Regulated non-quarantine organisms are PDHOs that are widespread in Switzerland, which are spread primarily via specific host plants intended for planting.
Owing to their pervasiveness, they do not – or do not any longer – meet the criteria for quarantine organisms. However, since their occurrence in planting stock carries a high potential for damage, phytosanitary measures are being taken with respect to the marketing of healthy propagation material – for example, the Sharka virus (plum pox virus) and the pathogen of apple proliferation (Candidatus Phytoplasma mali) are considered to be regulated non-quarantine organisms.