Plant viruses transmitted by thrips

All thrips (order Thysanoptera) that are known to be vectors of plant viruses are identified and described. Thrips transmit plant viruses in the Tospovirus, Ilarvirus, Carmovirus, Sobemovirus and Machlomovirus genera. Tospoviruses are the cause of a number of significant emerging diseases, such as capsicum chlorosis and scape blight of onion. They infect thrips as well as plant hosts and the relationship between pathogen and vector is intimate. Once infected at the larval stage, adult thrips usually transmit tospovirsuses for life. Transmission to plant hosts occurs when thrips feed. Information on the distribution and hosts of all recognised thrips vectors is provided. Fourteen tospovirus species are described with information provided on other tospoviruses that have not yet been designated as species. The history of the research that has led to present knowledge is reviewed in chronological order for each tospovirus. The possible origin of tospoviruses is discussed. Information is presented on viruses, which are thrips-transmitted by mechanical processes, in other genera. Pathways of spread of thrips vectors in relation to the threat of tospoviruses to European agriculture are discussed.