Taxonomy of European Damaeidae (Acari: Oribatida) VII. Redescription of Neobelba pseudopapillipes Bulanova-Zachvatkina, 1967 with comments on its generic status
Author
Miko, Ladislav
Author
Kolesnikov, Vasiliy B.
text
Zootaxa
2014
3796
2
374
384
journal article
45749
10.11646/zootaxa.3796.2.9
84507cde-4cb5-410e-9a57-7e1ea505b44f
1175-5326
229453
267D829B-9941-4A01-BA67-AA9C877F5413
Redescription of
Neobelba pseudopapillipes
Bulanova-Zachvatkina, 1967
Diagnosis (adult, immatures unknown).
Damaeid mite of medium size with increased number of setae on trochanters and femora: setal formula of trochanters 1-1-4-3, setal formula of femora
10-10-9-9.
Solenidia of all legs, with exception of
φ
1 on tibia I and
φ
on tibia IV, relatively short. All solenidia of genu I
–
III and tibia II
–
IV with associated companion seta
d
. Prodorsum without propodolateral apophysis
P
, with one pair of tubercles in dorsosejugal area (
B a–B p
). Both sensillus and interlamellar seta with elongated and attenuated, flagellate tips. Distinct round area (
apd
) resembling area porosa present anterior to insertion of interlamellar seta. Notogastral setae, at least in the posterior part of notogaster, clearly bent and characteristically thickened near base, when seen in lateral view. Ventral side without apparent tubercles. Discidium narrow, bent posterolaterad, claw-like.
Material examined.
Neotype
and 14 paraneotypes:
Russia
, Voronezh region, Ramonskiy district, forest near village of Aydarovo,
51°54’02”N
,
39°18’05”E
, about
157 m
a.s.l.: mixed broad-leaved forest with dominance of
Quercus spp
.
,
Populus tremula
,
Betula pendula
and
Pinus silvestris
,
in the forest floor; collected
16.6.2012
, leg. V. Kolesnikov.
The
type
series will be deposited in the following collections: The
neotype
and 2 paraneotypes in the Acarological Collections of Senckenberg Museum für Naturkunde Görlitz (
Germany
), 2 paraneotypes in Arachnological Collections in zoological department of the National Museum in Prague (
Czech Republic
), 3 paraneotypes in private collection of Ladislav Miko and remaining 7 paraneotypes in collection of V. Kolesnikov.
Further material examined (not included in the
neotype
series).
Slovakia
,
East Slovak region, Košice – Kavečany, in the area of zoological gardens,
48°47’25”N
,
21°11’54”E
),
430 m
a.s.l., mixed broad-leaved forest with dominance of
Carpinus betulus
and
Quercus
spp
., with deforested grassy patches, in the litter. 4 individuals, collected
2.8.1989
, leg Ľubomír Kováč. 2 individuals deposited in Arachnological Collections in zoological department of the National Museum in Prague (
Czech Republic
), 2 individuals in private collection of Ladislav Miko.
Description
(adult).
Figs 1
–
4
.
Dimensions
Total body length 480
–
530 (510), ventral length 430
–
498 (452); maximal width of notogaster 260
–
300 (278), maximal width of prodorsum 185
–
230 (208); n=10. Length of legs and other detailed measurements in
Table 1
.
TABLE 1.
Metabelba (Neobelba) pseudopapillipes
(Bulanova-Zachvatkina, 1967)
—measurements.
Lengths of setae (all in µm), n=5
Prodorsum Notogaster Ventral part of body
ro
67 (62
–
70)
c1
96 (90
–
99)
1a
31 (30
–
32)
le
75 (70
–
78)
l a
86 (81
–
90)
2a
32 (30
–
34)
in
124 (115
–
130)
l p
92 (87
–
97)
3c
37 (34
–
39)
ex
37 (34
–
39)
h3
95 (92
–
98)
4b
38 (37
–
39)
ss
165 (155
–
170)
h1
64 (63
–
66)
g1
28 (27
–
31)
p1
60 (58
–
62)
ag
37 (34
–
38)
p3
34 (33
–
36)
an1
34 (30
–
38)
ad1
40 (38
–
41) Lengths of legs and leg segments (n=5).
