Review of the genus Bilobella Caroli, 1912 in the Balkan Peninsula with description of a new species (Collembola: Neanuridae)AuthorDányi, LászlótextZootaxa201026052744journal article10.5281/zenodo.1976829575c091-be7c-4662-bc2b-1211eb2935a81175-5326197682Bilobella mahunkaisp. nov.Figs 1–37
,
Tab. 1–2Diagnosis.
Dorsal tubercles extremely developed. Colour sulphureous yellow. Buccal cone elongated. Labral chaetotaxy 4/2, 4. Maxilla without apical tooth. Ant. I with 9, ant. II with 11 chaetae. Absence of chaetae D and O on head. Tubercle (Di+De) of head with 4 chaetae. Tubercle De of th. I with 3 chaetae, tubercle De of th. II–III with 4 chaetae. Integumental granulation arranged into separated fields on papillae. Tubercle L of abd. IV with 8 chaetae. Tubercle (Di+De+Dl) of abd. V with 10 chaetae. Claws without teeth.
Type
material.
Holotype
: adult female in alcohol (vial Nr.: coll–619):
Montenegro
2008/19, Lovćen Mts,
2 km
from the Lovćen peak towards Njeguši,
1377 m
[beech forest] –
N42°23.994'E18°49.882'
leg. L. Dányi, Z. Fehér, J. Kontschán & D. Murányi,
8.x.2008
.
Paratypes
:
1 male
in alcohol (vial Nr.: coll–651) and on a slide (collpr–488 (left antenna): the same data as
holotype
;
1 female
on slides (Nr.: collpr–401 (body), collpr– 439 (labial cone), collpr–440 (head), collpr–449 (left legs)): same data as
holotype
.
Other material.1 female
in alcohol (vial Nr.: coll–652; coated with gold–palladium for scanning microscopy): same data as
holotype
.
Etymology
. The new species is named in honour of the renowned acarologist Professor Sándor Mahunka (Systematic Zoology Research Group of the Hungarian Academy of Sciences (HAS), and Department of Zoology, HNHM), colleague and friend, who initiated my work on springtails.
Description.
Habitus similar to
Bilobella digitata
with dorsal tubercles well developed, prolonged and of finger-shape (
Figs 2–3
).
Body length (without antennae) 2.75–5.2 mm (
holotype
5.2 mm). Tertiary granulation well developed, with reticular pattern formed by the grouping’s of granules into separated fields on papillae (
Figs 28–35
). Reticulation on ventral side of body present.
Colour of the body sulphureous yellow in living specimens (
Fig. 2
), but fading to white in alcohol. 2+2 medium, unpigmented eyes (
Figs 3
,
28
).
Dorsal ordinary chaetae: macrochaetae Ml thickened, narrowly sheathed, apically arc-like (
Figs 3
,
29–35
) and distinctly serrated (
Figs 36–37
); macrochaetae Mc with similar morphology, mesochaetae thin and pointed.
FIGURE 2.Bilobella mahunkaisp. nov.
: habitus and colour of living specimens.
FIGURES 3–6
.
Bilobella mahunkaisp. nov.
: 3, habitus and dorsal chaetotaxy; 4, head chaetotaxy with aberrant single G chaeta in Af (frontal view); 5, ventral chaetotaxy of head; 6, chaetotaxy of labium (ventral view).
FIGURES 7–15
.
Bilobella mahunkaisp. nov.
: 7, chaetotaxy of labrum. 8, mandible and maxilla; 9, head of mandible; 10, dorsal chaetotaxy of ant. I–II; 11, ventral chaetotaxy of ant. I–II; 12, apical vesicle of ant. IV; 13, antennal organ of ant. III (medial view); 14, dorsal chaetotaxy of ant. III–IV; 15, ventral chaetotaxy of ant. III–IV.
