Morphology and identification of the mature larvae of several species of the genus Otiorhynchus (Coleoptera, Curculionidae, Entiminae) from Central Europe with an update of the life history traits
Author
Rafał Gosik
Author
Peter Sprick
Author
Jiří Skuhrovec
Author
Magdalena Deruś
Author
Martin Hommes
text
Zootaxa
2016
4108
1
1
67
journal article
39126
10.11646/zootaxa.4108.1.1
015bce14-fc37-4afb-b997-4b1e974770f9
1175-5326
265725
B802F2B1-944E-4B84-A856-8091E60D88FC
Otiorhynchus
(
Nehrodistus
)
armatus
Boheman, 1846
Material examined:
61 larvae
(
Figs. 209
,
230
). JKI, Braunschweig, climate chamber,
Chaenomeles
x
superba
cultivar ‘Hollandia’, flowerpot, 0
4.10.2013
, 7 ex.; dto.,
Euonymus fortunei
,
25.09.2014
, 6 ex.; dto.,
Euonymus fortunei
, 0
7.10.2014
, 6 ex.; dto.,
Hedera helix
L., 0
7.10.2014
, 26 ex.; and
25.09.2014
, 13 ex.; dto.,
Prunus laurocerasus
cultivar ‘Van Nes’,
19.12.2013
, 3 ex.
Remarks about breeding and development.
The larvae of this species were obtained from two breeding attempts in the JKI in
2013 and 2014
.
Otiorhynchus armatus
is apparently easy to breed also in small flowerpots, and it accepted all tested plants (
Chaenomeles
x
superba,
Euonymus fortunei
,
Hedera helix
,
Prunus laurocerasus
). During the past 15 years this taxon as well as the closely related or even identical
O
. corruptor
(Host, 1789)
was introduced several times to
Germany
and became noxious in indoor greeneries. Up to now, no permanent population (of both taxa) is known from
Germany
.
All adults had been collected by Klaus Schrameyer in Merano / Northern
Italy
on
18.05.2013
, in the town from a hotel wall with ivy (
Hedera helix
). The weevils were not sclerotized, young adults at this point in time.
4 males
and
3 females
were used for the first breeding attempt (released on the plants on
24.05.2013
) and
8 specimens
of undetermined sex for the second (started on
24.06.2014
). Adults and larvae from 2014 represent the second reared generation. Breeding gave no indication for any diapause. Mature larvae were already obtained in September and October, and pupae in November and December.
The life-cycle of this species is apparently unknown, but seems to be in some kind resembling to that of
Otiorhynchus sulcatus
: emergence of newly hatched adults from (approximately) mid-May, larval development within a few months, pupation during the whole season if temperature remains high in autumn and winter, development also in small flowerpots. The most striking difference is—in Central Europe—the much stronger limitation to indoor situations, apparently due to the demand of higher temperatures.
Viggiani (1977)
reports about damage on
Fragaria
and an occurrence on
Vitis vinifera
L.,
Ficus carica
L.,
Hedera helix
,
Spiraea apulifolia
L. and
Citrus medica
L. in Campania (
Italy
).
FIGURES 45–50
.
Otiorhynchus armatus
; mature larva. 45—habitus, lateral view, 46—lateral view of thoracic segments, 47—lateral view of abdominal segment I, 48—lateral view of abdominal segments VIII–IX, 49—ventral view of abdominal segments VIII–X, 50—dorsal view of abdominal segments VIII–X. Abbreviations: Ab.—abdominal segment, Th.—thoracic s., I–X—number of segments,
prns
—pronotal seta(e),
prs
—prodorsal s.,
pds
—postdorsal s.,
pda
—pedal s.,
as
—alar s.,
lsts
—laterosternal s.,
eus
—eusternal s.,
ps
—pleural s.,
sps
—spiracular s.,
sts
—sternal s.,
ds
—dorsal s.,
ts
—terminal s.
FIGURES 51–55.
Otiorhynchus armatus
; mature larva and mouthparts. 51—dorsal view of head, 52—labrum and clypeus, 53—epipharynx, 54—left mandible, 55—maxillo-labial complex. Abbreviations:
des
—dorsoepicranial seta(e),
fs
—frontal s.,
les
—lateroepicranial s.,
ves
—ventroepicranial s., at—antenna, st—stemmata,
cls
—clypeal s.,
lms
—labral s.,
ams
—anteromedial s.,
als
—anterolateral s.,
mes
—medial s., lr—labral rods,
mds
—mandible dorsal s.,
dms
—dorsal malae s.,
vms
—ventral malae s.,
mxps
—maxillary palps s.,
pfs
—palpiferal s.,
stps
—stipal s.,
mbs
—mandible basiventral s.,
prms
—prelabial s.,
pms
—postlabial s.,
ligs
—ligular s.
