs III–IV, dorsolateral view; (B)—legs III–IV, ventrolateral view; (C)—leg III, dorsolateral view;
(D)—leg III, ventrolateral view; (E)—leg IV, dorsolateral view; (F)—leg IV, ventrolateral view; (G–
J)—spermatheca. Scale bar: 50 µm.
Figure 6. Thyreophagus ais sp. n., heteromorphic deutonymph: (A)—dorsal view; (B)—ventral view.
Scale bar: 100 µm.
Figure 6.
Thyreophagus ais sp. n., heteromorphic deutonymph: (
A
)—dorsal view; (
B
)—ventral view.
Scale bar: 100 µm.
Type material
. Holotype: One female—lab culture on bran, harvested 26 February
2021, culture started from specimens originated from the USA, Florida, Fort Pierce, branches
on ground in a small wooded area, subcortical, 27
◦
25
0
34.5
00
N 80
◦
24
0
22.7
00
W, 20 November
2020, Emilie Demard coll., BMOC 20-0101-014#S1.1. Paratypes: 3f (S1.2,3; S3.1), 6 HDNs
(S4.1; S5.1; S6.1-4)—same data; 2f—original wild sample (see above).
Depository
. Holotype, paratypes—University of Michigan, Museum of Zoology, Ann
Arbor, Michigan, USA.
Etymology
. The new species is named after the Ais people who lived in the eastern
coastal area of central Florida (including the type locality of the new species) but went
extinct after the arrival of European colonizers [27].
Habitat
. Thyreophagus ais lives under the bark of small fallen branches of deciduous
trees in wooded areas. These branches are typically in the initial stages of decomposition,
with approximately 80% of their natural sapwood retaining a white color, and 20% display-
ing brown discoloration, indicating the ongoing decomposition process. Additionally, the
bark usually exhibits boreholes from wood-boring beetles.

Life 2023,13, 2168 9 of 57
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Figure 7. Thyreophagus ais sp. n., heteromorphic deutonymph, DIC images: (A)—dorsal view; (B)—
ventral view. Scale bar: 100 µm.
Figure 7.
Thyreophagus ais sp. n., heteromorphic deutonymph, DIC images: (
A
)—dorsal view;
(B)—ventral view. Scale bar: 100 µm.
Life 2023, 13, 2168 10 of 62
Figure 8. Thyreophagus ais sp. n., heteromorphic deutonymph, DIC images: (A,D,F,H)—dorsal
views; (B,E,G,I)—ventral views; (C)—gnathosoma, ventral view. Scale bar: 50 µm.
Figure 8. Cont.

Life 2023,13, 2168 10 of 57
Life 2023, 13, 2168 10 of 62
Figure 8. Thyreophagus ais sp. n., heteromorphic deutonymph, DIC images: (A,D,F,H)—dorsal
views; (B,E,G,I)—ventral views; (C)—gnathosoma, ventral view. Scale bar: 50 µm.
Figure 8.
Thyreophagus ais sp. n., heteromorphic deutonymph, DIC images: (
A
,
D
,
F
,
H
)—dorsal views;
(B,E,G,I)—ventral views; (C)—gnathosoma, ventral view. Scale bar: 50 µm.
Description
Female
(Figures 1–5). Idiosoma elongate, 600
×
250 (holotype), 400–620
×
120–230
(paratype, n= 4), 2.4 (2.6–3.3, n= 4)-times longer than wide. Idiosomal cuticle smooth.
Subcapitular setae (h) long, widened basally; palp tibial setae (a), lateral dorsal palp tibial
setae (sup), dorsal palp tarsal seta (cm) filiform; supracoxal seta elcp absent; terminal
palp tarsal solenidion
ω
short; external part of eupathidium ul” dome-shaped; terminal
eupathidium ul’ not observed. Prodorsal sclerite 105 (70–94, n= 4) long, 96 (57–82,
n= 4)
wide, 1.1 (1.1–1.2, n= 4)-times longer than wide, both smoothly punctated and very
finely longitudinally striated, except in anterior 1/5 (smoothly punctate) and posterior 1/4
(ornamented with distinct pattern of broken striae arranged in a triangle). Prodorsal sclerite
with setae vi situated at anterior part of shield (bases touching but separated from each
other), rounded anterolateral incisions, and elongate midlateral incisions (corresponding to
insertion points of setae ve).

Life 2023,13, 2168 11 of 57
Grandjean’s organ (GO) expanded into 13 membranous finger-like extensions. Supra-
coxal seta (scx) smooth, sword-shaped, widened, and flattened, tapering at tip. Idiosomal
setae (vi,se,cp,d2,e2,h1,h2,h3,ps3) smooth, filiform, and short; opisthosomal gland open-
ings slightly anteriad of setal bases e
2
. One pair of fundamental cupules (ia) present (other
cupules not observed).
Ventral idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and one pair of
genital setae (g). Shape of coxal sclerites as shown in Figures 1B, 3C,D, and 5E,F. Ovipore
situated between coxal fields III and IV; genital valves of ovipore shaped as an inverted
Y; epigynal and medial apodemes well-developed. Genital papillae medium-sized, their
diameters approximately 5–6-times shorter than the length of genital setae. Anal opening on
posterior margin of idiosoma, mostly ventral, with substantial portion situated terminally
and dorsally. Copulatory tube weakly developed. Canal of spermatheca long, slender,
and uniform in diameter (not widened at entrance to spermatheca), forming a small, well-
sclerotized, cup-shaped atrium. Spermatheca simple, with small sclerotized base and small,
paired, Y-shaped sclerites of oviducts.
Legs short. Trochanters I–III each with long, filiform seta, pR I–II, sR III; trochanter
IV without setae. Femoral setation 1-1-0-1; setae vF I–II and wF IV long, filiform. Genual
setation 2-2-0-0; setae mG and cG I–II long, filiform; seta nG III absent. Tibial setation 2-2-1-1;
setae hT I-II filiform; setae gT I–II and kT III–IV elongated, somewhat spiniform. Tarsal
setation 10-10-10-10; all pretarsi with hooked empodial claws arising from tarsal apices
and short paired condylophores. Tarsus I with 10 setae; ra,la,f, and dfiliform; e,u,v,p,
qspiniform (pand qdistinctly shorter than uand v); sflattened, button-shaped; setae wa
absent. Tarsal II setation similar to that of tarsus I, except proral setae (p,q) represented by
small triangular rudiments (Figure 4J). Tarsus III with 10 setae; f,d,rfiliform; e,w,s,u,v,
p,qspiniform. Tarsus IV similar to tarsus III, except wfiliform. Solenidion
ω1
on tarsus I
cylindrical, with clavate apex, slightly curved; solenidion
ω1
on tarsus II simple, cylindrical,
with clavate apex, not bent, shorter than
ω1
on tarsus I. Solenidion
ω2
on tarsus I shorter
than
ω1
, cylindrical, with rounded apex, slightly widened at tip, situated slightly anterior
and external to
ω1
. Solenidion
ω3
on tarsus I cylindrical, with rounded apex, subequal
to
ω1
, longer than
ω2
. Famulus (
ε
) of tarsus I wide, spiniform, with broadly rounded
apex, widest at middle. Solenidia
ϕ
of tibiae I–III elongate, tapering, well-extended beyond
apices of respective tarsi with ambulacra; solenidion
ϕ
IV shorter, shorter than tarsus IV
(with ambulacra). On genu I, solenidion
σ
’ elongate, tapering, slightly not reaching bases
of
ϕ
I, about 1.8-times longer than
σ
”;
σ
” I slightly wider than
σ
’, about half the length of
tibia I. On genu II, solenidion
σ
very short and somewhat conical. Solenidion
σ
of genu III
absent.
Male. Absent.
Heteromorphic deutonymph
(Figures 6–8). Body elongate, 1.53–1.84-times longer
than wide (n= 4), widest in sejugal region; idiosomal length 210–240, n= 4 width 130–150,
n= 4. Gnathosoma short, subcapitulum and palp fused, bearing apical palpal solenidia
(
ω
) and filiform apicodorsal setae (sup); setae habsent from subcapitular remnant, their
positions marked by refractile spots.
Dorsum. Propodosoma and hysterosoma each covered by smoothly punctate shields;
distinct linear pattern present on anterior and lateral sides of propodosomal sclerite and hys-
terosomal shield. Anterior propodosoma with internal vertical setae (vi) (bases separated)
and a single sclerite. A pair of lateral ocelli present on propodosoma, widely separated from
each other (distance 35–42, n= 4); lenses and pigmented spots present; maximal diameter
of lenses 12–14, n= 4. External vertical setae (ve) absent; external scapular setae se situated
just below eye lenses; internal scapular setae (si) distinctly posterior and medial to external
scapulars (se). Supracoxal setae of legs I (scx) filiform, with extended base, satiated below
se. Sejugal furrow well-developed. Propodosomal sclerite 65–80, n= 4, hysterosomal shield
139–160, n= 4, ratio hysterosomal shield/propodosomal sclerite = 2.0–2.13. Hysterosomal
shield with 11 pairs of simple, filiform setae (c
1
,c
2
,c
p
,d
1
,d
2
,e
1
,e
2
,f
2
,h
1
,h
2
,h
3
), setae
h
3
distinctly longer than others. Opisthonotal gland openings (gla) ventral, situated on

Life 2023,13, 2168 12 of 57
hysterosomal shield, slightly posterior to setae c
3
. Of four fundamental pairs of cupules,
three pairs observed: ia posteriomediad of setae c
2
,im ventral, lateral to trochanter IV, ih
ventral, lateral to posterior portion of attachment organ.
Venter. Coxal fields sclerotized, smoothly punctate. Anterior apodemes of coxal
fields I fused forming sternum; sternum not reaching posterior border of sternal shield by
distance exceeding its length. Posterior border of sternal shield not sclerotized. Anterior
apodemes of coxal fields II curved medially. Posterior apodemes of coxal fields II weakly
developed, thin. Sternal and ventral shield adjacent. Anterior apodemes of coxal fields
III free, connected by thin transverse sclerotization. Posterior medial apodeme present
in area of coxal fields IV, well-separated from anterior apodemes IV and genital opening.
Posterior apodemes IV absent. Subhumeral setae (c
3
) filiform, situated on ventral surface
between legs II–III, adjacent to region separating sternal and ventral shields. Coxal setae 1a,
3a reduced, represented by very small structures each within an alveolus. Coxal setae (4b)
filiform, situated at tips anterior to coxal apodemes IV; 4a in form of small, rounded conoids.
Progenital region in posterior portion of coxal fields IV; genital opening elongate; two pairs
of genital papillae within genital atrium; genital papillae two-segmented, with rounded
apices; genital setae (g) filiform, situated laterad of genital opening. Attachment organ
posterior to coxal fields IV. Anterior suckers (ad
3
) round, median suckers (ad
1+2
) distinctly
larger, with paired vestigial alveoli; pair of small refractile spots anterolateral to median
suckers (ps
3
); lateral conoidal setae of attachment organ (ps
2
) situated distinctly posterior to
line joining centers of median suckers, slightly anterior conoids (ps
1
) and slightly posterior
to median suckers (ad
1+2
); anterior and posterior lateral and posterior median cuticular
conoids well-developed; anus situated between anterior suckers (ad3).
Legs. Legs elongate, all segments free. Trochanters I–III each with long, filiform seta,
pR I–II, sR III. Femoral setation 1-1-0-1; setae vF I–II and wF IV long, filiform. Genual
setation 2-2-0-0; setae mG and cG I–II filiform, seta nG III absent. Tibial setation 2-2-1-1;
setae hT I somewhat spiniform; setae gT I filiform (Figure 8B); setae gT and hT II spiniform;
setae kT III filiform; setae kT IV spiniform. Tarsal setation 7-8-8-8. All pretarsi consisting of
hooked empodial claws arising from tarsal apices attached to short, paired condylophores
within tarsal apices. Tarsus I with six filiform setae (ra,la,p,q,d, and f), setae delongate,
their bases situated at level anterior to bases of setae ra and la; one spoon-shaped seta
e; setae salveolar, setae wa,aa and ba I absent; tarsus II similar to tarsus I except seta ba
present and filiform, close to
ω1
. Tarsus III with eight setae (w,r,s,p,q,e,f,d) smooth;
all setae, except dIII more or less foliate; seta dequal to or longer than leg III. Tarsus IV
similar to tarsus III, except setae qand pshort, spiniform, seta rlonger, filiform, seta w
filiform and with distinct prong, seta ddistinctly longer than legs IV. Solenidia
ω1
on tarsi
I–II cylindrical, with slightly clavate apices;
ω3
on tarsus I slightly shorter than
ω
1, with
rounded apex, positioned slightly anterior to
ω1
;
ω1
and
ω3
separated by bulbous famulus
(
ε
); solenidion
ω2
of tarsus I slightly widened apically, situated somewhat more basal and
posterior to
ω1
+
ε
+
ω3
group; solenidia
ϕ
of tibiae I–III elongate, tapering;
ϕ
I longer than
tarsus I;
ϕ
II shorter than tarsus II;
ϕ
III reaching tip of tarsus III without ambulacrum;
ϕ
IV short;
σ
of genu I elongate, tapering slightly, nearly reaching tip of tibia I;
σ
of genu II
shorter, cylindrical, not reaching midlength of tibia II; σof genu III absent.
Diagnosis
Female. Thyreophagus ais is close to Th. calusorum,Th. mauritianus (Fain, 1982), Th.
gallegoi Portus and Gomez, 1979 and Th. vermicularis Fain and Lukoschus, 1982 in having
a very short solenidion
σ
II. Th. ais is similar to Th. calusorum and Th. mauritianus by
the shape of solenidion
σ
II, which has convex sides (sides straight and not convex in Th.
gallegoi and Th. vermicularis), but it differs from Th. calusorum by the following: sclerites
of oviducts are Y-shaped (V-shaped in Th. calusorum); the canal of spermatheca at the
entrance to spermatheca is not widened (Figure 2I) vs. widened in Th. calusorum [
8
]
(Figure 9); the canal of spermatheca forms a small, well-sclerotized, cup-shaped atrium
(Figures 2I and 5G–J)
vs. canal uniform in appearance, atrium absent [
8
] (Figure 9); bases
of setae vi are touching but separated (in common area in Th. calusorum). Th. ais differs from

