Ecological Description of Two Seed-Feeding Weevils of the GenusMononychusGermar (Coleoptera: Curculionidae) onIris ibericaHoffmann andIris spuriaL. in Northeastern Turkey
Author
Gültekin, Levent
Author
Korotyaev, Boris A.
text
The Coleopterists Bulletin
2012
2012-06-30
66
2
155
161
http://dx.doi.org/10.1649/072.066.0213
journal article
10.1649/072.066.0213
1938-4394
10108027
Mononychus schoenherrii
Kolenati, 1859
Biology.
Adults of this species started their activity in early spring, and were observed on 3 May. The adults fed on flowers of
I. iberica
, creating round holes in petal leaves. Adults were usually hidden inside the flower among petals, and were rarely seen on the flower surface on sunny days while feeding. In early morning and during cloudy weather, adults rested individually or in small groups inside the flower. Copulation was not observed. Adults were most abundant in the first week of June, and their numbers sharply declined after the second week of June as the flowering season ends. Females laid pearl-white eggs in very young seed capsules, drilling holes with their rostrum. Many eggs also were laid in the fruit. There can be five or
six eggs
in one oviposition place, and 15–
20 eggs
in one seed capsule. Several oviposition and feeding holes were present on a fruit (
Fig. 3
). The oviposition holes were not easily distinguishable from feeding holes in external appearance. They both were surrounded by paler areas about
3–5 mm
in diameter, indicating chlorophyll degradation, and their color gradually turned brown. Egg laying began at the end of May and lasted until mid-June.
The legless, white larvae with brown head capsules developed inside the seed capsule (
Fig. 4
). During their development, the larvae consumed all seeds inside the capsule, moving freely while filling the capsule with dry brown food remnants. Five or
six larvae
usually developed in one seed capsule. Mature larvae entered the pupal stage inside the seed capsules starting in the middle of July. The pupae were white at this time, and the seed capsules were nearly ripe and, starting to dry from the tip, turned brown at the end of July. Starting in the last week of July, the new generation of adults (
Fig. 5
) emerged from the seed capsule, opening a hole after resting some days inside. Immediately after emergence from the seed capsules, the new generation of adults flew away. No hibernating individuals could be found in the original habitat near the host plants. This finding implies that adults migrate somewhere else in the middle of summer for aestivation and hibernation. Only one generation per year is produced.
Taxonomic Notes.
The species has been considered by
Wagner (1938b)
as a color form of
Mononychus ireos
(Pallas, 1773)
.
Korotyaev and Cholokava (1989)
confirmed that this form is a good species based on differences in the shape of the aedeagus and the pygidium of both sexes. The bionomics of the species in northeastern
Turkey
would appear to confirm their conclusion. We found
M
.
schoenherrii
associated with
I. iberica
on mountain slopes with steppe vegetation, whereas
M. ireos
lives in the saline semi-deserts in
Kazakhstan
and central Asia on
Iris halophila
Pallas (
Wagner 1938b
)
.
Distribution.
Mononychus schoenherrii
has a Transcaucasian distribution in
Georgia
,
Armenia
,
Azerbaijan
(
Korotyaev and Cholokava 1989
), and northeastern
Turkey
(
Colonnelli 2004
). This study has revealed that
I. iberica
and
M. schoenherrii
co-occur. The weevil and host plant are mainly distributed throughout the Aras Valley in the
Erzurum
,
Kars
, and
Iğdır
Provinces, and have been found in a single locality at the western limit of
Erzurum Province
near the
Erzincan Province
border.
Figs. 1–5. 1)
Iris iberica
;
2)
An example of
I. iberica
habitat under agricultural pressure;
3)
Infested seed capsule of
I. iberica
with oviposition and feeding holes;
4)
Larvae of
Mononychus schoenherrii
feeding in a seed capsule;
5)
Young adult of
M. schoenherrii
newly emergent from a seed capsule.
Figs. 6–12. 6)
Iris spuria
;
7)
Habitat of
I. spuria
;
8)
Adult of
Mononychus punctumalbum
and an ant following the adult;
9)
Pair of adults resting on the host plant;
10)
Feeding and ovipositing holes on a seed capsule;
11)
Seeds damaged by adults;
12)
Larva feeding on a seed and a pupa of
M. punctumalbum
resting in a seed capsule of the host plant.
Material Examined.
Kars Prov.
:
27 km
E of
Horasan
,
Aras valley
,
40°7.822′N
42°29.351′E
,
1604 m
,
26
V
2000
(
1 adult
);
31 km
E of
Horasan
,
Aras valley
,
40°7.593′N
42°30.145′E
,
1480 m
,
24
V
2002
(
13 adults
);
5
VI
2002
(
15 adults
)
;
Erzurum Prov.
:
10 km
W of
Horasan
,
40°1.807′N
42°2.476′E
,
1575 m
,
1
VI
2002
(
13 adults
);
20 km
SE of
Horasan
,
39°55.913′N
42°18.976′E
,
1800 m
,
11
VI
2002
(
2 adults
)
;
Iğdır Prov.
:
23 km
E of
Tuzluca
,
4
V
2003
(
7 adults
);
10 km
W of Gaziler
,
1100 m
,
17
V
2005
(
1 adult
)
;
Erzurum and Erzincan Province
border,
14–15 km
W of Aşkale
,
1850 m
,
6
VI
2002
(
2 adults
)
.
Host Plant.
Iris iberica
is the only known host of
M. schoenherrii
. It occurs on mountain slopes with steppe vegetation in stony and sandy habitats at elevations of
1,100
–2,250
m
. It is distributed in northwestern
Iran
,
Armenia
,
Azerbaijan
,
Georgia
, and eastern
Turkey
(
Erzurum
,
Kars
,
Iğdır
,
Ağrı
, and
Van
Provinces:
Mathew 1984
,
1988
;
Güvenç
et al
. 2005
;
Avcı 2005
; Mikatadze- Pantsulaia 2011).