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
(
Dorymerus
)
sulcatus
(Fabricius, 1775)
Material examined:
71 larvae
(
Fig. 206
). Lampertheimer Wald near Heppenheim (
Germany
, South Hesse), 3 ex. introduced with young oak plants (
Quercus ilex
L. and
Q. frainetto
Ten.
) from
Italy
(tree nursery) to the test area “Wald der Zukunft” of Senckenberg / Frankfurt a.M.,
20.03.2010
, leg. W. Dorow; Hildesheim (
Germany
, Niedersachsen), nursery, 0 6.04.2011, 17 ex.: 7 ex. from
Primula vulgaris
flowerpots; 10 ex. from
Geum chiloense
Balb. ex Ser.
cultivar ‘Feuerball’; dto., 0 4.05.2011, 12 ex.: 3 ex. from
Eupatorium cannabinum
L. flowerpots, dto., 2 ex. from
Geum montanum
L. cultivar ‘Diana’, dto., 7 ex. from
Lysimachia clethroides
Duby
; dto., 4 ex. from
Primula vulgaris
Huds.
flowerpots,
11.05.2010
;
Germany
, Wiesbaden (South Hesse), nursery,
27.04.2011
, 21 ex.: 8 ex. from
Astilbe simplicifolia
Makino
cultivar ‘Sprite’ flowerpots, 10 ex. from
Astilbe japonica
(C. Morren & Decne) A. Gray
cultivar ‘Deutschland’, 3 ex. from
Astilbe japonica
cultivar ‘Red Sentinel’; Wiesbaden, nursery, 0 3.08.2011, 4 ex. from flowerpots with
Bergenia cordifolia
Sternb.
cultivar ‘Glockenturm’; JKI, Braunschweig, greenhouse, 10 ex. in flowerpots with
Euonymus fortunei
(contamination),
13.11.2013
.
Additional material
: West
France
, Angers, 5 ex.,
24.02.2012
, collected by Michael Barth outdoors in a tree nursery in 15 litre plant pots with
Cupressocyparis
x
leylandii
(A.B. Jacks. & Dallim.) Dallim..
2 larvae
were reared to adults (28.–
29.03.2012
) and one to pupa (pupation before
22.03.2012
).
Remarks about breeding and development.
The development of
Otiorhynchus sulcatus
is one of the best known of all soil-dwelling weevils which is due to the great impact of this species in horticulture and viticulture in many regions of the world. The damage of this species in the temperate and cooler regions to cultivated plants is mainly restricted to greenhouses, flowerpots, parks, orchards, roadside greeneries and other typical anthropogenic environments. About 110 years ago there were only few indications of a pest status of this species (
Moorhouse
et al
. 1992
). Its origin is (northern)
Italy
from where also males of this predominantly parthenogenetic species are documented (concluded from data of
Dieckmann 1980
and
Moorhouse
et al
. 1992
). Outdoors, pupation begins in April or May. Young weevils emerge from June to September on the soil (peak activity in July and August) and deposit eggs in this period. Larvae develop during summer and autumn, overwinter, continue feeding activity early in the season and pupate in spring. Development time of the larvae strongly depends on temperature and is over 200 days outdoors and less than 90 days in greenhouses (
La Lone & Clarke 1981
). Most adults die in late summer and autumn; only a few overwinter and start to lay eggs earlier in the season.
O
. sulcatus
did not show a diapause or developmental delay under long-day conditions in the climate chamber.
Description
(
Figs. 23–33
).
Coloration
. Head dark yellow; all thoracic and abdominal segments from yellow to dark yellow; cuticle almost smooth.
Body
elongated (
Fig. 23
).
Chaetotaxy
: Setae different in length, filiform.
Thorax
. Prothorax with 4 long and 6 medium long to short
prns
; and 2
ps,
different in length. Mesothorax with 1 short
prs
; 4
pds
(ordered: 2 medium and 2 long); 2
as
, different in length; 1 long
eps
; and 1 long
ps
. Chaetotaxy of meso- and metathorax similar (except
pds
, ordered: 1 medium, 1 long, 1 medium and 1 long). Each pedal area of thoracic segments well isolated, with 6
pda,
different in length. Each thoracic segment with 1 short
eus
(
Fig. 24
).
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 only with 1 microseta]; 2
eps,
different in length; 1 long and 1 minute
ps
; 1 long
lsts
; and 2
eus
(
Figs. 25, 27, 28
). Abdominal segment IX with 3
ds
, different in length; 1 very long and 1 minute
ps
; and 2
sts,
equal in length (
Figs. 26–28
). Each of four lateral lobes of abdominal segment X with 2–3 minute
ts
.
Head
subglobose, slightly narrowed bilaterally (
Fig. 29
). Setae relatively short. Head capsule with 4 relatively short
des
,
des
1 and
des
2 placed on central part of epicranium,
des
3 located on frontal suture,
des
5 located anterolaterally; 2 relatively short
fs
,
fs
4 placed anteromedially,
fs
5 located near to antenna; 2 relatively short
les
; 1 relatively short
ves
; and 1 minute
pes
. Postepicranial area with 2 pairs of sensilla, forming a group. Stemmata (2 pairs) feebly visible. Antennal segment membranous, bearing 1 conical sensorium and 2–3 filiform sensilla.
Clypeus
1.7 times as wide as long and with 2
cls,
equal in length, placed posterolaterally on each side (
Fig. 30
).
Labrum
about 2 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 the labrum; the anterior margin of labrum double sinuate (
Fig. 30
).
Epipharynx
with 3 finger-like
als,
different in length, 3
ams,
different in length, one very small
ams
similar to
mes
, but the position is more to
ams
; and 2 very short
mes
(see comments about
ams
and
mes
in Material and Methods); labral rods (lr) short, reniform, strong convergent (
Fig. 31
).
Mandible
(
Fig. 32
) feebly bifid, teeth almost of equal height; with 2
mds,
different in length; internal edge with a triangular tooth.
Maxilla
(
Fig. 33
) with 1 very long
stps
and 2 very long
pfs
, placed ventrolaterally; 1 very short
mbs
, situated ventrally. Mala with 8
dms,
different in length and 4 straight
vms
, almost equal in length. Maxillary palpi with two palpomeres of almost equal length; basal palpomere with 1
mxps
; distal palpomere with a group of 7 conical, cuticular apical processes; each palpomere with a sensillum.
Praelabium
heart-shaped (
Fig. 33
), with 3
ligs
and 1
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 long, almost 2 times as long as
pms
1 and
pms
2 (
Fig. 33
).
FIGURES 34–39
.
Otiorhynchus singularis
; mature larva. 34—habitus, lateral view, 35—lateral view of thoracic segments, 36—lateral view of abdominal segment I, 37—lateral view of abdominal segments VIII–IX, 38—ventral view of abdominal segments VIII–X, 39—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 40–44.
Otiorhynchus singularis
; mature larva and mouthparts. 40—dorsal view of head, 41—labrum and clypeus, 42—epipharynx, 43—left mandible, 44—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.
Differential diagnosis
. See “Key to larvae of selected
Otiorhynchus
species” and
Tables 1
,
2
.