ArticlePDF Available

Abstract and Figures

it>Metapygmephorellus Rahiminejad, Hajiqanbar & Khaustov gen. nov. (Acari: Prostigmata: Pygmephoridae) (type species Metapygmephorellus colydius Rahiminejad & Hajiqanbar sp. nov.) is described and illustrated based on females phoretic on Colydium elongatum (F., 1787) and Dorcus parallelipipedus (L., 1758) (Coleoptera: Zopheridae and Lucanidae), respectively, which were collected from the forests in northern Iran. Another new species, Metapygmephorellus orientalis Khaustov sp. nov., collected from the bark beetle Hylurgops interstitialis Chapuis, 1875 (Col.: Curculionidae), from Far East Russia is also described. Pygmephorellus brachycercus Cross & Moser, 1971 is transferred to Metapygmephorellus gen. nov. A key to species of the genus Metapygmephorellus is provided.
Content may be subject to copyright.
SYSTEMATICS
A New Genus and Two New Species of the Family
Pygmephoridae (Acari: Heterostigmata) Associated with
Beetles (Insecta: Coleoptera)
V. RAHIMINEJAD,
1
H. HAJIQANBAR,
1,2
A. A. KHAUSTOV,
3
AND A. A. TALEBI
1
Ann. Entomol. Soc. Am. 108(5): 893–901 (2015); DOI: 10.1093/aesa/sav073
Published online September 11, 2015
ABSTRACT Metapygmephorellus Rahiminejad, Hajiqanbar & Khaustov gen. nov. (Acari: Prostigmata:
Pygmephoridae) (type species Metapygmephorellus colydius Rahiminejad & Hajiqanbar sp. nov.) is de-
scribed and illustrated based on females phoretic on Colydium elongatum (F., 1787) and Dorcus paralle-
lipipedus (L., 1758) (Coleoptera: Zopheridae and Lucanidae), respectively, which were collected from
the forests in northern Iran. Another new species, Metapygmephorellus orientalis Khaustov sp. nov., col-
lected from the bark beetle Hylurgops interstitialis Chapuis, 1875 (Col.: Curculionidae), from Far East
Russia is also described. Pygmephorellus brachycercus Cross & Moser, 1971 is transferred to Metapyg-
mephorellus gen. nov. A key to species of the genus Metapygmephorellus is provided.
KEY WORDS mite, phoresy, subcortical, Iran, Russia
Symbiotic relationships with insects are typical in many
Heterostigmata (Acari: Trombidiformes: Prostigmata) in-
clusive of pygmephorid mites, which are often phoretic
(Kaliszewski et al. 1995). To date, the Pygmephoridae
Cross, 1965 encompasses 28 genera and more than 300
species distributed worldwide (Zhang et al. 2011, Khaus-
tov 2015). All of pygmephorid mites are probably fungiv-
orous (Khaustov 2008b) and inhabit soil, forest litter, and
nests of small mammals and insects (Walter et al. 2009).
Many pygmephorid mites utilize ephemeral resources,
such as dung or nest. Females of such genera are char-
acterized by phoretic associations with diverse groups of
insects, especially Coleoptera, Hymenoptera, and Dip-
tera (Kaliszewski et al. 1995, Walter et al. 2009). The
most specialized pygmephorid mites are phoretic on var-
ious beetles such as dung beetles (hosts of the genera
Pediculaster Vitzthum, 1931; Geotrupophorus Mahunka,
1970; Pygmephorellus Cross & Moser, 1971; Spatulapho-
rus Rack, 1993; and Pseudopygmephorellus Khaustov,
2008), scolytid and cerambycid beetles (hosts of the gen-
era Elattoma Mahunka, 1969 and Microdispodides Vitz-
thum, 1914) (Khaustov 2008a, Rahiminejad et al. 2011).
During a study of heterostigmatic mites phoretic on
subcortical insects, a new genus and two new species of
Pygmephoridae were revealed in Iran and Far East
Russia. Cross and Moser (1971) described Pygmephor-
ellus brachycercus Cross & Moser, 1971 collected from
inner surface of pine bark in USA. In this paper we
consider P. brachycercus as another member of the ge-
nus Metapygmephorellus gen. nov.
The purpose of this paper is to describe a new genus
and two new species of the family Pygmephoridae and
provide a key to species of the newly described genus
Metapygmephorellus gen. nov.
Material and Methods
The Mite specimens, after detachment from host
beetles, were cleared in lactophenol and mounted in
Hoyer’s medium. The morphology of the mites was
studied by a light microscope with phase contrast
(Olympus BX51, Tokyo, Japan) and DIC contrast (Axio
Imager.A2, Carl Zeiss, Germany). The terminology of
idiosoma and legs follows that of Lindquist (1986);the
nomenclature of subcapitular setae and the designation
of cheliceral setae follow that of Grandjean (1944,
1947), respectively. The classification system of Pygme-
phoroidea follows that of Khaustov (2004, 2008b). All
measurements in the description are given in microme-
ters (lm) for the holotype and (when available) five
paratypes (in parentheses). For leg chaetotaxy, the
number of solenidia is given in parentheses. Details of
geographical position were recorded using a global po-
sitioning system (GPS model: eTrex).
Nomenclature. This paper and the nomenclatural
acts it contains have been registered in Zoobank (www.
zoobank.com), the official register of the International
Commission on Zoological Nomenclature. The LSID
(Life Science Identifier) number of the publication is:
urn:lsid:zoobank.org:pub:91A64777-FC48-4B8F-
B9EF-3DB2371AF0D0.
Systematics
Family Pygmephoridae Cross, 1965
Genus Metapygmephorellus Rahiminejad, Hajiqan-
bar & Khaustov gen. nov.
1
Department of Entomology, Faculty of Agriculture, Tarbiat Mod-
ares University, 14115-336, Tehran, Iran.
2
Corresponding author, e-mail: hajiqanbar@modares.ac.ir.
3
Tyumen State University, Tyumen, 625003 Russia.
V
C
The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America.
All rights reserved. For Permissions, please email: journals.permissions@oup.com
Type species: Metapygmephorellus colydius Rahimi-
nejad & Hajiqanbar sp. nov.
(urn:lsid:zoobank.org:act:A660B55F-6103-4289-
A3F1-27805B009A42)
Diagnosis of Adult Female
Adult females of the new genus are characterized by
following character states. Gnathosomal capsule dor-
sally with two pairs of setae (cha, chb), dorsolateral
postpalpal setae (pp), and ventrally with vestiges of sub-
capitular setae n only. Posterior part of prodorsal shield
covering anterior part of tergite C. Coxal fields I with
three pairs of setae (1a,1b,1c), seta 1b bifurcate; coxal
fields II with two pairs of setae 2a and 2c. Posterior
margin of posterior sternal plate tripartite. Leg I four-
segmented, with large sedentary claw on massive tibio-
tarsus; genu I with four or three setae; genu II with
two setae (l
0
and v
0
); seta d of femur I hooked.