Leg I |
Leg II |
Leg III |
Leg IV |
trochanter - |
- |
62(60
–
63)
|
110 (109
–
111)
|
Femur 116 (114
–
117)
|
126 (122
–
131)
|
93 (89
–
95)
|
104 (102
–
106)
|
genu 46 (45
–
49)
|
46 (45
–
47)
|
32 (30
–
32)
|
45 (44
–
48)
|
Tibia 64 (62
–
66)
|
70 (68
–
73)
|
66 (65
–
67)
|
81 (79
–
84)
|
tarsus 148 (146
–
150)
|
151 (149
–
152)
|
162 (159
–
164)
|
161 (158
–
163)
|
total 374 (370
–
376)
|
393 (392
–
400)
|
413 (406
–
417)
|
501 (492
–
510)
|
leg/ventral length 0,83 |
0,87 |
0,91 |
1,11 |
leg/total body length 0,73 |
0,77 |
0,81 |
0,98 |
Integument.
Color medium reddish brown, individuals from
Slovakia
lighter, yellowish brown. Almost whole body surface covered by thick layer of cerotegument, mostly amorphous and/or granular (epimeral area), with filamentous excrescences present as well, being most prominent in sejugal area. Rostral and lamellar seta covered by cerotegument, except of tip of
ro
(
Fig. 1
D). Club-like bunch of filamentous and amorphous cerotegument present on distal part of sensillus, about between half and three quarters of its length, just before distal attenuated part (
Fig. 1
C). Notogastral setae without cerotegument cover. Legs covered by thick layer of cerotegument, except distal part of all tarsi (only showed on
Figs 3
and
4
, in other Figs omitted). Underlying cuticle smooth or microtuberculate. Adults bearing gastronotic exuviae of immature stages, often with small particles of adhered foreign material, exuviae however loosely attached and often lost during extraction.
Prodorsum
.
Figs 1
A, 2A, 2B. Prodorsum conical, broadly triangular in dorsal view, sharply narrowed in sejugal area. Rostrum rounded, centrally with weakened cuticle appearing dorsally as lighter triangular area. Insertions of rostral setae (
ro
) on small tubercles, which are positioned at end of short ridges or lines running parallel to prodorsum edge. Insertions of lamellar setae (
le
) on posterior edge of arch, created by more sclerotised ribs running along lateral edge of prodorsum, and further between
le
insertions, in this area less visible and forming 2-3 less distinct lines. Apophysis
P
absent, edge of prodorsum lateral to bothridia almost rounded, in some cases most lateral part of prodorsum with short, straight edges, subparallel to body axis. Single enantiophyse present in dorsosejugal area (considered to be centrodorsal enantiophyse
D
, for questions of homology see discussion in Remarks), well developed, with anterior tubercle (
Da
) smaller, broadly triangular and sitting on sclerotised oblique ridge running from posterior end of bothridial area. Posterior centrodorsal tubercle (
Dp
) larger, about twice longer than
Da
, conical, its base hidden under anterior edge of notogaster. Enantiophyses
B
(postbothridial) and
L
(lateral) absent, but slight elevations and thickenings of cuticle above the apophyse
S a
and posterior to bothridia may in dorsal view resemble flat tubercles
L a
.and
B a.
Parastigmatic apophyses spiniform, oblique, with tips overlapping in dorsal view.
S a
with broader base, and, when seen ventrally, much longer than (about twice as long as)
S p
. Apophyse
S p
more narrow, with subparallel edges, better observable in ventral view, sharp-tiped. Bothridium positioned on elevated and more sclerotised area, short but distinct ridge runs from its base anteromediad. Interlamellar seta (
in
) inserted on small, distinct tubercle. Small, pore-like opening present behind insertion of
ex
(
Fig 1
C, 2A), distinct pore visible also in lateral view behind acetabulum II in sejugal area (
Fig 2
A). Unusual, distinctly pronounced area, resembling porose areas of other oribatids, present anterior to
in
insertion (prodorsal area,
apd
). Rostral (
ro
) and lamellar (
le
) setae of subequal length, curved inwards, with spinuli (
le
) or barbs (
ro
) on outer curvature,
le
slightly stronger at their base. Interlamellar seta (
in
) longer than
ro
and
le
, with sparse barbs in middle part and with long, flagellate tip, the latter often broken away (
Fig. 1
C, 2B). Exobothridial seta (
ex
) relatively long, directed anteriad, bent, gradually attenuated distally, setiform. Bothridial funnel as usual in
Damaeidae
, cup-like, relatively large, positioned relatively far laterally. Distinct fields of sigillae (muscle insertions) present on prodorsum, two anteriad—anteriomediad to bothridia and
in
, one in interbothridial area. Lateral edges of two anterior fields strengthened and more sclerotised, creating a kind of narrow ridge.
Notogaster
.
