Possible causes of the emergence of tospovirus diseases.

Abstract Tomato spotted wilt virus, type species of the genus Tospovirus, ranks among the top ten of economically most important plant viruses. From 1980 on, a rapid emergence and geographic expansion of this, and some other tospoviruses, has occurred. This contribution will provide evidence that the recent emergence of tospoviruses, has two major causes. Firstly, these plant viruses have relatively recently evolved from the (animal-infecting) bunyaviruses and, secondly, one of their major vectors, the Western flower thrips, has dramatically expanded due to changes in agricultural practices and increase in transcontinental trading.