Nymphs of Peltoperla maria Needham & Smith were exposed to 15 species of autumn-shed leaves in the laboratory. The insects fed on the cuticle and mesophyll of the leaves, leaving most of the vascular system intact. This feeding resulted in a characteristic skeletonized pattern to the leaves. The insects consumed leaves inamounts (by dry weight) in excess of their dry body weight in a 2-week period. Feeding studies revealed that P. maria had definite preferences for specific kinds of leaves. Elm, alder, sourwood, and dogwood were the most preferred; rhododendron, white pine, white oak, and chestnut oak were the least preferred. There was evidently increased leaching of tannic acid from leaves on which the insects were feeding. The higher tannic acid content of the water from feeding containers was apparentlya result of increased leaching from the finely ground leaf material in the fecal pellets.