🐛 European hazelnut pests

1. Introduction

The European hazelnut (Corylus avellana) is a long-lived crop with high potential in Chile. However, like any fruit crop, it is exposed to pests that can affect development and productivity if not controlled in time.

The most important pests are concentrated in the soil, where larvae of insects known as weevils damage roots and weaken the plant from its earliest years. Other pests, such as the hazelnut aphid and the brown stink bug (leaf-footed bug), affect foliage and fruits, respectively.

At Vivero El Avellano, we understand that plant health is the foundation of a successful orchard. That’s why we rigorously control each production stage to ensure our plants are delivered pest-free and with the highest sanitary quality, ready for vigorous field development.

2. Most common European hazelnut pests in Chile

European hazelnut orchards in the south-central regions of Chile face three main pest groups that require special attention:

• Soil insect larvae (weevils): affect the root system
• Hazelnut aphid (Myzocallis coryli): sucks sap from leaves and tender shoots
• Brown stink bug (Leptoglossus chilensis): damages developing fruit
• Mites (Tetranychopsis horridus): damage the leaf blade

Prevention from the nursery is essential to minimize the impact of these pests during orchard establishment. At Vivero El Avellano, every plant undergoes rigorous sanitary controls before delivery.

3. Soil insects: weevils

The most relevant pest of European hazelnut in Chile is composed of so‑called weevils, a group of curculionids whose scientific names include:

• Aegorhinus superciliosus (raspberry weevil)
• Aegorhinus nodipennis (plum weevil)
• Aegorhinus albolineatus (striped weevil)
• Naupactus xanthographus (vine weevil)
• Asynonychus cervinus (fruit weevil)
• Sericoides viridis (raspberry beetle)
• Phytoloema herrmanni (brown May beetle)
• Hylamorpha elegans (green May beetle)

Life cycle and damage

The larvae of these curculionids live underground and feed on the plant’s root system. This damage causes:

• General decline of the plant
• Yellowing of foliage
• Reduced vigor and growth
• In severe cases, plant death

Adults emerge in spring and feed on foliage, but the most severe damage is caused by larvae on roots during autumn and winter.

Preventive control from the nursery

Detecting and controlling these pests is essential during orchard establishment. At Vivero El Avellano, we carry out constant monitoring of substrates, tools, and propagation environments to ensure none of these species are present in our plants.

Our protocols include:

• Substrate disinfection before use
• Regular visual inspection of roots

4. Hazelnut aphid (Myzocallis coryli)

This insect sucks sap from leaves and tender shoots, which can reduce plant vigor and photosynthesis. It is present in spring and summer, especially in temperate climates.

Symptoms and damage

• Aphid colonies on the underside of young leaves
• Deformation of shoots and new leaves
• Honeydew that favors sooty mold development
• Reduced growth in plants

Prevention and control

Thanks to our preventive management and biological control in the nursery, plants from Vivero El Avellano are delivered aphid-free and free of other foliage insects, minimizing early-field infestation risk.

In the orchard, integrated control includes:

• Early monitoring in spring
• Conservation of natural enemies (parasitoids and predators)
• Potassium soap or oil applications in light infestations

5. Brown stink bug (Leptoglossus chilensis)

During fruit development, this species can pierce hazelnuts, causing abortion or deformation. Although damage is more visible in adult orchards, prevention starts in the nursery with exclusion protocols and environmental monitoring.

Fruit damage

• Punctures in young hazelnuts that cause abortion
• Deformations in fruits that continue development
• Reduced size and commercial quality
• Higher incidence in orchards near fences or spontaneous vegetation

Management strategies

Managing this pest requires a preventive approach starting at orchard design:

• Control of host weeds along orchard edges
• Trap monitoring during fruit set and development
• Perimeter vegetation management
• Targeted applications during critical periods if needed

At Vivero El Avellano we guarantee clean plant material that facilitates integrated management protocols from the first year.

6. Prevention and quality: our commitment

European hazelnut pests are a real threat in Chilean fields, but control begins well before planting. The sanitary quality of plant material largely determines establishment success and reduced management costs in the early years.

Plant health protocols at Vivero El Avellano

At Vivero El Avellano we apply preventive measures that include:

• Disinfection and continuous control of soils
• Internal entomological monitoring throughout the production process
• Visual and phytosanitary inspection before delivery
• Traceability protocols ensuring each plant comes from healthy material
• Physical traps to prevent insect entry
• Preventive biological control to keep populations below threshold

Advantages of starting with healthy plants

Our goal is for every grower to receive a pest-free plant with strong roots and a healthy structure, ready to develop without limitations from day one in the orchard. This translates into:

• Lower pest pressure in critical early years
• Reduced control costs during establishment
• Greater uniformity and orchard vigor
• Earlier entry into production
• Solid foundation for implementing integrated pest management

7. Integrated pest management in the orchard

Once the orchard is established with quality plants, integrated pest management (IPM) is the most effective and sustainable strategy to keep insect populations under control.

IPM principles in hazelnut

• Regular monitoring to detect pests before they cause economic damage
• Correct identification of species and their life cycle
• Action thresholds based on phenological stages
• Prioritizing cultural and biological control over chemical
• Conservation of natural enemies

Monitoring calendar

Spring (Sep–Nov): watch for aphids and the first adult weevils; monitor natural enemies.

Summer (Dec–Feb): brown stink bug control during fruit development; inspect fallen fruit.

Autumn (Mar–May): monitor adult weevils; evaluate root damage caused by weevil and beetle larvae.

Winter (Jun–Aug): monitor root damage caused by weevil and beetle larvae.

Conclusion

Pests such as soil weevils (larvae), beetles (larvae), the hazelnut aphid, mites, and the brown stink bug are common challenges in European hazelnut cultivation, especially in the productive regions of south‑central Chile. However, when the orchard starts with healthy plants, risk drops dramatically.

At Vivero El Avellano, we control all these factors in our facilities and guarantee plants of high genetic quality, pest-free, and ready for productive success.

Because the first step toward a healthy, profitable orchard always starts with a healthy plant.