Quarantine pests
Quarantine pests are plant pests that have a limited distribution or do not exist at all in Sweden, but which can cause great harm if they spread. When quarantine pests are detected in Sweden measures are taken with the aim to eradicate the pest. On this page, you can read about which plant pests which you should pay attention to. If you suspect an infestation by a quarantine pest, you must notify us.
Plant pests are all types of organisms that are harmful to plants, such as insects, mites, nematodes, fungi, bacteria and viruses.
Some plant pests are subject to special regulations. This applies, for example, to quarantine pests, which we inform about on this page. If you would like to know how we manage plant pests that are not regulated, you should visit our page on plant protection measures.
Quarantine pests are a category of regulated plant pests
The plant health legislation regulates two categories of plant pests:
- quarantine pests
- regulated non-quarantine pests.
Quarantine pests are plant pests that are not found in the EU or are only found to a limited extent, and that can have unacceptable environmental, economic or social consequences if they are spread. If quarantine pests are found in Sweden, measures must be taken with the aim of eradication. The Swedish Board of Agriculture co-ordinates this work.
A few quarantine pests are so called priority pests, whose potential consequences are very serious. There are also quarantine pests that are classified as quarantine pests in certain protected zones. Pests of this category occur in the EU, but specific requirements prevent introduction of these pests into the protected zone. Sweden is a protected zone for three pests: silverleaf white fly, chestnut blight and Colorado beetle.
Plants for planting can also harbour other plant pests besides quarantine pests. There are regulations on some of these as there can be unacceptable economic consequences if they infest plants for planting. These pests are called regulated non-quarantine pests.
There are many regulated plant pests but not all are equally relevant in Sweden. On this page, you can read more about what you should pay attention ,to in Sweden. If you would like to read about other plant pests, you can search for information in the EPPO Global Database.
The regulations are intended to prevent spread in the EU
To protect us from infestation by quarantine pests, common regulations are applied for all EU Member States. The regulations mean that we
- perform surveys for plant pests to enable early detection
- inspect plant material imported to the EU
- conduct tracing of origin of infections or infestations
- destroy infected or infested plant material.
If we find quarantine pests, we carry out measures to ensure that healthy plants are protected. We may, for example, introduce restrictions on what may be cultivated or how to handle soil and agricultural machinery. We also limit the trading and movement of plants, plant products and other objects that can spread plant pests, on the basis of common regulations.
We ensure that pests are a quarantine pest by diagnosis at laboratories. We have a national reference laboratory to assist us, Sweden’s national reference laboratory is located in Denmark at Fødevarestyrelsen [The Danish Veterinary and Food Administration].
You are responsible for not spreading quarantine pests
Plant pests are good hitchhikers on plants and plant material. They can hitchhike for example on plants for planting, timber, wood packaging material, seeds and soil.
Every time you move plant material, there is thus a risk of plant pests being moved too without being visible. It is therefore important that you comply with the regulations when you trade with other countries and when you move plants within Sweden.
Only move plant material if you know that it is healthy
Global trade with plant material is the single largest risk for introducing new pests into the EU and Sweden. If you are unsure about whether the plant material you move is healthy, it is better not to move it.
Always report infestations by quarantine pests
If you suspect an infestation by a quarantine pest, you are legally obligated to notify the Swedish Board of Agriculture. You can do this by completing our notification form.
You can also notify plant pests by e-mailing us, if you can’t or don’t want to use the form. A tip is to base your e-mail on the questions in the form; it will be easier then to include all the important information.
You can receive compensation when your crops are affected by quarantine plant pests
You can receive compensation if you have received a decision from the Swedish Board of Agriculture forcing you to carry out eradication measures for quarantine pests. This compensation is available for decisions dated after July 1, 2022.
You can receive compensation for
- costs for treatment, destruction and removal of plants, plant products and other objects
- cleaning and disinfection of premises, land, water, soil, growing media, establishments, machinery and equipment
- loss of value of plants, plant products or other items subject to eradication measures
- loss of production.
The possibility to obtain compensation is regulated in the Swedish plant health law with its associated regulation.
Surveys of quarantine pests
We survey for quarantine pests every year. The survey is co-ordinated in 9 different environments: coniferous forest, mixed forest, ports, nurseries and garden centres, potato cultivation, urban risk areas, urban green areas, greenhouses, and orchards. The survey is risk-based and focused on areas with a higher probability of introduction by quarantine pests.
Summary of the 2024 survey for quarantine plant pests Pdf, 342.8 kB.
Would you like to be a citizen scientist and look for insect pests?
We need people who are interested in being citizen scientists during the summer of 2025. We cooperate with Fritidsodlingens riksorganisation (FOR) to survey for plant pests in private gardens.
Quarantine pests on potatoes
Here you can find quarantine pests that could affect potatoes or other potato plants in Sweden. The potato family includes, for example, tomatoes, bell peppers and petunia.
Colorado beetles
The Colorado beetle belong to the leaf beetle family, Chrysomelidae. The Colorado beetle reproduces itself quickly and is gluttonous, which makes it a difficult and feared plant pest. The damage to the potato leaf caused by the beetle considerably reduces the harvest.
The adult Colorado beetle is easy to recognise. The body of the beetle is oval or round with characteristic black and white stripes running the length of the body. It has black spots on its head and pronotum. It is about 1 cm long, somewhat larger than a ladybird.
The Colorado beetle’s eggs are yellow to bright orange and around 2 mm long. They are laid in clusters on the underside of the leaf and are difficult to distinguish from ladybird eggs.
