Plant parasitic nematodes of Dorylaimida occur only in the Longidoridae. Longidorus is one of important genera in this family, which it,s species are parasite on many plants and act as a vector for some of plant viruses. From 1999 to 2001, more than 250 soil samples were collected from several localities of Iran. Nematodes were extracted, fixed (De Grisse, 1969) and mounted on glass slides in d...