Mononychus schoenherrii Kolenati, 1859

Gültekin, Levent & Korotyaev, Boris A., 2012, Ecological Description of Two Seed-Feeding Weevils of the GenusMononychusGermar (Coleoptera: Curculionidae) onIris ibericaHoffmann andIris spuriaL. in Northeastern Turkey, The Coleopterists Bulletin 66 (2), pp. 155-161 : 156-159

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.

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).

Figures

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.