Newly hatched Colorado beetle larvae are just under two millimetres long and tomato red in colour. Older larvae are lighter red to orange and can be up to 12 mm long. The larvae are oval or round and have two rows of black dots running down each side of the body.
Symptoms
Adult individuals and larvae both eat potato leaves and, in the case of severe infestation, the Colorado beetles can eat so much that the potato blast becomes completely bare. The beetle also leaves black sticky faeces on the potato leaf.
Distribution
The Colorado beetle is present in North America, parts of Asia and in most European countries.
How they spread
Full-grown beetles and larvae spread with potato plants, tubers and in packages with potatoes. Colorado beetles are also spread in packages with fresh vegetables that come from areas where the beetle is present. Adult individuals can be spread far by wind and even on water.
Risk of misidentification
There are one insect that can be misidentified as a Colorado beetle. The pupas and larvae of the Colorado beetle can be confused with the pupas and larvae of a ladybird.
If you have a Colorado beetle infestation
The Colorado beetle can cause great damage to a potato field. Previous assessments showed that the Colorado beetle could most probably become established in Blekinge, Gotland, Halland, Kalmar and Skåne counties if it were to be introduced. In these counties, the Colorado beetle is a quarantine pest, which requires official measures to be taken if it is found.
If you suspect that you have found a Colorado beetle, its egg or larvae, you must notify the county administrative board or the Swedish Board of Agriculture. Collect and kill the beetles, for example, by putting them in boiling water or the freezer.
The Epitrix flea beetles
Epitrix is a genus of small beetles which are flea beetles. The beetles are 1.5–2 mm long and jump away like a flea when disturbed. Four species of Epitrix infest potato plants and can cause great damage to potatoes. Leaves, roots and tubers are infested by beetles and their larvae, and the harvest can be impossible to sell because of the damage.
Symptoms
Adult beetles chew on leaves, creating shot-like round holes. The holes are approximately 1–1.5 mm in diameter. Larvae chew on the surface of the potato tubers. The passages can extend for up to 1.5 cm in the tubers. The tunnels created by larvae can lead to the tuber splitting and the surrounding tissue becomes cork-like.
Distribution
The flea beetles as a group include approximately 180 species, most of which are found in North and Central America. Within the EU, there are a couple of species of Epitrix in Spain and Portugal but we have not yet found any of these species in Sweden.
If Epitrix comes to Sweden, it is likely that they would survive here. Then they would also be a great risk for our potato cultivation.
How they spread
Epitrix spreads through trading with potatoes or through accompanying soil, for example, plants and root crops that come from an area where Epitrix occurs. Trading with potatoes to Sweden from areas in Spain and Portugal where Epitrix is present is insignificant. However, there is a risk that you as a private individual may bring Epitrix home with you if you have potatoes with you from a trip abroad.
If you have an infestation of Epitrix
If you suspect that you have an infestation of Epitrix, you must notify us.
The root knot nematodes Meloidogyne chitwoodi and Meloidogyne fallax
The root knot nematodes Meloidogyne chitwoodi and Meloidogyne fallax are closely related species that live in soil and plant material. The nematodes’ life cycle consists of three stages: egg, larva and the adult stage.
Meloidogyne chitwoodi and Meloidogyne fallax have many different species of plant as hosts. The potato is the root knot nematodes’ preferred host, but it can also live on carrot, sugar beet and all types of grass, including cereals. Nematodes are not dangerous for human beings but are a threat to potato crops if they spread.
Symptoms
Common symptoms are weak plants with poor growth. This can lead to infection by other diseases and crop yield and losses. Tuber-like swellings can be seen on tubers and roots, so called galls. Potato tubers have dead brown patches in areas underneath the skin.
Distribution
IIn the EU, the nematodes have been found in Belgium, Denmark, France, Germany, Lithuania, the Netherlands, Portugal, Spain and Sweden. In Sweden, nematodes have been found in four areas: Blekinge, Skåne, Halland and Västra Götaland. They also exist outside Europe but import of seed potatoes and soil from countries outside the EU is prohibited.
How it spreads
Nematodes have little ability to move. They are most effectively spread by potato seed and soil from infected fields. Sharing agricultural machinery is believed to further spread nematodes between fields once they have been introduced into a field.
Prevent spread
Be aware of the risks and spread of the nematodes. Risk mitigation measures include appropriate crop rotations and using only certified seed potatoes as a common cultivation practise. Make sure to clean machines prior to moving them between fields, especially when sharing equipment between many places of production.
If you have an infestation of root knot nematodes
Plots found to be infested by the root knot nematodes will be subject to measures with the aim to eradicate the infestation. Measures entail black fallow for at least a year, followed by cropping restrictions and prohibitions on movement of soil, until nematodes have been eradicated.
If you suspect that you have an infestation of root knot nematodes, you must notify us.
Potato cyst nematodes
Potato cyst nematodes are microscopic eelworms that live in and damage the roots of potatoes. The potato is the potato cyst nematode’s most important host plant, although it may also infest tomatoes and wild plants of the potato family (for example, black nightshade and bittersweet).
Potato cyst nematodes can cause great losses in potato cultivations in the case of major infestations. It is therefore important to take measures to eradicate and prevent spread of the potato cyst nematode before they have time to propagate too much.
There are two species of potato cyst nematodes:
- the yellow potato cyst nematode, Globodera rostochiensis
- the white potato cyst nematode, Globodera pallida.
Symptoms
The symptoms are rather diffuse and include patches with reduced growth and sometimes yellowing or withered potato blast. When infested, the size of the tubers may be reduced.