Life 2023,13, 2168 13 of 57
Th. mauritianus as follows: the cuplike portions of the sclerites of oviducts are subequal
to their stems (Figure 5G–J vs. shorter than stems in Th. mauritianus [
8
] (Figure 31B–D);
solenidion
σ
’ is distinctly longer than
σ
” (subequal in Th. mauritianus); solenidion
ω1
II
is three-times longer than its width (five-times longer in Th. mauritianus); and solenidion
ϕ
IV is nearly reaching the bases of setae dIV (reaching the middle of tarsus IV in Th.
mauritianus). Th. ais differs from Th. gallegoi by the absence of linear sclerites near the
typical sclerites of oviducts (present in Th. gallegoi) and from Th. vermicularis by the Y-
shaped paired sclerites of oviducts, which are at least three-times longer than their width
(V-shaped, more than five-times longer than their width in Th. vermicularis).
Life 2023, 13, x FOR PEER REVIEW 14 of 62
Figure 9. Thyreophagus hobe sp. n., female (holotype): (A)—dorsal view; (B)—ventral view. Scale bar:
100 µm.
Figure 9.
Thyreophagus hobe sp. n., female (holotype): (
A
)—dorsal view; (
B
)—ventral view. Scale bar:
100 µm.
Heteromorphic deutonymph. Th. ais is very similar to Th. calusorum, but differs by
short, spiniform setae qand pIV (foliate in Th. calusorum), setae dIII are longer than leg
III (shorter in Th. calusorum), dIV distinctly longer than leg IV (subequal to leg IV in Th.

Life 2023,13, 2168 14 of 57
calusorum). Setae hT I and kT IV are always spiniform in Th. ais, but it can be variable, either
spiniform or filiform in Th. calusorum (Klimov et al., 2022).
Thyreophagus hobe Klimov, Kolesnikov, Demard, Vangansbeke, sp. n.
(Figures 9–13).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Life 2023, 13, x FOR PEER REVIEW 15 of 62
Figure 10. Thyreophagus hobe sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsolateral view; F—tarsus III,
ventrolateral view; G—leg IV, dorsolateral view; H—tarsus IV, ventrolateral view; I—spermatheca.
Scale bar: 50 µm.
Figure 10.
Thyreophagus hobe sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsolateral view; F—tarsus III,
ventrolateral view; G—leg IV, dorsolateral view; H—tarsus IV, ventrolateral view; I—spermatheca.
Scale bar: 50 µm.

Life 2023,13, 2168 15 of 57
Life 2023, 13, x FOR PEER REVIEW 16 of 62
Figure 11. Thyreophagus hobe sp. n., female (holotype), DIC images: (A)—dorsal view; (B)—ventral
view. Scale bar: 100 µm.
Figure 11.
Thyreophagus hobe sp. n., female (holotype), DIC images: (
A
)—dorsal view; (
B
)—ventral
view. Scale bar: 100 µm.

Life 2023,13, 2168 16 of 57
Life 2023, 13, x FOR PEER REVIEW 17 of 62
Figure 12. Thyreophagus hobe sp. n., female (holotype), DIC images: (A)—prodorsal shield; (B)—gna-
thosoma, ventral view; (C)—coxal fields I–II; (D)—ovipore and coxal fields III–IV; (E)—sperma-
theca. Scale bar: 50 µm.
Figure 12.
Thyreophagus hobe sp. n., female (holotype), DIC images: (
A
)—prodorsal shield;
(
B
)—gnathosoma, ventral view; (
C
)—coxal fields I–II; (
D
)—ovipore and coxal fields III–IV; (
E
)—
spermatheca. Scale bar: 50 µm.
Type material
. Holotype: female—USA: Florida, Fort Pierce, branches on ground in
a small, wooded area, subcortical, stick3, 27
◦
25
0
34.5
00
N 80
◦
24
0
22.7
00
W, 12 October 2020,
Emilie Demard, BMOC 20-0101-008. Culture maintained until 26 February 2021 but then
was accidentally lost (no specimens from these cultures were preserved).
Depository
. Holotype—University of Michigan, Museum of Zoology, Ann Arbor,
Michigan, USA.
Etymology
. The new species is named after the Hobe Indians who lived in the eastern
coastal area of central Florida (between St. Lucie and Jupiter inlets), but went extinct after
the arrival of European colonizers [
27
]. The men of the Hobe Indians had long hair
6
, which
is reminiscent of the long dorsal setae of Thyreophagus hobe.
Habitat
.Thyreophagus hobe lives under the bark of small fallen branches found in
wooded areas. These branches are typically in the initial stages of decomposition, with

Life 2023,13, 2168 17 of 57
approximately 80% of their natural sapwood retaining a white color, and 20% displaying
brown discoloration, indicating the ongoing decomposition process.
Life 2023, 13, x FOR PEER REVIEW 18 of 62
Figure 13. Thyreophagus hobe sp. n., female (holotype), DIC images: (A)—leg I, dorsal view; (B)—leg
I, ventral view; (C)—leg II, dorsal view; (D,E)—leg II, ventral view; (F)—legs III–IV, dorsal view;
(G)—legs III–IV, ventral view. Scale bar: 50 µm.
Type material. Holotype: female—USA: Florida, Fort Pierce, branches on ground in
a small, wooded area, subcortical, stick3, 27°25′34.5″ N 80°24′22.7″ W, 12 October 2020,
Emilie Demard, BMOC 20-0101-008. Culture maintained until 26 February 2021 but then
was accidentally lost (no specimens from these cultures were preserved).
Depository. Holotype—University of Michigan, Museum of Zoology, Ann Arbor,
Michigan, USA.
Etymology. The new species is named after the Hobe Indians who lived in the eastern
coastal area of central Florida (between St. Lucie and Jupiter inlets), but went extinct after
the arrival of European colonizers [27]. The men of the Hobe Indians had long hair 6, which
is reminiscent of the long dorsal setae of Thyreophagus hobe.
Habitat. Thyreophagus hobe lives under the bark of small fallen branches found in
wooded areas. These branches are typically in the initial stages of decomposition, with
approximately 80% of their natural sapwood retaining a white color, and 20% displaying
brown discoloration, indicating the ongoing decomposition process.
Figure 13.
Thyreophagus hobe sp. n., female (holotype), DIC images: (
A
)—leg I, dorsal view; (
B
)—leg
I, ventral view; (
C
)—leg II, dorsal view; (
D
,
E
)—leg II, ventral view; (
F
)—legs III–IV, dorsal view;
(G)—legs III–IV, ventral view. Scale bar: 50 µm.
Description
Female
(Figures 9–13). Idiosoma elongate, 350
×
120 (holotype), 2.9-times longer
than wide. Idiosomal cuticle smooth. Subcapitular setae (h) long, widened basally; palp
tibial setae (a), lateral dorsal palp tibial setae (sup), dorsal palp tarsal seta (cm) filiform;
supracoxal seta elcp present, slightly widened basally; terminal palp tarsal solenidion
ω
short; external part of terminal eupathidium ul” dome-shaped; terminal eupathidium ul’
not observed. Prodorsal sclerite 63 long, 46 wide, 1.4-times longer than wide, with setae vi
(situated at anterior part of shield, bases in common area of unsclerotized cuticle), rounded
anterolateral incisions, and elongate midlateral incisions (corresponding to insertion points
of setae ve); shield punctate, 3/4 of posterior central region with linear pattern. Grandjean’s
organ (GO) expanded anteriorly into membranous finger-shaped extensions (exact number

Life 2023,13, 2168 18 of 57
cannot be observed on the single specimen). Supracoxal seta (scx) smooth, sword-shaped,
widened and flattened, tapering at tip. Idiosomal setae (vi,se,c
p
,d
2
,e
2
,h
1
,h
2
,h
3
,ps
3
)
smooth, filiform, setae h
2
and h
3
very long (2.3-times longer than length of prodorsal shield);
opisthosomal gland openings slightly anteriad of setal bases e
2
. Four pairs of fundamental
cupules (ia,im,ip,ih) present.
Ventral surface of idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and one
pair of genital setae (g), seta 4b unpaired in holotype (abnormality). Shape of coxal sclerites
as shown in Figures 1B and 4C,D. Genital region between coxal fields III and IV; genital
valves shaped in an inverted Y; epigynal and medial apodemes well-developed. Genital
papillae medium-sized, their diameter approximately 5–6-times shorter than length of
genital setae. Anal opening situated on posterior margin of idiosoma, mostly ventral, with
substantial portion positioned terminally and dorsally. Copulatory tube weakly developed.
Canal of spermatheca medium-sized, slender, uniformly wide, not widening at entrance
to spermatheca. Spermatheca simple, with sclerotized, dome-shaped atrium (length and
width subequal), small, paired Y-shaped sclerites of oviducts, and large sperm storage sac.
Legs short, all segments free. Trochanters I–III each with long, filiform seta, pR I–II, sR
III; trochanter IV without setae. Femoral setation 1-1-0-0; setae vF I–II long, filiform, wF IV
absent. Genual setation 2-2-0-0; setae mG and cG I–II long, filiform; seta nG III absent. Tibial
setation 2-2-1-1; setae hT I-II represented by alveoli; setae gT I–II and kT III–IV elongated,
filiform. Tarsal setation 8-8-8-8; all pretarsi have hooked empodial claws arising from tarsal
apices and attached to short paired condylophores. Tarsus I with eight setae; ra,la,f, and d
filiform; e,s,p, and qspiniform, small; uand vabsent (represented by weakly developed
rounded structures), setae wa absent. Tarsus II setation similar to that of tarsus I. Tarsus III
with eight setae; f,d,rfiliform; eand sspiniform; p,q,u, and vsimilar to these of tarsus I–II;
seta wflattened, button-shaped. Tarsus IV similar to tarsus III, except wfiliform. Solenidion
ω1
on tarsus I cylindrical, with clavate apex, slightly curved; solenidion
ω1
on tarsus II
simple, cylindrical, with clavate apex, not bent, longer than
ω1
on tarsus I. Solenidion
ω2
on tarsus I shorter than
ω1
, cylindrical, with rounded apex, slightly expanded at tip,
situated slightly anterior and external to
ω1
. Solenidion
ω3
on tarsus I cylindrical, with
rounded apex, shorter than
ω1
I. Famulus (
ε
) of tarsus I spiniform, with pointed apex.
Solenidia
ϕ
of tibiae I–III elongate, tapering, well extending beyond apices of respective
tarsi with ambulacra; solenidion
ϕ
IV shorter than tarsus IV (with ambulacra). Genual
solenidia
σ
’ and
σ
” I elongate, tapering, subequal, slightly not reaching bases of
ϕ
I. Genual
solenidion
σ
II 7–9-times longer than its width, with rounded tip. Genual solenidion
σ
III
absent.
Male. Absent.
Heteromorphic deutonymph. Unknown.
Diagnosis
Female. Thyreophagus hobe differs from all known species of Thyreophagus by the
absence of femoral setae wF IV and unguinal setae u,vI–IV. Like Th. australis Clark, 2009,
Th. hobe has very long setae h
2
and h
3
(2.3-times longer than the length of the prodorsal
shield in Th. hobe (2.5–2.8-times longer than the length of the prodorsal sclerite in Th.
australis), but in Th. hobe, setae h
1
five-times shorter than h
2
and h
3
(vs. h
1
,h
2
, and h
3
are
subequal in Th. australis).
Thyreophagus ojibwe Klimov, Kolesnikov, Vangansbeke, sp. n.
(Figures 14–20).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Type material
. Holotype female (f1), paratype female (f2)—USA: Michigan, Michigan
State University Chestnut Plantation, Castanea dentata (Fagales: Fagaceae), branch on
ground (tree1.stick1), 42
◦
09
0
06.6
00
N 84
◦
25
0
33.2
00
W, 23 November 2020, P. Klimov, BMOC
20-0101-010#slide1; 1 paratype female—same data, slide 2; 1 paratype female—same data,
C. dentata blight tissues, BMOC 20-0101-012#slide3.
Non-type material
. One male, two females—CANADA: Ontario C.E.F., Ottawa, under
bark of dead willow twigs, Salix sp. (Malpighiales: Salicaceae), O. Peck, 1974 CNC788949

