Immatures of Palaearctic species of the weevil genus Sibinia (Coleoptera, Curculionidae): new descriptions and new bionomic data with suggestions on their potential value in a phylogenetic reconstruction of the genus
Author
Skuhrovec, Jiří
Author
Gosik, Rafał
Author
Caldara, Roberto
Author
Košťál, Michael
text
Zootaxa
2015
2
151
187
journal article
http://dx.doi.org/10.11646/zootaxa.3955.2.1
ef3ddc5d-a90b-49df-a2b8-01282c0509fe
1175-5326
239116
2C428174-7C02-4F0C-BB34-E1BC81F58CB1
Sibinia tibialis
Gyllenhal,
1835
Caldara,
1985
:
36
.
Material examined
.
12
larvae
from seeds of
Silene otites
(L.) Wib. collected
5
.viii.
2014
in southern
Slovakia
(Borská nížina, Malacky env.
150 m
a. s. l.,
N
48
°
24.7
´
,
E
17
°04.0´
), leg. J. Skuhrovec, M. Košťál & Z. Košťálová, and
7
(
4
♂♂,
3
♀♀) pupae obtained from larvae collected similarly to the others, all determined by association with reared adults.
Differential diagnosis.
See Key to the immatures of the Palaearctic species of the genus
Sibinia
and
Table.
3
.
Description of mature larva.
COLORATION. Head brown to dark yellow. All thoracic and abdominal segments light yellow.
HEAD
CAPSULE AND
MOUTH
PARTS
. Head width:
0.53–0.63 mm
(see
Table.
1
). Endocarinal line present, reaching middle of frons.
Des
1
minute, located near frontal suture;
des
2
minute, located almost in central parts of epicarnium;
des
3
long, located along frontal suture;
des
4
absent;
des
5
long, located anterolaterally (
Fig.
31
).
Fs
1
and
fs
2
absent;
fs
3
minute, located medially;
fs
4
long, located anteromedially (along epistoma);
fs
5
very long, located anterolaterally (along epistoma),
fs
5
1.5
times as long as
fs
4
(
Fig.
31
).
Les
almost as long as
des
3
;
ves
1
short and
ves
2
long. Postepicranial area with
1
pes
and with
2–3
sensilla. Antennal segment membranous, bearing conical sensorium and
2
very short, conical, sensilla (
Fig.
34
).
Clypeus (
Fig.
35
)
3
times as wide as long; with
2
very short
cls
, and
1
sensillum, all located posterolaterally; anterior margin slightly rounded inside. Labrum (
Fig.
35
) approximately
3.5
times as wide as long;
lms
1
distinctly shorter than
lms
2
, and slightly longer and larger than
lms
3
; anterior margin slightly sinuate. Epipharynx (
Fig.
36
) with
2
elongated, finger-like
als
, similar in length; with
3
short
ams
, similar in length; with
2
very short and fingerlike
mes
(see comments about
ams
and
mes
in Material and Methods); labral rods elongate, kidney-shaped, strongly converging posteriorly. Mandibles (
Fig.
33
) with
2
mds
different in length. Maxilla (
Fig.
32
): stipes with
1
long
stps
, and with
2
long
pfs
, almost of equal length,
1
very short
mbs
; mala with
4
slightly curved
dms
, different in length; with
3
very short
vms
, almost of equal length. Maxillary palpi: length ratio of basal and distal palpomeres
1
:
1.6
; basal palpomera with
1
short
mxps
; distal palpomera with group of
3–4
conical, cuticular apical processes. Prementum (
Fig.
32
) almost rounded, with
1
prms
; margin of ligula slightly curved inside; ligula with
2
very short
ligs
; premental sclerite clearly visible. Postmentum (
Fig.
32
) with
2
pms
,
pms
1
absent, very long
pms
2
, 4 times as long as
pms
3
.
THORAX AND ABDOMEN. Body length
3.50–4.30 mm
(see
Table.
1
), elongate (
Fig.
37
). Abdominal segments I– V almost equal in length, slightly larger than abdominal segment VI and VII (
Fig.
37
). Spiracles on abdomen in posterior parts of segments (abdominal seg. I–VIII).
Chaetotaxy of body rather reduced. Setae long to very short and light yellow.
Thorax.
Prothorax (
Fig.
38
) with
10
prn
,
9
macro- and
1
microsetae;
2
moderately long
ps
of same length;
1
eus
. Meso- and metathorax (
Fig.
38
) with
1
moderately long
prs
;
1
moderately long and
1
short
pds
; alar area with moderately long
1
as
;
1
very short
ss
;
1
moderately long
eps
;
1
moderately long
ps
; and
1
eus
. Each pedal area of thoracic segments well-separated and with
2
pda
.
Abdomen.
Abdominal segments I–VII (
Figs. 39, 40
) with
1
long
prs
;
3
pds
of different length,
pds
1
and
pds
3
very short,
pds
2
long;
2
ss
of different length,
ss
1
very short to minute,
ss
2
moderately long;
2
eps
in equal length;
2
ps
of different length,
ps
1
short and
ps
2
moderately long;
1
long
lsts
; and
2
moderately long
eus
. Abdominal segment VIII (
Fig.
40
) with
1
moderately long
prs
;
3
pds
of different length,
pds
1
and
pds
3
very short,
pds
2
moderately long;
1
very short to minute
ss
;
2
moderately long
eps
in equal length;
2
ps
of different length,
ps
1
short and
ps
2
moderately long;
1
moderately long
lsts
; and
2
moderately long
eus
. Abdominal segment IX (
Fig.
40
) with
2
ds
of different length,
ds
1
short and
ds
2
moderately long;
2
ps
of different length,
ps
1
very short and
ps
2
moderately long; and
2
moderately long
sts
in equal length. Anal lobes on abdominal segment X (
Fig.
40
) with
2
minute setae.
Description of pupa.
COLORATION. Body white.
MORPHOLOGY (
Figs.
41–45
). Body length
2.35
–3.00 mm; widest part
1.15
–2.00 mm (see
Table.
2
). Body rather stocky. Rostrum moderately long, approximately
4
times as long as wide, reaching mesocoxae. Pronotum
1.6
times as wide as long.
CHAETOTAXY (
Figs.
41–45
). Setae distinct, medium long, unequal in length, brown; on pronotum and head placed on small protuberances. Setae clearly visible, medium long, unequal in length, brown; on pronotum and head placed on small protuberances. Setae on head different in length,
sos
3–4
times shorter than
os
;
rs
as long as
pas
(
Fig.
42
).
Ds
2
slightly shorter than other setae on pronotum (
Fig.
44
). Setae on abdominal segments I–VIII placed posteromedially and posterolaterally; all abdominal setae located on thorn-like protuberances. Pseudocerci short, triangular in shape.
Biological observations.
The larvae fed on seeds, and mature larvae left the capsule and entered the soil to pupate. Pupation was observed
8–10
days after the larvae entered the soil. Adults were found in the cells
7–9
days later.
Remarks.
This species is primarily distributed in Central Europe and reached northern
France
in the west and central
Italy
and
Romania
in the south. It is also reported to be in Asia and the Far East (
Caldara 1985
,
2013
).
Sibinia tibialis
seems monophagous on
Silene otites
(L.) Wib. (
Dieckmann
1988
;
Rheinheimer & Hassler
2010
), although the adult was also collected on
S
.
tatarica
(L.)
Pers
. in
Germany
(
Neresheimer & Wagner
1939
) and on
Minuartia setacea
(Thuill) Hayek
in
France
(
Hoffmann
1955
under
S
.
guillebeaui
Desbrochers
des Loges,
1897
).