Section outline
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CORaV has been confirmed in ringspot-diseased oaks in various locations in Germany, Southern Sweden and Southern Norway. Typical leaf symptoms of chlorotic ringspots, chlorotic spots and mottling have also been reported to occur in Quercus sp. in further European countries, for instance the UK, Hungary and the Czech Republic (Biddle 1968, Cooper 1979). The ringspot disease has been shown to be graft transmissible (Büttner & Führling, 1996), while it is neither mechanically transmissible nor by seeds. The natural vector, which is most likely an eriophyid mite species is so far unknown.
Diverse chlorotic spots and ringspots in leaves of CORaV-infected common oak (Quercus robur), in some cases chlorosis turns into necrosis (left).