Gnathosoma. Spherical in shape; dorsally with
two pairs of cheliceral setae cha, chb, dorsolateral post-
palpal setae (pp) and palpal dFe, dGe, ventrally with
one pair of pits (vestiges of subcapitular setae n), sub-
capitular setae m absent. Palps ventrally with relatively
small accessory setigenous structure and tiny soleni-
dion. Pharyngeal system difficult to discern, pump 1
smallest, pump 2 largest and striated, pump 3 oval-
shaped.
Idiosoma. Dorsal shields strongly sclerotized and
punctate. Prodorsal shield with one pair of single-
chambered oval stigmata, three pairs of simple setae
(v
1
, v
2
, sc
2
), and one pair of capitate trichobothria.
Opisthosomal setation complete, three pairs of round
cupuli (ia, im,andih) on tergites D, EF, and H,
respectively. Ventral apodemes 1 (ap1) and 2 (ap2)
joined with prosternal apodeme (appr), sejugal apo-
deme (apsej) thickened and joined with appr, apo-
demes 3 weak and diffuse, apodemes 4 reaching to
base of trochanter III, poststernal apodeme (appo)
short, apodeme 5 absent; posterior border of postster-
nal plate tripartite. Coxal fields I with three pairs of
setae 1a,1b,and1c,seta1b bifurcate; Coxal fields II
with two pairs of setae 2a and 2b; Coxal fields III with
three pairs of setae 3a,3b, and 3c; coxal fields IV with
three pairs of setae 4a,4b,and4c; pseudanal segment
with three pairs of setae (ps
1
, ps
2
,andps
3
); genital
sclerites weakly sclerotized, usually represented by oval
posterior genital sclerite. Tiny anterior genital sclerite
sometimes evident.
Legs. Legs I four-segmented, tibiotarsus (TiTa) with
one thick and stout claw. Legs II–IV: five-segmented,
with pair of simple claws and small empodium. Legs
chaeto- and solenidiotaxy given in Table 1.
Male, Larva, and Non-phoretic Female
unknown.
Etymology. The generic name refers to some simi-
larities with the genera Pygmephorellus and Pseudo-
pygmephorellus, and somewhat more derivative
characters than these two genera (“Meta meaning
“after" þ Pygmephorellus).
Differential Diagnosis. Adult females of the new
genus are similar to genera Pygmephorellus Cross &
Moser, 1971 and Pseudopygmephorellus Khaustov,
2008 by the following characters. Gnathosomal capsule
dorsally with two pairs of setae; prodorsal shield with
three pairs of unmodified setae and one pair of capitate
trichobothria. Stigmata oval or round. Coxal fields I
with three pairs of setae, coxal fields II with two pairs
of setae, legs I four-segmented, with large sedentary
claw on massive tibiotarsus; seta d on femur I hooked.
The new genus differs from Pygmephorellus and Pseu-
dopygmephorellus by the absence of subcapitular setae
m (present in Pygmephorellus and Pseudopygmephorel-
lus), posterior margin of posterior sternal plate tripar-
tite (entire in Pygmephorellus and Pseudopygm
ephorellus), seta 1b bifurcate (not bifurcate in Pygme-
phorellus and Pseudopygmephorellus). The new genus
differs from Pygmephorellus by absence of setae l
00
on
genu II (present in Pygmephorellus).
Species Included. The new genus includes three
species: Metapygmephorellus colydius Rahiminejad &
Hajiqanbar sp. nov. (type species), M. orientalis Khaus-
tov sp. nov., and M. brachycercus (Cross & Moser,
1971)comb.nov.
Distribution and Habitat. All known species of
this new genus are associated with subcortical beetles.
M. colydius Rahiminejad & Hajiqanbar sp. nov. col-
lected from Colydium elongatum (F., 1787) and Dorcus
parallelipipedus (L., 1758) (Coleoptera: Zopheridae
and Lucanidae) in Iran; M. orientalis Khaustov sp. nov.
collected from the bark beetle Hylurgops interstitialis
Chapuis, 1875 (Col.: Curculionidae) from Far East
Russia, and M. brachycercus (Cross & Moser, 1971)
comb. nov. known from USA (Louisiana) where it was
collected under the bark of Pinus palustris infected
with Ips calligraphus (Germar, 1824), and the tenebrio-
nid beetle Corticeus glaber (LeConte, 1878), a subcort-
ical associate of pine bark beetles (Cross and Moser
1971).
Metapygmephorellus colydius Rahiminejad &
Hajiqanbar sp. nov.
(urn:lsid:zoobank.org:act:B30BFD64-EE82-4FC4-
8D7F-BAA3C2E28E50)
Diagnosis. The new species is distinguished by the
following character states: genu I with four setae; setae
c
1
and d not reaching to posterior borders of tergites C
and D, respectively; seta h
2
half as long as h
1
;setaeps
1-
3
pointed; seta 4a blunt-ended; setae pl
00
on tarsi II and
III modified, spine-like.
Adult Female. (Figs. 1–7). Length of idiosoma 193
(160–196), width 83 (81–97).
Gnathosoma: Length of gnathosomal capsule 22
(17–24), width 24 (18–28); cheliceral setae cha 6(58),
chb 5 (5–7), palpal dFe 4(46),dGe 4(37);pharyng-
eal system (Fig. 3) with three pumps, pump 1 smallest,
pump 2 largest and striated, pump 3 oval-shaped, diffi-
cult to discern.
Idiosomal dorsum (Fig. 1): Body oval, all tergites
well-sclerotized and punctate. Prodorsal shield with
smooth trichobothria. All dorsal setae smooth and
blunt-ended, except pointed c
2
.Setac
2
nearly two
times longer and placed on same transverse line with
894 A
NNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 108, no. 5
c
1
, seta c
1
not extending to posterior border of tergite
C, posterior border of tergite C slightly concave; setae
d not extending to posterior border of tergite D.
Lengths of dorsal setae: v
1
16 (15–19), v
2
15 (15–17),
sc
2
31 (25–35), c
1
18 (16–19), c
2
33 (28–35), d 21 (16–
21), e 14 (13–16), f 25 (22–27), h
1
24 (21–24), h
2
15
(12–15). Distances between dorsal setae: v
1
- v
1
9(8
14), v
2
- v
2
16 (15–20), sc
2
-sc
2
15 (13–19), c
1
-c
1
25 (23–
26), c
1
-c
2
17 (11–22), d-d 33 (27–33), e-f 6 (5–8), f-f 32
(31–36), h
1
-h
1
21 (18–24), h
1
-h
2
8 (7–9).