Figs 1
A, 2A. Notogaster circular or sub-circular in dorsal view, in lateral view almost hemispherical, very slightly eccentric with maximum height slightly posterior to center. Notogastral setae strong, setiform to spiniform, relatively long, pointing more or less radially outwards of notogaster. In dorsal view they may appear straight or almost straight (
Fig. 1
D), but almost all clearly bent when seen in lateral view. Proximal part of some setae, seen in lateral view, with distinct and very characteristic thickening, with external edge curved proximally almost rectangularly (
Fig. 1
D–
h1
,
Fig. 2
A). In some individuals, some notogastral setae (usually of rows
l
or
h
) may be bent outwards distally, creating slightly S-form shape in lateral view (
Fig. 2
E). Posterior notogastral setae (
p1-p3
)
shorter, bent, without thickening at base, pointing laterad or posterolaterad. Circumgastric row of muscle sigillae distinct, well visible. Two pairs of minute light spots present on notogaster posteriad or posteromediad to insertions of setae
la
and
lp
(indicated by black arrows on
Fig. 1
A).
FIGURE 1.
Metabelba
(
Neobelba
)
pseudopapillipes
(Bulanova-Zachvatkina, 1967)
—habitus and dorsal setae. A—dorsal view, B—ventral view, C—bothridial area and sensillus, D—dorsal setae. Bar representing 100 µm (A, B) or 50 µm (C–D). Abbreviations: bo—bothridium, dis—discidium, apd—prodorsal area. Other markings refer to the name of setae or tubercular structures. Black arrows indicate the light spots on the notogaster.
FIGURE 2.
Metabelba
(
Neobelba
)
pseudopapillipes
(Bulanova-Zachvatkina, 1967)
—lateral view, details of prodorsum and gnatosoma. A—lateral view of the body, B—prodorsum, C—chelicere, D—palp, E—notogastral setae of individuals collected in Slovakia. Bar representing 100 µm (A, E) or 50 µm (B–D). Details of chelicere (setae
cha
and
chb
) and palp (distal part of palp tarsus) further enlarged to allow observation of details. Abbreviations: apd—area prodorsal, dis—discidium, gl—notogastral gland opening. Other markings represent names of setae, tubercles or lyrifissures.
Gnathosoma
. Subcapitulum as usual for family, diarthric, with three pairs of setae. Setae fine, setiform, curved, in ventral view seta
m
appearing longest, but in lateral view almost equal to
h
, seta
a
slightly shorter. Setal formula of palp 0-2-1-3-9(1), solenidion
ω
adhered to surface of palp tarsus and hard to observe (
Fig. 2
D). Chelicera of shape and relative size as usual in
Damaeidae
, seta
cha
longer, bent outwards proximally and inwards distally, with short barbs on external curvature and attenuated tip, seta
chb
straight, distally bent and with fringe of diminishing barbs (
Fig. 2
C).
Epimeral region
.
Fig 1
B. Mentotectum relatively narrow, low. Ventral tubercles absent, however, pair of triangular internal cuticular thickenings present at place of posterior ventrosejugal tubercles (
Vp
), which may be misinterpreted as tubercles. Ventrosejugal groove relatively broad and quite deep, laterally distinctly bordered by posterior edge of elongated apophyse
S a
. Epimeres III with standard set of 3 setae, epimeral setal formula 3-1-3-4. Epimeral setae subequal in length, fine, setiform and smooth, shorter than other setae of body. Epimeres with muscular sigillae, well visible, particularly closer to axial part.
Anogenital region
.
Fig. 1
B. Discidium (
dis
) narrow, elongated and bent backwards, claw-like. Genital opening larger than anal opening, circumgenital area framed by indistinct anterior and posterior ridge, surface of genital plates along setal insertions rugged. Preanal sclerite with two distinct lateral projections. Setal formula of anogenital region as in other
Damaeidae
: genital
g:
6; aggenital
ag
: 1; anal
an
: 2; adanal
ad
: 3. Adanal setae, particularly
ad3
, inserted far from anal opening and closer to lateral edge of ventral plate. All anogenital setae smooth, setiform, subequal in length, similar to epimeral setae. Lyrifissure
iad
apoanal—oblique and divergent from body axis posteriad.
FIGURE 3.
Metabelba
(
Neobelba
)
pseudopapillipes
(Bulanova-Zachvatkina, 1967)
—legs. A—leg I, B—femur and genu II, C—femur and genu III, D—leg IV, E—enlarged detail of solenidion and coupled seta
d
of tibia IV. Bar representing 100 µm (A–D).
FIGURE 4.