Life 2023,13, 2168 19 of 57
(Canadian National Collection) (studied as high-resolution images, provided by Fred
Beaulieu, Canadian National Collection of Insects, Arachnids & Nematodes (CNC)).
Depository
. Holotype, paratypes—University of Michigan, Museum of Zoology, Ann
Arbor, Michigan, USA.
Etymology
. The new species is named after the Ojibwe, North American indigenous
people from what is currently southern Canada and Midwestern United States, including
the state of Michigan.
Habitat
. Thyreophagus ojibwe lives under the bark of small fallen branches typically
found around American chestnut trees. These branches are generally in the initial stages of
decomposition. Additionally, mites were found on the blight-infected tissues, suggesting
that these mites can likely feed on this harmful fungus and potentially transmit hypoviruses.
Life 2023, 13, x FOR PEER REVIEW 20 of 62
shield in Th. hobe (2.5–2.8-times longer than the length of the prodorsal sclerite in Th. aus-
tralis), but in Th. hobe, setae h1 five-times shorter than h2 and h3 (vs. h1, h2, and h3 are sube-
qual in Th. australis).
Thyreophagus ojibwe Klimov, Kolesnikov, Vangansbeke, sp. n.
(Figures 14–20).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Figure 14. Thyreophagus ojibwe sp. n., female (holotype): (A)—dorsal view; (B)—ventral view. Scale
bar: 100 µm.
Figure 14.
Thyreophagus ojibwe sp. n., female (holotype): (
A
)—dorsal view; (
B
)—ventral view. Scale
bar: 100 µm.

Life 2023,13, 2168 20 of 57
Life 2023, 13, x FOR PEER REVIEW 21 of 62
Figure 15. Thyreophagus ojibwe sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsolateral view; F—tarsus III,
ventrolateral view; G—leg IV, dorsolateral view; H—tarsus IV, ventrolateral view; I—spermatheca.
Scale bar: 50 µm.
Figure 15.
Thyreophagus ojibwe sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsolateral view; F—tarsus III,
ventrolateral view; G—leg IV, dorsolateral view; H—tarsus IV, ventrolateral view; I—spermatheca.
Scale bar: 50 µm.

Life 2023,13, 2168 21 of 57
Life 2023, 13, x FOR PEER REVIEW 22 of 62
Figure 16. Thyreophagus ojibwe sp. n., female (holotype), DIC images: (A)—dorsal view; (B)—ventral
view. Scale bar: 100 µm.
Figure 16.
Thyreophagus ojibwe sp. n., female (holotype), DIC images: (
A
)—dorsal view; (
B
)—ventral
view. Scale bar: 100 µm.

Life 2023,13, 2168 22 of 57
Life 2023, 13, x FOR PEER REVIEW 23 of 62
Figure 17. Thyreophagus ojibwe sp. n., female (holotype (D) and paratype (E,F)), DIC images: (A)—
prodorsal shield; (B)—supracoxal sclerite and Grandjean’s organ; (C)—ovipore and coxal fields III–
IV; (D–F)—spermatheca. Scale bar: 50 µm.
Figure 17.
Thyreophagus ojibwe sp. n., female (holotype (
D
) and paratype (
E
,
F
)), DIC images: (
A
)—
prodorsal shield; (
B
)—supracoxal sclerite and Grandjean’s organ; (
C
)—ovipore and coxal fields III–IV;
(D–F)—spermatheca. Scale bar: 50 µm.
Life 2023, 13, x FOR PEER REVIEW 24 of 62
Figure 18. Thyreophagus ojibwe sp. n., female (holotype (D) and paratype (E,F)), DIC images: (A)—
leg I, dorsal view; (B)—leg I, ventral view; (C)—leg I, lateral view; (D)—legs I–II, lateral view; (E)—
leg II, dorsal view; (F)—leg II, ventral view; (G)—legs III–IV, dorsal view; (H)—legs III–IV, ventral
view. Scale bar: 50 µm.
Figure 18.
Thyreophagus ojibwe sp. n., female (holotype (
D
) and paratype (
E
,
F
)), DIC images: (
A
)—leg
I, dorsal view; (
B
)—leg I, ventral view; (
C
)—leg I, lateral view; (
D
)—legs I–II, lateral view; (
E
)—leg II,
dorsal view; (
F
)—leg II, ventral view; (
G
)—legs III–IV, dorsal view; (
H
)—legs III–IV, ventral view.
Scale bar: 50 µm.

Life 2023,13, 2168 23 of 57
Life 2023, 13, x FOR PEER REVIEW 25 of 62
Figure 19. Thyreophagus ojibwe sp. n., male (paratype): (A)—dorsal view; (B)—ventral view. Scale
bar: 100 µm.
Figure 19.
Thyreophagus ojibwe sp. n., male (paratype): (
A
)—dorsal view; (
B
)—ventral view. Scale bar:
100 µm.
Description
Female
(Figures 14–18). Idiosoma elongate, 460
×
200 (holotype), 420-450
×
180-200
(paratype, n= 3), 2.3 (2.3, n= 3)-times longer than wide. Idiosomal cuticle smooth. Subca-
pitular setae (h) long, widened basally; palp tibial setae (a), lateral dorsal palp tibial setae
(sup), dorsal palp tarsal seta (cm) filiform; supracoxal seta elcp present, slightly widened
basally; terminal palp tarsal solenidion
ω
short; external part of terminal eupathidium
ul” dome-shaped; terminal eupathidium ul’ not observed. Prodorsal sclerite 85 (71–80,
n= 3)
long, 75 (60–68, n= 3) wide, 1.1 (1.1–1.2, n= 3)-times longer than wide, with setae
vi (situated at anterior part of sclerite, bases touching but distinctly separated), rounded
anterolateral incisions, and elongate midlateral incisions (corresponding to insertion points
of setae ve); shield smoothly punctate, 3/4 of posterior central region with linear pattern.
Grandjean’s organ (GO) with 8 membranous, finger-shaped extensions. Supracoxal seta
(scx) smooth, sword-shaped, widened and flattened, tapering at tip. Idiosomal setae (vi,
se,c
p
,d
2
,e
2
,h
1
,h
2
,h
3
,ps
3
) smooth, filiform; setae h
2
and h
3
long, 1.75-times longer than
length of prodorsal sclerite; opisthosomal gland openings slightly anteriad of setal bases of
e2. Four pairs of fundamental cupules (ia,im,ip,ih) present.

Life 2023,13, 2168 24 of 57
Life 2023, 13, x FOR PEER REVIEW 26 of 62
Figure 20. Thyreophagus ojibwe sp. n., male (paratype), DIC images: (A)—dorsal view; (B)—ventral
view. Scale bar: 100 µm.
Figure 20.
Thyreophagus ojibwe sp. n., male (paratype), DIC images: (
A
)—dorsal view; (
B
)—ventral
view. Scale bar: 100 µm.
Ventral surface of idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and one
pair of genital setae (g). Shape of coxal sclerites as shown in Figure 1B. Genital region

Life 2023,13, 2168 25 of 57
between coxal fields III and IV; genital valves shaped as an inverted Y; epigynal and
medial apodemes well-developed. Genital papillae large, their diameters approximately
four-times shorter than length of genital setae. Anal opening on posterior margin of
idiosoma, mostly ventral, with substantial portion positioned terminally and dorsally.
Canal of spermatheca short, slender tube, uniformly wide, slightly expanded at entrance to
spermatheca. Spermatheca with elongated, vase-shaped atrium (longer than width); paired
Y-shaped sclerites of oviducts small (their stems short, shorter than atrium in its narrowest
part); and large sperm storage sac.
Legs short, all segments free. Trochanters I–III each with long, filiform seta, pR I–II,
sR III; trochanter IV without setae. Femoral setation 1-1-0-1; setae vF I–II and wF IV long,
filiform. Genual setation 2-2-0-0; setae mG and cG I–II long, filiform; seta nG III absent.
Tibial setation 2-2-1-1; setae hT I-II alveolar; setae gT I–II elongated, somewhat spiniform;
setae kT III–IV filiform. Tarsal setation 10-10-10-10; all pretarsi with hooked empodial claws
attached to short, paired condylophores. Tarsus I with 10 setae; ra,la,f, and dfiliform;
e,u,vspiniform; pand qrepresented by small triangular rudiments; sflattened, button-
shaped; setae wa absent. Tarsus II setation similar to that of tarsus I, except seta ssmall,
spiniform. Tarsus III with 10 setae, f,d,rfiliform, e,s,u,vspiniform, wsmall spiniform,
pand qrepresented by small triangular rudiments. Tarsus IV similar to tarsus III, except
wfiliform. Solenidia
ω1
on tarsi I and II cylindrical, with clavate apices, slightly curved,
almost reaching tip of tarsus (without ambulacra). Solenidion
ω2
on tarsus I shorter than
ω1
, cylindrical, with rounded apex, slightly widened at tip, situated slightly anterior and
external to
ω1
. Solenidion
ω3
on tarsus I cylindrical, with rounded apex, shorter than
ω1
,
longer than
ω2
. Famulus (
ε
) of tarsus I wide, spiniform, with broadly rounded apex, widest
at middle. Solenidia
ϕ
of tibiae I–III elongate, tapering, well extending beyond apices of
respective tarsi with ambulacra; solenidion
ϕ
IV shorter, almost reaching tip of tarsus IV
(without ambulacra). Genual solenidia
σ
’ and
σ
” I elongate, tapering, subequal, slightly not
reaching bases of
ϕ
I. Genual solenidion
σ
II 10-times longer than its width) and somewhat
conical. Genual solenidion σIII absent.
Male
(n= 1) (Figures 19 and 20). Idiosoma elongate, 250
×
120, 2.1-times longer than
wide. Idiosomal cuticle smooth. Gnathosoma as in female. Prodorsal sclerite 50 long,
38 wide, 1.3-times longer than wide, with setae vi, incisions and ornamented as in female.
Grandjean’s organ (GO) and supracoxal seta (scx) as in female. Idiosomal setae (vi,se,
c
p
,d
2
,e
2
,h
1
,h
2
,h
3
) smooth, filiform, setae h
2
and h
3
long (1.8-times longer than length of
prodorsal shield); opisthosomal gland openings slightly anteriad of setal bases e
2
. Four
pairs of fundamental cupules (ia,im,ip,ih) present. Opisthonotal shield solid, whole,
smoothly punctated; ventral part of shield extends to anal suckers.
Ventral surface of idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and
one pair of genital setae (g). Shape of coxal sclerites shown in Figure 19. Genital region
between coxal fields IV; arms of genital capsule rounded; aedeagus short, not protruding
beyond anterior edge of supporting sclerite. Genital papillae medium-sized, their diameter
approximately 4–5-times shorter than genital setae. Anal sucker rounded in outline. Setae
ps1-3 very short.
Legs I–III as in female, except solenidion
ω3
on tarsus I very short, truncated and
solenidion
σ
” about two-times longer than
σ
’. Trochanter and genua IV without setae,
femur IV with setae wF IV long, filiform, tibia IV with kT IV elongated, somewhat spiniform.
Tarsus IV with 10 setae; f,r,wfiliform; dand erepresented by suckers; u,v,p,qspiniform; s
flattened, button-shaped or minute, spiniform. Solenidion ϕon tibia IV short and wider.
Heteromorphic deutonymph. Unknown.
Diagnosis
Female. Th. ojibwe is very similar to Th. corticalis, but differs as follows: setae h
2
and h
3
are 1.75-times longer than the length of the prodorsal sclerite (1.1–1.25 times in Th.
corticalis); the diameter of the genital papillae is approximately four-times shorter than the
length of genital setae (six-times shorter in Th. corticalis); the stem of the Y-shaped sclerites
of oviducts is about 3–4-times shorter than the length of Y-shaped sclerites of oviducts

