The well-known root-knot nematode genus Meloidogyne induces usually small root galls on European trees. Recently we detected big galls on Elm root close to Wageningen. Within the galls a heavy infection of Meloidogyne ulmi was observed, i.e. a new observation for the Netherlands. M. ulmi was described from Italian Elm tree in 2001 and is morphologically close related to M. mali, a species described from a Japanese apple tree.
(Click on the pictures for an enlargement, © NVWA/Pictures: Gerrit Karssen)