Distribution
Both yellow and white potato cyst nematodes have been present in Sweden for a long time, although the white potato cyst nematode is not especially common.
How they spread
Nematodes are spread as cysts with seed, plants for planting, soil, bulbs, and potatoes for consumption or industrial processing.
If you have an infestation of potato cyst nematodes
If you notice or suspect an infestation of white potato cyst nematodes, you must notify it to the Swedish Board of Agriculture or the County Administrative board.
You must also contact the Swedish Board of Agriculture if you suspect or note that a specific potato variety that has been resistant to potato cyst nematodes is no longer resistant.
You do not need to notify if you suspect that it is yellow potato cyst nematode. Yellow potato cyst nematode is today such a common plant pest in potato cultivation that there is an exemption from the obligation to notify to the Swedish Board of Agriculture.
Brown rot
Brown rot is caused by the bacterium Ralstonia solanacearum.
Symptoms
The symptoms can be most clearly seen by cutting through a potato tuber. Yellowish-brown discolouring will then be visible in and yellowish-white bacteria drops will ooze out from the vascular ring without needing to squeeze the tuber.
The disease can also exist in a latent form for several generations of potatoes.
Distribution
Many European countries have detected the bacterium Ralstonia solanacearum.
How it spreads
Brown rot spreads in a number of ways. The most common pathway for spreading is by seed potatoes, but it can also be spread through machinery, equipment, weeds and irrigation water. Bacteria can survive freely in the soil but it is unclear how long they would survive during Swedish conditions.
If you an infestation of brown rot
If you suspect that you have an infestation of brown rot, you must notify us.
Potato ring rot
Potato ring rot is caused by the bacterium Clavibacter sepedonicus.
Symptoms
The symptoms can be most clearly seen by cutting through a potato tuber. An infected potato with mild symptoms shows scattered or contiguous yellow spots at the vascular ring. If you squeeze a cut tuber, the yellow-coloured tissue will be pressed out as a creamy ooze. In more severe infestation, the vascular ring may be more liquid and brown-coloured. There are seldom symptoms one the aboveground parts of potato plants.
The disease can also exist in a latent form for several generations of potatoes.
Distribution
Potato ring rot is present in many European countries but also in some countries in Asia and in North America.
How it spreads
Bacteria are most commonly spread via infested seed potatoes. Other means of spreading the bacterium is through shared machinery used in potato cultivation and equipment for sorting and packaging potatoes.
If you use machines such as potato harvesters which also are used by other potato growers, you must clean and preferably disinfect these machines when moving from farm to farm. It should be noted that cold temperatures does not kill the infection.
If you have an infestation of potato ring rot
If you suspect that you have an infestation of potato ring rot, you must notify us.
If you would like to read more
Potato wart disease
Potato wart disease is a soil-borne disease caused by the fungus Synchytrium endobioticum. The fungus lives as a parasite inside the cells of the potato plant and causes uncontrolled growth. Infestation of potato wart disease leads to a deterioration of the quality of the tubers and the number of tubers decreases.
Dormant spores of the fungus can survive for more than 20 years in soil. Potato wart disease may cause extensive financial losses for growers.
Symptoms
Young tubers that are infested may become spongy and deformed. The fungus infects the eyes of older tubers which subsequently develop warty growths resembling the shape of cauliflowers. Initially the warts are white or green but they darken over time. Warts can also appear on stems and stem bases.
Distribution
There are around 40 different pathotypes of potato wart disease in the world and most of them are spread in the EU.
There are four pathotypes in Sweden: pathotype 1, 8, 18 and 40. Strain 8, 18 and 40 have to date only been found in eastern Skåne and western Blekinge, while pathotype 1 is found at a number of places from Skåne up to the counties of Västerbotten and Norrbotten.
How it spreads
Potato wart disease spreads with seeds or soil from fields which are infected with potato wart disease.
If you have an infestation of potato wart disease
If you suspect that you have an infestation of potato wart disease, you must notify us.
Quarantine pests on trees and bushes
Here follows a list of quarantine pests that can affect trees and bushes in, for example, forests, gardens and parks.
The bronze birch borer (Agrilus anxius)
The bronze birch borer is a buprestid beetle that infests birch.
Symptoms
The larvae chew tunnels through conducting tissue that transports nutrition in the tree. If the damage is sufficiently severe, the transport of nutrition decreases or ceases and the tree dies. Species of birch that are common in Europe, for example, Betula pendula and Betula pubescens, are very sensitive to infestation.
Distribution
The bronze birch borer originates in North America. They have not been found outside North America.
How they spread
Long-distance spread takes place most probably through transport of infested plants and wood products that are manufactured from infested wood. Wood products are, for example, wood packaging material and dunnage used in transport. The greatest risk is untreated wood products such as tree chips that are used to produce energy, in particular if the chips are stored outdoors close to a stand of birch trees.
Risk of misidentification
The bronze birch borer is similar to the emerald ash borer, Agrilus planipennis, both in appearance and in behaviour except that Agrilus planipennis infests other species of trees. In Sweden, there is Agrilus betuleti which is found on birch trees and which also resembles the bronze birch borer.
If you suspect an infestation by the bronze birch borer
If you suspect an infestation by the bronze birch borer, you must notify us.
The citrus long-horned beetle (Anoplophora chinensis) and Asian long-horned beetle (Anoplophora glabripennis)
The citrus long-horned beetle and the Asian long-horned beetle are large beetles that live in deciduous trees. The trees are damaged and eventually die as the larvae chew large tunnels in the wood. They both infest deciduous trees of various species.