Idiosomal venter (Fig. 2): All ventral plates smooth;
all ventral setae smooth. Posterior margin of aggenital
plate rounded. Lengths of ventral setae: 1a 10 (9–13),
1b 16 (14–18), 1c 15 (13–18), 2a 12 (10–14), 2c 19 (17–
21), 3a 11 (9–12), 3b 12 (10–13), 3c 19 (18–22), 4a 10
(7–11), 4b 12 (9–14), 4c 15 (12–17), ps
1
11 (8–13), ps
2
12 (9–13), ps
3
18 (14–21). Setae 2a,3b,3c,4a,and4c
needle-like. Anterior genital sclerite triangular, posterior
genital sclerite small, oval. Setae ps
1
-ps
3
blunt-ended.
Legs (Figs. 4–7): Leg I (Fig. 4). Thicker and longer
than other legs. Setal formula (number of solenidia in
parenthesis): Tr1–Fe4–Ge4–TiTa17 (þx
1
, x
2
, u
1
, u
2
).
Tibiotarsus I with thick and robust claw, with seven
blunt-ended eupathidial setae (p
0
, p
00
, tc
0
, tc
00
, ft
0
and
ft
00
), and eupathidium k placed near solenidion u
2
,sole-
nidion x
1
5(45),x
2
3(24),u
1
6 (5–6) and u
2
4(3
4), all finger-shaped except x
2
, baculiform; genu
with seta v
00
shorter than others; femur with setae l
0
needle-like and shorter than others, seta d hook-like;
trochanter with one seta v
0
same form as l
0
on femur.
Leg II (Fig. 5). Setal formula: Tr1–Fe3–Ge2–
Ti4(þu)–Ta6(þx). Tarsus with sickle-like simple claws
Table 1. Leg chaeto- and solenidiotaxy of the genus Metapygmephorellus gen. nov. (adult phoretic females)
Segment Leg I Leg II Leg III Leg IV
No. of
setae
Name of
setae
No. of
setae
Name of
setae
No. of
setae
Name of
setae
No. of
setae
Name of
setae
Trochanter 1 v
0
1 v
0
1 v
0
1 v
0
Femur 4 l
0
, l
00
, d, v
00
3 l
0
, d, v
00
2 d, v
0
2 d, v
0
Genu 4 or 3 l
0
, l
00
, v
0
, v
00
2 l
0
, v
0
2 l
0
, v
0
1 v
0
Tibia 17(4) d, l
0
, l
00
, v
0
, v
00
, k, u
1
, u
2
4(1) d, l
0
, v
0
, v
00
u 4(1) d, l
0
, v
0
, v
00
, u 4(1) d, l
0
, v
0
, v
00
, u
Tarsus pl
0
, pl
00
, pv
0
, pv
00
, s, tc
0
,
tc
00
, p
0
, p
00
, ft
0
, ft
00
x
1
,
x
2
6(1) pl
00
, pv
0
, pv
00
, tc
0
,
tc
00
, u
0
, x
6 pl
00
, pv
0
, pv
00
, tc
0
,
tc
00
, u
0
6 pl
00
, pv
0
, pv
00
, tc
0
,
tc
00
, u
0
Figs. 1–3. Metapygmephorellus colydius Rahiminejad and Hajiqanbar sp. nov., female. (1) Body in dorsal view; (2) Body
in ventral view. Scale bar 50 mm. (3) Pharynx. Scale bar 20 mm.
September 2015 RAHIMINEJAD ET AL.: A NEW GENUS OF THE PYGMEPHORIDAE—2 NEW SPECIES 895
and empodium. Solenidion x 6 (5–6) finger-shaped,
seta pl
00
modified, spine-like, seta tc
0
longest on tarsus;
tibia with solenidion u 4 (2–5) finger-shaped, seta v
00
longer than others; genu with two setae l
0
and v
0
,setav
0
robust and barbed; femur with setae d, v
0
and l
0
,setad
barbed, seta l
0
needle-like; trochanter with seta v
0
shorter than v
0
on femur.
Leg III (Fig. 6). Setal formula: Tr1–Fe2–Ge2–
Ti4(þu)–Ta6. Tarsus with seta pl
00
modified, spine-
like, seta pv
00
and tc
0
subequal; tibia with solenidion u 4
(2–4) finger-shaped, seta v
00
longest on tibia; genu with
seta l
0
longer than v
0
; femur divided into basi- and
telofemur, telofemur with seta d longer than seta v
0
;
trochanter with seta v
0
, longer than seta v
0
on femur.
Leg IV (Fig. 7). Setal formula: Tr1–Fe2–Ge1–
Ti4(þu)–Ta6. Seta tc
0
whip-like and longest seta on the
legs; tibia with solenidion u 2 (1–2) finger-shaped; seta
v
0
longer than others; genu with one seta v
0
;femurdiv-
ided into basi- and telofemur, setae d and v
0
,barbed;
trochanter with seta v
0
as long as v
0
on femur.
Male and Larva. Unknown.
Type, Host, and Locality Data. Female holotype
(VR-20130609-1), Gorgan, Golestan province, northern
Iran, phoretic on Colydium elongatum (F.) (Coleoptera:
Tenebrionoidea: Zopheridae) attached to ventral
surface, captured by light trap from Alangdareh forest,
36.46
N, 54.27
E, altitude 450 m.a.s.l., 9-VI-2013,
coll. V. Rahiminejad; paratypes: 30 females, same data
as holotype; 10 females, northern Iran, Mazandaran
province, phoretic on Dorcus parallelipipedus (L.,
1758) (Coleoptera: Scarabaeoidea: Lucanidae), col-
lected directly by forceps from a rotten stump in
Abbas-Abad forests, 36
37
0
N, 51
06
0
E, alt. 401 m.
a.s.l., 19-VII-2014, coll. A. Katlav.
Type Depositories. Theholotypeisdepositedin
the Acarological Collection, Department of Entomol-
ogy, Faculty of Agriculture, Tarbiat Modares University,
Tehran, Iran and paratypes are deposited in the follow-
ing collections: U.S. National Museum of Natural His-
tory, Washington D.C., U.S.A.; Tyumen State
University, Tyumen, Russia; and Acarological Collec-
tion, Zoological Museum, College of Agriculture, Uni-
versity of Tehran, Karaj, Iran.
Etymology. The species epithet refers to the
generic name of one of the host beetles (Colydium).
