Although butterflies can be a beautiful addition to a garden and an effective pollinator, they can also present a danger with their larvae, otherwise known as caterpillars. These can damage peach trees significantly as they eat up all the leaves, flowers and fruits of the tree before turning into butterflies. It is important to control caterpillar populations in order to have a healthy, successful peach tree.
Use pruning shears (for smaller branches) and loppers (for branches larger than 4 inches in diameter) to cut back any damaged or infested peach tree branches. Burn or discard of the infested wood.
Thin out the fruiting buds in the spring to decrease the chances of infestation. This means pruning out any double- or triple-fruiting buds on one stem, resulting in just one bud per stem.
Treat the peach tree with a bacterial spray such as Bacillus thuringiensis. Follow the directions and apply it as instructed, usually thoroughly soaking the tree, leaves (including the undersides), flowers and branches to prevent future infestation. Use a ladder to apply it to hard-to-reach areas.
Water the peach tree deeply, about 8 inches at a time, only once a week in the summer. This promotes deep root growth but doesn't allow a moist or humid environment for insects to thrive in. Keep in mind that you must water the peach tree more often depending on your region. If in arid regions, water twice a week, while in more rainy climates, you may only water once every two weeks.