Apple Maggot Control
Description: Slightly smaller than a house fly, adult apple maggots (Rhagoletis pomonella) are 1/5 inch long and have conspicuous black bands running across their transparent wings. The larvae (1/4 inch long) are white, tapered maggots that tunnel throughout the flesh of fruit. They are often found in large numbers and can quickly reduce a beautiful apple to a brown, pulpy mess. External signs of maggot infestation appear as pinpricks made on the apple surface. These are often small, distorted or pitted areas. Alternate host plants include plum, apricot, pear, crab apple, cherry and hawthorn.
Life Cycle: The apple maggot overwinters as pupae in the soil. Adult flies emerge in late spring and begin to lay eggs just under the apple skin. The eggs hatch, and the larvae begin to tunnel through the fruit. When mature, the maggot leaves through a small opening made in the side of the fruit and enters the soil. One or two generations per year.
Apple Maggot Control: Most maggots leave the fruit several days after it has fallen from the tree. As a result, a certain level of control can be achieved by picking up and discarding the dropped apples. Apply beneficial nematodes in spring or fall to kill remaining pupae in the soil. Red sphere traps work well to capture and reduce the number of egg laying adults. Traps should be placed within the canopy just as trees are finished blossoming. Hang spheres high in the brightest areas of the tree, 6-7 feet from the ground. Set out one trap for every 150 apples (2 traps per dwarf tree). Botanical insecticides should only be applied if pest levels become intolerable.
Tip: Kaolin clay will suppress a broad range of apple pests and has shown over 90% control of apple maggot, codling moth, and plum curculio. It also has a positive effect on fungal diseases like fire blight, sooty blotch and fly speck.
Photo Credit: Missouri Botanical Garden