Research Article |
Corresponding author: Celal Tuncer ( celalt@omu.edu.tr ) Academic editor: Miguel Alonso-Zarazaga
© 2017 Celal Tuncer, Milos Knizek, Jiri Hulcr.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tuncer C, Knizek M, Hulcr J (2017) Scolytinae (Coleoptera, Curculionidae) in hazelnut orchards of Turkey: clarification of species and identification key. ZooKeys 710: 65-76. https://doi.org/10.3897/zookeys.710.15047
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Hazelnut, a very important cash crop in Turkey, is frequently colonized by bark and ambrosia beetle species (Scolytinae). Some scolytine species may cause economic damage while other species do not; therefore, proper identification is important in orchard management. Extensive sampling demonstrated that the most common pest species in Turkey’s hazelnut orchards are Anisandrus dispar, Xylosandrus germanus, and Xyleborinus saxesenii. Hypothenemus eruditus can also be common, but only colonizes branches that are already dead. Lymantor coryli, Hypoborus ficus, Taphrorychus ramicola, and Taphrorychus hirtellus are rare and do not causes damage to live plants. Xyleborinus saxesenii appears to have been frequently misidentified and misreported as either L. coryli or Xyleborus xylographus. The former is rare, and the latter probably does not occur in Turkey. To avoid future misidentifications, a dichotomous identification key is provided for bark and ambrosia beetles of hazelnut orchards in Turkey.
ambrosia beetles, bark beetles, pests
Turkey is the world’s largest hazelnut producer, supplying nearly 80% of the total global production. The plantations in Turkey occupy nearly 690,000 ha (
Although Turkey is the world’s primary hazelnut producer, its productivity per area is lower than that of hazelnut-growing Western countries. Besides agronomic reasons, insect and mite pests appear to be a major impediment to efficient production. Hundreds of insect and mite species have been found to be pests in Turkish hazelnut orchards (
Bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) are a well-known and diverse group of insects often capable of causing serious damage estimated in millions of US dollars (
Bark and ambrosia beetles are a diverse group of small insects with uniform morphology making them notoriously difficult to identify (
Without experience in identification, X. saxesenii tended to be mistaken for L. coryli, and A. dispar (male) for X. germanus. Frequent misidentification occurred whether the specimen was viewed under a microscope or with the naked eye and are especially troublesome during field studies. Therefore, to prevent future misidentifications of these species and to increase the efficiency of hazelnut pest management, a simple and easy identification key for bark and ambrosia beetles in hazelnut orchards is needed.
Examined material consisted of samples belonging to five species which were obtained from hazelnut orchards in the mid-Black Sea region. Specimens were collected with ethanol-baited traps as well as extracted from infested hazelnut trunks. Two species (H. ficus and T. hirtellus) were only obtained by excision directly from hazelnut wood. Though T. ramicola and X. xylographus were not sampled in this work, they were included in the key due to their presence in early records. X. xylographus was provided by the Museum of Entomology (
A list of the bark and ambrosia beetles present in hazelnut orchards of Turkey is provided in Table
Scolytinae species in hazelnut orchards of Turkey and their distribution in Turkey and in the World.
Species | Distribution in Turkey | World distribution |
---|---|---|
Anisandrus dispar (Fabricius, 1792) | Adana, Ankara, Artvin, Bartın, Bolu, Bursa, Çorum, Denizli, Duzce, Giresun, Gümüşhane, Hatay, İstanbul, Karabük, Kastamonu, Muğla, Niğde, Ordu, Rize, Sakarya, Samsun, Trabzon, Zonguldak, Western Mediterranien | Asia, Europe, Nearctic, Oriental |
Hypoborus ficus Erichson, 1836 | Adana, İstanbul, İzmir, Mersin, Sakarya | Asia, Europe, North Africa |
Hypothenemus eruditus (Westwood, 1834) | Aydın, Mersin, Samsun | Afrotropical, Asia, Australia, Europe, Nearctic, Neotropical, North Africa, Oriental |
Lymantor coryli (Perris, 1855) | Düzce, Samsun | Asia, Europe |
Taphrorychus hirtellus Eichhoff, 1878 | Hatay, İstanbul, Sakarya, Sinop | Asia, Europe, North Africa |
Taphrorychus ramicola Reitter, 1895 | Bartın, Hatay, Sakarya, Trabzon, Western Mediterranien, | Asia, Europe |
Xyleborinus saxesenii (Ratzeburg, 1937) | Amasya, Antalya, Artvin, Bolu, Düzce, Giresun, Hatay, Isparta, İstanbul, Kocaeli, Konya, Mersin, Muğla, Ordu, Rize, Sakarya, Samsun, Sinop, Trabzon, Zonguldak | Afrotropical, Asia, Australia, Europe, Nearctic, Neotropical, North Africa, Oriental |