Life 2023,13, 2168 26 of 57
(subequal in Th. corticalis); ventral apical spines pand qof tarsi III–IV are shorter than
spines uand vIII–IV (subequal in Th. corticalis).
Male. Th. ojibwe differs from Th. corticalis by the longer setae h
2
and h
3
(their length is
1.8-times longer than the length of prodorsal sclerite (1.1–1.25-times longer in Th. corticalis)
and by spines pand qon tarsi III–IV, which are shorter than spines uand v(subequal in Th.
corticalis).
Thyreophagus potawatomorum Klimov, Kolesnikov, Vangansbeke, sp. n.
(Figures 21–34).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.
Life 2023, 13, x FOR PEER REVIEW 29 of 62
Figure 21. Thyreophagus potawatomorum sp. n., female (holotype): (A)—dorsal view; (B)—ventral
view. Scale bar: 100 µm.
Figure 21.
Thyreophagus potawatomorum sp. n., female (holotype): (
A
)—dorsal view; (
B
)—ventral
view. Scale bar: 100 µm.

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Figure 22. Thyreophagus potawatomorum sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I,
ventral view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsal view; F—tarsus
III, ventral view; G—leg IV, dorsal view; H—tarsus IV, ventral view. Scale bar: 50 µm.
Figure 22.
Thyreophagus potawatomorum sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I,
ventral view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsal view; F—tarsus III,
ventral view; G—leg IV, dorsal view; H—tarsus IV, ventral view. Scale bar: 50 µm.

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Figure 23. Thyreophagus potawatomorum sp. n., female (holotype): A—subcapitulum, ventral view;
B—subcapitulum lobes, ventral view; C—supracoxal sclerite and Grandjean’s organ; D—sperma-
theca. Scale bar: 50 µm.
Figure 23.
Thyreophagus potawatomorum sp. n., female (holotype): A—subcapitulum, ventral view; B—
subcapitulum lobes, ventral view; C—supracoxal sclerite and Grandjean’s organ; D—spermatheca.
Scale bar: 50 µm.
Type material
. Holotype female (f2) and one paratype female (f1)—USA: Michigan,
Ann Arbor, Hansen Nature Area, stick 5, 42
◦
16
0
03.8
00
N 83
◦
46
0
53.2
00
W, 14 October 2020, P.
Klimov, BMOC 20-0101-004#slide 1; four paratype females—same data (culture, harvested
26 February 2021), slide 2; six paratype females—same data, slide 3; two paratype HDNs—
same data, slide 5; one paratype HDN—same data, slide 6; one paratype HDN—same data,
slide 8.
Non-type material. Two DNs, one pharate DN—same data, slide 7.
Depository
. Holotype, paratypes—University of Michigan, Museum of Zoology, Ann
Arbor, Michigan, USA.
Etymology
. This species is named after Potawatomi, native American people of the
Great Plains, upper Mississippi River, and western Great Lakes region (including the state
of Michigan).
Habitat
. Thyreophagus potawatomorum lives under the bark of small fallen branches
of deciduous trees in wooded areas. These branches are typically in the initial stages of
decomposition, with approximately 80% of their natural sapwood retaining a white color,
and 20% displaying brown discoloration, indicating the ongoing decomposition process.
Additionally, the bark usually exhibits boreholes from wood-boring beetles.

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Figure 24. Thyreophagus potawatomorum sp. n., female (holotype), DIC images: (A)—dorsal view;
(B)—ventral view. Scale bar: 100 µm.
Figure 24.
Thyreophagus potawatomorum sp. n., female (holotype), DIC images: (
A
)—dorsal view;
(B)—ventral view. Scale bar: 100 µm.

Life 2023,13, 2168 30 of 57
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Figure 25. Thyreophagus potawatomorum sp. n., female ((D–G) holotype and (A–C,H) paratypes), DIC
images: (A)—prodorsal shield; (B)—prodorsal shield; (C)—supracoxal sclerite and Grandjean’s or-
gan; (D)—gnathosoma, ventral view; (E)—gnathosoma, optical section at level labrum, ventral
view; (F)—coxal fields I–II; (G)—ovipore and coxal fields III–IV; (H)—ovipore. Scale bar: 50 µm.
Figure 25.
Thyreophagus potawatomorum sp. n., female ((
D
–
G
) holotype and (
A
–
C
,
H
) paratypes),
DIC images: (
A
)—prodorsal shield; (
B
)—prodorsal shield; (
C
)—supracoxal sclerite and Grandjean’s
organ; (
D
)—gnathosoma, ventral view; (
E
)—gnathosoma, optical section at level labrum, ventral
view; (F)—coxal fields I–II; (G)—ovipore and coxal fields III–IV; (H)—ovipore. Scale bar: 50 µm.

Life 2023,13, 2168 31 of 57
Life 2023, 13, x FOR PEER REVIEW 34 of 62
Figure 26. Thyreophagus potawatomorum sp. n., female (holotype), DIC images: (A)—leg I, dorsal
view; (B)—leg I, ventral view; (C)—leg II, dorsal view; (D)—leg II, ventral view. Scale bar: 50 µm.
Figure 26.
Thyreophagus potawatomorum sp. n., female (holotype), DIC images: (
A
)—leg I, dorsal view;
(B)—leg I, ventral view; (C)—leg II, dorsal view; (D)—leg II, ventral view. Scale bar: 50 µm.

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Figure 27. Thyreophagus potawatomorum sp. n., female ((A–D) holotype and (E,F) paratype), DIC im-
ages: (A)—legs III–IV, dorsal view; (B)—leg III, ventral view; (C)—leg IV, dorsal view; (D)—leg IV,
ventral view; (E)—legs III–IV, dorsal view; (F)—legs III–IV, ventral view. Scale: bar 50 µm.
Figure 27.
Thyreophagus potawatomorum sp. n., female ((
A
–
D
) holotype and (
E
,
F
) paratype), DIC
images: (
A
)—legs III–IV, dorsal view; (
B
)—leg III, ventral view; (
C
)—leg IV, dorsal view; (
D
)—leg IV,
ventral view; (E)—legs III–IV, dorsal view; (F)—legs III–IV, ventral view. Scale: bar 50 µm.
Life 2023, 13, x FOR PEER REVIEW 36 of 62
Figure 28. Thyreophagus potawatomorum sp. n., female ((A) holotype and (B–D) paratypes), sperma-
theca, DIC images. Scale bar: 50 µm.
Figure 28.
Thyreophagus potawatomorum sp. n., female ((
A
) holotype and (
B
–
D
) paratypes), spermath-
eca, DIC images. Scale bar: 50 µm.

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Figure 29. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), dorsal view.
Scale bar: 100 µm.
Figure 29.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), dorsal view.
Scale bar: 100 µm.

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Figure 30. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), ventral view.
Scale bar: 100 µm.
Figure 30.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), ventral view.
Scale bar: 100 µm.

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Figure 31. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(A)—dorsal view; (B)—ventral view. Scale bar: 100 µm.
Figure 31.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(A)—dorsal view; (B)—ventral view. Scale bar: 100 µm.
Description
Female
(Figures 21–28). Idiosoma elongate, 580 (holotype), 164 wide, 3.5-times longer
than wide. Idiosomal cuticle smooth. Subcapitular setae (h) long, widened basally; palp
tibial setae (a), lateral dorsal palp tibial setae (sup), dorsal palp tarsal seta (cm) filiform;
supracoxal seta elcp present, widened basally; terminal palp tarsal solenidion
ω
short,
bacilliform; external part of terminal eupathidium ul” dome-shaped; terminal eupathidium
ul’ not observed. Prodorsal sclerite 88 (77–82, n= 6) long, 80 (65–70, n= 6) wide, 1.1 (1.1–1.2,
n= 6)-times
longer than wide, with setae vi (situated at anterior part of sclerite, bases
separate but touching each other), rounded anterolateral incisions, and elongate midlateral
incisions (insertion points of setae ve). Prodorsal sclerite punctate, with longitudinal linear
pattern extending anteriorly from posterior end of sclerite and covering area exceeding
75% of sclerite; anterior lateral and medial areas have only punctate patterns; lines form
a triangle at posterior end of sclerite. Grandjean’s organ (GO) with seven membranous
finger-like processes; central process distinctly wider than remaining processes. Supracoxal
seta (scx) smooth, sword-shaped, widened and flattened, tapering at tip, slightly curved.
Idiosomal setae (vi,se,c
p
,d
2
,e
2
,h
1
,h
2
,h
3
,ps
3
) smooth, filiform, short and slender; opistho-
somal gland openings slightly anteriad of setal bases e
2
. Four pairs of fundamental cupules
(ia,im,ip,ih) present.

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Figure 32. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype): A—leg I,
dorsal view; B—tarsus I, ventral view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III,
ventral view; F—leg IV, ventral view; G—gnathosoma, ventral view. Scale bar: 50 µm.
Figure 32.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype): A—leg I,
dorsal view; B—tarsus I, ventral view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III,
ventral view; F—leg IV, ventral view; G—gnathosoma, ventral view. Scale bar: 50 µm.

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Figure 33. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(A)—hysterosoma, part, ventral view; (B)—propodosoma and hysterosoma, part, dorsal view; (C)—
gnathosoma and propodosoma, part, ventral view; (D)—propodosoma and hysterosoma, part, ven-
tral view. Scale bar: 50 µm.
Figure 33.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(
A
)—hysterosoma, part, ventral view; (
B
)—propodosoma and hysterosoma, part, dorsal view; (
C
)—
gnathosoma and propodosoma, part, ventral view; (
D
)—propodosoma and hysterosoma, part,
ventral view. Scale bar: 50 µm.
Ventral idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and one pair of genital
setae (g). Shape of coxal sclerites as shown in Figures 1B and 5F,G. Ovipore between coxal
fields III and IV; genital valves shaped as an inverted Y; epigynal and medial apodemes
well-developed. Genital papillae medium-sized, their diameter approximately 5–6-times
shorter than length of genital setae. Anal opening on posterior margin of idiosoma, mostly
ventral, with substantial portion positioned terminally and dorsally. Copulatory tube
situated anteriad of dorsal end of anus. Canal of spermatheca long, slender tube of uniform
width, not widened at entrance to spermatheca; atrium of spermatheca vase-shaped (length
greater than width) with a rounded capsule at junction with canal of spermatheca. Small,
paired Y-shaped sclerites of oviducts with short stems.

