Organisms harmful to plants are organisms of plant or animal origin, viruses, mycoplasmas and other pathogens harmful to plants or plant products. Quarantine organisms, on their turn, are organisms harmful to plants which at this stage are not present in this country despite existing favourable circumstances for their development or the presence of which is restricted and actively controlled and which can bring about massive economic losses. The occurrence of quarantine organisms is promoted by a usually wide spectrum of hosts and lack of natural enemies in the new territory.

Quarantine organisms incidental in Latvia:

 

1. Insects, ticks and nematodes:
1.1. Globodera rostochiensis (Wollenweber) Behrens.

2.Bacteria:
2.1. Clavibacter michiganensis subsp. sepedonicus (Spieckermann & Kotthoff) Davis et al.
2.2. Clavibacter michiganensis subsp. michiganensis (Smith) Davis et al.

3.Fungi:
3.1. Mycosphaerella linicola Naumov
3.2. Phialophora cinerescens (Wollenweber) van Beyma
3.4. Puccinia horiana P. Hennings
3.5. Synchytrium endobioticum (Schilbersky) Percival

4.Viruses and virus like organisms:
4.1. Chrysanthemum stunt viroid

4.2. Apple proliferation phytoplasma