Metabelba
(
Neobelba
)
pseudopapillipes
(Bulanova-Zachvatkina, 1967)
—legs II and III (drawings of V. B. Kolesnikov). A—leg II (segments individually depicted), B—leg III (segments individually depicted). Bar representing 50 µm.
Legs
.
Figs 3
,
4
. Legs monodactylous, relatively short (leg I shorter than body, leg IV about as long as body length, slightly longer than ventral length, other legs also shorter than body, and overall length of legs increasing from leg I to leg IV—see
Table 1
). Leg segments with distinctly swollen distal parts (moniliform), except tarsi, where swollen part is proximal. Leg setae strong, setiform to spiniform, short to medium long, always shorter than their respective segment, mostly slightly bent, often with barbs or small spines at their outer curvatures. Dorsal setae of trochanters, femora, genua, and seta
ft”
of all tarsi very strong, robust, strongly and almost rectangularly bent proximally, mostly with long distinct spines at external curvature. Lateral setae of genua and tibiae usually similarly developed, but slightly smaller, other setae more narrow, or almost simply setiform, more straight and usually shorter. Leg setal formula except of seta
d
on tibia IV identical to species of
Metabelba
, as follows: leg I:
1- 10-4
[1]-4(2)-20(2); leg II:
1-10-4
[1]-5[1]-17(2); leg III: 4-9-4[1]-5[1]-17(0); leg IV: 3-9-4-5[1]-14(0). Famulus (e) normal, setiform, emergent, relatively long. Solenidia of genu I, II and III each coupled with companion seta
d
, as well as solenidia of tibia II, III and IV. Length of solenidia on genua subequal to length of companion seta, tibial solenidia II–III slightly longer than respective companion setae, tibial solenidion IV about twice as long as companion seta or even slightly longer (
Fig. 3
D, E). Solenidia of tibia I free as typical for
Damaeidae
, setiform, tactile,
φ1
very long, about 2,8 times longer than
φ2
. Solenidia of tarsus I relatively short, setiform, pointed, solenidion
ω1
about twice as long as
ω2
, distally bent. Solenidia of tarsus II straight, blunt, subequal in length.
Ontogeny
. Unknown.
Geographical distribution and ecology.
N. pseudopapillipes
is recorded only very rarely. Except classical localities of
Bulanova-Zachvatkina (1967)
in
Moldova
and Central
Russia
, and two localities presented here (
Slovakia
and Russia—Voronezh region), we are aware of only two other potential records, both from Italy—one from Alps in province of Trentino (
Baratti
et al.
, 2000
), from ski slopes in elevation of about
1600-1700 m
a.s.l., and another one from beech and oak forests in southern Tuscany, from elevation between 300 and
800 m
a.s.l. (
Migliorini
et al.
, 2002
). However, in both cases the species found was reported as “
N.
cf.
pseudopapillipes
”, so there is no definitive clarity, if the species indeed belonged to
N. pseudopapillipes
.
Subías (2004
,
2013
) reported this species from “Europa Meridional”, but it remains unclear to us on which basis. Looking on confirmed localities of the species, it may be expected in lowland, alluvial and midland forests, dominated by
Quercus
and
Carpinus
, even if it cannot be excluded that the species occurs also in other
type
of litter of the forests in the (?southern) temperate zone and also in forest-steppic habitats in the south-eastern Europe. The species may be therefore expected, besides known localities in
Russia
,
Moldova
and
Slovakia
, also in
Ukraine
,
Kazakhstan
,
Romania
and
Hungary
at least.
Remarks on species and its generic status.
N. pseudopapillipes
as re-described here fits very well to known characters of the species, as defined by
Bulanova-Zachvatkina (1967
,
1975
) and reviewed above. Nevertheless, few differences appeared and raised the question of the identity of our material with original
pseudopapillipes
. The observed discrepancies relate to the sejugal enantiophyses. While in original description there is recorded unspecified presence of paired tubercles in dorsosejugal area, and no ventral tubercles mentioned, in updated version
Bulanova-Zachvatkina (1975)
states, that dorsal tubercles should be
B1
and
B2
, i.e anterior and posterior postbothridial tubercle (
B a
and
B p
as they are named today). In the same place, the presence of posterior ventrosejugal tubercle
V2
is recorded (
V p
in recent notation).