Head. Buccal cone distinctly elongated. Labrum with ventral sclerifications as in
Fig. 7
. Labrum chaetotaxy 4/2, 4 (
Fig. 7
), prelabral chaetae very tiny, two medial ones in a forward position. Chaetotaxy of labium as in
Fig. 6
and
Tab. 1
. Maxilla styliform (
Fig. 8
) with two coherent lamellae. Mandible thin with 2 basal and one three-branched apical teeth (
Figs 8–9
). Ant. I and II with 9 and 11 chaetae respectively (
Figs 10–11
). Ant. III and IV fused dorsally. Dorsal and ventral chaetotaxy of ant. III–IV as in
Figs 14–15
, respectively. Apical vesicle distinct, trilobed. Ant. III or. as in
Figs 13 and 15
, subapical organite of antenna IV as in
Fig. 14
. Ant. IV with 8 moderately thickened S–chaetae, of which S3, S4, S7 and S8 distinctly longer than other sensilla (
Figs 14–15
). S1 and S2 weaker. Chaetotaxy of head as in
Figs 3–4, 5
and
Tab. 1
. Chaetae D and O absent.
Thorax, abdomen, legs. Dorsal chaetotaxy of thorax and abdomen as in
Figs 3
,
16
,
20
,
29–35
and
Tab. 2
. Th. I: De with 2Mc, 1Ml; Dl with Ml. Th. II and III: Di with 1Mc, 1Ml; De with 2Mc, 1Ml, 1S; Dl th. II with 2Mc, 1Ml, 1S, 1ms; Dl th. III with 2Mc, 1Ml, 1S; L with 2Mc, 1Ml. Abd. I–III: Di with 1Mc, 1Ml; De with 1Mc, 1Ml, 1S; Dl with 1Mc, 1Ml; L abd. I with 2Mc, 1Ml; L abd. II with 3me, 1Mc, 1Ml; L abd. III with 4(3– 5, in
holotype
3–4)me, 1Mc, 1Ml. Abd. IV: Di with 1Mc, 1Ml; (De+Dl) with 2Mc, 2Ml, 1S; L with 3me, 4Mc, 1Ml. Abd. V: (Di+De+Dl+L) with 6Mc, 3Ml, 1S. Abd. VI: (Di+De+Dl+L) with 4Mc, 3Ml.
Ventral chaetotaxy of thorax as in
Fig. 20
and
Tab. 2
, of abdomen as in
Fig. 16
and
Tab. 2
. VT with 4– 5+4–5 chaetae. Furca rudimentary, with 4–6 (in
holotype
4) mesochaetae, without microchaetae (
Figs 16, 18
). Cryptopygy present (
Figs 3
,
34
). Chaetotaxy of legs as in
Figs 20–22, 24–27
and
Tab. 2
. M chaeta present. Claw without tooth (
Figs 21–27
). Posterior surface of each trochanter with one modified chaeta as in
Figs 22, 25 and 27
. Anterior and posterior sides of femur I–III with one modified chaeta as in
Figs 21–22, 24–27
.
TABLE 1.
Cephalic chaetotaxy of
Bilobella mahunkaisp. nov.
Tubercle
Number of chaetae
Types of chaetae
Names of chaetae
Cl
4
Ml
F
Af
6
Mc Ml
G B
Mc C, E Number of other cephalic chaetae: Vi, 6; Ve, 9; labrum, 4/2, 4; labium, 10, 0x; ant. I, 9; ant. II, 11; ant. III, 13+5s; ant. IV, 8S+i+or+12mou.
Oc
2
Ml Mc
Ocm Oca
(Di+De)
4
Ml
Di1, De1
(Dl+L+So)
9–10
Mc Ml, Mc, me
Di2, De2 impossible to recognise
TABLE 2.
Postcephalic chaetotaxy of
Bilobella mahunkaisp. nov.
Terga Legs
Di De Dl L Scx2 Cx Tr Fe T th.
I – 3
1 – 0 3(4)
6 13 19 th
.
II 2
3+s 3+s+ms 3 2
7 6 12
19 th.
III 2
3+s 3+
s 3 2
8
6 11 18
Sterna
Abd.
I 2
2+
s 2 3
VT: 4–5
Abd.
