Monitoring tree health and protecting our trees, woods and forests from pests and diseases is an increasingly important part of sustainable tree and forest management. This means you need to be able to identify specific pests and diseases to tackle any obvious problems. Once you know what’s affecting your trees, you can find advice on what action to take.
Specific tree pests and diseases
If you know the name of the tree pest or disease affecting your trees, see the Forestry Commission guidance giving detailed information on specific tree pests or diseases known to be present in the UK. You can also find out about those that pose a potential risk to the UK but are not present yet.
Identify by tree species
If you’re unsure what’s causing the problem, use the alphabetical table below to narrow down the options for the relevant tree species and find out which pests and diseases can affect it.
Once you’ve found the likely culprit for your tree species, you can read Forestry Commission guidance giving detailed information on that specific pest or disease and how to deal with it.
A
| Tree species | Pest or disease names |
|---|---|
| Alder (Alnus) | Asian longhorn beetle, Phytophthora alni |
| Apple (Malus domestica) | Citrus longhorn beetle |
| Ash (Fraxinus species) | Asian longhorn beetle, chalara ash dieback, emerald ash borer |
B
| Tree species | Pest or disease names |
|---|---|
| Beech (Fagus species) | Asian longhorn beetle, Citrus longhorn beetle, Phytophthora kernoviae, Phytophthora ramorum |
| Birch (Betula species) | Asian longhorn beetle, Citrus longhorn beetle |
C
| Tree species | Pest or disease names |
|---|---|
| Cedar (Cedrus species) | Pinewood nematode, Sirococcus blight |
| Cherry (Prunus species) | Asian longhorn beetle, citrus longhorn beetle |
| Citrus trees (Citrus species) | Xylella fastidiosa |
| Common ash (Fraxinus excelsior) | Asian longhorn beetle, chalara ash dieback, emerald ash borer |
| Corsican pine (Pinus nigra) | Dothistroma needle blight |
| Cypress (Cupressus species) | No significant threats |
D
| Tree species | Pest or disease names |
|---|---|
| Douglas fir (Pseudotsuga menziesii) | Phytophthora ramorum, pine-tree lappet moth |
E
| Tree species | Pest or disease names |
|---|---|
| Elder (Sambucus nigra) | No significant threats |
| Elm (Ulmus species) | Asian longhorn beetle, citrus longhorn beetle, Dutch elm disease, elm zig-zag sawfly, Xylella fastidiosa |
F
| Tree species | Pest or disease name |
|---|---|
| Field maple (Acer campestre) | No significant threats |
G
| Tree species | Pest or disease name |
|---|---|
| Grand fir (Abies grandis) | No significant threats |
H
| Tree species | Pest or disease names |
|---|---|
| Hawthorn (Crataegus monogyna) | No significant threats |
| Hazel (Corylus species) | Asian longhorn beetle, citrus longhorn beetle |
| Hornbeam (Carpinus species) | Asian longhorn beetle, citrus longhorn beetle |
| Horse chestnut (Aesculus hippocastanum) | Asian longhorn beetle, citrus longhorn beetle, horse chestnut leaf miner, Phytophthora ramorum |
J
| Tree species | Pest or disease name |
|---|---|
| Juniper (Juniperus communis) | Phytophthora austrocedri |
L
| Tree species | Pest or disease names |
|---|---|
| Larch (Larix species) | Phytophthora ramorum, pinewood nematode, pine processionary moth |
| Lawson cypress (Chamaecyparis lawsoniana) | Phytophthora austrocedrae, Phytophthora lateralis |
| Lodgepole pine (Pinus contorta) | Dothistroma needle blight, pinewood nematode, pine processionary moth |
M
| Tree species | Pest or disease names |
|---|---|
| Maple (Acer saccharum) | Asian longhorn beetle, citrus longhorn beetle, sweet chestnut blight |
| Mountain ash or rowan (Sorbus aucuparia) | Asian longhorn beetle |
N
| Tree species | Pest or disease names |
|---|---|
| Narrow-leaved ash (Fraxinus angustifolia) | Asian longhorn beetle, chalara ash dieback, emerald ash borer |
| Noble fir (Abies procera) | No significant threats |
| Norway spruce (Picea abies) | Great spruce bark beetle, 8-toothed spruce bark beetle, pine-tree lappet moth, pinewood nematode |
O
| Tree species | Pest or disease names |
|---|---|
| Oak – holm (Quercus ilex) | Sweet chestnut blight, oak pinhole borer, oak processionary moth, Phytophthora kernoviae |
| Oak – northern red (Quercus rubra) | Xylella fastidiosa |
| Oak – pedunculate or ‘English’ (Quercus robur) | Acute oak decline, Asian longhorn beetle, sweet chestnut blight, oak pinhole borer, oak processionary moth, Phytophthora kernoviae, Xylella fastidiosa |
| Oak – sessile (Quercus petraea) | Sweet chestnut blight, oak pinhole borer, oak processionary moth |
| Oak – turkey (Quercus cerris) | Phytophthora ramorum |
| Olive (Olea europaea) | Xylella fastidiosa |
P
| Tree species | Pest or disease names |
|---|---|
| Pear (Pyrus species) | Citrus longhorn beetle |
| Pine – Corsican (Pinus nigra) | Dothistroma needle blight |
| Pine – lodgepole (Pinus contorta) | Dothistroma needle blight, pinewood nematode, pine processionary moth |
| Pine – Scots (Pinus sylvestris) | Dothistroma needle blight, pine-tree lappet moth, pinewood nematode |
| Plane (Platanus species) | Asian longhorn beetle, citrus longhorn beetle, Xylella fastidiosa |
| Plum (Prunus species) | Asian longhorn beetle |
| Poplar (Populus species) | Asian longhorn beetle, citrus longhorn beetle |
R
| Tree species | Pest or disease name |
|---|---|
| Rowan or mountain ash (Sorbus aucuparia) | Asian longhorn beetle |
S
| Tree species | Pest or disease names |
|---|---|
| Scots pine (Pinus sylvestris) | Dothistroma needle blight, pine-tree lappet moth, pinewood nematode |
| Spruce – Norway (Picea abies) | Great spruce bark beetle, 8-toothed spruce bark beetle, pine-tree lappet moth, pinewood nematode |
| Spruce – Sitka (Picea sitchensis) | Great spruce bark beetle, 8-toothed spruce bark beetle, pine-tree lappet moth, pinewood nematode, Phytophthora ramorum |
| Sweet chestnut (Castanea sativa) | Sweet chestnut blight, Oriental chestnut gall wasp, Phytophthora ramorum |
| Sycamore (Acer pseudoplatanus) | Asian longhorn beetle |
W
| Tree species | pest or disease names |
|---|---|
| Western hemlock (Tsuga heterophylla) | Sirococcus blight |
| Western red cedar (Thuja plicata) | Sirococcus blight |
| Willow (Salix species) | Asian longhorn beetle, citrus longhorn beetle |
Y
| Tree species | pest or disease name |
|---|---|
| Yew (Taxus baccata) | Phytophthora lateralis |
Note: this list of trees is not exhaustive.
Request a diagnosis
The information in the table above is not exhaustive. You may discover a different pest or disease attacking your trees and you should report it or request a diagnosis from Forest Research’s Tree Health Diagnostic and Advisory Service. There might be a fee for this service.
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