Fruit Tree Pests & Diseases

Many gardeners enjoy growing their own vegetables and fruits. While commercial growers provide the majority of fruit, home gardeners and hobby orchardists can produce their own crops of fresh fruit. Growing fruit requires adequate planting and pruning procedures, as well as taking measures to reduce the growth of pests and diseases. Many types of fruit trees suffer from pest infestations and disorders that can reduce fruit production and damage the trees.

Scale Insects

Scale insects attack many varieties of fruit trees, including apples, peaches and pears. These common pests feed on the soft bark. Large infestations of scale insects can damage the fruits and retard the growth of your trees. Look for tiny scales that measure between 2 and 5 mm long. Examine your fruit trees’ small twigs and limbs for evidence of these pests. Treat this type of infestation by scraping the scales off the limbs and applying a therapeutic dose of dormant oil to the trees during the late winter or early spring.


These tiny insects feed on the leaves and shoots of your fruit trees. Although they are very small, between 2 and 3 mm, they can cause plenty of damage to your trees’ leaves and fruits. They usually live in colonies and sometimes transmit viral diseases. Like scale insects, these bugs succumb to dormant oil treatments. Apply the oil before the flower buds begin to turn pink. Biological controls, such as ladybugs and lacewings, can help reduce the population of aphids in your orchard.


Many types of small caterpillars, including leaf rollers, feed on the leaves of fruit trees. These crawling bugs gnaw away at the leaves, leaving behind large holes or skeletonized leaf surfaces. Look for these bugs to appear on your trees early in the springtime. One type of insecticide, Bt (Bacillus thuringiensis), kills just the caterpillars and does not harm bees or other insects and birds.


Mildew can damage a variety of fruit-bearing trees and vines. Apple scab, fire blight, powdery mildew, cedar apple rust, white rot and flyspeck are all types of mildew conditions that affect various types of fruit trees. Undesirable growing conditions, such as poor drainage, insufficient airflow and rotting vegetation, can promote the growth and spread of mildew. Reduce the likelihood of mildew by correcting poor growing conditions. Treat existing cases with a fungicide that controls the growth and spread of mildew.

Keywords: fruit tree pests, fruit tree diseases, orchard pests

About this Author

Piper Li, a professional freelance writer, began writing in 1989. Her articles appear in Modern Mom, Biz Mojo, Walden University and GardenGuides. She is the co-editor for "Kansas Women: Focus on Health." With a bachelor’s degree in journalism from Mesa State, Li enjoys writing about health, horticulture and business management.