II 2
2+
s 2 5
(4) Ve: 3–4 Ve1: 3–4
Abd.
III 2
2+
s 2 6
(5–7) Ve: 5–8 Fu: 4–6, 0 mi Abd.
IV 2
4+s 8 Ve: 5 + 1 Vl: 5 Abd.
V 9
+s Ag: 4–5 Vl: 3–4 Abd.
VI 7
Ve: 13–14 An:
2 miVariability and aberrations.
Ve of abd. II weakly reticulated in female
paratype
(
Fig. 16
), but missing in other specimens.
The following features observed in some of the specimens are considered as aberrations:
Holotype
Di tubercle on th. II. asymmetrically with one additional Mc on the right side, right coxa I with an extra (4th) chaeta asymmetrically. Female
paratype
with only one G chaeta in medial position on clypeal tubercle (
Fig. 4
). Male
paratype
with only 4 (instead of 5) chaetae on one side on L tubercles of abd. II. Tubercles L on abd. III with asymmetrical chaetal numbers in two specimens (5+
6 inholotype
, 6+
7 in
male
paratype
). Female
paratype
with an extra (5th) chaeta on VT asymmetrically.
Ecology.
The specimens were collected in the thick layer of leaf litter in a beech forest on limestone, at
1377 m
above sea level. All four specimens were aggregated in one group on the surface of only one leaf, while carefully searching an area of about
50 m
2 did not result in finding any further specimens.
FIGURES 20–27
.
Bilobella mahunkaisp. nov.
: 20, ventral chaetotaxy of th. I–III and chaetotaxy of Scx2 and Cx of legs I–III; 21, anterior chaetotaxy of leg I; 22, posterior chaetotaxy of leg I; 23, claw of leg I (anterior view); 24, anterior chaetotaxy of leg II; 25, posterior chaetotaxy of leg II; 26, anterior chaetotaxy of leg III; 27, posterior chaetotaxy of leg III. (arrowheads indicate modified chaetae).
Three of the four specimens were infected by Nematoda specimens (
Fig. 38
). There is one on the holotype’s (De+Dl) tubercle on abd. VI and one on lateral side of the head on both other females. The nematodes in question are larvae and probably belong to the order Rhabditida (István Andrássy pers. comm.). These larvae are merely phoretic, they do not parasite hosts otherwise but use them for changing places (István Andrássy pers. comm.). Nematode phoresis on springtails seems to be not a rare phenomenon (e.g.
Frans
Janssens in litt.), although there are only few cases documented (
Miles 1971
,
1976
,
1986
).
Discussion
.
Bilobella mahunkaisp. nov
.
is unique in the genus
Bilobella
because of the presence of three chaetae on tubercle De of thoracal tergum I (in each other species: 2). Among the
Bilobella
species with 4 chaetae on tubercle De of thoracal terga II, there are only three other ones bearing finger-like elongated posterior tubercles:
B. coiffaiti
,
B. digitata
and
B. zekoi
.
B. zekoi
differs from the new species in colour (red in
B. zekoi
and yellow in
B. mahunkai
) and in abdominal chaetotaxy (
B. zekoi
with about twice the number of chaetae than
B. mahunkai
on L tubercle of abd. I–IV and on (Di+De+Dl) tubercle of abd. V–VI). The new species is similar to
B. coiffaiti
in the reticulation formed by the integumental granulation’s grouping that is missing in
B. digitata
and it is similar to
B. digitata
in simple cuticular papillae which are more complex (conifer cone-like) in
B. coiffaiti
(
Cassagnau 1968:
Figs 7
A, 7C
).
B. mahunkaisp. nov.
differs from both
B. coiffaiti
and
B. digitata
in the chaetotaxy of the tubercle L on abd. IV (8 chaetae in
B. mahunkai
, 5 and
6 inB. coiffaiti
and
B. digitata
respectively) and in the chaetotaxy of tubercle (Di+De+Dl) of abd. V (10 chaetae in
B. mahunkai
and
8 inB. coiffaiti
and
B. digitata
).