Differential Diagnosis. The new species is most
similar to M. brachycercus (Cross & Moser, 1971)
comb. nov. by the presence of four setae on genu I but
differs by setae c
1
and f on the same longitudinal level
(setae f further apart than setae c
1
in M. brachycercus);
Figs. 4–5. Metapygmephorellus colydius Rahiminejad and Hajiqanbar sp. nov., female: (4) Leg I in dorsal view; (5) Leg II
in dorsal view. Scale bar 20 mm.
896 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 108, no. 5
setae e and f not reaching to posterior margin of the
body (setae e and f protruding beyond posterior margin
of the body in M. brachycercus); setae f and h
1
subeq-
ual (seta f shorter than h
1
in M. brachycercus); seta h
2
half as long as h
1
(seta h
2
longer than half of h
1
in M.
brachycercus); seta 1c about 1.5 times longer than 1a
(seta 1a and 1c subequal in M. brachycercus); seta ps
2
longer than ps
1
(seta ps
2
as long as ps
1
in M. brachycer-
cus); and seta 3c longer than 4b (setae 3c and 4b sub-
equal in M. brachycercus).
Metapygmephorellus orientalis Khaustov sp. nov.
(urn:lsid:zoobank.org:act:FC540221-3EC3-45FC-
910F-D406EB8CFE1C)
Diagnosis. The new species has the following char-
acter states: genu I with three setae; setae c
1
and d
extending to posterior border of tergites C and D,
respectively; seta h
2
longer than half of h
1
;setaeps
1-3
blunt-ended; seta pl
00
on tarsi II and III simple and
pointed.
Adult Female. (Figs. 8–13). Length of idiosoma
176, width 114.
Gnathosoma: Length of gnathosomal capsule 19,
width 21.
Spherical in shape; setae cha 11 pointed, chb 9
blunt-ended, palpal dFe 5 blunt-ended, dGe 9pointed,
postpalpal setae 4 needle-like. Pharyngeal system tri-
partite, difficult to discern.
Idiosomal dorsum (Fig. 8): Body elliptic, all tergites
punctate; stigmata oval; prodorsal shield with barbed
trichobothria. All dorsal setae weakly barbed and blunt-
ended, except pointed setae c
1
and h
2
. Posterior border
of tergite C slightly concave. Setae d extending to pos-
terior border of tergite. Cupules not evident. Lengths
of dorsal setae: v
1
21, v
2
25, sc
2
36, c
1
30, c
2
46, d 29, e
25, f 44, h
1
41, h
2
33. Distances between dorsal setae:
v
1
-v
1
11, v
2
-v
2
25, sc
2
-sc
2
27, c
1
-c
1
46, c
1
-c
2
15, d-d 53,
e-f 10, f-f 42, h
1
-h
1
21, h
1
-h
2
14.
Idiosomal venter (Fig. 9): Apodemes 1 and 2 strongly
developed and joined with appr. All ventral plates
smooth. All ventral setae smooth. Apodemes 3 weakly
developed. Apodemes 5 absent. Posterior margin of
aggenital plate rounded with short tongue-like elonga-
tion. Lengths of ventral setae: 1a 16, 1b 18, 1c 17, 2a
11, 2c 21, 3a 15, 3b 12, 3c 15, 4a 12, 4b 17, 4c 17, ps
1
5, ps
2
11, ps
3
24. Seta 2a,3a,3b, ps
1
-ps
3
blunt-ended.
Figs. 6–7. Metapygmephorellus colydius Rahiminejad and Hajiqanbar sp. nov., female: (6) Leg III in dorsal view; (7) Leg
IV in dorsal view. Scale bar 20 mm.
September 2015 RAHIMINEJAD ET AL.: A NEW GENUS OF THE PYGMEPHORIDAE—2 NEW SPECIES 897
Anterior genital sclerite very small, difficult to discern,
posterior genital sclerite oval.
Legs (Figs. 10–13): Leg chaetotaxy similar with that
of M. colydius Rahiminejad and Hajiqanbar sp. nov.,
but genu I with 3 setae (v
00
absent).
Leg I (Fig. 10). Thicker than other legs. Solenidia x
1
7, x
2
5, u
1
6, u
2
5, all finger-shaped except baculiform
u
2
; femur with setae v
00
longer than others, seta d
hook-like; seta v
0
of trochanter shortest on leg I.
Leg II (Fig. 11). Tarsus with sickle-like simple claws
and empodium. Solenidion x 5 finger-shaped, seta u
0
shortest on tarsus; tibia with solenidion u 4finger-
shaped; seta d of femur weakly barbed; trochanter with
seta v
0
longer than l
0
of femur.
Leg III (Fig. 12). Tarsus with seta u
0
shortest on leg;
tibia with solenidion u 3finger-shaped,setav
00
longest
on tibia; genu with seta v
0
longer than l
0
; femur divided
into basi- and telofemur, seta d of femur longer than
seta v
0
; trochanter with seta v
0
, longer than seta v
0
of
femur.
Leg IV (Fig. 13). Setae pv
0
barbed and shorter than
tc
00
; tibia with solenidion u 2finger-shaped;setav
0
barbed; seta v
0
of genu weakly barbed; femur divided
into basi- and telofemur, seta d of femur barbed and
longer than v
0
; trochanter with seta v
0
as long as v
0
of
femur.
Male and larva. Unknown.
Type, Host, and Locality Data. Female holotype:
slide MM280890, Russia, Primorsky Krai, Pidan moun-
tain, on the bark beetle Hylurgops interstitialis Cha-
puis, 1875 (Col.: Curculionidae: Scolytinae) under the
bark of Pinus koraiensis, 28-VIII-1990, coll. M.Y.
Mandelshtam.
Type Depositories. Theholotypeisdepositedin
the Tyumen State University Museum of Zoology, Tyu-
men, Russia.
Etymology. The name of a new species refers to
distribution at Far East region.
Differential Diagnosis. The new species can be
distinguished from two other species of the genus by
genu I with three setae (genu I with four setae in M.
colydius and M. brachycercus); seta pl
00
on tarsi II and
III simple and pointed (seta pl
00
on tarsi II and III
modified, spine-like in M. colydius and M. brachycer-
cus); setae c
1
and d extending to posterior border of
tergite C and D, respectively (setae c
1
and d not reach-
ing to posterior border of tergite C and D, respectively
in M. colydius and M. brachycercus); setae ps
1-3
blunt
ended (setae ps
1-3
pointed in M. colydius and M. bra-
chycercus). Also the new species can be separated from
M. brachycercus by setae c
1
and f on the same longitu-
dinal level (setae f further apart than setae c
1
in
Figs 8–9. Metapygmephorellus orientalis Khaustov sp. nov., female. (8) Body in dorsal view; (9) Body in ventral view.
Scale bar 50 mm.
