Opinion of the Scientific Panel on Plant Healthon the pest risk assessment made by Poland on Ambrosia spp.

Following a request from the European Commission, the Panel on Plant Heath was asked to issue a scientific opinion on the pest risk assessment made by Poland on Ambrosia spp., requested by Poland to be inserted as a harmful organism in point c of section II, part A of Annex I to the Council Directive 2000/29/EC.The Polish risk assessment relates to three species of the genus Ambrosia: A. artemisiifolia L. (common ragweed), A. trifida L. (giant ragweed) and A. psilostachya DC (perennial ragweed). These plants are native to North America and are considered invasive both in their native area and in other parts of the world, including several countries in Europe. Ambrosia spp. are of particular public concern due to the allergenic properties of their pollen.The Panel examined in detail the document provided by Poland. The review evaluated the accuracy and relevance of data, the information provided for pest risk assessment purposes, the quality and quantity of data considered, and the quality of methods applied to conduct the risk assessment. The review was based on the principles and terminology of the International Standard on Phytosanitary Measures ISPM No. 11: Pest risk analysis for quarantine pests including analysis of environmental risks and living modified organisms (2004) by the International Plant Protection Convention (FAO IPPC, 2006).With regard to the criteria of a quarantine pest, the Panel on Plant Health concludes that the Polish document does not provide sufficient evidence to assess on a scientifically sound basis whether Ambrosia spp. qualify as quarantine pests for Poland.The most important shortcomings are:- The pest of phytosanitary concern for Poland has been identified at a genus level. The genus Ambrosia includes too many species to be considered together, even if only three species A. artemisiifolia, A. trifida and A. psilostachya are deemed to pose a threat. Biological and ecological data clearly indicate that each of the three species would require its own or a better structured pest risk assessment clearly discriminating among the species of concern.- The document clearly states that Ambrosia spp. are present in Poland. Detailed information on the current distribution and the abundance in Poland of each of the three Ambrosia species is necessary. Moreover, more species-specific details are needed on their habitats, the locations of occurrence and their status (established or not).- Data on the different introduction pathways need to be revised. The current distribution for each of the three species outside Poland, especially in countries that are important trading partners of Poland, should be added to identify in more detail the risk for further introduction. More accurate data are required on the assessed pathways of the three species; alternative pathways (via bird seed, spreading by soil, machinery and tyres) should also be considered.- It is not possible to conclude from the document whether Ambrosia spp. would be of potential economic importance for Poland, i.e. through direct or indirect effects on cultivated plants in agriculture, uncultivated/unmanaged plants, wild flora, habitats or ecosystems. Impacts on human health are also not given sufficient attention.- The endangered area is not defined.However, there is scientific evidence both in the provided document and the existing literature that Ambrosia spp. can cause detrimental impacts on human health due to their allergenic properties. The control of Ambrosia spp. is difficult in certain crops and in non-cultivated areas.The Panel on Plant Health therefore recommends that the pest risk assessment should be revised and updated. As stated above, it should be undertaken for each of the species of concern. In order to assess the risks related to each Ambrosia spp., additional information and amendments would be needed regarding the following aspects:- current distribution and abundance in Poland (providing references and/or official surveys data), including listing of habitats, the locations and the status (established or not);- current distribution outside Poland, to identify in more detail the risk of further introduction into the country;- more accurate data on the pathways already assessed; consideration of alternative pathways (bird seed, spreading by soil, machinery and tyres);- more accurate assessment of the potential for establishment in Poland (including photoperiod and climatic conditions, and other abiotic factors);- update on the efficacy of control measures;- effects on crop yield, at least for the main crops. This is important as the levels of infestation with Ambrosia spp. and the efficiency of the methods of control are not the same for all crops;- potential economic importance (including impacts on human health and other social impacts);- identification of the endangered area;- discussion of uncertainties on all aspects of the pest risk assessment.