VKM has assessed the risk that 69 plant pests pose to Norwegian plant health. None of them pose a very high or high risk, but six pose moderate risk.

The Norwegian Scientific Committee for Food and Environment (VKM) has assessed and ranked 69 plant pests that the European and Mediterranean Plant Protection Organization (EPPO) recommends that member countries regulate as quarantine pests. These are organisms that can cause damage to plants and are currently not regulated in Norway. The assessment was commissioned by the Norwegian Food Safety Authority.

Of the six pests assessed to pose moderate risk the following probability and impact invasion was assessed for: 

Two pests were assessed to have moderate probability and impact of invasion:

• The virus Potexvirus pepini (PEPMV0) is mechanically transmitted with plant sap and can infest tomato and pepino, causing considerable yield losses. Its main entry pathway is infected tomato fruits and, to a lesser extent, seeds. The pest is present in many countries in Europe, including countries with a temperate climate. The risk of introduction and spread in Norway with infected fruits is considerable. Establishment will probably have significant economic consequences, as symptoms and yield losses in tomato are considerable. 

• The virus Tobamovirus fructirugosum (TOBRFV) was described as recently as 2015 and infests tomato and peppers. The virus is considered ‘present’ or ‘transient and under eradication’ in several countries in Europe and elsewhere. Pathways for movement are seeds, fruits or vegetables, and plants for planting. Entry is likely by seeds and fruits (mechanical transmission), and to a lesser extent by plants for planting. Establishment is likely in greenhouses and the economic impact for tomato production would be significant. 

Four pests were assessed to have low probability of invasion but high potential impact: 

• The moth Choristoneura fumiferana (CHONFU) attacks several hosts in the pine family, including species that are important forest trees in Norway. The main pathway for movement is plants for planting and other living conifer plant parts. Import of conifers from the pest's current distribution is not allowed. Most forested areas in Norway have similar climatic conditions as the pest’s native range in North America, suggesting that outdoor establishment in Norway is likely. The potential impact is high because the pest is a highly destructive pest of spruce and fir trees, causing widespread defoliation, reduced growth and periodic tree mortality in its native range. 

• The moth Dendrolimus superans (DENDSU) is a severe defoliator of conifers in its native range in China, Japan, and Russia. Documented host plants include species of Pinus, Larix, Abies, and Picea, including species that are important forest trees in Norway. The most likely entry pathways are plants for planting and timber but such imports from the pest's current range is small, and phytosanitary measures further reduce the likelihood of entry. The pest’s climatic requirements are uncertain, but it can probably establish in the southernmost parts of Norway. The potential impact is high, as the pest probably will cause repeated defoliation and possibly tree mortality in some areas during outbreak years, with significant consequences for timber production. 

• The moth Grapholita packardi (LASPPA) has larvae that feed in fruit or terminal shoots. It has a relatively wide host range, including plants used in commercial fruit orchards, gardens, as ornamentals and in natural habitats in Norway. The pest’s current distribution in Northern America suggests that it may establish in southern Norway, but the probability of entry is low. Due to the large number of potential hosts, significant economic losses could be expected in a situation with few or no pesticides available for Norwegian production. 

• The bacterium Xylella fastidiosa (XYLEFA) is a serious plant pathogen that can cause wilt disease in several hundred host plants, including species of Prunus, other deciduous trees, and ornamental plants. The pest is established in several European countries, and the most likely entry pathway is with plants for planting. Infected plants can remain asymptomatic, and this makes early detection difficult. There are suitable vectors in Norway (mainly native xylem sap feeders) and susceptible wild and cultivated host plants. It is moderately likely (with high uncertainty) that the pest can establishment in protected conditions and outdoors in Norway.