898 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 108, no. 5
M. brachycercus); setae f and h
1
subequal (seta f
shorter than h
1
in M. brachycercus); seta ps
2
longer
than ps
1
(seta ps
2
as long as ps
1
in M. brachycercus).
Moreover, the new species differs from M. colydius by
seta f protruding beyond posterior margin of the body
(seta f not reaching to posterior margin of the body in
M. colydius); seta h
2
longer than half of h
1
(seta h
2
half
as long as h
1
in M. colydius); setae 1c and 1a subequal
(seta 1c about 1.5 times longer than 1a in M. colydius);
setae 3c and 4b subequal (seta 3c longer than 4b in M.
colydius).
Discussion
The newly described genus is characterized by sev-
eral apomorphic characters: subcapitular setae m
absent; two pairs of setae on coxisternal plate II (setae
2b absent); two setae on genu II (seta l
00
absent); seta d
on femur I hook-like; setae 1b bifurcate; tripartite pos-
terior margin of poststernal plate. The absence of sub-
capitular setae is a unique character which not
recorded in other genera of pygmephoroid mites. Pres-
ence of only two setae on genu II (l
00
absent) is
known in other pygmephorid genera such as
Pseudopygmephorellus,someNeositeroptes,and
Ultrasiteroptes. Also, hook-like seta d on femur I could
be found in most pygmephorid genera with four-
segmented leg I, such as Pseudopygmephorellus
Khaustov, 2008; Pygmephorellus Cross & Moser, 1971;
Parapediculaster Khaustov, 2015; Elattoma Mahunka,
1969; Brasilopsis Mahunka, 1975; Luciaphorus
Mahunka, 1981; Pygmephorus Kramer, 1877; Mesopo-
tamiophorus Sevastianov & Zahida Al Douri, 1991; and
Microdispodides Vitzthum, 1914. Smooth and bifur-
cated seta 1b represented in some early-derivative pyg-
mephorid genera: Siteroptes Amerling, 1861;
Parasiteroptes Livshits, Mitrofanov and Sharonov, 1986;
Sevastianoviella Livshits, Mitrofanov and Sharonov,
1986; Neositeroptes Livshits, Mitrofanov & Sharonov,
1986; Krczaldania Sasa, 1961; Ultrasiteroptes Livshits,
Mitrofanov & Sharonov, 1986; and Parapediculaster
Khaustov, 2015.InsomePygmephorus Kramer, 1877
setae 1b also bifurcate, but always distinctly barbed;
similar condition of seta 1b alsoknowninsomeneo-
pygmephorid mites (Kerdabania Khaustov, 2009; Pseu-
dopygmephorus Cross, 1965; Petalomium Cross, 1965).
Among the pygmephorid mites, the tripartite posterior
margin of the poststernal plate is known only in
Figs. 10–11. Metapygmephorellus orientalis Khaustov sp. nov., female: (10) Leg I in dorsal view; (11) Leg II in dorsal
view. Scale bar 20 mm.
September 2015 RAHIMINEJAD ET AL.: A NEW GENUS OF THE PYGMEPHORIDAE—2 NEW SPECIES 899
Pediculaster Vitzthum, 1931, Metasiteroptes Cross,
1965, and Mesopotamiophorus Sevastianov & Zahida
Al Douri, 1991, but character states for the poststernal
plate are unknown for many pygmephorid genera. A
similar partitioning in poststernal plate is found in Elat-
toma, but the posterior margin of poststernal plate is
divided into two parts overlapping each other, indicat-
ing this character state is convergent.
The new genus is also well separated ecologically.
Species of Metapygmephorellus inhabit subcortical gal-
leries of various beetles. Among pygmephorid mites
similar habitats have species from the genera Elattoma
Mahunka, 1969, Microdispodides Vitzthum, 1914, and
some Pediculaster Vitzthum, 1931 (Smiley and Moser
1976, 1984; Rahiminejad et al. 2011), but they clearly
differ from Metapygmephorellus Rahiminejad, Haji-
qanbar & Khaustov gen. nov. morphologically. Mem-
bers of the most morphologically similar genera
Pygmephorellus Cross & Moser, 1971 and Pseudopyg-
mephorellus Khaustov, 2008 are associated with dung
beetles or inhabit soil (Khaustov 2007, 2008a; Katlav
et al. 2015).
Key to Species of the Genus Metapygmephorellus
Rahiminejad, Hajiqanbar & Khaustov gen. nov.
(females)
1- Genu I with four setae; seta pl
00
on tarsi II and III
modified, spine-like; setae c
1
and d not reaching to
posterior border of tergites C and D, respectively;
setae ps
1-3
pointed ................................................... 2
Genu I with three setae; seta pl
00
on tarsi II and III
simple and pointed; setae c
1
and d extending to pos-
terior border of tergites C and D, respectively; setae
ps
1-3
blunt ended .... M. orientalis Khaustov sp. nov.
Figs. 12–13. Metapygmephorellus orientalis Khaustov sp. nov., female: (12) Leg III in dorsal view; (13) Leg IV in dorsal
view. Scale bar 20 mm.
900 ANNALS OF THE ENTOMOLOGICAL SOCIETY OF AMERICA Vol. 108, no. 5
2- Setae f and h
1
subequal; seta 1c about 1.5 times lon-
ger than 1a; seta 3c longer than 4b; seta ps
2
longer
than ps
1
.....M. colydius Rahiminejad & Hajiqanbar
sp. nov.
Seta f shorter than h
1
; setae 1c and 1a subequal;
setae 3c and 4b subequal; seta ps
2
as long as ps
1
.. M.
brachycercus (Cross & Moser, 1971) comb. nov.
Acknowledgments
We thank Dr. M.Y. Mandelshtam (St.-Petersburg, Russia)
for materials of mites from bark beetles and for identification
of bark beetles, and Dr. Alexander G. Kirejtshuk (Zoological
Institute, Academy of Sciences, St. Petersburg, Russia) for
identification of the host zopherid beetle. We express our sin-
cere thanks to Alihan Katlav for collecting parts of material.
References Cited
Cross, E., and J. C. Moser. 1971. Taxonomy and biology of
some Pyemotidae (Acarina: Tarsonemoidea) inhabiting bark
beetle galleries in North American conifers. Acarologia 13:
47–64.
Grandjean, F. 1944. Observations sur les Acariens de la famille
des Stigmaeidae. Arch. Sci. Phys. Nat. 26: 103–131.
Grandjean, F. 1947. L’origine pileuse des mors et la chaetotaxie
de la mandibule chez les Acariens actinochitineux. C. R.
Seances. Acad. Sci. 224: 1251–1254.
Kaliszewski, M., F. Athias-Binche, and E. E. Lindquist.
