Attraction of Twospotted Spider Mite to Bean Rust Uredinia. L. R. BATRA, Research Microbiologist, Molecular Plant Pathology Laboratory, Plant Sciences Institute, Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705. J. R. STAVELY, Research Plant Pathologist, Molecular Plant Pathology Laboratory, Plant Sciences Institute, Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705. Plant Dis. 78:282-284. Accepted for publication 20 November 1993. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1994. DOI: 10.1094/PD-78-0282.

Adults of the twospotted spider mite, Tetranychns urticae, were two- to sixfold greater on bean leaves, Phaseolus vulgaris, containing multiple uredinia of the rust fungus, Uromyces appendiculatus, than on rust-free bean leaves. On rust-free plants, freshly released mites went to the young trifoliolate leaves; but on rust-infected plants, they initially migrated to uredinia on older leaves. Mites became covered with echinulate urediniospores and vectored them to rust-free plants. The smooth-walled teliospores seldom adhered to the mites.