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 conti-nent 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. The European apple sawfly overwinters as a mature larva in a cocoon a few inches below the surface of the soil. Adults are 6 to 8 mm in length, with the male smaller than the female. The head is yellow with yellow antennae and black eyes. The wings are covered with tiny black hairs, giving them a dusky appearance.