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Figure 34. Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(A)—leg I, dorsal view; (B)—leg I, ventral view; (C)—leg II, dorsal view; (D)—leg II, ventral view;
(E)—legs III–IV, dorsal view; (F)—legs III–IV, ventral views. Scale bar: 50 µm.
Type material. Holotype female (f2) and one paratype female (f1)—USA: Michigan,
Ann Arbor, Hansen Nature Area, stick 5, 42°16′03.8″ N 83°46′53.2″ W, 14 October 2020, P.
Klimov, BMOC 20-0101-004#slide 1; four paratype females—same data (culture, har-
vested 26 February 2021), slide 2; six paratype females—same data, slide 3; two paratype
HDNs—same data, slide 5; one paratype HDN—same data, slide 6; one paratype HDN—
same data, slide 8.
Non-type material. Two DNs, one pharate DN—same data, slide 7.
Depository. Holotype, paratypes—University of Michigan, Museum of Zoology,
Ann Arbor, Michigan, USA.
Figure 34.
Thyreophagus potawatomorum sp. n., heteromorphic deutonymph (paratype), DIC images:
(
A
)—leg I, dorsal view; (
B
)—leg I, ventral view; (
C
)—leg II, dorsal view; (
D
)—leg II, ventral view;
(E)—legs III–IV, dorsal view; (F)—legs III–IV, ventral views. Scale bar: 50 µm.
Legs short, all segments free. Trochanters I–III each with filiform seta, pR I–II, sR
III; trochanter IV without setae. Femoral setation 1-1-0-1; setae vF I–II and wF IV long,
filiform. Genual setation 2-2-0-0; setae mG and cG I–II long, filiform; seta nG III absent.
Tibial setation 2-2-1-1; setae hT I-II small, short, thin; setae gT I–II elongated, somewhat
spiniform; setae kT III–IV elongated, somewhat spiniform. Tarsal setation 10-10-10-10;
all pretarsi with hooked empodial claws and short, paired condylophores. Tarsus I with
10 setae;
ra,la,f, and dfiliform; e,u,v,p,qspiniform; sflattened, button-shaped; setae wa
absent. Tarsus II setation similar to that of tarsus I, except proral setae (p,q) represented by
small triangular rudiments. Tarsus III with 10 setae; f,d,rfiliform; e,w,s,u,v,p,qspiniform.

Life 2023,13, 2168 39 of 57
Tarsus IV similar to tarsus III, except wfiliform. Solenidion
ω1
on tarsus I cylindrical, with
clavate apex, bent and pointed outward, to posterior side of tarsus; solenidion
ω1
on tarsus
II simple, cylindrical, with clavate apex, not bent, shorter than
ω1
on tarsus I. Solenidion
ω2
on tarsus I shorter than
ω1
, cylindrical, with rounded apex, slightly widened at tip,
situated slightly anterior and external to
ω1
. Solenidion
ω3
on tarsus I cylindrical, with
rounded apex, shorter than
ω1
, longer than
ω2
. Famulus (
ε
) of tarsus I wide, spiniform,
with broadly rounded apex. Solenidia
ϕ
of tibiae I–III elongate, tapering, well extending
beyond apices of respective tarsi with ambulacra; solenidion
ϕ
IV shorter than tarsus IV
(with ambulacra). On genu I, solenidion
σ
’ elongate, with rounded tip, slightly not reaching
bases of
ϕ
I, about 1.5-times longer than
σ
”;
σ
” I distinctly wider than
σ
’, about half the
length of tibia I. On genu II, solenidion
σ
short (more than three-times longer than its
width), with rounded tip. Solenidia σIII and IV absent.
Male. Absent.
Heteromorphic deutonymph
(n= 1) (Figures 29–34). Body elongate, 1.67-times longer
than wide, widest in sejugal region; idiosomal length 235, width 140. Gnathosoma short,
subcapitulum and palp fused, with apical palpal solenidia
ω
and filiform apicodorsal
setae (sup); setae habsent from subcapitular remnant, their positions marked by somewhat
refractile spots.
Dorsum. Propodosomal and hysterosomal smoothly punctate; distinct linear pattern
present on anterior and lateral sides of propodosomal sclerite and hysterosomal shield.
Apex of propodosomal sclerite shaped as obtuse triangle. Internal vertical setae (vi),
sitiated on apex of propodosoma, long, bases separated. A pair of lateral ocelli present on
propodosoma; widely separated from each other (distance 36, n= 1); lenses and pigmented
spots present, maximal diameter of lenses 16. External vertical setae (ve) absent; external
scapular setae se situated just below eye lenses; internal scapular setae (si) distinctly
posterior and medial to external scapulars (se). Supracoxal setae of legs I (scx) filiform,
situated below se. Sejugal furrow well-developed. Propodosomal sclerite 73, hysterosomal
shield 160, ratio hysterosoma shield/propodosomal sclerite, length = 2.19. Hysterosoma
with 11 pairs of simple, filiform setae on hysterosomal shield (c
1
,c
2
,c
p
,d
1
,d
2
,e
1
,e
2
,f
2
,h
1
,
h
2
,h
3
), setae h
3
distinctly longer than others. Opisthonotal gland openings (gla) ventral;
situated slightly posterior to setae c
3
off hysterosomal shield. Of four fundamental pairs of
cupules, only three pairs observed: ia posteriomedial of setae c
2
,im posterior of d
2
level
and ih ventral, lateral to posterior sides of attachment organ.
Venter. Coxal fields sclerotized, smoothly punctate. Anterior apodemes of coxal
fields I fused forming sternum. Sternum not reaching posterior border of sternal shield
by distance exceeding its length. Posterior border of sternal shield weakly sclerotized.
Anterior apodemes of coxal fields II curved medially. Posterior apodemes of coxal fields II
weakly developed, thin. Sternal and ventral shields adjacent. Anterior apodemes of coxal
fields III free. Posterior medial apodeme present between coxal fields IV, well-separated
from anterior apodemes IV and genital opening. Posterior apodemes IV absent. Dorsal
hysterosomal shield separated from ventral surface by a distinct suture on each side. Sub-
humeral setae (c
3
) long, filiform, positioned on ventral surface between legs II–III, adjacent
to region separating sternal and ventral shields. Coxal setae 1a,3a reduced, represented
by minute structures each situated in an alveolus. Setae 4b,gfiliform; 4a in form of small,
rounded conoids, 4b longer than g. Genital region in posterior portion of coxal fields IV;
genital opening elongate, there are two pairs of genital papillae inside progenital atrium;
papillae two-segmented, with rounded apices. Coxal setae (4b) situated at tips anterior to
coxal apodemes IV; genital setae (g) situated laterad of genital opening. Attachment organ
posterior to coxal fields IV. Anterior suckers (ad
3
) round, median suckers (ad
1+2
) distinctly
larger, with paired vestigial alveoli; pair of small refractile spots anterolateral to median
suckers (ps
3
); lateral conoidal setae of attachment organ (ps
2
) situated slightly posterior to a
line joining centers of median suckers, distinctly anterior conoidal setae (ps
1
) and slightly
posterior to median suckers (ad
1+2
); anterior and posterior lateral and posterior median
cuticular conoids well-developed; anus positioned between anterior suckers (ad3).

Life 2023,13, 2168 40 of 57
Legs. Legs elongate, all segments free. Trochanters I–III each with long, filiform
seta, pR I–II, sR III. Femoral setation 1-1-0-1; setae vF I–II and wF IV long, filiform. Genual
setation 2-2-0-0; setae mG and cG I–II filiform, seta nG III absent. Tibial setation 2-2-1-1; setae
hT I and II spiniform; setae gT I filiform; setae kT III filiform; kT IV somewhat spiniform.
Tarsal setation 7-8-8-8. All pretarsi consisting of hooked empodial claws arising from tarsal
apices, attached to short paired condylophores within tarsal apices. Tarsus I with three
filiform setae (p,qand d), three slightly foliate seate (ra,la and f), and one spoon-shaped
seta e. Seta dI elongate, longer than tarsus (its base situated at level of setae ra and la); seta
sI alveolar; setae wa,aa and ba I absent. Tarsus II similar to tarsus I except seta ba present
and filiform, base of seta dposterior to level of setae ra and la. Tarsus III with eight setae (w,
r,s,p,q,e,f,d) smooth, all setae, except dIII foliate. Tarsus IV similar to tarsus III, except
seta rlonger, filiform, and setae wfiliform and has a distinct prong. Solenidia
ω1
on tarsi
I–II cylindrical, with slightly clavate apices,
ω1
II longer than
ω1
I. Solenidion
ω3
on tarsus
I slightly shorter than
ω1
, with rounded apex, positioned slightly anterior to
ω1
; famulus
(
ε
) bulbous, situated between
ω1
and
ω3
. Solenidion
ω2
of tarsus I thin, with rounded
apex, positioned somewhat more basal and posterior to
ω1
+
ε
+
ω3
group. Solenidia
ϕ
of
tibiae I–III elongate, tapering;
ϕ
I and III, longer than tarsus I and III, respectively;
ϕ
II
shorter than tarsus II;
ϕ
IV short. Solenidion
σ
of genu I elongate, slightly tapering, nearly
reaching tip of tibia I;
σ
of genu II shorter, cylindrical, not reaching midlength of tibia II;
σ
of genu III absent.
Diagnosis
Females. Thyreophagus potawatomorum is similar to Th. spinitarsis (Fain, 1982) by the
linear striations of the prodorsal sclerite extending over at least 75% of the sclerite length
and by tarsi III having seven spiniform setae (e,u,v,p,q,s,w), but differs by the widened,
vase-shaped atrium (dome-shaped in Th. spinitarsis). Th. potawatomorum is very close to Th.
berxi sp. n., but differs by the following character states: setae vi are not extending beyond
the anterior margin of the prodorsum (extending in Th. berxi); bases of vi touch each other
(distinctly separated in Th. berxi), lines of the prodorsal sclerite are longer than the diameter
of the bases of vi (shorter in Th. berxi); on the prodorsal sclerite, the anterior medial striated
area differs from the posterior medial striated area (medial striated area has a uniform
pattern in Th. berxi); opisthosomal setae h
2
and h
3
are shorter than the anus (distinctly
longer in Th. berxi); a rounded capsule is present between the canal of spermatheca and the
atrium (absent in Th. berxi).
Heteromorphic deutonymph. Th. potawatomorum is close to Th. corticalis and Th. berxi
by the following character states: body elongate (more than 1.7-times longer than wide),
setae hT and gT I–II are present, different in shape, bases of setae dare at the level with
bases of setae of ra and la on tarsus I. Th. potawatomorum differs from Th. corticalis and Th.
berxi by the following character states: posterior median apodeme present, well-developed
(absent in Th. corticalis and weakly developed in Th. berxi); the diameter of ocelli is about 16
(19 in Th. corticalis; 23 in Th. berxi); the distance between the ocelli is 36 (60 in Th. corticalis;
50 in Th. berxi or); setae wa I are absent (present in Th. corticalis; absent in Th. berxi); on
tibia IV, seta kT IV without distinct prong (with a distinct prong in Th. berxi; without in Th.
corticalis).
Thyreophagus berxi Klimov, Kolesnikov, Wäckers, Merckx, Duarte, Vangansbeke, sp. n.
(Figures 35–42).
urn:lsid:zoobank.org:pub:7C7FEAA7-EB57-4A12-A489-196D2BEEA5D9.

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Figure 35. Thyreophagus berxi sp. n., female (holotype): (A)—dorsal view; (B)—ventral view. Scale
bar: 100 µm.
Figure 35.
Thyreophagus berxi sp. n., female (holotype): (
A
)—dorsal view; (
B
)—ventral view. Scale
bar: 100 µm.

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Life 2023, 13, x FOR PEER REVIEW 47 of 62
Figure 36. Thyreophagus berxi sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsal view; F—tarsus III, ventral
view; G—leg IV, dorsal view; H—tarsus IV, ventral view; I—spermatheca. Scale bar: 50 µm.
Figure 36.
Thyreophagus berxi sp. n., female (holotype): A—leg I, dorsal view; B—tarsus I, ventral
view; C—leg II, dorsal view; D—tarsus II, ventral view; E—leg III, dorsal view; F—tarsus III, ventral
view; G—leg IV, dorsal view; H—tarsus IV, ventral view; I—spermatheca. Scale bar: 50 µm.

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Life 2023, 13, x FOR PEER REVIEW 48 of 62
Figure 37. Thyreophagus berxi sp. n., female (holotype), DIC images: (A)—dorsal view; (B)—ventral
view. Scale bar: 100 µm.
Figure 37.
Thyreophagus berxi sp. n., female (holotype), DIC images: (
A
)—dorsal view; (
B
)—ventral
view. Scale bar: 100 µm.