In present work, we consider (consistently with situation in several
Metabelba
species) the present dorsal tubercles to be
D a
and
D p
, based on their rather central position axial to the level of
in
insertions. Nevertheless, homology of these tubercles remains unclear, as they may be more linked to the development of latero
–
posterior rather than postero-axial end of bothridial cuticular protuberance. This is supported by the argumentation of Behan
Pelletier & Norton (1985)
and by the fact that protuberance on which is positioned bothridium is in
N. pseudopapillipes
connected with anterior tubercle of this enantiophysis by oblique ridge (
Fig. 2
B). Shift of the whole enantiophyse in axial direction may be also explained by narrowing of the whole body in the sejugal area. Regarding presence of ventrosejugal posterior tubercle
V
p (corresponding to
V
2
of Bulanova-Zachvatkina), we note that cuticular triangular thickenings in corresponding area may be interpreted as apophyses, when seen purely in ventral view. Nevertheless, observation from another angle (lateral) shows that there is no protuberance present, and tubercle
V
p is missing.
As
all other characters fit exactly the description of Bulanova-Zachvatkina, and no other similar species was found yet, we consider the identity of our individuals with
Neobelba pseudopapillipes
proved.
The species shows important similarities with species of the genus
Metabelba
Grandjean, 1936
. Development of prodorsum and notogaster and their setae, characters of ventral part of the body as well as the legs are identical or very similar.
As
far as we know, the following characters can be considered as unique for
pseudopapillipes
: (a) presence of companion seta
d
, coupled with solenidion on tibia IV, (b) presence of distinct prodorsal area (
apd
), resembling area porosa, anterior to insertion of interlamellar seta
in
, (c) characteristic form of notogastral setae, bent and thickened at the base in lateral view. Absence or presence of accompanied setae related to tibial solenidia is broadly accepted as important distinguishing character at generic or even supra-generic level; however, this mostly applies to total absence (all tibial solenidia free) than to the absence of individual companion seta. On the other hand, setation of the leg IV seems to be of greater importance than in legs II and III, and absence of companion seta on tibia IV was used as one of the distinguishing characters,
e.g.
, between
Belba
von Heyden, 1826 and
Caenobelba
Norton, 1979
or
Dyobelba
Norton, 1980
.
Subías (2004)
placed genus
Neobelba
as a subgenus to genus
Metabelba
, and later (
Subías, 2013
) even synonymized it with
Metabelba
s. str.
We assume that the motivation for this move was in great morphological similarity of
N. pseudopapillipes
and species of the genus
Metabelba
. Mourek
et al.
(2012) considered
Neobelba
as a separate genus, until more information about morphology of this taxon will be available, and mentioned namely the chaetotaxy of leg femora. To decide about the status of
Neobelba
it is crucial to weight the value of presence vs. loss of seta
d
on tibia IV, accompanying the respective solenidion.
As
demonstrated above, this character can be used as distinguishing between the genera. This supports the idea that presence or loss of seta
d
on tibia IV is rather a generic than a specific character within
Damaeidae
. In all cases where it differentiates between the genera, however, this character is combined with some additional distinguishing characters. Two other distinguishing characters of
N. pseudopapillipes
mentioned above can hardly be seen as generic: variability of notogastral setae within the genus
Metabelba
is very broad, and areas similar to prodorsal area
apd
appear on different places and different species throughout the family. This leaves only single generic character to distinguish
Neobelba
from
Metabelba
.
In our view, the only solution of the problem is in placing
Neobelba
to broader
Metabelba
concept at the subgeneric level. The proposed synonymy of
Neobelba
and
Metabelba
s. str.
must be rejected. Nominal subgenus of
Metabelba
has well developed propodolateral apophysis
P
, which is clearly missing in
Neobelba
. On the other hand,
N. pseudopapillipes
closely resembles some of the species of recently defined subgenus
Pateribelba
Mourek, Miko & Bernini, 2012. It has to be noted that notation of the prodorsal tubercles in Mourek
et al.
(2012) followed the same approach of designation based on the physical position of tubercles (axially to the level of setae
in
insertions), the discussion above on homology of tubercles observed in
Neobelba
applies as well.
Particularly interesting is the common presence of such subtle characters like the presence of 2 pairs of light spots on the notogaster near the insertions of
l a
and
l p
in most of
Pateribelba
species studied and in
Neobelba
; or the form and size of setae on leg segments (
e.g.
dorsal setae on trochanters, femora and genua or length and form of solenidia except solenidion of tibia IV) very similar
e.g.
in both
M.(P.) sphagni
Strenzke, 1950
and
N. pseudopapillipes
. These common characters further support inclusion of
Neobelba
into
Metabelba
.
As
argued above, we consider the presence of companion seta on tibia IV to be a character at generic level, and therefore reject the synonymy with
Pateribelba
and support the original proposal of
Subías (2004)
, i.e. to place
Neobelba
as a separate subgenus of the genus
Metabelba
, with close relation to subgenus
Pateribelba
.