Overall assessment of risk: H. irregulare presents the case of an unusual pathway of introduction in the EPPO region, but this PRA shows that trade pathways also exist. 

The probability of entry is considered as moderate-high for natural spread from the infested area in Italy and untreated wood packaging material. Entry on wood of conifer host species (with the higher likelihood of association) and particle wood of conifers and waste wood (from countries where the pest occurs) was rated as moderate/low. 

Although plants for planting were assessed with a low risk, they may be traded as large ornamental, which would present an increased risk. Entry on other pathways is less likely.

2021: This PRA document was modified in relation to the recommended distance for the establishment of a pest free area, and to clarify the phytosanitary measures recommended.