Life 2023,13, 2168 44 of 57
Life 2023, 13, x FOR PEER REVIEW 49 of 62
Figure 38. Thyreophagus berxi sp. n., female (holotype), DIC images: (A)—prodorsal shield; (B)—
gnathosoma, dorsal view; (C)—gnathosoma, ventral view; (D)—lateral part of subcapitulum with
seta elcp; (E)—tibia and tarsus I, dorsal view; (F)—tibia and tarsus I, ventral view; (G)—legs III and
IV, dorsal view; (H)—legs III and IV, ventral view. Scale bar: 50 µm.
Figure 38.
Thyreophagus berxi sp. n., female (holotype), DIC images: (
A
)—prodorsal shield; (
B
)—
gnathosoma, dorsal view; (
C
)—gnathosoma, ventral view; (
D
)—lateral part of subcapitulum with
seta elcp; (
E
)—tibia and tarsus I, dorsal view; (
F
)—tibia and tarsus I, ventral view; (
G
)—legs III and
IV, dorsal view; (H)—legs III and IV, ventral view. Scale bar: 50 µm.

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Life 2023, 13, x FOR PEER REVIEW 50 of 62
Figure 39. Thyreophagus berxi sp. n., female ((A,B,E,F) holotype and (C,D,G,H) paratypes), DIC im-
ages: (A)—coxal fields I–II; (B)—coxal fields III–IV; (C)—leg I, dorsal view; (D)—leg I, antiaxial
view; (E)—ovipore; (F–H)—spermatheca. Scale bar: 50 µm.
Figure 39.
Thyreophagus berxi sp. n., female ((
A
,
B
,
E
,
F
) holotype and (
C
,
D
,
G
,
H
) paratypes), DIC
images: (
A
)—coxal fields I–II; (
B
)—coxal fields III–IV; (
C
)—leg I, dorsal view; (
D
)—leg I, antiaxial
view; (E)—ovipore; (F–H)—spermatheca. Scale bar: 50 µm.

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Life 2023, 13, x FOR PEER REVIEW 51 of 62
Figure 40. Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), dorsal view. Scale bar:
100 µm.
Figure 40.
Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), dorsal view. Scale bar:
100 µm.

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Life 2023, 13, x FOR PEER REVIEW 52 of 62
Figure 41. Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), ventral view. Scale bar:
100 µm.
Figure 41.
Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), ventral view. Scale bar:
100 µm.

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Life 2023, 13, x FOR PEER REVIEW 53 of 62
Figure 42. Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), DIC images: (A)—
propodosoma, dorsal view; (B)—sejugal furrow; (C)—hysterosoma, part, ventral view; (D)—legs I
and II, dorsal view; (E,F)—legs III and IV and hysterosoma, part, dorsal view. Scale bar: 50 µm.
Type material. Holotype female, five paratype females—BELGIUM: East Flanders,
Gentbrugge, Moscou, Fagus sylvatica (Fagales: Fagaceae) twig, subcortical, 51°01′50.7″ N
3°44′54.6″ E, 16 November 2019, Dominiek Vangansbeke, PBK 22-0905-033#slide1; one
Figure 42.
Thyreophagus berxi sp. n., heteromorphic deutonymph (paratype), DIC images: (
A
)—
propodosoma, dorsal view; (
B
)—sejugal furrow; (
C
)—hysterosoma, part, ventral view; (
D
)—legs I
and II, dorsal view; (E,F)—legs III and IV and hysterosoma, part, dorsal view. Scale bar: 50 µm.
Type material
. Holotype female, five paratype females—BELGIUM: East Flanders,
Gentbrugge, Moscou, Fagus sylvatica (Fagales: Fagaceae) twig, subcortical, 51
◦
01
0
50.7
00
N

Life 2023,13, 2168 49 of 57
3
◦
44
0
54.6
00
E, 16 November 2019, Dominiek Vangansbeke, PBK 22-0905-033#slide1; one
paratype female, same data, slide 2. One paratype female—BELGIUM: Flemish Brabant,
Arenberg Castle, Leuven, Fagus sylvatica (label on slide = “19-1-20 Tr. Sp. LA Arenberg beech
1”), 50
◦
51
0
32.6
00
N 4
◦
39
0
54.4
00
E, 19 January 2020, Jonas Merckx, PBK 22-0905-034#slide1.
Six paratype females, one paratype HDN—GERMANY: Saxony, Dresden, Betula (Fagales:
Betulaceae) (original label says: “birch twig, Felix white bag” comment = most likely
birch twig”), 51
◦
05’38.7
00
N 13
◦
50’35.6
00
E, 22 November 2020, Felix Wäckers (received via
Dominiek Vangansbeke), PBK 22-0905-035#slide1. Six paratype females, three paratype
HDNs—FRANCE: Grand Est, Verzenay, Marcus Duarte, 8 April 2023, DV_2023-037.
Depository
. Holotype, paratypes (Belgium, Germany)—University of Michigan, Mu-
seum of Zoology, Ann Arbor, Michigan, USA. Paratypes (France)—Royal Belgian Institute
of Natural Sciences, Brussels, Belgium.
Etymology. The new species is named after the Belgian entomologist Peter Berx.
Habitat
. Thyreophagus berxi lives under the bark of small fallen branches of deciduous
trees, such as European beech and birch trees.
Description
Female
(Figures 35–39). Idiosoma elongate, 670 (600–630, n= 2) (holotype, range),
230 (200–240, n= 2) wide, 2.9 (2.5–3.1, n= 2)-times longer than wide. Idiosomal cuticle
smooth. Subcapitular setae (h) long, widened basally; palp tibial setae (a), lateral dorsal
palp tibial setae (sup), dorsal palp tarsal seta (cm) filiform; supracoxal seta elcp present,
widened basally; terminal palp tarsal solenidion
ω
short, bacilliform; external part of
terminal eupathidium ul” dome-shaped; terminal eupathidium ul’ small, dome-shaped.
Prodorsal sclerite 98 (100) long, 94 (96) wide, 1.1 (1.1, n= 1)-times longer than wide, with
setae vi (situated at anterior part of shield, bases distinctly separated), rounded anterolateral
incisions, and elongate midlateral incisions (insertion points of setae ve). Prodorsal sclerite
has three types of patterns: smoothly punctated (anterior lateral 1/3 and anterior medial 1/2
parts of sclerite), longitudinal lines (posterior medial part of sclerite), smoothly punctated
smaller lines (posterior lateral part). Grandjean’s organ (GO) with 9–10 membranous
finger-like extensions. Supracoxal seta (scx) smooth, sword-shaped, widened and flattened,
tapering at tip, slightly curved. Idiosomal setae (vi,se,c
p
,d
2
,e
2
,h
1
,h
2
,h
3
,ps
3
) smooth,
filiform, medium length and slender; opisthosomal gland openings slightly anteriad of
setal bases e2. Only one pair of fundamental cupules (ih) observed.
Ventral surface of idiosoma with four pairs of coxal setae (1a,3a,4a, and 4b) and
one pair of genital setae (g). Shape of coxal sclerites as in Figures 1B and 5A,B. Ovipore
between coxal fields III and IV; genital valves shaped as an inverted Y; epigynal and medial
apodeme well-developed. Genital papillae medium-sized, their diameter approximately
0.3–0.4-times the length of coxal and genital setae. Anal opening on posterior margin
of idiosoma, mostly ventral, with substantial portion situated terminally and dorsally.
Copulatory tube present, short, situated anteriad of dorsal end of anus, with opening
developed. Canal of spermatheca long, slender, uniformly wide, except slightly widened
at entrance to atrium of spermatheca. Atrium vase-shaped, length greater than width. A
capsule between atrium and canal of spermatheca absent. Y-shaped sclerites of oviducts
with long stems.
Legs short, all segments free. Trochanters I–III each with filiform seta, pR I–II, sR III;
trochanter IV without setae. Femoral setation 1-1-0-1; setae vF I–II and wF IV long, filiform.
Genual setation 2-2-0-0; setae mG and cG I–II long, filiform; seta nG III absent. Tibial setation
2-2-1-1; setae hT I–II alveoli or small, short, and thin; setae gT I–II elongated, somewhat
spiniform; setae kT III–IV elongated, somewhat spiniform. Tarsal setation 10-10-10-10; all
pretarsi with hooked empodial claws and short paired condylophores. Tarsus I and II with
10 setae; ra,la,f, and dfiliform; e,u,v, spiniform; sflattened, button-shaped; proral setae
(p,q) represented by small triangular rudiments; setae wa absent. Tarsus III with 10 setae;
f,d,rfiliform; e,w,s,u,v,p,qspiniform. Tarsus IV similar to tarsus III, except wfiliform.
Solenidion
ω1
on tarsus I cylindrical, with clavate apex, bent and pointed outward, to
posterior side of tarsus; solenidion
ω1
on tarsus II simple, cylindrical, with clavate apex,

Life 2023,13, 2168 50 of 57
not bent, shorter than
ω1
on tarsus I. Solenidion
ω2
on tarsus I shorter than
ω1
, cylindrical,
with rounded apex, slightly widened at tip, situated slightly anterior and external to
ω1
.
Solenidion
ω3
on tarsus I cylindrical, with rounded apex, as long as
ω1
, longer than
ω2
.
Famulus (
ε
) of tarsus I wide, spiniform, with broadly rounded apex. Solenidia
ϕ
of tibiae
I–III elongate, tapering, well extending beyond apices of respective tarsi with ambulacra;
solenidion
ϕ
IV shorter, shorter than tarsus IV (with ambulacra). On genu I, solenidion
σ
’
elongate, with rounded tip, reaching bases of
ϕ
I;
σ
” I distinctly wider than
σ
’, slightly not
reaching bases of
ϕ
I. On genu II, solenidion
σ
short (more than three-times longer than its
width), with rounded tip. Solenidion σof genu III and IV absent.
Male. Absent.
Heteromorphic deutonymph
(n= 1) (Figures 40–42). Body elongate, 1.7-times longer
than wide, widest in sejugal region; idiosomal length 270, width 160. Gnathosoma short,
subcapitulum and palp fused, with apical palpal solenidia (
ω
) and filiform apicodorsal
setae (sup); setae habsent from subcapitular remnant, their positions marked by somewhat
refractile spots.
Dorsum. Propodosomal sclerite and hysterosomal shield smoothly punctate; distinct
linear pattern present on anterior and lateral sides of propodosomal sclerite. A small area
of linear pattern present on hysterosomal shield. Anterior end p of propodosoma shaped
as obtuse triangle. Internal vertical setae (vi) apical, long, bases separated. A pair of lateral
ocelli present on propodosoma; ocelli widely separated from each other (distance 50); lenses
and pigmented spots present, maximum diameter of lenses 23. External vertical setae (ve)
absent; external scapular setae se situated just below eye lenses; internal scapular setae (si)
distinctly posterior and medial to external scapulars (se). Supracoxal setae of legs I (scx)
filiform, situated below setae se. Sejugal furrow well-developed. Propodosomal sclerite 80,
hysterosomal shield 180, ratio hysterosomal shield/propodosomal sclerite
length = 2.25.
Hysterosomal shield with 11 pairs of simple, filiform setae (c
1
,c
2
,c
p
,d
1
,d
2
,e
1
,e
2
,f
2
,h
1
,
h
2
,h
3
), setae h
3
distinctly longer than others. Opisthonotal gland openings (gla) ventral;
situated ventrally on hysterosomal shield, slightly posterior to setae c
3
. Of four fundamental
pairs of cupules, only three pairs observed: ia posteriomedial of setae c
2
,im posterior to
level of d2and ih ventral, lateral to posterior sides of attachment organ.
Venter. Coxal fields sclerotized, smoothly punctate. Anterior apodemes of coxal
fields I fused forming sternum. Sternum not reaching posterior border of sternal shield
by distance exceeding its length. Posterior border of sternal shield weakly sclerotized.
Anterior apodemes of coxal fields II curved medially. Posterior apodemes of coxal fields
II weakly developed, thin, sternal and ventral shield adjacent. Anterior apodemes of
coxal fields III free. Posterior medial apodeme in area of coxal fields IV weakly expressed.
Posterior apodemes IV absent. Subhumeral setae (c
3
) long, filiform, situated ventrally
between legs II–III, adjacent to region separating sternal and ventral shields. Coxal setae
1a,3a reduced, represented by minute structures each situated in an alveolus. Setae 4b,g
filiform; 4a small, rounded conoids, 4b longer than g. Genital region in posterior portion
of coxal fields IV; genital opening elongate; there are two pairs of genital papillae; genital
papillae two-segmented, with rounded apices. Coxal setae (4b) situated at anterior tips of
coxal apodemes IV; genital setae (g) laterad of genital opening. Attachment organ posterior
to coxal fields IV. Anterior suckers (ad
3
) round, median suckers (ad
1+2
) distinctly larger,
with paired vestigial alveoli (not situated on a common sclerite); pair of small refractile
spots anterolateral to median suckers (ps
3
); lateral conoidal setae of attachment organ (ps
2
)
situated slightly posterior to line joining centers of median suckers, distinctly anterior
conoidal setae (ps
1
) and slightly posterior to median suckers (ad
1+2
); anterior and posterior
lateral and posterior median cuticular conoids well-developed; anus situated between
anterior suckers (ad3).
Legs. Legs elongate, all segments free. Trochanters I–III each with long, filiform seta,
pR I–II, sR III. Femoral setation 1-1-0-1; setae vF I–II and wF IV long, filiform. Genual
setation 2-2-0-0; setae mG and cG I–II filiform, seta nG III absent. Tibial setation 2-2-1-1;
setae hT I and II spiniform; setae gT I filiform, long (reaching the base
ω3
I); gT II shorter,