The different species resemble one another in appearance but differ somewhat in lifestyle.
- The citrus long-horned beetle infests the lower part of the stem, the stem base and roots of host trees with a trunk diameter exceeding 1 cm.
- The Asian-long horned beetle infests high up on the stem and in the crown of host trees with a trunk diameter exceeding 5 cm.
- Pictures of citrus long-horned beetle (Anoplophora chinensis) (gd.eppo.int)
- Pictures of the Asian long-horned beetle (Anoplophora glabripennis) (gd.eppo.int)
Symptoms
Large exit holes (10–15 mm i diameter) in trees that have been purchased in the past three years, or frass resembling sawdust on the ground, is an indication that there are pests in the tree. Other indications that should raise suspicion is larval tunnels larger than three mm in wood packaging material originating from areas where the pests are known to be present.
Distribution
While originating from China, the beetles are also found in Indonesia, Japan, Korea, Malaysia, Myanmar, the Philippines, Taiwan, and Vietnam.
The citrus long-horned beetle is established in Lombardy in northern Italy where it can no longer be eradicated.
The Asian long-horned beetle has spread on repeated occasions in Europe, often from larvae that have arrived here in wood packaging material in connection with import from Asia, in particular China. The longhorn beetle causes significant costs due to the destruction of trees and the extensive efforts required for eradication. In our vicinity, the citrus longhorn beetle was combated in an industrial area in Finland between 2015 and 2020, when the outbreak was declared eradicated. The Finnish plant protection authority Ruokavirasto confirmed that the beetle had reproduced at the site, and the outbreak primarily affected birch trees.
We have not found any citrus long-horned beetles or Asian long-horned beetles on trees in Sweden. If the long-horned beetles were to be introduced into Sweden, they could survive and reproduce in Götaland and the coastal regions up to the lake Mälaren area.
How they spread
Long-distance spread of eggs, larvae, or pupae occurs through trade with infested plants for planting and infested wood materials such as wood packaging material and dunnage.
Risk of misidentification
The small white-marmorated longhorn beetle (Monochamus sutor) which is common in Sweden is often mistaken for the citrus long-horned beetle or Asian long-horned beetle.
If you suspect an infestation of citrus long-horned or Asian beetle
If you suspect an infestation of citrus long-horned beetle or Asian long-horned beetle, you must notify us. You must contact us if you find living larvae or insects in wood packaging material from countries outside the EU.
Red-necked longhorn beetle (Aromia bungii)
The red-necked longhorn beetle is a long-horned beetle that inhabits forests, urban areas, and orchards. It attacks, lives in, and causes damage to trees of the Prunus genus, such as bird cherry, cherry, damson, wild cherry, and plum. The beetles can be found in both living plants and in timber, wood products, and wood packaging materials.
In the event of an outbreak in Sweden, the most important measure is to fell and destroy all infested trees. If this pest were to be introduced into the country, it would have serious consequences, both through damage to trees and economic losses.
The flight period of the red-necked longhorn beetle extends from March to August, with peak activity from May to mid-July. The adult female lays eggs in cracks in the bark near the base of the trunk, no more than 30 cm above the ground, but also in larger branches.
Symptoms
The greatest chance of detecting infested trees is during the most active period of the larvae. At that time, reddish frass resembling sawdust from larvae can be found after emergence. The frass is located on the ground near the tree, mixed with larval excrement.
It is the larvae that cause damage to the trees by gnawing on and underneath the bark, as well as into the wood. They create tunnels in branches and the trunk, disrupting the nutrient supply of the host tree. The most obvious symptom is round exit holes, usually found on the trunk up to about 30 cm above the ground.
Distribution
The beetle’s historical distribution includes China, North and South Korea, Mongolia, and Vietnam. More recently, the red-necked longhorn beetle has been found in Japan and in three locations within the EU: Italy (in the regions of Campania and Lombardy) and Germany (Bavaria).
How it spreads
The spread can occur through trade in plants, wood, wood products, and wood packaging material from infested areas.
Special rules for import to the EU and movement within the EU
As the pest has probably been spread through plants, wood, wooden products or wood packaging material of the Prunus family, there are rules on imports to the EU and movement within the EU from countries where the beetle is present.
If you intend to import plants for planting or move such plants within the EU, there are special rules for plants whose trunk or root crown diameter is at least 1 cm at the thickest point. These plants are large enough for the long-horned beetle to go through a complete life cycle.
Risk of misidentification
The goat moth (Cossus cossus) which lives on deciduous trees, including the species that the red-necked longhorn beetle infests, can also give rise to a collection of feces on the ground by the tree. However, there is no risk of misidentification if one sees individual goat moths as they do not at all resemble the red-necked longhorn beetle.
If you suspect an infestation by the red-necked longhorn beetle
If you suspect an infestation by the red-necked longhorn beetle, you must notify us.
Siberian conifer silk moth (Dendrolimus sibiricus) and white-lined silk moth (Dendrolimus superans)
The Siberian conifer silk moth and the white-lined silk moth are two closely related lappet moths which infest different species of coniferous trees.
Symptoms
Larvae can cause noticeable defoliation of infested pine trees, larches and spruce trees. Fully grown larvae of the Siberian conifer silk moth (50–80 mm) and the white-lined silk moth (60–82 mm) are large and visible.
Distribution
Both pests originate from Asia, and the Siberian conifer silk moth has spread to central Russia.
If they were to establish in Sweden, it could have serious consequences, as Swedish conifer species and the Swedish climate are favourable for both species of lappet moths.
