There are two types of boring insects that attack apple trees, according to Texas A&M University. There are primary invaders and secondary invaders. Primary invaders attack healthy trees and secondary invaders infest trees that are already unhealthy. Secondary invaders are another symptom of an unhealthy apple tree’s decline, but primary invaders can cause a tree’s eventual death. While application of chemical pesticides will prevent attacks by primary invaders, the best means to protect an apple tree from secondary invaders is to keep it healthy.
Wear protective clothing, including a long-sleeved shirt, gloves, goggles and breathing protection.
Mix chemical pesticides according to package directions.
Pour the chemicals into the holding chamber of a pesticide spray applicator. Close the lid and prime the applicator by working the applicator’s pump handle up and down until sufficient pressure has built in the applicator.
Grasp the applicator’s wand in one hand and the holding tank in the other. Squeeze the trigger on the applicator wand to release the chemical in a thin spray from the end of the applicator.
Pass the wand over the apple tree in long even strokes to distribute pesticide over the tree’s trunk and branches.
Repeat steps 1 through 6 for every application of the pesticide. Pesticide treatments should be applied once before flowering, once after the blossoms have fallen off trees and every two weeks thereafter until a week before harvesting apples.
Plant the tree where it will be protected from freezing damage, sun scald, wind burn and other conditions that can place stress on the tree.
Water the apple tree at a rate of 5 gallons weekly in summer months that have less than a cumulative week of rainfall. Watering prevents drought stress.
Fertlize with 1 oz. of nitrogen applied in a 12-inch circle around the base of the tree before mid-June to keep the tree healthy.
Protect the trunk from scarring due to mowing, string trimming or construction with a plastic shield.
Prune the apple tree in the winter months to prevent disease. Remove and destroy any infested limbs to prevent the spread of diseases that can weaken a tree and leave it open to boring insects. Treat all wounds with wound paint except during cold winter months.