Numerous insect herbivores and leaf pathogens influenced seedling establishment of sugar maple (Acer saccharum) in six forests in central New York. The pear thrips (Taeniothrips inconsequens), an introduced pest of maples and orchard trees, was the primary mortality factor for seedlings in a sugar maple stand, although overstory defoliation by thrips was minor. At both sites where mortality was monitored, many emerging seedlings were killed in early spring by tortricid caterpillars, especially Clepsis melaleucana. Leaves of older seedlings were damaged by various caterpillars, Typhlocyba leafhoppers, Cristulariella depraedans leaf spot disease, and others. After the spring of their first year, seedling mortality decreased, and following mast years many new sugar maples were recruited into the seedling bank.