How they spread
Natural spread can occur over long distances, as adult lappet moths can fly up to 100 km per year. All life stages can be transported on host plants or cut branches, such as those from spruce. Transport of roundwood with bark left, wood packaging material, and dunnage from areas with infested trees could also carry the lappet moths.
Risk of misidentification
The pine lappet moth (Dendrolimus pini) which is common in Sweden is very similar to the Siberian conifer silk moth.
If you suspect an infestation of the Siberian conifer silk moth or white-lined silk moth
The Siberian silk moth (Dendrolimus sibiricus) is a quarantine pest.
We also encourage you to notify us of suspected incidences of the white-lined silk moth (Dendrolimus superans). While not a quarantine pest yet there is no legal obligation to notify us. However, it is a pest of concern that has not been found in Sweden before.
Pitch canker of pine (Fusarium circinatum)
The fungus Fusarium circinatum can infect all parts of pine trees and cause severe damage. It can also affect Douglas fir.
Another older name for Fusarium circinatum is Gibberella circinata.
Symptoms
In nurseries, the fungus can cause significant damage in seedbeds, resulting in poor seedling emergence. On branches and stems of larger plants, it causes cankers with heavy resin flow. Inside the cankers, brown rot is visible, often encircling the branch. The branch dies above the point of infection.
Distribution
In Europe, the fungus is present in forests in northern Spain. It has also been found in France and Portugal.
How it spreads
Over long distances, plants and seeds are the main pathways for spread. Locally, the fungus spreads via wind and insects.
The risk of spread to Swedish forest nurseries is low, as seeds from areas where the fungus occurs are not used. Additionally, the fungus does not thrive in our cold climate.
If you suspect an infestation by Fusarium circinatum
If you suspect an outbreak of pitch canker of pine (Fusarium circinatum), you must notify us.
Japanese beetle (Popillia japonica)
The Japanese beetle infests over 300 different species of trees, bushes and agricultural crops. Adult individuals infest leaves, fruit and flowers while larvae infest roots and sometimes grass.
The beetle has a charismatic appearance that is easy to recognise. It is oval in shape and metallic green with a bronze shell. There are five white tufts of hair on each side of its shell and a couple of white tufts at its rear end. The Japanese beetle is 8–11 millimetres long and 5–7 millimetres wide.
Symptoms
Adult individuals like to infest the sunlit parts of host plants where they chew holes on leaves and the petals of flowers. The Japanese beetle is gregarious and aggregates when there are a number of individuals. Clusters of beetles can be seen on infested leaves, flowers or fruit. The infestation usually begins at the top of the plant and the beetles then work their way downwards. In the event of severe infestation with a large number of beetles, they can chew the leaves so much that only the midrib remains. Infested leaves turn brown and may fall off. Whole plants can be consumed when there is a large beetle population.
The larvae cause damage by chewing on the roots of the host plants, giving rise to various symptoms depending on the variety of plant.
Symptoms appear on infested grass such as thinner growth or withered sections or brown patches where the grass has died.
Distribution
The beetle is widespread in Japan, Canada, and the United States. It has also been found in eastern Russia, Italy, Portugal, Switzerland, and Slovenia.
How it spreads
It spreads through international trade, in particular with plants for planting, plant products, in packaging or hitching a ride on, for example, boats and aircraft. Larvae can be transported in soil around plants for planting, for example, grass rolls.
When Japanese beetles have been introduced and become established in an area, they can spread by themselves. Adult individuals can fly up to 8 kilometres but most of them do not fly more than 50 metres at a time. In ongoing outbreaks in Italy, the beetle has a spread rate of about 10 kilometres a year.
Risk of misidentification
I Sweden, there is the garden chafer Phyllopertha horticola which resembles the Japanese beetle to some extent. However, the garden chafer lacks the white tufts of hair along its shell and at its rear which the Japanese beetle has.
If you suspect an infestation of Japanese beetles
If you suspect an infestation by Japanese beetles, you must notify the Swedish Board of Agriculture.
Chestnut blight (Cryphonectria parasitica)
Chestnut blight is a serious fungal disease on sweet chestnut (Castanea sativa). The fungus damages sweet chestnut severely or kills it. Once the disease is introduced it is difficult to eradicate.
Chestnut blight does not affect the common horse chestnut (Aesculus hippocastanum).
Symptoms
Infected branches develop light brown sunken lesions, and cracked wounds may appear on the trunks of infected trees. The fungus can grow so rapidly that branches become girdled before a callus (healing tissue) has time to form around the wounds. The trunk or branches above the cankers die, and the leaves remain wilted and hanging on the dead branches.
Fruiting bodies known as pycnidia form and produce spores in bark lesions. In humid weather, spores may ooze out, appearing as orange-yellowish threads. Spores are the life stage of the fungus that spreads and infect healthy trees. Under the bark in the wounds, a pale brown fungal mycelium may also develop, often in a fan-shaped pattern.
Distribution
Chestnut blight exists in most European countries, Australia and some countries in Asia, the Middle East and North America.
How it spreads
The chestnut blight is spread over long distances through trading with plants and timber made of sweet chestnut. The fungus spreads over shorter distances by wind, water and insects.
If you suspect an infestation by chestnut blight
If you suspect an infestation by chestnut blight, you must notify the Swedish Board of Agriculture.
Ramorum blight (Phytophthora ramorum)
Phytophthora ramorum is an oomycete (water mold) that causes the disease ramorum blight. This plant disease has been shown to affect a wide range of plant species, and new host species are continually being discovered. The disease is very difficult to control, and if the oomycete were to establish itself in Sweden, it could cause significant economic and ecological damage.
