Dispersal of Verticillium albo-atrum by the Fungus Gnat (Bradysia impatiens). D. W. Kalb, Research Technician, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. R. L. Millar, Professor, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Plant Dis. 70:752-753. Accepted for publication 1 March 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-752.

Adult flies of Bradysia impatiens collected from a greenhouse or growth chamber that contained alfalfa plants affected with Verticillium wilt were contaminated 79% with propagules of the alfalfa strain of Verticillium albo-atrum. Individual flies washed in 1 ml of sterile distilled water yielded 0–> 100 colony-forming-units of V. albo-atrum on ethanol-streptomycin agar. When Bradysia flies either naturally or artificially infested with V. albo-atrum were caged on clipped, 10- to 12-wk-old plants of Iroquois alfalfa for 5–7 days, the incidence of Verticillium-infected plants ranged from 31 to 41%. Plants caged with Trichoderma-infested flies or with uninfested flies did not become infected.