Xylosandrus germanus (Blandford, 1894) | Duzce, Ordu, Samsun | Asia, Europe, Nearctic, Oriental |
1 | Body shortly oval, stout, length-to-width ratio of pronotum 0.6, basal margin of elytra procurved, elevated and armed by marginal crenulations. 1.0–1.3 mm. | tribe Hypoborini, Hypoborus ficus (Figs |
– | Body elongated, cylindrical, length-to-width ratio of pronotum 0.9–1.1, basal margin of elytra straight, transverse, unarmed | tribes Cryphalini, Dryocoetini and Xyleborini...2 |
2 | Body covered with flattened setae or erect scales, particularly the elytral declivity; antennal club segments of approximately the same size, with a distinct partial septum (dark incision) (Fig. |
tribe Cryphalini, Hypothenemus eruditus (Figs |
- | Body mostly shining, covered with fine setae which are not flattened, antennal club rounded, the first segment much more prominent than the second and third, septum absent, (Figs |
tribes Dryocoetini and Xyleborini...3 |
3 | First suture on the antennal club procurved, convex, the first segment round (Fig. |
tribe Dryocoetini...4 |
– | First suture on the antennal club recurved, concave, the first segment sickle-shaped (Fig. |
tribe Xyleborini...6 |
4 | Pronotum oval from dorsal view, convex with no distinct summit from lateral view, approximately first third asperate, posterior two thirds punctate, smooth and shining in between the punctures, hair-like setae missing in elytral and declivital disc, restricted only along the suture and lateral parts on elytral declivity. 1.6–2.2 mm |
Lymantor coryli (Figs |
– | Pronotum cylindrical from dorsal view and with an indicated summit from lateral view, first half asperate, posterior half punctate, smooth and shagreened, semi-shining in-between the punctures, elytral vestiture occurring on the whole surface of elytral disc and declivity | Taphrorychus...5 |
5 | Pronotum convex with no distinct summit from lateral view; elytra shining, with clearly visible slightly impressed punctured striae. 1.2–2.0 mm |
Taphrorychus ramicola (Figs |
– | Pronotum clearly marked by summit in the middle from lateral view; elytra matt, without punctured impressed striae. 1.6–1.8 mm |
Taphrorychus hirtellus (Figs |
6 | Robust; black or very dark brown when mature; the anterior margin of pronotum with a row of flat teeth (serrations) | 7 |
– | Slender; orange to brown, if dark brown then elytra darker than pronotum; the anterior margin of pronotum without elevated teeth (only with asperities appressed to the surface); | 8 |
7 | Procoxae widely separated, the gap wider than antennal scapus (the first long segment) (Fig. |
Xylosandrus germanus (Figs |
– | Procoxae only narrowly separated (Fig. |
Anisandrus dispar (Figs |
8 | Scutellum small, conical (“knob-like”), nearly concealed by a tuft of setae (Fig. |
Xyleborinus saxesenii (Figs |
– | Scutellum triangular, flush with surface of elytra, easily visible; all striae on elytral declivity with uniform small dull granules in all striae, 1.9 mm in ♂, 2.3–2.7 mm in ♀ |
Xyleborus xylographus (Figs |
The sampling revealed that A. dispar, X. saxesenii, X. germanus, and H. eruditus are common in hazelnut plantations. In addition, a few specimens of L. coryli, T. hirtellus, and H. ficus were collected by examining the hazelnut tree trunks. It therefore appears that A. dispar, H. eruditus, X. germanus, and X. saxesenii are regularly found in hazelnut orchards, while T. hirtellus and L. coryli are not very common. Hypoborus ficus is a common species on fig trees in Turkey (
It is worth noting that several species treated here [A. dispar, X. germanus (
Additional species are likely to be found on hazelnut in Turkey in the future. One reason is that bark beetle surveys in the country have by no means been comprehensive, and many areas remain to be explored. For example, Scolytus carpini (Ratzeburg, 1837) and Dryocoetes alni (Georg, 1856) were both reported as pests on hazelnut in western Russia and may also occur in Turkey (
We thank to Turkish MEVLANA program and TUBITAK project (TOVAG-111O788) that financially supported the travels for studies in this paper. This research was also partly supported by the project of the Ministry of Agriculture of the Czech Republic – Resolution RO0116 (reference number 10462/2016-MZE-17011), by the USDA Forest Service, USDA Farm Bill Section 10007, the National Science Foundation. The Florida State Collection of Arthropods kindly loaned several specimens. The authors wish to thank Mr. Zachary Nolen (M.Sc.) from University of Florida (USA), who assisted in improving the language of the manuscript, and Drs. Bjarte H. Jordal and Michail Yu. Mandelshtam for their helpful reviews.