Symptoms
Symptoms vary widely and may include wilted leaves, shoots, and branches, as well as sunken lesions on the lower part of the trunk that exude a reddish-brown fluid.
Distribution
The disease is widespread in many parts of Europe and the United States. In Sweden, Phytophthora ramorum has only been confirmed in a few isolated cases on rhododendrons imported from other EU countries.
How it spreads
Long-distance spread occurs through trade in ornamental plants such as Rhododendron and Viburnum from countries where the pathogen is present. Trade in bark, timber, and soil from infected areas can also spread Phytophthora ramorum.
If you suspect an infestation by Phytophthora ramorum
If you suspect an outbreak of ramorum blight (Phytophthora ramorum), you must notify the Swedish Board of Agriculture.
Isolates of Phytophthora ramorum that are established within the EU are classified as regulated non-quarantine pests. Other isolates are considered EU quarantine pests. In the event of a confirmed case, the Swedish Board of Agriculture will determine the type of isolate. Regardless of your assessment of the isolate’s origin, you are required to report any suspected outbreak.
The plum curculio (Conotrachelus nenuphar)
The plum curculio is a weevil that attacks plants in the rose family, such as roses, apples, plums, cherries, and pears. The weevil has also been found on plants in the currant and blueberry family.
Adult individuals are about 7 millimeters long, with a snout and reddish-brown elytra marked with black, bumpy spots. When disturbed, the weevil plays dead and drops to the ground.
Symptoms
Adults feed on flowers, leaves, and young fruit. When attacking young fruit, the weevil creates characteristic egg-laying scars shaped like a crescent or a swallow. Infestations lead to premature fruit drop, except in cherries, where the fruit continues to develop and ripen on the tree. Small exit holes caused by the weevil larvae may be observed on fruit that have dropped to the ground.
Distribution
The plum curculio is found in Canada and the United States.
How it spreads
The pest spreads through international trade, most likely as pupae in soil or as adults in packaging materials. Spread through infested fruit, with the exception of cherries, is less likely, as attacks usually cause premature fruit drop.
Risk of misidentification
There are over 400 weevil species in Sweden, so misidentification with similar species is likely.
If you suspect an infestation by plum curculio
If you suspect an infestation by the plum curculio, you must notify the Swedish Board of Agriculture.
Emaravirus rosae
Emaravirus rosae infests all plants belonging to the rose family. Emaravirus rosae was previously called rose rosette virus (RRV).
Symptoms
Symptoms on roses can vary. The most common symptom is abnormally increased growth. Symptoms may appear in the following ways:
- Thickened stems, making the plants resemble succulents
- increased leaf production
- deformed leaves
- leaves displaying patterns in various shades of green (known as mosaic)
- shoots with intense red pigmentation
- deformed flower buds and flowers
Infected plants have reduced winter hardiness, and the disease causes a gradual decline in plant health. Infected plants typically die within 1 to 5 years post infection.
Distribution
The virus is present in India, Canada and the USA. The virus is widespread in the USA where an increased occurrence has been seen in roses.
How it spreads
The virus is spread in the following ways:
- a gall mite, Phyllocoptes fructiphilus
- mechanically through, for example, pruning or grafting
- trade with infected plant material.
If you suspect an infestation by Emaravirus rosae
If you suspect an infestation by Emaravirus rosae you must notify us.
Emerald ash borer (Agrilus planipennis)
The emerald ash borer is a beetle that infests ash trees. As the ash is a common tree species in Sweden, an establishment of Agrilus planipennis could have major ecological and financial consequences.
Symptoms
The larvae eat the cambium layer under the bark of ash trees. The damage caused by chewing leads to foliage being thinned out or turning yellow and branches that wilt and die. Infestation by the emerald ash borer leads to the tree dying after a few years. The exit holes created by adult beetles in infested trees are characteristically D-shaped. There are no other jewel beetles in Europe that infest ash trees and cause damage similar to that caused by the emerald ash borer.
Distribution
The beetle originated in East Asia but has spread to Canada, the USA and Russia and most recently to Ukraine. In Canada and the USA, Agrilus planipennis has caused great destruction of ash trees, which are a common component of urban environments as street trees. The emerald ash borer has not been found in Sweden.
How it spreads
Long-distance spreading takes place through trade with plants and wood products such as timber, wood packaging material, dunnage, wood chips and wood. In the USA, most observations of the emerald ash borer have been in connection with import of dunnage. The emerald ash borer can moreover fly up to 1 km and in this way spread locally.
If you suspect an infestation by the emerald ash borer
If you suspect an infestation by the emerald ash borer, you must notify us.
If you would like to read more
The pine wood nematode (Bursaphelenchus xylophilus)
The pine wood nematode is a millimetre long nematode (a kind of round worm) that causes pine wilt disease. The pest is capable of causing severe wilting and death of coniferous forest stands. The nematode lives inside trees where it causes damage to the vascular system which in turn prevents trees from taking up water.
Symptoms
Needles of infested conifers first turn yellow before wilting and falling off. Infected pines can ultimately die.
Distribution
The pine wood nematode is naturally spread with the aid of various species of long-horn beetles belonging to the genus Monochamus. There are several species of Monochamus present in Sweden that can spread pine wood nematode.
How it spreads
The pine wood nematode is primarily spread through trade with infested wood or wood packaging material.