Description
(
Figs. 45–55
).
Coloration
. Head yellow; all thoracic and abdominal segments white; except brownish pronotum; cuticle almost smooth, microcuticular processes, brown, poorly visible.
Body
moderately elongated (
Fig. 45
).
Chaetotaxy
. Setae different in length, filiform; brown.
Thorax
. Prothorax with 4 long and 4 medium long to short
prns
; and 2
ps,
different in length. Mesothorax with 1 short
prs
; 4
pds
(ordered: 1 short, 1 medium long and 2 long); 1 long
as
; 1 long
eps
; and 1 long
ps
. Chaetotaxy of meso- and metathorax similar, with the exception of
pds
on metathorax (ordered: 1 short, 1 long, 1 medium long and 1 long). Each pedal area of thoracic segments well isolated, with 5
pda,
different in length. Each thoracic segment with 1 short
eus
(
Fig. 46
).
Abdomen
. Abdominal segments I–VIII with 1 short
prs
; 5
pds
(ordered: 2 short, 1 long, 1 short and 1 long); 1 long and 1 minute
sps
[abd. seg. VIII with only 4
pds
(1 long, 1 short, 1 long and 1 short) and 1 minute
sps
]; 2
eps,
different in length; 1 long and 1 minute
ps
; 1 long
lsts
; and 2
eus
(
Figs. 47, 49, 50
). Abdominal segment IX with 3
ds
, different in length; 2
ps,
different in length; and 2
sts,
equal in length (
Figs. 48–50
). Each lateral lobe of abdominal segment X with 2–3 minute
ts
.
Head
subglobose, narrowed bilaterally (
Fig. 51
). Head capsule with 4 relatively short and 1 minute
des
,
des
1 and
des
2 placed on central part of epicranium,
des
3 located on frontal suture,
des
5 located anterolaterally, minute
des
4 located close to stemmata, all
des
equal in length; 2 relatively short
fs, fs
4 placed anteromedially,
fs
5 located near to antenna; 2 relatively short
les
; and 1 very short
ves
. Postepicranial area with a group of 2 pairs of sensilla, frons with 2 pairs of sensilla. Stemmata (2 pairs) feebly visible. Antennal segment membranous, bearing 1 conical sensorium and 4 filiform sensilla.
Clypeus
3.6 times as wide as long with 2 very short
cls,
equal in length, placed posterolaterally (
Fig. 52
).
Labrum
about 1.7 times as wide as long with 3 straight
lms
of different length, placed medially or mediolaterally;
lms
3 distinctly shorter than other setae, all
lms
exceeding the outline of labrum; anterior margin of labrum rounded (
Fig. 52
).
Epipharynx
with 3 finger-like
als,
different in length; 2
ams,
different in length; and 2 very short
mes
; labral rods (lr) short, reniform, strong convergent; epipharynx covered by nodular cuticular processes (
Fig. 53
).
Mandible
(
Fig. 54
) bifid, teeth almost of equal height; with 2
mds,
different in length; internal egde with a triangular tooth.
Maxilla
(
Fig. 55
) with 1 very long
stps
and 2 very long
pfs
, placed ventrolaterally; 1 very short
mbs
, situated ventrally. Mala with 6
dms,
different in length and 3 straight
vms
, different in length. Maxillary palpi with two palpomeres; basal palpomere distinctly wider than distal; basal palpomere with 1
mxps
; distal palpomere with a group of 6 conical, cuticular processes apically; each palpomere with a sensillum.
Praelabium
heart-shaped (
Fig. 55
), with 2 very short
ligs
and 1 long
prms
. Labial palpi with two palpomeres, relatively elongated; both palpomeres almost equal in length; praemental sclerite well visible.
Postlabium
with 3
pms
, different in length;
pms
2 very long, 3–4 times as long as
pms
1, and 5 times as long as
pms
3 (
Fig. 55
).
Differential diagnosis
. See “Key to larvae of selected
Otiorhynchus
species” and
Tables 1
,
2
.