1995. Parasitism and parasitoidism in Tarsonemina (Acari:
Heterostigmata) and Evolutionary Considerations. Adv. Para-
sitol. 35: 335–367.
Katlav,A.,H.Hajiqanbar,andA.A.Talebi.2015.Pseudo-
pygmephorellus mazandaranicus sp.nov.(Acari:Heterostig-
mata: Pygmephoridae), phoretic on scarabaeid dung beetles
(Coleoptera: Scarabaeidae) from Iran. Zootaxa 3919: 100–
110.
Khaustov,A.A.2004.Mites of the family Neopygmephoridae
Cross, 1965 stat. n. and their position in Heterostigmata, p.
137. In Y. S. Balashov (eds.), VIII Russian Acarological
Conference, St.-Petersburg. Zoological Institute of RAS, St.-
Petersburg.
Khaustov, A. A. 2007. A new species of the genus Pygmephorel-
lus (Acari: Heterostigmata: Pygmephoridae) associated with
Geotrupes stercorarius (Coleoptera: Geotrupidae) from Cri-
mea. Acarina 15: 287–289.
Khaustov,A.A.2008a.A new genus of mites of the family Pyg-
mephoridae (Acari, Heterostigmata) from Russia. Zool. Zh.
87: 891–896.
Khaustov,A.A.2008b.Mites of the family Scutacaridae of
Eastern Palaearctic, p. 291. Akademperiodyka, Kiev.
Khaustov,A.A.2015.A new genus and species of the family
Pygmephoridae (Acari: Pygmephoroidea) from southern
Chile. Int. J. Acarol. 41: 202–209.
Lindquist, E. E. 1986. The world genera of Tarsonemidae
(Acari: Heterostigmata): A morphological, phylogenetic and
system-atic revision, with a reclassification of family-group
taxainHeterostigmata.Mem.Entomol.Soc.Can.136:1
517.
Rahiminejad, V., H. Hajiqanbar, and Y. Fathipour. 2011.
Two new species of the genus Elattoma (Acari: Heterostigma-
tina: Pygmephoridae) phoretic on Morimus verecundus
(Coleoptera: Cerambycidae) from Iran. Zootaxa 2903: 48–56.
Smiley, R. L., and J. C. Moser. 1976. Two new phoretomor-
phic Siteroptes from galleries of the Southern Pine Beetle.
Beitr. Entomol. 26: 307–322.
Smiley, R. L., and J. C. Moser. 1984. AnewMicrodispodides
(Acari: Pygmephoridae) associated with a western bark bee-
tle. Int. J. Acarol. 10: 19–22.
Walter,D.E.,E.E.,Lindquist,I.M.Smith,D.R.Cook,
and G. W. Krantz. 2009. Order Trombidiformes, pp. 233–
420. In G. W. Krantz and D. E. Walter (eds.), A manual of
Acarology, 3rd ed. Texas Tech University Press, Lub-bock,
TX.
Zhang,Z.,Q.H.Fan,V.Pesic,H.Smit,A.V.Bochkov,A.A.
Khaustov,A.Baker,A.Wohltmann,T.Wen,J.W.
Amrine, et al. 2011. Order Trombidiformes Reuter, 1909.
In: Z-Q, Zhang, editor. Animal biodiversity: an outline of
higher-level classification and survey of taxonomic richness.
Zootaxa 3148: 129–138.
Received 30 April 2015; accepted 6 July 2015.
September 2015 RAHIMINEJAD ET AL.: A NEW GENUS OF THE PYGMEPHORIDAE—2 NEW SPECIES 901
... Elattoma abeskoun Rahiminejad & Hajiqanbar, 2011, in: Rahiminejad et al. (2011b E. cerambycidum Rahiminejad & Hajiqanbar, 2011, in: Rahiminejad et al. (2011b Metapygmephorellus colydius Rahiminejad & Hajiqanbar, 2015, in: Rahiminejad et al. (2015a Propygmephorus crossi Katlav & Hajiqanbar, 2016, in: Katlav et al. (2016 Pseudopygmephorellus mazandaranicus Katlav & Hajiqanbar, 2015, in: Katlav et al. (2015a Spatulaphorus gorganica Rahiminejad & Hajiqanbar, 2011, in: Rahiminejad et al. (2011c S. gymnopleuri Sobhi & Hajiqanbar, 2017, in: Sobhi et al. (2017b Archidispus esfarayenicus Hajiqanbar & Khaustov, 2014A. irregularis Katlav & Hajiqanbar, 2016, in: Katlav et al. (2016 Lophodispus tapinoma Sobhi & Hajiqanbar, 2017 Iranitrombium miandoabicum Saboori & Hajiqanbar, 2003, in: Saboori et al. (2003 ...
... At present, representatives of four genera of the family Pygmephoridae are known as associates of subcortical beetles: Elattoma Mahunka, 1969, Metapygmephorellus Rahiminejad, Hajiqanbar and Khaustov, 2015, Pediculaster Vitzthum, 1931, and Microdispodides Vitzthum, 1914 (Cross & Moser 1971;Smiley & Moser 1976, 1984Rahiminejad et al. 2011Rahiminejad et al. , 2015. The genus Microdispodides currently includes four described species: M. amaniensis (Oudemans, 1912) (=M. ...
Article
Full-text available
A new species, Microdispodides moseri sp. nov. (Acari: Pygmephoridae), from alcohol sediments containing bark beetle Ips typographus Linnaeus (Coleoptera: Curculionidae: Scolytinae) collected in pheromone traps in Western Siberia, Russia, is described. The genus Microdispodides Vitzthum, 1914 is recorded from Palaearctic for the first time. A key to species of Microdispodides is provided.
Article
A new species of Heterostigmatic mites from the family Microdispidae, Premicrodispus (Premicrodispus) abani Rahiminejad & Majidi sp. n., is described and illustrated based on female individuals recovered from macro-fungi, Trichaptum sp. (Fungi: Polyporales), in forestry areas of Gorgan, northern Iran. Additionally, distributional records of four pygmephoroid species belonging to Pediculaster Vitzthum, 1931, Metapygmephorellus Rahiminejad, Hajiqanbar & Khaustov, 2015, and Krczaldania Sasa, 1961 genera are reported from various mushrooms over the sampling region. All the fungi, including Trichaptum sp. (Polyporales), Psathyrella sp., and Pleurotus sp. (Fungi: Agaricales), are recorded for the first time as hosts of Heterostigmata. Moreover, Pediculaster sklarii Sevastianov & Chydyrov, 1994 and P. amerahae Sevastianov & Abo-korah, 1984, are recorded for the first time in the arthropod fauna of Iran. Eventually, an overview of heterostigmatic mites associated with macro-fungi, as well as their host range and distribution, has been provided.
