| Rhagoletis pomonella is known as the apple maggot
fly, the apple fruit fly, or the railroad worm. Apples
aren't the only host plants for the apple maggot;
they can sometimes be found on blueberries,
cherries, pears, and plums as well. Most of the
damage caused is to the fruit. Apple maggot is a
more serious problem on early-maturing varieties of
apples. This insect also causes damage to fruit of
ornamental flowering crabapples and hawthorn trees.
Symptoms and Diagnosis
Apple maggot injury will vary among apple
cultivars. Fruit may be dimpled or distorted where
the female fly has laid eggs. White or yellowish
worms emerge from the eggs and are found in the
developing fruit. The young larvae tunnel through
the fruit, leaving small, brown trails. Small pits may
be observed on the skin; these holes are where
mature larvae have emerged from the fruit. Infested
fruit drop prematurely. If you slice open a fallen
fruit, numerous brown thread-like tunnels are
evidence of larval feeding damage.
Life Cycle
Pupae overwinter in the soil, and adults begin
emerging in late May continuing through August.
Eggs are laid on the fruit and larvae will hatch in
about three weeks. At 1/4 inch long, the adult is
slightly smaller than a common housefly. It has a
black body with markings on the legs and white
bands across the abdomen. The wings of the adult
fly are clear with distinguishing black bands. There
may be up to two generations per year.
Integrated Pest Management Strategies
1.Prevent adult flies from laying eggs within the
developing fruit. There is no control once the
maggots are feeding inside the fruit. Yellow sticky
traps for flies can be found in most garden supply
shops. Six to eight traps should be hung in a fullsized
tree. Do not leave traps in trees for more
than a month from the time adults begin to
emerge because the traps may attract some
beneficials as well.
2. Clean up fallen fruit regularly so that larvae don't
have a chance to burrow into the ground and
pupate, becoming a problem the following season.
3. Avoid planting ‘Cortland’, ‘Wealthy’, ‘Delicious’,
and other early-maturing apple varieties because
they are the most susceptible varieties.
4. Do not plant hawthorns or crabapples in the
vicinity of apple trees because these ornamentals
may harbor apple maggots that may also infest
the fruit on nearby apple trees.
5. Use chemicals. Pesticides registered for use include carbaryl (Sevin) phosmet (Imidan) esfenvalerate (Ortho Bug-B-Gon Garden and Landscape Insect Killer) and pyrethrins. | 
