The apple maggot or railroad worm is a native, extending from Canada to North Carolina and west to North Dakota and Arkansas.
The maggot is particularly injurious to summer varieties in northern sections of the country. It also attacks blueberries, plums, and related flies infest peaches, cherries, and walnut trees.
Apple Maggot Appearance and Habits
Hibernation takes place inside a small brown puparium buried 1 to 6 in. deep in the soil. The adult flies do not emerge until summer (late June in some sections, early July in most). They are a little smaller than house flies, black, with white bands on the abdomen and conspicuous zigzag black bands on the wings.
The females lay their eggs singly through punctures in the apple skin; in 5 to 10 days these hatch into legless whitish maggots which tunnel through the fruit by rasping and tearing the pulp into brown winding galleries. Early varieties soon become a soft mass of rotten pulp; later varieties have corky streaks through the flesh and a distorted pitted surface. Completing their growth about a week after the apples have fallen to the ground, the larvae leave the fruit and burrow in the ground to pupate.
Ordinarily pupation continues until the next summer, but in its southem range, the apple maggot may have a partial second generation.
How to Manage Apple Maggots
Immediately remove and destroy dropped fruit on a large scale; this is effective only if implemented over several acres. If the fruit is not too badly infested, it can be turned into cider.
Plant white clover, home to beetles.
Hang fly-traps in trees from mid-June through the harvest, baited with a mixture of molasses, water, and yeast.
Maggots in picked fruit may be killed by holding the apples in cold storage for a month.