N	Risk mitigation measure	Effect on the pest	Evaluation and uncertainties
1	Registration of production sites	Yes	Although E. excrescens is not a quarantine pest, it has been listed the UK Plant Health Risk Register until 2020 and it is easy to spot. The risk mitigation measure could have some effects in reducing the likelihood of the presence of the pest on the commodity. Uncertainties: – None.
2	Physical separation	No	Not relevant. Physical separation is not a barrier for E. excrescens because crawlers can be easily spread by wind and air currents.
3	Certified plant material	Yes	The risk mitigation measure could have some effects in reducing the likelihood of the presence of the pest on the commodity. Uncertainties: – None.
4	Growing media	No	Not relevant. Eulecanium excrescens is not present in soil.
5	Surveillance, monitoring and sampling	Yes	Incoming plant material is thoroughly checked, E. excrescens is easy to spot. The risk mitigation measure could have some effects in reducing the likelihood of the presence of the pest on the commodity. Uncertainties: – None.
6	Hygiene measures	Yes	Nymphs could move with equipment/clothes of the nursery staff. The described measures could have very little effect in reducing the likelihood of the presence of the pest on the commodity. Eulecanium excrescens is not present on weeds. Uncertainties: – None.
7	Removal of infested plant material	Yes	Removal of generically damaged plants could reduce the probability of carrying E. excrescens. Uncertainties: – None.
8	Irrigation water	No	Not relevant.
9	Application of pest control products	Yes	Chemical control measures adopted when the pest is found may have a substantial effect of pest suppression. Uncertainties: – The active substances of chemical treatments and their level of efficacy against the pest.
10	Measures against soil pests	No	Not relevant.
11	Inspections and management of plants before export	Yes	Inspection should detect E. excrescens as signs are clear (honeydew). Uncertainties: – Capacity of detecting symptoms at low pest density.
12	Separation during transport to the destination	No	Not relevant. Acer plants are not individually separated during transportation.