Life 2023,13, 2168 51 of 57
filiform; setae kT III somewhat spiniform, kT IV and has a distinct prong. Tarsal setation
7-8-8-8. All pretarsi consisting of hooked empodial claws arising from tarsal apices, and
short, paired condylophores within tarsal apices. Tarsus I with three filiform setae (p,q,
and d), three slightly foliate (ra,la, and f), and one spoon-shaped seta e; seta delongated,
longer than tarsus (its base situated at level of bases ra and la); seta salveolar; setae wa,
aa, and ba I absent; tarsus II similar to tarsus I except seta ba present and filiform, base of
seta dposterior of bases ra and la. Tarsus III with eight setae (w,r,s,p,q,e,f,d) smooth;
all setae, except dIII foliate. Tarsus IV similar to tarsus III, except seta wfiliform, with
a distinct prong. Solenidia
ω1
on tarsi I–II cylindrical, with slightly clavate apices,
ω1
II
longer than
ω1
I. Solenidion
ω3
on tarsus I longer and thinner than
ω1
, with rounded apex,
positioned slightly anterior to
ω1
;
ω1
and
ω3
separated by bulbous famulus (
ε
). Solenidion
ω2
of tarsus I thin, slightly widened apically, situated somewhat more basal and posterior
to
ω1
+
ε
+
ω3
group. Solenidia
ϕ
of tibiae I–III elongate, tapering;
ϕ
I and III longer than
tarsus I and III, respectively;
ϕ
II shorter than tarsus II;
ϕ
IV short. Solenidia
σ
of genu I
elongate, slightly tapering, nearly reaching tip of tibia I;
σ
of genu II shorter, cylindrical,
not reaching midlength of tibia II; σof genu III absent.
Diagnosis
Female. Thyreophagus berxi is close to Th. spinitarsis (Fain, 1982) and Th. potawatomorum
sp. n. by tarsi III with seven spiniform setae (e,u,v,p,q,s,w) and the prodorsal sclerite
with linear striation extending over at least 75% of its length. Th. berxi differs from Th.
spinitarsis by the vase-shaped atrium of the spermatheca, with the width in the central part
two-times shorter than the width at the entrance to spermatheca (dome-shaped, width in
central part vs. basal part is subequal in Th. spinitarsis). See above for the differences from
Th. potawatomorum.
Heteromorphic deutonymph. Th. berxi is close to Th. corticalis and Th. potawatomorum
by the following characters: body elongate (more than 1.7-times longer than wide), setae hT
and gT I–II present, different in shape, bases of seta dare at the level of bases of ra and la on
tarsus I. Th. berxi differs from Th. corticalis by the following character states: the posterior
medial apodeme is weakly developed (absent in Th. corticalis); the diameter of ocelli is
about 23 (19 in Th. corticalis); setae wa I are absent (present in Th. corticalis); seta kT IV with
a distinct prong (vs. prong absent in Th. corticalis). See above for the differences from Th.
potawatomorum.
4. Keys to Species of Thyreophagus of the World
Females
Adults of the following species are unknown: Th. africanus (Mahunka, 1974), Th.
javensis (Oudemans, 1911), Th. sminthurus (Fain and Johnston, 1974), Th. johnstoni (Fain,
1982), Th. leclercqi (Fain, 1982), Th. rwandanus (Fain, 1982).
Not included (species inquirendae): Th. aleurophagus (Sicher, 1894), Th. angustus (Banks,
1906), Th. berlesianus (Zachvatkin, 1941), Th. entomophagus nominalis (Kadzhaya, 1973), Th.
lignieri (Zachvatkin, 1953), Th. magnus (Berlese, 1910), Th. polezhaevi (Zachvatkin, 1953), Th.
ponticus (Kadzhaya, 1973).
1 Very large species, body length > 1500
µ
m. Egypt
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. cynododactylon (El-Bishlawy, 1990).
- Smaller species, body length < 700
µ
m
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
2
2 Setae uand von tarsi III–IV vestigial; seta wF IV absent. USA (Florida)
. . .. . .. . .. . .. . .
... . ... . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ... . .Th. hobe sp. n.
- Setae uand von tarsi III–IV well-developed, spiniform; seta wF IV present
. . .. . .. . .. . .
3.
3 Tarsus III with three ventral apical spiniform setae (s,uand v) well-developed, proral
setae pand qvestigial or absent
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.
. . .
.......4.
- Tarsus III with five ventral apical spiniform setae well-developed (s,u,v,p, and
q). . ... . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...7.
4 Prodorsal sclerite wider than long, almost entirely punctate, with a few short longitu-
dinal striations in posteromedian region; atrium of spermatheca in form of an inverted bell,

Life 2023,13, 2168 52 of 57
with base 18–20
µ
m wide; seta wIII filiform. Widespread
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. entomophagus (Laboulbène and Robin, 1862).
- Prodorsal shield distinctly longer than wide, almost entirely covered with fine longitu-
dinal striations; atrium of spermatheca smaller, not in form of a bell; seta wIII small spine or
absent
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.5
5 Prodorsal sclerite with linear striation in posterior half of shield. Italy. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.
. . .. . .. . .. . .
Th. italicus (Vacante, 1989).
- Prodorsal sclerite with linear striation extending over at least 75% of its length
. . .
.
. . .
6
6 Idiosomal length 270–360
µ
m, width 87–150
µ
m; atrium of spermatheca dome-
shaped, wider (6
µ
m) than long (5
µ
m) and not narrowed toward its center; seta wIII a very
short spine; seta se not longer than prodorsal shield. Morocco
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..Th. cooremani (Fain, 1982).
- Idiosomal length 525–675
µ
m, width 210–280
µ
m; atrium of spermatheca vase-
shaped, 12
µ
m long, maximum width 12
µ
m, narrowed toward the center where it 5
µ
m
wide; narrowed toward middle and widened in its proximal part; seta wIII vestigial; seta se
longer than prodorsal sclerite. Europe..
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..Th. odyneri (Fain, 1982).
7 Seta wIII filiform. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...8
- Seta wIII spiniform or vestigial
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
13
8 Anterior margin of prodorsal sclerite without paired indentations
. . .. . .. . .. . .. . .. . .. . .
9
- Anterior margin of prodorsal sclerite with paired indentations
. . .. . .. . .. . .. . .. . .. . .. . .
10
9 Atrium of spermatheca weakly developed; sclerotized portion of spermatheca in
form of a broad arc, much wider than long. Cuba
. . .. . .. . .. . .
.....Th. passerinus (Cruz, 1990).
- Atrium of spermatheca well-developed, vase-shaped. Kenya. . .. . .. . .. . .. . .. . .. . ........
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. plocepasseri (Klimov, Mwangi, Vangansbeke, 2020).
10 Seta wa I absent. Ukraine
. . .
.
. . .. . .. . .. . .
Th. annae (Sevastianov and Kivganov, 1992).
- Seta wa I present, spiniform or vestigial
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
11
11 Solenidion
σ
’ I longer than
σ
” I; prodorsal sclerite at most 1.3-times as long as
wide.................................................................................................................................................12
- Solenidion
σ
’ I shorter than
σ
” I; prodorsal sclerite 1.5-times longer than wide.
Ireland
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. evansi (Fain, 1982).
12 Long terminal setae h
2
and h
3
with bases inflated, conical; base of spermatheca
forming thin sclerotized arc that divided anteriorly into four short, fine sclerotized lines;
genu I with solenidion
σ
’ short, 8
µ
m long,
σ
” 6
µ
m long (ratio 1.4:1); Great Britain
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. macfarlanei (Fain, 1982).
- Long terminal setae h
2
and h
3
with very thin bases; atrium U-shaped with thick sides,
6
µ
m long, 5
µ
m wide; genu I with solenidion
σ
’ thin, 18–20
µ
m,
σ
” slightly thickened,
12 µm
long (ratio 1.58: 1); Morocco
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.
. . .
Th. athiasae (Fain, 1982).
13 Seta wIII well-developed, spiniform
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
14
- Seta wIII vestigial
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
25
14 Solenidion
σ
II very short, 2–3-times longer than its width; atrium absent or minute,
much shorter than sclerites of oviducts (in Th. ais). Base of spermatheca in form of a broad
arc, much wider than long, or small and rounded
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..
. . .
15
- Solenidion
σ
II longer; atrium, well-developed, longer than wide. Base of spermath-
eca variable . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...19
15 Solenidion
σ
II short and filiform or nearly conical, but with sides straight and not
convex. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...16
- Solenidion
σ
II with convex sides
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.17
16 Solenidion
σ
II short and filiform or nearly conical, but with sides straight and
not convex; linear sclerites near the typical sclerites of oviducts present; paired sclerites of
oviducts Y-shaped, not elongated, at least three-times longer than its width. Widespread
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. gallegoi (Portus and Gomez, 1979).
- Solenidion
σ
II short and filiform; linear sclerites near the typical sclerites of oviducts
absent; paired sclerites of oviducts elongated, more than five-times longer than their width,
V-shaped. Great Britain . . .. . .. . .. . .. . .. . .. . ... . .Th. vermicularis (Fain and Lukoschus, 1982).