Preprint
Full-text available
A new species of Heterostigmatic mites from the family Microdispidae, Premicrodispus ( Premicrodispus ) abani Rahiminejad & Majidi sp. nov., is described and illustrated based on female individuals recovered from macro-fungi, Trichaptum sp. (Fungi: Polyporales), in forestry areas of Gorgan, northern Iran. Additionally, distributional records of four pygmephoroid species belonging to Pediculaster Vitzthum, 1931, Metapygmephorellus Rahiminejad, Hajiqanbar & Khaustov, 2015 , and Krczaldania Sasa, 1961 are reported from various mushrooms over the sampling region. All the fungi, including Trichaptum sp. (Polyporales), Psathyrella sp., and Pleurotus sp. (Fungi: Agaricales), are recorded for the first time as host of Heterostigmata. Moreover, Pediculaster sklarii Sevastianov & Chydyrov, 1994 and P. amerahae Sevastianov & Abo-korah , 1984,are recorded for the first time in the arthropod fauna of Iran. Eventually, an overview of heterostigmatic mites associated with macro-fungi, as well as their host range and location, has been provided.
Article
Full-text available
In this study, we conducted a comprehensive review of all heterostigmatic mites that have previously been recorded from Iran. Thus far, 319 species, 70 genera, 12 families and 6 superfamilies of Heterostigmata (Acari: Prostigmata) (of 2265 known world species, 232 genera, 18 families and 8 superfamilies) have been recorded from different regions of Iran. Our study reveals a substantially immense diversity of Iranian heterostigmatic mite fauna, representing 15% and 4% of all heterostigmatic mites recorded and described from Iran, respectively by reviewing research of many scientists during more than 50 years. In addition to Iranian heterostigmatic mite taxa, all genera, families and superfamilies of world's Heterostigmata have been mentioned.
Article
Phoretic females of Acarothorectes curculionium (Cross) and a new species Brasilopsis floridensis sp. nov. (Acari: Pygmephoridae) were collected as associates of ambrosia beetles in Florida, USA. The genera Acarothorectes and Brasilopsis are recorded from USA for the first time and redefined. Acarothorectes curculionium is redescribed based on material from USA. Some morphological structures of described mites and the present state of knowledge of taxonomy of Pygmephoroidea are discussed.
Article
A new species of pygmephorid mites, Pediculaster absentia sp. n. (Acari: Prostigmata: Pygmephoridae) is described and illustrated based on phoretic female found in northern forests of Iran, phoretic on muscid flies, Helina spp. (Diptera: Muscidae). Also, Pediculaster muscarius (Martin, 1978), P. martyani Khaustov, 2008 and P. montanus Khaustov, 2008 are recorded on the flies from Iran for the first time. As well as, the variation of hysterosomal setae, along with distributions and host range of recorded species is reviewed.
Article
Full-text available
Moderate and humid region in north of Iran is home to a rich arthropod fauna, yet the mite fauna of Golestan province, with moderate Caspian climate, is poorly studied systematically. In this study, we conducted a faunistic study on heterostigmatic mites (Acari: Prostigmata: Eleutherengonides) associated with insects in Golestan Province. We used both day and overnight sampling methods to capture host insects in sampling sites. Thirteen species of seven heterostigmatic families were identified: Dolichocybidae (one species), Caraboacaridae (one species), Trochometridi-idae (one species), Neopygmephoridae (three species), Pygmephoridae (three species), Scutacaridae (two species) and Microdispidae (two species). The genus Formicomotes and subgenus Imparipes (Sporichneuthes) are new records for Iran and Asia, respectively. Beyond this, 13 new insect host records are reported for heterostigmatic mites. Finally, the world distribution of the recovered mites is reviewed. KEY WORDS: Female; insect; new host record; north of Iran; phoresy.
Article
Full-text available
In a study on insect-associated heterostigmatic mites (Acari: Trombidiformes: Prostigmata) carried out in Mazandaran province, northern Iran, during spring and summer 2016-2017, a total of 13 species from 11 genera of six families were identified. Among them, three species Imparipes sevastianovi Khaustov, 2008, Scutacarus hystrichocentrus Sevastianov, 1983 (Scutacaridae), and Petalomium kurosai Khaustov, 2014 (Neopygmephoridae) are new records for mite fauna of Iran. The S. hystrichocentrus is also new for Asian mite fauna. Eight new host records are documented and the distributions of the mites are revised. Beetles of the family Cerambycidae are recorded as host of the mite families Microdispidae and Scutacaridae for the first time.
Article
Full-text available
The genus Cerattoma Mahunka, 1972 (Acari: Pygmephoridae) is redefined. Cerattoma ursulae (Krczal, 1959) is redescribed, based on phoretic females collected under the elytra of a Crypticus sp. (Coleoptera: Tenebrionidae) darkling beetle in European Russia. An updated key to the genera of the Pygmephoridae family is provided.
Article
Full-text available
A new monotypic genus Parapediculaster Khaustov gen. nov. (Acari: Pygmephoroidea: Pygmephoridae) with type species P. patagoniensis sp. nov. is described from Sphagnum mosses in southern Chile. A key to genera of the family Pygmephoridae is provided.
Article
Full-text available
The mite species Pseudopygmephorellus mazandaranicus Katlav and Hajiqanbar sp. nov. (Acari: Prostigmata: Pygme-phoridae) is described and illustrated from northern Iran. This new species was discovered phoretic on three different scarabaeid dung beetles: Onthophagus sp., Aphodius depressus (Kugelann, 1792), Aphodius varians Duftschmid, 1805. This finding presents the first record of the genus Pseudopygmephorellus Khaustov, 2008 from Asia. The host range/hab-itat and worldwide distribution of species of the genus Pseudopygmephorellus is reviewed and a key to world species of the genus is provided.
Article
Full-text available
A new mite genus, Pseudopygmephorellus gen. n. (Acari, Pygmephoridae), is described. P. reductus sp. n. from Arkhangelsk Province (Russia) is described, and supplements to the descriptions of P. szekessyi (Mahunka, 1970) comb. n. and P. artemjevi (Sevastianov, 1981) comb. n. are given.
