A Survey of Tospoviruses in Bulgaria

A survey of tospoviruses present in Bulgaria was conducted during three vegetation periods. A total of 258 di€erent virus isolates were obtained from tobacco, tomato, weeds and ornamentals in the open ®elds and from glasshouses. Virus isolates were identi®ed by inoculation to test plants and serology as Tomato spotted wilt virus (TSWV). No indications were obtained that other Tospovirus species were present in Bulgaria. In addition the transmission ability and eciency of several Bulgarian populations of Thrips tabaci (Lind.) and Frankliniella occidentalis (Perg.) was determined. The experimental results indicated that Bulgarian TSWV isolates are transmitted with high eciency by F. occidentalis and that only arrhenotokous and not thelytokouse populations of T. tabaci could transmit TSWV.