Life 2023,13, 2168 53 of 57
17 Paired sclerites of oviducts V-shaped; canal of spermatheca at entrance to spermath-
eca widened; bases of setae vi nearly touching, situated in common unsclerotized area. USA
(Florida). . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....
. . .. . .
.Th. Calusorum (Klimov, Demard, Stinson, Duarte, Wäckers, and Vangansbeke, 2022).
- Paired sclerites of oviducts Y-shaped; canal of spermatheca at entrance to sper-
matheca, uniform in width, not widened; bases of setae vi, separated, not in common area
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.18
18 Cuplike portions of sclerites of oviducts distinctly shorter than their stems; solenidia
σ
’ and
σ
” subequal; solenidion
ω1
II five-times longer than its width; solenidion
ϕ
IV
reaching middle of tarsus IV. Mauritius . . .. . .. . .. . .. . .. . .. . .. . ..Th. mauritianus (Fain, 1982).
- Cuplike portions of sclerites of oviducts subequal; solenidia
σ
’ distinctly longer
than σ”; solenidion ω1II three-times longer than its width; solenidion ϕIV longer, nearly
reaching bases of setae dIV. USA (Florida) . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .Th. ais sp. n.
19 Seta wa I present
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
20
- Seta wa I absent
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
21
20 Anterior margin of prodorsal shield without paired indentations; prodorsal shield
smoothly punctated; posterior hysterosomal seta h
1
less than half of length of h
2
. Colombia..
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..Th. incanus (Fain and Rack, 1987).
- Anterior margin of prodorsal shield with paired indentations; prodorsal shield with
linear striation extending over at least 75% of its length; posterior hysterosomal seta h
1
half
of length of h2. Europe. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. spinitarsis (Fain, 1982).
21 With one pair of large, sclerotized, funnel-like, internal structures near posterior end
of body (not to be confused with sclerites oviducts) . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...22
- Without paired, funnel-like structures in posterior body
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
23
22 Solenidion
ϕ
of tibia IV very short (4
µ
m); USA (California)
. . .. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
...Th. tridens (Fain and Lukoschus, 1986).
- Solenidion ϕof tibia IV longer (14 µm). Brazil. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. cracentiseta Barbosa, (OConnor and Moraes, 2016).
23 Setae h
1
,h
2
, and h
3
very long (2.5–2.8-times longer than length of prodorsal shield),
similar in length. New Zealand. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. australis (Clark, 2009).
- Setae h
2
and h
3
less than 2.5-times longer than length of prodorsal shield, seta h
1
less
than half of length of h
2. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..24
24 Setae vi short, not extending beyond anterior margin of prodorsum; bases of vi
touching; medial area of prodorsal shield with non-uniform pattern of striations in its
anterior and posterior parts; setae h
2
and h
3
shorter than anus; rounded sclerotized capsule
at junction of canal of spermatheca and atrium present. USA (Michigan)
. . .. . .. . .. . .. . .. . .. . .
.. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. potawatomorum sp. n.
- Setae vi long, extending beyond anterior margin of prodorsum; bases of setae vi
distinctly separated; entire medial area of prodorsal shield uniformly striated; setae h
2
and
h
3
longer than anus; rounded capsule at junction of canal of spermatheca and atrium absent.
France, Belgium, Germany. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. berxi sp. n.
25 Setae h
2
and h
3
1.1–1.25-times longer than length of prodorsal shield; diameter of
genital papillae approximately six-times shorter than length of genital setae. Palaearctic
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..Th. corticalis (Michael, 1885).
- Setae h
2
and h
3
, long, their lengths 1.75-times longer than length of prodorsal shield;
diameter of genital papillae approximately four-times shorter than length of genital setae.
USA (Michigan), Canada (Ontario)
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. ojibwe sp. n.
Males (modified after [1])
Adults of the following species are unknown: Th. africanus (Mahunka, 1974), Th.
javensis (Oudemans, 1911), Th. sminthurus (Fain and Johnston, 1974), Th. johnstoni (Fain,
1982), Th. leclercqi (Fain, 1982), and Th. rwandanus (Fain, 1982).
Not included (species inquirendae): Th. aleurophagus (Sicher, 1894), Th. angustus (Banks,
1906), Th. berlesianus (Zachvatkin, 1941), Th. entomophagus nominalis (Kadzhaya, 1973), Th.

Life 2023,13, 2168 54 of 57
lignieri (Zachvatkin, 1953), Th. magnus (Berlese, 1910), Th. polezhaevi (Zachvatkin, 1953), and
Th. ponticus (Kadzhaya, 1973).
Males are unknown in Th. athiasae,Th. plocepasseri,Th. polezhaevi,Th. cooremani, Th.
calusorum,Th. evansi,Th. macfarlanei,Th. spinitarsis,Th. tridens,Th. vermicularis,Th. ais,Th.
berxi,Th. hobe,Th. potawatomorum, and Th. mauritianus.
Not included (species inquirendae): Th. aleurophagus,Th. angustus,Th. berlesianus,Th.
italicus,Th. lignieri,Th. magnus, and Th. ponticus.
1 Prodorsal sclerite smoothly punctulate, without longitudinal striations. . .. . .. . .. . ..2
- Prodorsal sclerite with short longitudinal striations, at least near posterior margin
. . .
5
2 Posterior venter with sclerotized projection very poorly developed or absent. Colombia
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..Th. incanus (Fain and Rack, 1987).
- Posterior venter with sclerotized projection well-developed
. . .. . .. . .. . .. . .. . .. . .. . .. . .
..3
3 Body elongate, six-times longer than wide; large species, length > 700
µ
m. Egypt
. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
...Th. cynododactylon (El-Bishlawy, 1990).
- Body ovoid, 1.5–2-times longer than wide; small species, length < 500
µ
m. Widespread
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
...4
4 Tarsus IV with five spine-like setae (s,u,v,p,q), three filiform setae (f,r,w), and two
suckers (d,e). Ireland. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. evansi (Fain, 1982).
- Tarsus IV with three spine-like setae (s,u,v), three filiform setae (f,r,w), and two
suckers (d,e). Widespread
. . .. . .. . .. . .. . .. . .
Th. entomophagus (Laboulbène and Robin, 1862).
5 Posterior venter with distinct rounded, sclerotized projection
. . .. . .. . .. . .. . .. . .. . .. . .
..6
- Posterior body smoothly rounded, without ventral projection
. . .. . .. . .. . .. . .. . .. . .. . .
..8
6 Entire width of prodorsal sclerite covered by longitudinal striation. Europe
. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..Th. odyneri (Fain, 1982).
- Longitudinal striation on prodorsal sclerite restricted to median region, lateral areas
simply punctulate. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....7
7 Setae h
2
and h
3
1.1–1.25-times longer than length of prodorsal shield; spines p,q, and
u,vIII–IV subequal. Palaearctic. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..Th. corticalis (Michael, 1885).
- Setae h
2
and h
3
long, their lengths are 1.8-times longer than the length of the prodorsal
shield; spines pand qshorter than spines uand von tarsi III–IV. USA (Michigan), Canada
(Ontario). . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .Th. ojibwe sp. n.
8 Posterior hysterosoma with a large sclerotized area extending posteriad from level of
setae e2. Ukraine. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. annae (Sevastyanov and Kivganov, 1992).
- Posterior hysterosoma unsclerotized or at most with short terminal sclerotization pos-
terior to setae h1. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ..9
9 Posterior idiosoma with short sclerotized area posterior to setae h
1. . .. . .. . .. . .. . .. . .
.10
- Posterior idiosoma unsclerotized
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..11
10 Genu I with solenidia
σ
’ and
σ
” approximately equal in length. Widespread
. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. gallegoi (Portus and Gomez, 1979).
- Genu I with solenidion
σ
’ only half of length of
σ
”. Cuba
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. passerinus (Cruz, 1990).
11 Dorsal hysterosomal setae relatively long, setae d
2
and e
2
much longer than distance
between their alveoli. New Zealand
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. australis (Clark, 2009).
- Dorsal hysterosomal setae much shorter, setae d
2
and e
2
shorter than distance between
their alveoli. Brazil. . ... . .. . .. . .. . .. . ..Th. cracentiseta (Barbosa, Oconnor, and Moraes, 2016).
Heteromorphic deutonymphs
Unknown for the following species: Th. aleurophagus,Th. angustus,Th. annae,Th.
athiasae,Th. cooremani,Th. cracentiseta,Th. cynododactylon,Th. entomophagus nominalis,
Th. evansi,Th. gallegoi,Th. hobe,Th. incanus,Th. italicus,Th. macfarlanei,Th. magnus,
Th. mauritianus,Th. ojibwe,Th. odyneri,Th. passerinus,Th. plocepasseri,Th. polezhaevi,Th.
ponticus,Th. spinitarsis,Th. tridens, and Th. vermicularis.
Not included (species inquirendae): Th. berlesianus,Th. lignieri.
Published measurements of T. corticalis (distance between ocelli) were corrected.

Life 2023,13, 2168 55 of 57
1 Dorsal surface completely striated. Afrotropical
. . .. . .
.Th. africanus (Mahunka, 1974).
- Dorsal surface smoothly punctate, without striations
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
2
2 Body ovoid, 1.3–1.5-times longer than wide
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.3
- Body elongate, more than 1.7-times longer than wide
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..5
3 Seta hT I more than half the length of gT I. Europe
. . .. . .. . .. . .
.Th. leclercqi (Fain, 1982).
- Seta hT I less than half the length of gT I
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
4
4 Opisthonotal gland openings approximately equidistant from setae c
3
and c
p
; seta
kT III filiform; setae wa I–II absent. Widespread. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. entomophagus (Laboulbène and Robin, 1862).
- Opisthonotal gland openings much closer to ventral seta c
3
than to dorsolateral seta
c
p
; seta kT III with distinct prong; setae wa I-II present. New Zealand
. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. australis (Clark, 2009).
5 Hysterosomal sclerite about 1.7-times longer than prodorsal sclerite
. . .. . .. . .. . .. . .. . .
.6
- Hysterosomal sclerite about two-times longer than prodorsal sclerite
. . .. . .. . .. . .. . .
.7
6 Seta hT I absent; posterior medial apodeme in area of coxal fields IV present; seta kT
III with distinct prong. Great Britain, USA (Washington)
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. sminthurus (Fain and Johnston, 1974).
- Seta hT I present; posterior medial apodeme in area of coxal fields IV absent; seta kT
III without prong, filiform. USA (Maryland)
. . .. . .. . .. . .. . .. . .. . .. . .
Th. johnstoni (Fain, 1982).
7 Setae hT II and gT II subequal
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.8
- Setae hT II twice the length of gT II
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..9
8 Setae hT II and gT II filiform, both subequal to tibia II. Java
. . .. . .. . .. . .. . .. . .. . .. . .. . .
.
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ...Th. javensis (Oudemans, 1911).
- Setae hT II and gT II spiniform, shorter than half the length of tibia. Afrotropical
. . .. . .
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
.Th. rwandanus (Fain, 1982).
9 On tarsus I, bases of setae dsituated at the same level with bases of setae ra and la; di-
ameter of ocellus 16–23
µ
m
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
10
- On tarsus I, bases of setae ddistal to bases of setae ra and la; diameter of ocellus
10–14 µm . . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
..12
10 Width of ocellus 16
µ
m, distance between ocelli 36
µ
m; posterior medial apodeme
in area of coxal fields IV present. USA (Michigan). . .. . .. . .. . .. . ....Th. potawatomorum sp. n.
- Width of ocellus about 18–23
µ
m, distance between ocelli about 40–50
µ
m; posterior
medial apodeme in area of coxal fields IV weakly developed or absent
. . .. . .. . .. . .. . .. . .. . .
.11
11 On tibia IV, seta kT IV with distinct prong; width of ocellus 23
µ
m, distance between
ocelli 50
µ
m; posterior medial apodeme in area of coxal fields IV weakly developed.
Europe
. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .
Th. berxi sp. n.
- On tibia IV, seta kT IV without prong; width of ocellus about 18–19
µ
m, distance
between ocelli about 40–42
µ
m; posterior medial apodeme in area of coxal fields IV absent.
Widespread. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . ....Th. corticalis (Michael, 1885).
12 Tarsal setae pand qon tarsus IV foliate; seta dIII shorter than leg III; setae dIV
shorter or slightly longer than leg IV; diameter of ocellus 10–13. USA (Florida). . .. . .. . .. ...
. . .. . .. . .
Th. calusorum (Klimov, Demard, Stinson, Duarte, Wäckers and Vangansbeke, 2022)
- Tarsal setae pand qon tarsus IV short, spiniform; setae dIII longer than leg III, dIV
distinctly longer than leg IV; diameter of ocellus 12–14. USA (Florida)
. . .. . .. . .
.Th. ais sp. n.
Author Contributions:
Conceptualization, P.B.K. and V.B.K.; methodology, P.B.K. and V.B.K.; val-
idation, P.B.K. and V.B.K.; resources, P.B.K., E.P.D., C.S.A.S., M.V.A.D., F.L.W., J.L.M.-H. and D.V.;
data curation, P.B.K.; writing—original draft preparation, V.B.K.; writing—review and editing, P.B.K.,
V.B.K., A.A.K., J.M., J.L.M.-H. and. D.V.; visualization, V.B.K. and L.G.A.P.; supervision, P.B.K. and
V.B.K.; project administration, P.B.K.; funding acquisition, P.B.K. All authors have read and agreed to
the published version of the manuscript.
Funding:
Grant from the Ministry of Science and Higher Education of the Russian Federation within
the framework of the Federal Scientific and Technical Program for the Development of Genetic
Technologies for 2019–2027 (agreement №075-15-2021-1345, unique identifier RF----193021X0012).

Life 2023,13, 2168 56 of 57
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement:
No new data were created or analyzed in this study. Data sharing is
not applicable to this article.
Acknowledgments:
We thank Fred Beaulieu, Canadian National Collection of Insects, Arachnids &
Nematodes for providing high-resolution images of Thyreophagus ojibwe.
Conflicts of Interest: The authors declare no conflict of interest.
References
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