Macropterous (winged), Brachypterous (reduced-wing), and larval tobacco
thrips on peanut (Arachis hypogaea) leaf.

Photograph courtesy Lenny Wells
University of Georgia, Coastal Plain Experiment Station
Department of Plant Pathology, Tifton, GA 31794

Host: Frankliniella fusca; Tobacco thrips
Disease name: Vector of spotted wilt disease
Pathogen name: Tomato Spotted Wilt Tospovirus 

 
Spotted wilt disease, caused by Tomato spotted wilt tospovirus (TSWV), serves as a continuing threat to the production of peanut, tobacco, tomato, and pepper in the southeastern United States. The tobacco thrips, Frankliniella fusca, along with the western flower thrips, Frankliniella occidentalis, are the major vectors of spotted wilt disease in the southeastern region. TSWV can be acquired by thrips only during the larval stage and is transmitted by adult thrips. Control of thrips does not necessarily control the disease itself. A key question concerning TSWV epidemics regards the source of viruliferous thrips responsible for primary infection of the crop.  During the early spring a large proportion of the F. fusca population is brachypterous; however, these proportions are considerably reduced with the advent of warm temperatures and longer day length. The macropterous morph of the tobacco thrips is capable of flight and may enter the crop from an external weed source. Brachypterous thrips are incapable of flight, therefore suggesting that some populations of tobacco thrips develop and remain within a crop field throughout the year under appropriate conditions, providing a potential source of disease inoculum for emerging plants within the field itself.