Both the PRA and the PRA report are available.

Expert working group in 2013-07, review in 2014. This PRA supported the addition of the plant to the EPPO A2 List in 2014.

P. hysterophorus is a major pest in pastures and crops in its exotic range, and has major detrimental impact on human and animal health through allergies and dermatitis. If introduced in the area of potential establishment, eradication or containment would be unlikely to be successful due to its high reproductive potential and high spread capacity through human activities. 

The probability of entry is considered likely with a medium uncertainty. Many entry pathways are identified and given the past history of introduction around the world of P. hysterophorus and its occurrence in Israel, it is likely that the species will enter in further EPPO countries. 

The probability of establishment is high with a low uncertainty. 

The rate of spread of the pest is likely to be high with a medium uncertainty as the species can spread naturally on a local scale through wind and wild animals, as well as over long distances through human activities as a contaminant of seeds, of grain, on people, in farm yard manure or composts, construction materials, land filling and movement of soil and of vehicles, of fodder, pasture seed, etc

The potential economic impact in the area of potential establishment is considered as major with medium uncertainty. P. hysterophorus would have moderate to major impact on crops and pastures, depending on the intensivity of the production techniques. Environmental impacts are considered to be minor to moderate. Impacts on human and animal health through allergies and dermatitis are considered as major as 50% of the population is reported to be sensitive in case of regular exposure by direct contact. The human health impact is expected to be worse than the one experienced with Ambrosia artemisiifolia.

2021: The PRA report was modified to clarify the phytosanitary measures recommended