Tomato spotted wilt virus (TSWV) is spread by Thrips tabaci tabaci nominate subspecies in the field under climatic conditions of Carpathian Basin. The overwintered females harbouring the pathogen proved to be the most important vector in the outbreak of epidemics in the tobacco growing district. Among the numerous host plants, the winter annual and the perennial weeds provide the survival of the pathogen. Infected weeds as Asclepias syriaca, Convolvulus arvensis grown in vineyards far from the tobacco fields and greenhouses indicate the wide spread of TSWV. Chickweed (Stellaria media) being a suitable host both for TSWV and the overwintering T. tabaci specimens constitutes the most dangerous source of epidemics. As a result of the common effect of the application of insecticides in accordance with the monitoring of T. tabaci, the centralized cultivation of the seedlings and the weed-free surroundings of the nurseries, the occurrence of TSWV was reduced to the minimum level in tobacco fields.