Current pest risks to trees in the UK

Blog Current pest risks to trees in the UK

by Wilson Tree Surgery | 11th Jul 2024

As we navigate the changing seasons, it’s crucial to stay informed about the various pests that pose significant risks to our environment, health, and industry. From aggressive Asian hornets to the irritating oak processionary moth, here’s a comprehensive update on the current pest threats and how to mitigate their impact.

Asian Hornets

Since 2004, Asian hornets have steadily spread across Europe, now covering France, Portugal, northern Spain, and more recently, Holland, Belgium, and Germany. These hornets are highly aggressive predators of native insects and pose a significant threat to pollinators, including honey bees.

In 2023, Britain saw a dramatic increase in Asian hornet nests, with 78 nests destroyed, marking a sevenfold increase from previous years. The Island of Jersey reported 338 nests, with nearly half found in trees, some at heights exceeding 10 meters, making them difficult to spot and more hazardous for tree climbers and workers.

Precautions and Advice:

• Vigilance: Enhance your examination of trees and shrubs for hornet activity before commencing any work.
• Protection: Use full-body protective gear, including goggles, when working near known nests. Helmets with flip-down visors are not sufficient.
• Emergency Response: If you encounter a nest, cover your head and face, and move away quickly.

Brown-Tail Moths

The brown-tail moth, native to the UK, has seen a significant increase in numbers. The caterpillars of this moth are notorious for their irritating hairs, which can cause painful rashes and, in rare cases, respiratory problems.

These caterpillars are commonly found on hedgerows and various plants, especially those in the Rosaceae family, such as hawthorn and blackthorn. The highest risk period is from April to late summer when the caterpillars are most active and visible.

Precautions and Advice:

• Identification: Look for black caterpillars with brown hairs and distinctive orangey-red warts.
• Avoid Contact: Do not handle the caterpillars; their hairs can cause severe skin reactions. Wear protective clothing and masks if working in infested areas.
• Treatment: Use calamine lotion to relieve symptoms if contact occurs.

Oak Processionary Moths

The oak processionary moth poses a significant health risk due to its caterpillars, which have toxic hairs that can cause skin irritation, rashes, and respiratory issues. Found mainly on oak trees, these caterpillars move in distinctive nose-to-tail processions, making them easier to identify.

The moths are currently present in several regions and are subject to control measures to prevent their spread.

Precautions and Advice:

• Identification: Look for caterpillars with white hairs moving in processions on oak trees.
• Avoid Contact: Do not touch the caterpillars, and avoid areas where they are known to be present.
• Reporting: Report any sightings to the Forestry Commission to help manage and control the spread.

Ips Typographus: Spruce Bark Beetle Alert

The Forestry Commission has confirmed the presence of the larger eight-toothed spruce bark beetle in several counties, including Norfolk, Suffolk, and Kent. This beetle poses a severe threat to spruce trees and can cause extensive damage.

New Regulations:

• Demarcated Areas: Specific counties have been demarcated for increased monitoring and control.
• Felling and Killing Restrictions: Notification to the Forestry Commission is required before felling or killing any spruce trees over three meters in height.
• Movement Prohibitions: Movement of susceptible materials within or out of the demarcated areas is prohibited without authorisation.

Precautions and Advice:

• Compliance: Adhere to the new regulations to help control the spread of the beetle.
• Monitoring: Regularly inspect spruce trees for signs of infestation and report any findings to the Forestry Commission.

Staying Informed and Prepared

The increasing numbers and spread of these pests highlight the importance of vigilance and proactive measures. By staying informed and following recommended guidelines, we can mitigate the impact of these pests on our environment and health. Whether you’re working in arboriculture, landscaping, or simply enjoying outdoor spaces, being aware of these risks and prepared to respond appropriately is crucial.

For further information and to report sightings, you can use the following resources:

• Asian Hornet Watch App: Available for both iPhone and Android.
• Forestry Commission Tree Alert: Forestry Commission Tree Alert
• Forest Research on Brown-Tail Moths: Forest Research
• Oak Processionary Moth Reporting: Forestry Commission OPM Reporting

Stay safe and vigilant out there!