Four known species of plant-parasitic nematodes of the genera Crossonema Mehta & Raski, 1971 and Ogma Southern, 1914 in Ramsar forests, northern Iran

In order to identify the plant parasitic nematodes in Ramsar forests, 90 samples of soil and root of trees were collected in October 2012. Nematodes were extracted, fixed and transferred to anhydrous glycerin, and identified. 27 nematode species belonging to 16 genera were identified. The species Crossonema dryum, C. menzeli, Ogma fagini, and O. murrayi are recorded or described from Iran for the first time. C. dryum by having 20-44 short scales on body annuli at midbody and different shape of scales on body of fourth-stage juvenile (J4); C. menzeli by presence of 55-65 digitate or slender scales on body annuli at midbody, 8-10 µm long; O. fagini by having less than 10 longitudinal rows of scales on body annuli and a convex-conoid posterior region, and O. murrayi by having eight longitudinal rows of triangular scales on body annuli and a head with two equal annuli; can be differentiated from closely related species