In 1979 it was discovered in Oregon and more recently in California, Washington, and other Western states. Hawthorn and apples are favored host plants, but cherries, pears, and other fruits have also been attacked.
Female flies have four crossbands on the abdomen, and males have three.
Larvae are cream-colored maggots with a blunt posterior and a tapered front end that contains two black mouth hooks. The apple maggot is closely related to the walnut husk fly and cherry fruit fly. The adult fly can be distinguished from these other pests by the banding on its wings. It is difficult to distinguish apple maggot from snowberry maggot, a close lookalike that occurs throughout California but does not attack apples and pears. Female apple maggot adults deposit eggs singly under the pear skin, using a needlelike ovipositor at the tip of the abdomen.