Rose rosette virus (RRV) and its vector, the eriophyoid mite P. fructiphilus, have had high economic and social impacts in the USA. All species and cultivars of Rosa are considered at risk from the virus and vector, as no known tolerant or resistant species or varieties have been identified. The virus causes witches’ broom, flower abortion or flower malformation, distorted leaf growth and reduction in cold hardiness, leading to mortality of roses.

Current measures in the EPPO region do not significantly reduce the probability of entry. Risk of entry on Rosa plants for planting (except seeds and pollen) is considered to be high with moderate uncertainty, and on cut flowers of Rosa it is considered to be low to moderate with moderate uncertainty. The likelihood of establishment in the EPPO region is considered very high. If introduced, the magnitude of spread would be moderate to high, due to the extensive trade in Rosa and because of the aerial dispersal of P. fructiphilus, with a moderate uncertainty.

As for the USA, potential impacts in the EPPO region could be high, and locally may be very high. The highest economic impacts are expected to be incurred by nurseries and areas producing rose products such as rose oil. Potential environmental impacts are expected to occur if native (especially endangered) Rosa species in the EPPO region are susceptible hosts. Social impacts would occur through the loss of employment and income in the production and transformation industry (especially for rose flowers for oil) and in those countries where Rosa has significant cultural importance.

The EWG considers RRV to be a high risk to the EPPO region. P. fructiphilus is considered to be a potential pest for the EPPO region, as vector of RRV and possibly through direct feeding damage (see section 4.1.1). Establishment of P. fructiphilus in the EPPO region in the absence of RRV would also increase the risk of the virus, as the vector is very unlikely to be eradicated if found in the wider environment and would spread quickly. Measures to prevent the introduction of P. fructiphilus irrespective of the virus should also be considered.