Pest categorisation of non‐EU viruses of Rubus L.

Abstract

The Panel on Plant Health of EFSA conducted a pest categorisation of 17 viruses of Rubus L. that were previously classified as either non-EU or of undetermined standing in a previous opinion. These infectious agents belong to different genera and are heterogeneous in their biology. Blackberry virus X, blackberry virus Z and wineberry latent virus were not categorised because of lack of information while grapevine red blotch virus was excluded because it does not infect Rubus. All 17 viruses are efficiently transmitted by vegetative propagation, with plants for planting representing the major pathway for entry and spread. For some viruses, additional pathway(s) are Rubus seeds, pollen and/or vector(s). Most of the viruses categorised here infect only one or few plant genera, but some of them have a wide host range, thus extending the possible entry pathways. Cherry rasp leaf virus, raspberry latent virus, raspberry leaf curl virus, strawberry necrotic shock virus, tobacco ringspot virus and tomato ringspot virus meet all the criteria to qualify as potential Union quarantine pests (QPs). With the exception of impact in the EU territory, on which the Panel was unable to conclude, blackberry chlorotic ringspot virus, blackberry leaf mottle-associated virus, blackberry vein banding-associated virus, blackberry virus E, blackberry virus F, blackberry virus S, blackberry virus Y and blackberry yellow vein-associated virus satisfy all the other criteria to be considered as potential QPs. Black raspberry cryptic virus, blackberry calico virus and Rubus canadensis virus 1 do not meet the criterion of having a potential negative impact in the EU. For several viruses, the categorisation is associated with high uncertainties, mainly because of the absence of data on biology, distribution and impact. Since the opinion addresses non-EU viruses, they do not meet the criteria to qualify as potential Union regulated non-quarantine pests.

Known and Potential Invertebrate Vectors of Raspberry Viruses

“…idaei colonies are more efficient in virus transmission than dispersed individuals [ 79 ]. Two non-EU raspberry viruses that are transmitted by an arthropod vector are RpLV and raspberry leaf curl virus (RpLCV) [ 29 , 36 , 59 ]. The small raspberry aphid, Aphis ( Ap. )…”

“…The small raspberry aphid, Aphis ( Ap. ) rubicola Oestlund, which is reported only in North America, is believed to be the only known vector of RpLCV [ 30 , 36 ]. Thus far, the RpLCV is only present in North America [ 80 ].…”

“…However, this does not exclude them from being a potential raspberry virus vector. This is because whiteflies vector two significant blackberry viruses, namely blackberry yellow vein-associated virus (BYVaV) and beet pseudo-yellows virus (BPYV) [ 30 , 36 ]. Both of these viruses are from genus Crinivirus ( Closteroviridae ) and thus transmitted in a semi-persistent manner [ 86 , 87 ].…”

“…Xiphinema americanum is associated with several viruses infecting Rubus . It is known as a vector of ToRSV, CLRV, and CRLV in raspberry [ 36 , 59 , 122 ] and vector of tobacco ringspot virus (TRSV) in blackberry [ 123 , 124 ]. Among the three raspberry viruses transmitted by X. americanum , ToRSV and CLRV are economically important in raspberry cultivation, while the economic impact of CRLV is more uncertain [ 30 , 125 ].…”