Association of Frankliniella fusca and Three Winter Weeds with Tomato Spotted Wilt Virus in Louisiana. R. R. Johnson, Department of Plant Pathology and Crop Physiology; Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803 . L. L. Black, H. A. Hobbs, R. A. Valverde, Department of Plant Pathology and Crop Physiology, R. N. Story, Department of Entomology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803, and W. P. Bond, Department of Biological Sciences, Southeastern Louisiana University, Hammond 70402. Plant Dis. 79:572-576. Accepted for publication 14 February 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0572.

Random surveys of three common winter weed species using the enzyme-linked immunosorb-ent assay (ELISA) and vector transmission studies demonstrated that tomato spotted wilt to-spovirus (TSWV) overwinters in Louisiana. Natural TSWV infection in Ranunculus sardous, Lactuca floridana, and Sonchus asper was detected by ELISA during the winter months and prior to spring vegetable production periods. Recovery of thrips from R. sardous, L. floridana, and 5. asper washings yielded all developmental stages of Frankliniella fusca during the winter and spring. Ranunculus sardous appeared to be the species most often associated with natural TSWV infection and thrips during the winter and prior to spring production periods. Frank-liniella fusca adults collected from Ranunculus spp. from three areas transmitted TSWV to to-mato. Other TSWV-vectoring thrips species known to occur in Louisiana were not detected in association with the weed species studied during the winter and spring months. Results of this study suggest that F. fusca is an important vector of TSWV in Louisiana.

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