Аннотация:Population dynamics of all taxonomic groups of nematodes, including nematode vectors of plant viruses, were studied in meadow, swamp and agrocenoses in Moscow region during the growing seasons (May-September) 2012-2014 years. Plant viruses and their nematode vectors occurred both in natural and agrocenoses. The dangerous ectoparasitic vector species L. elongatus was the most common in the rhizosphere of both wild and cultivated plants in high numbers (on raspberry, strawberry, black and red currants and others). For the first time a large number of L. elongatus (240 individuals per 1000 g of soil) was revealed in the rhizosphere of spirea in natural biocenoses. Two peaks of number rise of nematodes of all taxonomic groups and species L. elongatus (late-spring – early-summer and late-summer – early-autumn population peaks) were observed. Nematode numbers declined in the dry season in the middle of summer, mainly in July. Identified fluctuations in numbers conform to previous data and depended on climatic and soil conditions and species of host plants. The findings have both scientific and practical significance, can be used in phytoparasitological researches and implementation of protective measures to reduce and suppress the size of parasitic nematode complexes including virus vectors and dangerous viral infections they transfer.