Pest categorisation of High Plains wheat mosaic virus

Abstract

The EFSA Panel on Plant Health conducted a pest categorisation of High Plains wheat mosaic virus (HPWMoV) for the EU territory. The identity of HPWMoV, a member of the genus Emaravirus (family Fimoviridae ), is well established and reliable identification methods are available. The pathogen is not included in the EU Commission Implementing Regulation 2019/2072. HPWMoV has been reported from Argentina, Australia, Canada, Ukraine and USA, and it is not known to be present in the EU. HPWMoV infects plant species of the family Poaceae (i.e. wheat, maize and several other cultivated or wild Poaceae species). It is the causal agent of High Plains disease of wheat and maize, inducing symptoms ranging from mild to severe mosaic, chlorosis and necrosis in wheat, and chlorotic streaks in maize plants. The virus is transmitted by the wheat curl mite Aceria tosichella, which is present in the EU. HPWMoV transmission via seeds was reported to occur in sweet corn. Sweet corn seeds for sowing were identified as the most relevant pathway for entry of HPWMoV into the EU. Seeds from other hosts and viruliferous wheat curl mites were identified as entry pathways associated with uncertainties. Machinery not appropriately cleaned may move infected seeds and/or parts of cereals infested by viruliferous mites. Cultivated and wild hosts of HPWMoV are distributed across the EU. Would the pest enter and establish in the EU territory, economic impact on the production of cultivated hosts is expected. Phytosanitary measures are available to prevent entry and spread of the virus in the EU. HPWMoV fulfils the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Distribution of Wheat-Infecting Viruses and Genetic Variability of Wheat Streak Mosaic Virus and Barley Stripe Mosaic Virus in Kazakhstan

“…TriMV was not detected outside North America before 2023 [ 77 ], and its limited distribution in Iraq suggests a recent introduction. So far, Ukraine [ 78 ] and Iran [ 79 ] report the presence of HPWMoV in Eurasia, and EFSA considers it a potential quarantine pest for the EU [ 80 ]. Notably, both research groups used the same set of primers targeting the HPWMoV nucleocapsid region developed by Lebas et al [ 81 ], which is located within genomic RNA 3 characterized by two heterogenous variants [ 45 ].…”

The Complex World of Emaraviruses—Challenges, Insights, and Prospects

“…The virus and its vector were added to the A1 alert list by the European and Mediterranean Plant Protection Organization (EPPO) and the UK and RRV was listed as a quarantine pest in Morocco [159,160]. Third, the EU is currently planning to categorize HPWMoV as a potential Union quarantine pest due to its wide distribution in America, Australia, and the Ukraine [97,161].…”

The Complex World of Emaraviruses – Challenges, Insights and Prospects

“…The virus and its vector were added to the A1 alert list by the European and Mediterranean Plant Protection Organization (EPPO) and the UK and RRV was listed as a quarantine pest in Morocco [160,161]. Third, the EU is currently planning to categorize HPWMoV as a potential Union quarantine pest due to its wide distribution in America, Australia and the Ukraine [97,162].…”