The pine wood nematode was discovered for the first time in Europe in 1999 and is now established in Portugal, on the mainland and the island of Madeira. The pine wood nematode has also spread to Spain. An infected tree was found in Extremadura in 2008. Since then, three new infestations have been found in Spain. These are small outbreaks of the pine wood nematode and Spain has succeeded in eliminating three of these cases by pest management. It is therefore untreated wood from Portugal which is the greatest risk.
If you suspect an infestation by the pine wood nematode
If you suspect an infestation by the pine wood nematode, you must notify us.
The round-headed apple-tree borer (Saperda candida)
The round-headed apple-tree borer (Saperda candida) is a beetle belonging to the longhorn beetle family. In Sweden, other species of the genus Saperda are known as wood borers. The round-headed apple-tree borer primarily attacks apple trees, but other trees and shrubs in the rose family can also serve as host plants.
If this beetle were to be introduced and spread in Sweden, it could have serious economic consequences, especially for apple orchards, but also for nurseries, as a range of fruit trees and shrubs could be affected.
Symptoms
The larvae cause the most damage by boring tunnels, primarily in the lower part of the trunk of both healthy and weakened trees. Their feeding can girdle the trunk, eventually leading to the death of the tree.
Distribution
Saperda candida is native to North America and is not currently found in Sweden. The pest has only been detected once outside its natural range, in northern Germany.
How it spreads
Long-distance spread most likely occurs through the trade of plants for planting. There is also a risk that wood could carry the pest.
If you suspect an infestation by the round-headed apple-tree borer
If you suspect an infestation by the round-headed apple-tree borer, you must notify us.
Xylella fastidiosa
Xylella fastidiosa is an aggressive bacterium that causes extensive damage to plants. The bacterium has many different host plants and more have been detected as we have gained more experience. It causes great damage to various crops such as cherries, plums, olives, grapes and citrus fruit as well as oak, elm and ornamental plants. The bacterium has also been found, for example, in rosemary and myrtle.
Symptoms
The symptoms are very varied and infected plants can be symptom-free. The symptoms may include yellowing and dying leaves or wilting of leaves or plant parts. If a fruit tree is infested, the size of the fruits may be reduced.
Distribution
The bacterium originates in the USA and Latin America. At present, damage from the bacterium has been noted in certain areas in Italy, France, Spain and Portugal. Xylella fastidiosa has probably arrived in southern Italy with coffee bushes imported as ornamental plants from Costa Rica.
How it spreads
The bacterium is spread to new places by trading of plants for planting that may carry either the bacterium or insects that spread the Xylella fastidiosa. One of the insects that spread the bacterium is the meadow spittlebug, Philaenus spumarius.
The import of ornamental plants is the most probable scenario for how both Xylella fastidiosa and insects that carry the bacterium could spread to Sweden.
If you suspect an infestation by Xylella fastidiosa
If you suspect an infestation by Xylella fastidiosa, you must notify us.
If you would like to read more
The apple maggot (Rhagoletis pomonella)
The apple maggot is a fruit fly which mainly infest apples but also species of the hawthorn family.
Adult flies are 4–5 millimetres long with a wing span of 7.5–9 millimetres. The body is mainly black with a white marking on the back and three lighter stripes over its rear end. The wings are transparent with black wing markings which characteristically form the letter F.
Symptoms
Adult individuals lay eggs in fruit. Infested fruits appear lumpy or scarred as a result of repeated egg-laying wounds. Some discolouring is visible around the wounds. The larvae in the fruit damage the pulp and cause brown-coloured streaks.
Distribution
The apple maggot is present in Canada, Mexico and the USA.
How it spreads
It spreads through international trade and transport of infested fruit or soil that contains pupas. Once the fly has been introduced, it can fly further and establish itself in new areas. The apple maggot is able to fly as far as 4.5 kilometres.
Risk of misidentification
The cherry fruit fly (Rhagoletis cerasi) which is common in Sweden, may be mistaken for the apple maggot. However, the cherry fruit fly has a yellow instead of a white marking on its back and its wing bands do not form the letter F as in the apple maggot.
If you suspect an infestation by the apple maggot
If you suspect an infestation by the apple maggot, you must notify the Swedish Board of Agriculture.
Quarantine pests in greenhouses
Here you can read more about the quarantine pests that can damage greenhouse crops in Sweden.
The silverleaf whitefly (Bemisia tabaci)
The silverleaf whitefly is a tiny insect, about one millimetre in length.
The silverleaf whitefly can infest more than 300 plant species, including common greenhouse vegetables, many potted plants, and bedding plants. In addition to poinsettia, begonia, fuchsia, gerbera, hibiscus, and verbena are also known hosts. Bemisia tabaci has been shown to transmit up to 60 different viruses, with the Geminivirus genus causing the most significant economic losses.
Sweden is a protected zone for Bemisia tabaci (European populations), which means the country must remain free from the pest or actively work to eradicate it. Plants or plant products imported into Sweden from other EU countries or from outside the EU must not contain the silverleaf whitefly.
Symptoms
The symptoms caused by the silverleaf whitefly can be confused with those caused by the greenhouse whitefly (Trialeurodes vaporariorum), which is relatively common in Europe.
Nymphs and adult whiteflies are found on the undersides of leaves, where they feed on plant sap. This leads to yellow (chlorotic) spots. Excretions from the feeding whiteflies, known as honeydew, contaminate the plant and provide a breeding ground for sooty molds, which hinder plant growth. Additional symptoms caused by virus transmission may include leaf curling, yellowing, mosaic patterns in various shades of green, or yellowing of leaf veins.
Distribution
The silverleaf whitefly is widespread in Europe and on all other continents. It is not established in Sweden, as infestations have so far been successfully eradicated through control and sanitation measures.
