Amerikan beyaz kelebeği, Hyphantria cunea Drury (Lepidoptera: Erebidae) dünyada önemli bir karantina zararlısıdır. Polifag bir zararlı olan H. cunea, başlıca meyveler, orman ağaçları ve süs bitkilerinde önemli ekonomik kayıplara neden olmaktadır. Zararlının larvaları yapraklar üzerinde beslenerek yaz sonunda ve sonbaharda ağaçların dallarında karakteristik ağdan örülmüş büyük yuvalar oluşturmaktadır. Bu çalışmada, H. cunea erginleri 2016-2017 yılları arasında Düzce ilinde eşeysel feromon tuzaklarla izlenmiştir. Ayrıca, zararlının larva ve yumurtaları haftalık olarak fındık sürgünlerinde sayılmıştır. Tuzak yakalamaları, 24 Mayıs-02 Haziran ile 27 Temmuz-23 Ağustos tarihleri arasında iki döl verdiğini, birinci dölün haziran başında, ikincisinin ise ağustos ayı ortalarında en yüksek sayıya ulaştığını göstermiştir. İlginç bir şekilde, ikinci dölün erginleri iki alanda da daha uzun süre görülmüş ve en yüksek sayıya 2017’de ulaştığı belirlenmiştir. Zararlının iki dölü için ilk erginler ortalama en düşük 16.2 °C sıcaklık ve %75 nemde, ikinci dölün erginleri ise ortalama en düşük 23.3 °C sıcaklık ve %72.1 nemde tespit edilmiştir.

The fall webworm is an injurious pest for many host plants in agriculture, forest, and urban environments. Recent observations showed that the faster spread of this pest can be supported by temperature increases, with a subsequent higher severity of the outbreaks and higher impact on the environment. Traditional chemical control is not effective on this pest, while biological control is a valuable alternative, especially if native natural enemies are used. In this study, the performance of Turkish populations of two parasitoids—Chouioia cunea and Psychophagus omnivorus—at different temperatures is evaluated. Laboratory trials were conducted in climatic chambers under five constant temperatures (10, 15, 20, 25, and 30 °C) and cold storage conditions (6 and 12 °C) for periods of 15, 30, and 45 days. The optimal developmental temperature and the upper thermal threshold of the two parasitoids were similar, while C. cunea showed a lower thermal threshold temperature. Both species could develop and survive between 20 and 30 °C, whereas development below 20 °C for C. cunea, and below 15 °C for P. omnivorus was not possible, respectively. Chouioia cunae was less tolerant to temperature changes than P. omnivorus in terms of offspring survival, development, reproduction, and parasitism. Under cold storage temperatures, the two species did not develop into adults. This study provided relevant eco-biological information that can further support biological control programmes.

Suckers that develop rapidly in hazelnut bottoms compete with the main branches, resulting in yield and quality losses as well as a risk for pest and diseases. Hazelnut suckers are controlled by mechanical, physical and chemical methods. A majority of mechanical methods are impractical in large production areas and physical and chemical methods come to the forefront. Among the physical methods, flaming is an effective method preferred for this purpose. As a result of studies carried out in different countries on the effect of herbicides on suckers, 2.4-D, glufosinate ammonium, paraquat, carfentrazone-ethyl, and saflufenacil have been recommended. For this purpose, 2.4-D, diquat and glyphosate are applied in Türkiye. Aside from herbicides, some nitrogen fertilizers and plant growth regulators were also effective. In Türkiye, hazelnut growers prefer mechanical and chemical applications for controlling suckers, which they consider as a problem. Within the scope of this study, in order to determine effective, economical, and practical methods and to develop control strategies for Türkiye, a literature review was carried out on the methods for controlling hazelnut suckers in Türkiye and in other countries. In the light of compiled information, current methods and their alternatives have been evaluated. As a result, it is concluded that scientific research is needed and region-specific management strategies should be developed by integrating cultural, physical, mechanical and chemical methods which are effective, economical, and practical for the sustainable management of suckers in hazelnut orchards in Türkiye.