If you follow the life cycle of the thrip,it forms eggs that drop to the soil and emerge.So since thrips can transmit TSWV if it is present internally and punctures leaves and fruit you can say TSWV is in the soil(inside the thrips)I have not read anything that all thrips have TSWV just that they are one of the main vectors of the transmission of.If you throw or use infected plant material as compost I would imagine that eggs,fecal matter,from the thrips are "in the soil"waiting to emerge on new fresh plant material.
|