How it spreads
Long-distance spread occurs through trade in infested plants for planting and cut flowers. Trade in poinsettias appears to be a major factor in the spread of the silverleaf whitefly within Europe and the Mediterranean region. Although adult whiteflies are poor fliers, they can be carried over longer distances by wind.
If you suspect an infestation by the silverlead whitefly
The silverleaf whitefly is a quarantine pest in Sweden and must be reported. If you detect an infestation, you are required to notify the Swedish Board of Agriculture.
Melon thrips, Thrips palmi
Thrips palmi is a thrips species and a serious pest that attacks a wide range of plant species. Plants in the cucumber, legume, and nightshade families are particularly vulnerable. Among ornamental plants, chrysanthemum, cyclamen, and orchids are frequently affected. Ornamental plants such as weeping fig (Ficus benjamina) can also be infested.
Thrips palmi has developed resistance to certain common pesticides, making it difficult to control. In Japan, biological control using predatory mites has shown success. In Australia, insecticidal soap is recommended for vegetable cultivation.
Symptoms
Melon thrips hides in crevices on host plants. It feeds by sucking sap from plant cells, leaving behind empty cells that give the tissue a silvery appearance. Leaves, shoot tips, and flowers develop silvery streaks and spots that later dry out and turn brown, especially along the leaf veins. During severe infestations, leaves may appear silver or bronze-coloured. Additionally, leaves, fruits, and shoot tips may become deformed and stunted.
Distribution
Thrips palmi originates from Southeast Asia and has spread across much of Asia. It has also been found in some African countries, Australia, Iraq, South America, the Caribbean, Hawaii, and Florida. In European greenhouses, occasional outbreaks have occurred, but no permanent establishment has been reported.
How it spreads
Long-distance spread occurs through trade of infested plants for planting, fruits, or packaging materials. Thrips palmi has been intercepted multiple times in shipments to European and Mediterranean countries during import inspections of host plants. The species has limited ability to spread long distances on its own.
Risk of misidentification
The melon thrips is just over one millimeter long and resembles the onion thrips (Thrips tabaci), which is common in Swedish greenhouses during cultivation of cucumbers. Expert identification is required for accurate diagnosis.
Thrips palmi can also be confused with the honeysuckle thrips (Thrips flavus), a relatively common thrips species. Microscopic examination is necessary to distinguish Thrips palmi from Thrips flavus.
Thrips palmi can also be confused with Thrips flavus, a relatively common thrips. Microscopic investigation is required to be able to distinguish Thrips palmi from Thrips flavus.
If you suspect an infestation by melon thrips
If you suspect an outbreak of the melon thrips, you must notify the Swedish Board of Agriculture.
Contingency Plans for Quarantine Pests
The Swedish Board of Agriculture has developed contingency plans for the quarantine pests that are considered the highest priority within the EU. These are pests that could cause significant economic, environmental, and social consequences if they were to become established here.
Quarantine pests must always be subjected to control measures with the aim to eradicate these pests. The contingency plans describe how the Swedish Board of Agriculture will respond to a suspected presence of a pest in Sweden and how eradication efforts will be initiated. The main purpose is to provide guidance at the beginning of an outbreak to prevent the pest from spreading and becoming established in the country.
Please note that the contingency plans are only available in Swedish.
Contingency plans for priority quarantine pests
Exemptions from import bans or the requirement for phytosanitary certificates for scientific and certain other purposes
If you wish to import plants, plant products, soil, growing media or quarantine pests, you can apply for a derogation from the requirement for a phytosanitary certificate or exemptions from the import ban. You can then obtain an exemption for official testing, scientific or educational purposes, experiments, trials, varietal selection or breeding.
In order to obtain an exemption, you must be able to show that you can handle the product you wish to import for your activity in a secure way. This may, for example, concern the appearance of your premises where the material is to be dealt with and how you will destroy the material after completion of experiments.
The activity shall be conducted at a designated containment facility. You should state a facility in your application. If you do not do this, you will automatically apply for your place of operation to be approved as a temporary containment facility.
We may visit the facility to look at the premises and at how routines for the activity are organised before we grant a permit. We may also inspect your activity during the period that it is taking place.
If we grant an exemption, you will receive a document called a letter of authority which you use when importing the material and which should accompany the material to the facility. You will then also receive a permit to process the material at the facility you have stated in the application. The permit is for a set period of time.
When the activity ceases, the material must be destroyed or kept in a secure way if you plan to continue to use the material. In order to be able to continue to process the material, you must make a new application to be allowed to continue the activity. The new application must be made before the earlier application ceases to apply.
You can apply for an exemption in our e-service. The processing time is approximately one month.
E-mail us if you would like more information about exemptions for scientific purposes.
Fee for processing and inspections of exemptions for scientific purposes
- The basic fee for processing an application is SEK 700. If the processing takes longer than an hour, an additional fee of SEK 690 per hour commenced will be applied.
- Inspection prior to the decision costs SEK 3,000. If the inspection takes more than an hour, another SEK 690 per hour commenced will be charged.
- Inspection of activity costs SEK 3,000. If the inspection takes more than two hours, another SEK 950 per hour commenced will be charged.
- Laboratory analysis connected to inspection of the activity will be charged for at the actual cost of transport and analysis.
Please contact us if you have any questions
Please get in touch with us if you have any questions. You can either mail us or call to the Swedish Board of Agriculture’s customer services and ask to be connected to the plant regulation unit.
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Surveys of some quarantine pests are partially co‑financed by the EU.
Revision date: 2025-06-02