Apple growers usually find themselves battling insects on their trees each year. Insecticides will take care of many of the pests, and other tools such as white latex paint and hanging red sticky spheres can also be effective. The key is to find the right insecticide and spray when the pests are hatching. Growers must also be able to identify the type of pest. There are indirect pests, which feed on the trunk, roots or leaves, and direct pests, which feed on the apples themselves.
Use insecticide, cardboard strips and plastic bags to control codling moths and oriental fruit moths, some of the most common direct pests. These moths lay eggs on the apples or leaves, says James Walgenbach, N.C. State professor and Extension entomologist with the Mountain Horticultural Crops Research and Extension Center. The eggs hatch and the larvae bore into the fruit to feed. To get rid of them, seal infected apples in bags and throw them away every few days. Put corrugated cardboard strips 2 to 4 inches wide on the trunk and branches in the summer for larvae to make their cocoons in, then destroy. Spray insecticide when petals begin to fall up, continuing every 10 to 14 days until 30 days before harvest, according to the Colorado State University Extension Service. Use an all-purpose fruit tree mixture such as the insecticide phosmet or Carbaryl, suggests the Ohio State University College of Food, Agricultural and Environmental Sciences.
Use insecticides and plastic bags to control apple maggots, also known as the railroad worm. These are fruit flies that lay eggs right under the skin of the apple, causing discoloration and rot. Cover apples with plastic bags before the apple maggots emerge, cutting holes in the bottom to prevent moisture accumulation. Spray insecticide on the ground around the apple tree in the summer. Use an all-purpose fruit spray mixture as well as insecticides phosmet or carbaryl, suggests Ohio State. Hanging red sticky spheres will also help catch maggots.