The European apple sawfly is an introduced pest that was first noted in North America infesting crabapples on Long Island (Farmingdale, N.Y.) and Vancouver Island (Victoria, B.C.) during 1939 and 1940, respectively. Since then it has spread into southern New Jersey, Vermont, New Hampshire, and the Southern Tier of New York State. The pest is especially troublesome in the apple-growing regions of Massachusetts, Connecticut, Rhode Island, and the Hudson Valley of New York. In the Pacific Northwest, the European apple sawfly appears to be limited to Vancouver Island. The pest is distributed over the entire continent of Europe but is most common in the north. It is found throughout England but is abundant only in certain localities. The larvae feed on all apple and crabapple varieties but show a preference for early or long-blooming varieties with a heavy set of fruit. Sawflies are primitive hymenopterous insects and are related to bees, wasps, and ants. Although two generations a year have been reported in England, only one seems to occur in populations in North America.