Depending on where you live, a variety of insects attack apple trees. To avoid the destruction of your fruit and to keep your fruit healthy so you can make delicious pies or cider, you can employ some natural control methods rather than chemical ones. Some are preventative and others may be used after the pests have arrived. Before spraying a chemical pesticide, consider going "au naturel" to keep your animals, children and local ecosystem safe from chemical toxins.
Corrugated Cardboard and Molasses Traps
Adult coddling moths may lay eggs on the leaves and fruit of apple trees. The eggs develop into larvae, which are tan to white in color and approximately 3/4 inch long; the larvae pierce and attack the interior of apples. One preventative measure to stop adults from continuing the cycle is to wrap apple tree trunks with corrugated cardboard. The cardboard makes an ideal site for coddling moth cocoons, states the Small Farm Permaculture and Sustainable Living website. Dodge County's University of Wisconsin Extension recommends removing the cardboard covered with cocoons approximately once a week and burning it. Another natural control method to trap coddling moth adults is to make a one part molasses to 10 parts water mixture and to pour it in open plastic containers. Hang two containers from the branches of each tree. Finally, remove any fallen apples from the ground and any apples still on the tree that look like they have been pierced, and thus attacked, by larvae.
If you notice dark tracks strewn throughout the inside of apples, this may be a sign that apple maggots have attacked the fruit. At the adult phase, these pests morph into flies with black and white splotches and stripes along their wings and bodies. To prevent future generations, you can trap the flies with hanging insect traps. You can buy red traps shaped like apples or yellow flat traps; both are coated with a sticky adhesive that will trap and kill the flies.
Beneficial Insects and Soap Spray
Woolly apple aphids attack apple trees all over North America, states the Utah State University Cooperative Extension. From a distance, you can tell if they are among your trees by looking for a white, woolly mass covering tree branches or trunks. Up close, the insects are reddish-purple. If the aphids have already attacked the roots, it may be too late to save a particular tree. However, promoting a community of natural predators that will prey on the aphid pests is quite effective. Through planting flowering plants near your apple trees, you can attract predators, such as green lacewings and lady bugs. Golden Harvest Organics specifically recommends planting trailing nasturtiums at the base of apple trees, and wrapping their vines around apple tree trunks, as these beautiful flowers repel woolly aphids. You can also make a homemade soap spray by grating 2/3 of a bar of soap into a gallon of hot water, and spraying the mixture on all areas attacked by aphids.
Homemade Oil Mixture
If the leaves of your apple trees are turning brown or bronze and dropping off the tree too early, they may be victims of spider mites. The pests are extremely tiny, clear to green in color, round and have six legs. Spraying a homemade soap or oil mixture on leaves may successfully repel spider mites. For example, Great Harvest Organics recommends making a mixture of 1/2 oz. coriander oil with 24 oz. water, or a mixture of 1 tbsp. castile soap with 1 gallon water. Again, encouraging natural predators, such as damsel bugs and ladybugs, will help control these pests. Also, briefly spraying infected leaves with water may wash the spider mites away.