The effects of various infestation levels ofForcipata locaDelong&Caldwell on the yield, tillers/plant, yield/tiller, leaf elongation rate, carbon dioxide exchange rate, specific leaf weight, leaf diffusive resistance, and water soluble carbohydrate concentration of ‘Kentucky-31’, tall fescue,Festuca arundinaceaSchreb., were studied. The growth response of tall fescue to 9 and 27 leafhoppers/9.5 cm diam. plastic pot was increased tillering with corresponding decreases in yield and yield/tiller after each of 2 infestation periods. Leaf elongation rates were less at the low infestation level of 3 leafhoppers/pot. Photosynthesis and specific leaf weight were only affected at the high feeding level (27 leafhoppers/pot) and only after a second infestation period. There was no significant reduction in leaf diffusive resistance at either infestation level. Water soluble carbohydrate concentration in the leaves decreased with increasing infestation levels.