Biosecurity Blog 1: Notifiable Plants, Pests and Diseases
Notifiable Pests & Diseases
Quarantine organisms which are subject to statutory control have to be reported if you suspect they, or host materials are present. These have to be reported if being imported/exported. If you suspect a notifiable you should quarantine suspicious item(s) immediately, and immediately contact the Animal & Plant Health Agency or Forestry Commission. APHA: 01904 405 138, Forestry Commission: https://www.forestresearch.gov.uk/tools-and-resources/tree-alert/. Lists are provided on the forestry commission and DEFRA, and EPPO websites
Protected Zones & Plant Passports
Plant Health Protected Zones (PZ) are set up where a pest or disease is endemic in a part of the EU but not present within the zone. Restrictions/prohibitions are imposed on the supply and movements of plants into a protected zone from infected areas. Plant passports are required if importing host plants. Outbreaks within protected zones have to be eradicated, with the cost nominally borne by the owner of the infected material/location. 8 non-forestry and 16 forestry related plant protection zones exist within the UK (including for 8-Toothed Spruce Beetle, Chestnut Blight, and Oak Processionary Moth).
By Nathan Fall
Pest and Disease Update – 8-Toothed Spruce Beetle (Ips typographus)
FC identified a breeding population of 8-Toothed Spruce Beetles near Ashford in Kent in December 2018 which is considered a major economic threat to the UK’s spruce dominated commercial timber crops. In January 2019 movement of any spruce material within a 50km zone was prohibited to minimise the risk of onward spread whilst investigations and extermination continue
An indiscriminate generalist, bacterial infection of the xylem. Some species of plant will host but not display symptoms. Impact ranges from weakness to death of the plant. Xylella is spread by biting sap-feeding insects – 4 varieties – multiplex of most risk to the UK. Established in Americas. Major outbreaks in Southern France, Spain and Italy. Smaller outbreaks in traded plants contained in Belgium and Germany in 2018. Notifiable.
Signs: Dieback starting at leaf margins, central leaf veins remain, yellow halo between dead and live material. Causes wilt, die-back, stunting, scorch.
Consequences of a Xylella outbreak
Destruction of all known Xylella ‘hosts’ species within 100m of the infected plants, plus any other plants which may be infected (90+ species). 10km statutory movement restrictions for five years minimum. Insecticide application in the demarcated area is obligatory to control insect vectors.
Oak Processionary Moth (Thaumetopoea processionea)
Hairs of caterpillars and associated nests pose localised but persistent human and animal health risks. Defoliate and weaken oak trees if heavily infested. Only present on early-mature to mature oak trees. Introduced through a landscaping project in West London. Now established in Greater London and spreading through natural and human activity. Well established on continent. Movement of standard size oak trees out of Greater London area prohibited. Notifiable.
Signs: Skeletonised leaves, silk nests, caterpillars moving head to tail, egg plates, defoliation, rashes and breathing difficulty.
Bronze Birch Borer (Agrilus anxius)
Causes extensive mortality to European and Asian birch populations. Burrow into stems greater than 2 cm in diameter and branches of 1 cm in diameter. Damage is caused by larvae feeding on the inner bark and cambium of the tree cause disruption to water and nutrient transportation. Trees die within a few years. Present in North America. Not established in UK or EU. Notifiable.
Signs: Epicormic growth, D-Shaped exit holes, Wilt, larval tunnels under bark. 0.7-1.2cm beetle.
Emerald Ash Borer (Agrilus planipennis)
A boring beetle which attacks native UK ash (Fraxinus excelsior) as well as ‘exotic’ ash species. Beetle utilises trees of all ages and sizes (larvae found in branches with 1-2cm diameter). Damage is caused by larvae feeding on the inner bark and cambium of the tree cause disruption to water and nutrient transportation. Infested trees typically dead within 3-4 years. Not present in the UK. Established in Russia, North America and Far East. Notifiable.
Signs: 0.5-1.5cm green beetle, Lesions/cracking on bark, irregular shaped feeding notches on leaves, D-shaped exit holes, larval galleries under bark, die back, death and epicormic growth.
Asian Longhorn Beetle (Anoplophora glabripennis)
Native to the Far East. Utilises wide range of UK and exotic tree species. Spends most of its life as larvae inside the trunk, branch or root of the trees. The larvae tunnel and feed under the bark within the woody tissue of the tree. Damage is also caused by the adult beetles feeding on the foliage, they often de-vein the leaves, leaving the majority of the laminae in place. Also strip areas of young bark from shoots as they feed. 2-3 year life cycle with beetles emerging during the summer (between June and September) to mate and lay eggs, after which they die. Untreated wood packaging is a known pathway. Not currently in the UK, though 2012 outbreak in Maidstone Kent identified and destroyed. Present in Asia, Americas, and Europe (EU eradication programme). Notifiable.
Signs: Feeding damage on leaf veins, frass, 1cm circular exit holes, large 5cm larvae, 5-10cm beetle with long antenna. Results in wilting, branch loss, die-back, and death.
In reality what do you look for?
On plants: Signs of damage, signs of stress, cankers, deformities, fungal fruiting bodies, exit holes, egg plates, larvae, signs of feeding.
On packaging: Signs of damage, signs of boring, frass, exit holes, fungal fruiting bodies, eggs or larvae, IPPC Stamp (or lack thereof).
Useful Sources of Information
There are no joined-up sources of information, especially between government departments. Expect to have to work to find information.