It is a major pest of homegrown apples in Ohio and, occasionally, is damaging in commercial orchards when certain insecticides are omitted. Hawthorn, plum, pear, crab apple, and cherry may serve as alternate hosts. The adult fly is a little more than 6 mm in length, dark brown, with light and dark markings on the wings. The larvae are white, tapered maggots.
Female flies lay eggs just under the skin of the apple.
The larvae, or maggots, which hatch from the eggs, tunnel at random throughout the flesh of the fruit, usually avoiding the core. External signs of maggot infestation are the minute brownish egg punctures in the skin. These are often small, distorted or pitted areas on the surface of the apple, and sometimes a white wax covers the puncture. In early-maturing apple varieties, small tunnels occur throughout the flesh and under the skin through which the trails of the larvae may be visible. Rapid decay and browning along the trails in infested fruit occur as the maggots feed.