Cereal Rust Mites
Cereal rust mites are very small and sometimes hard to see with the naked eye. Using hand lens will aid in searching for the mite. Mites are of a small elongated shape (~1 mm) ranging in color from white, pale yellow to orange. Scouting should take place before green up for the eggs and/or adults. Select random plants from across the field and inspect the leaves of the plant, especially between the leaf veins.
Cereal rust mites overwinter in the adult and egg stage and overwinter in the lower portion of the Timothy plant. Eggs hatch sometime in March and peak in early April feeding on the lower portion of the young plant. Most damage is found during this time until first cutting. Cereal rust mites exhibit a piercing mouth part, which pierce the cells and damage the cell. Once cells are damaged, the leaf will appear drought stressed and rolled, and the plant may appear stunted and slightly yellow in color. A general threshold for treatment of cereal rust mites would be approximately twenty-five percent infestation of the plants selected. Consult your regional chemical representative for approved insecticides