Adults of Conotrachelus crataegi Walsh (which originally infested hawthorn but became adapted to quince) was observed on apple trees in an abandoned orchard on Mount Carmel in Connecticut in 1977, and larvae developed in apples both in the field and in the laboratory. Other insects reared from field-collected samples of apple were C. nenuphar (Hbst.) (which originally developed on plum and later became adapted to quince, apple and pear) and Cholomyia inaequipes Big., a tachinid parasite of Conotrachelus larvae. The abundance of adults and larvae of C. crataegi on fruits in the abandoned apple orchard but their absence from samples of apple from trees growing near hawthorn or quince in other localities in Connecticut, and also a difference in the size of adults reared from apple and hawthorn, suggested that a new larger race of C. crataegi adapted to apple may be evolving, probably from quince-feeders rather than from hawthorn-feeders.