Article
A critical historical review of previous classifications and other work on tarsonemid and related mites is presented. General information concerning tarsonemids is reviewed, including the following: geographical distribution, life history, sex determination, sex ratio, copulation, adult female reproductive capacity and longevity, dispersal, food and host preferences, economic importance, and natural enemies.The generic and suprageneric taxa of Tarsonemidae, as known from the world fauna, are revised systematically and phylogenetically, based on a comprehensive assessment of morphology, ontogeny, and homology of tarsonemid structures, including their condition as found in other families of Heterostigmata. The fundamental systems of setal notation developed by Grandjean for the body and appendages of acariform mites are applied, including use for the first time of his special terminology for tarsal setae among heterostigmatic mites.Character transformation series (polarities) for the great majority of characters used in classifying tarsonemid mites are presented for the first time. The out-group method of comparison was used to propose character state polarities, based on the cladistic methodology of Hennig. The transformation series hypothesized for each of 157 characters are numbered, diagrammed in detail, and summarized in tabular form, both for the families of Tarsonemina and Heterostigmata in general and for the genera of Tarsonemidae in particular.Based on the above character transformation series, a tentative phylogeny of the genera of Tarsonemidae is proposed and illustrated by dendrograms. Three subfamilies are recognized, with Pseudotarsonemoidinae new subfam.being the sister-group of [Tarsoneminae + Acarapinae]. Seven tribes are recognized: the sister-groups Pseudotarsonemoidini and Tarsonemellini new tribes in Pseudotarsonemoidinae; the sister-groups Acarapini and Coreitarsonemini in Acarapinae; and sister-groups Steneotarsonemini and Hemitarsonemini new tribes, which together form the sister-group of Tarsonemini, in Tarsoneminae. Similar sister-groupings are proposed for the genera within each tribe, with 31 genera (7 new) and 5 subgenera allotted as follows. Pseudotarsonemoidini: Ununguitarsonemus Beer & Nucifora, 1965; Pseudotarsonemoides Vitzthum, 1921; Polyphagotarsonemus Beer & Nucifora, 1965; Nasutitarsonemus Beer & Nucifora, 1965; and Tarsanonychus new genus. Tarsonemellini: Tarsonemella Hirst, 1923. Coreitarsonemini: Amcortarsonemus Fain, 1971; Asiocortarsonemus Fain, 1971; and Coreitarsonemus Fain, 1970. Acarapini: Acarapis Hirst, 1923. Hemitarsonemini: Hemitarsonemus Ewing, 1939; Eotarsonemus De Leon, 1966; and questionably Heterotarsonemus Smiley, 1969. Steneotarsonemini: Steneotarsonemus Beer, 1954 (including subgenera Parasteneotarsonemus Beer & Nucifora, 1965, new status; Mahunkacarus Vainshtein, 1979; and Neosteneotarsonemus Tseng & Lo, 1980, new status), Ogmotarsonemus new genus, Suskia new genus, Phytonemus new genus, Dendroptus Kramer, 1876, new status; and Acaronemus Lindquist & Smiley, 1978. Tarsonemini: Fungitarsonemus Cromroy, 1958; Rhynchotarsonemus Beer, 1954; Deleonia new genus, Ceratotarsonemus De Leon, 1956; Daidalotarsonemus De Leon, 1956; Iponemus Lindquist, 1969; Pseudotarsonemus new genus; Suctarsonemus Mahunka, 1974; Xenotarsonemus Beer, 1954; Neotarsonemoides Kaliszewski, 1984; and Tarsonemus Canestrini & Fanzago, 1876 (including subgenera Chaetotarsonemus Beer & Nucifora, 1965, new status; and Floridotarsonemus Attiah, 1970, new status ). Tribal placement of Pseudacarapis new genus is uncertain, though it belongs in Tarsoneminae.New generic synonymies include the following: Neotarsonemus Smiley, 1967 objectively under Polyphagotarsonemus Beer & Nucifora, 1965; Parasteneotarsonemus Beer & Nucifora, 1965, and Neosteneotarsonemus Tseng & Lo, 1980 subjectively under, but subgenera of, Steneotarsonemus Beer, 1954; Praeacaronemus Kaliszewski & Magowski, 1985 subjectively under Acaronemus Lindquist & Smiley, 1978; Ditarsonemoides Kaliszewski, in prep. subjectively under Neotarsonemoides Kaliszewski, 1984; Lupotarsonemus Beer & Nucifora, 1965, Metatarsonemus Attiah, 1970, and Cheylotarsonemus Tseng & Lo, 1980 subjectively under Tarsonemus Canestrini & Fanzago, 1876; and Chaetotarsonemus Beer & Nucifora, 1965, and Floridotarsonemus Attiah, 1970 subjectively under, but subgenera of, Tarsonemus Canestrini & Fanzago, 1876. Newly designated nomina nuda are Punctatutarsonemus Nucifora, 1964, referred to Iponemus Lindquist, 1969, and Lupotarsonemus Beer & Nucifora, 1965, referred to Tarsonemus Canestrini & Fanzago, 1876.Descriptions are provided of the subfamily Tarsonemoidea and of all family-group taxa of Tarsonemidae. A key to the adult females, and to the adult males and larvae so far as they are known, together with diagnoses, detailed descriptions, and habitus figures, are presented for the genera and subgenera of Tarsonemidae. Definitions of each genus- and family-group taxon, based primarily on apomorphies, are also given in the section on phylogenetic relationships. Remarks on the distribution, habitats, habits, and other taxonomic and nomenclatorial aspects are given under each genus, followed by a world list of nominate species thought to belong to each genus, and indication of material examined. Descriptions of type-species, either new or inadequately described previously, are given for genera and subgenera as follows: Nasutitarsonemus brontispae Beer & Nucifora, 1965; Tarsanonychus emblematus n.sp.; Steneotarsonemus ( Neosteneotarsonemus ) arcticus n.sp.; Ogmotarsonemus erepsis n.sp.; Suskia mansoni n.sp.; Pseudotarsonemus eueides n.sp.; Neotarsonemoides adae Kaliszewski, 1984; Tarsonemus ( Floridotarsonemus ) scaber Attiah, 1970.Based on transformation series of the same characters mentioned above, a tentative phylogeny of Tarsonemidae and other families of Tarsonemina and Heterostigmata is proposed. A sister-grouping of Tarsonemidae and Podapolipidae is strongly supported apomorphically, with Pyemotoidea being the sister-group of Tarsonemoidea. Pygmephoroidea is strongly supported as the sister-group of [Pyemotoidea + Tarsonemoidea]. Of special note is a series of successive out-group relationships to [Pygmephoroidea + Pyemotoidea + Tarsonemoidea] of Trochometridiidae, then Dolichocybidae, then Heterocheylidae, and finally the Tarsocheylidae as the out-group of all other families of Heterostigmata. Each of the latter four families, therefore, warrants superfamilial status, with Trochometridiidae and Dolichocybidae being outside of Pygmephoroidea and Pyemotoidea, respectively. The Tarsonemina is strongly supported apomorphically as a subcohort. However, Heterocheyloidea appears to represent a sister-group to Tarsonemina rather than to Tarsocheyloidea, such that a grouping of Heterocheyloidea with Tarsocheyloidea, to form a subcohort Tarsocheylina, would be paraphyletic.