Fruit trees grown without chemical pesticides, or organically, or susceptible to the same pests as conventionally grown fruit trees. A variety of pests attack fruit trees all year, from dormancy until the fruit is ready to harvest. Some pests live in the ground from season to season and can damage the fruit crops every year, eventually killing the tree.
The peachtree borer (Anarsia lineatella) affects many fruit trees, including peaches, plums and cherry trees. They look like small wasps when mature and lay their eggs at the base of the tree or in the soil. When the eggs hatch, the larvae burrow into the lower portion of the tree to feed on plant tissue until maturity. The entrance and exit holes, usually oozing sap, or easy to spot with the naked eye.
The brown leaf-footed bug resembles a stink bug and emits an offensive odor when smashed. It has a flat body with a white stripe across the lower back. The top half of the back legs are flattened, giving that part of the back legs a leaf-like look. They suck the sap and juices from the tree and fruit causing extensive damage to the developing fruit. The damage shows up as a mottling on the fruit or the fruit is deformed as it grows.
The plum circulio (Conotrachelus nenuphar) is another pest that lives in the soil over the winter and attacks fruit pear, peach, apple, plum, pear and cherry trees. The adult weevils emerge from the ground in the spring, climb up the tree and lay eggs in the developing fruit, leaving a half-moon shaped scar. After the eggs hatch, the developing larva burrow into the center of the fruit during the feeding process. This causes the fruit to fall to the ground where the larva leaves the fruit, enters the ground and grows into adulthood.
Two-Spotted Spider Mite
The two-spotted spider mite (Tetranychus urticae) is a common pest of fruit trees grown organically. The tiny mites thrive under the leaves of fruit trees, giving the leaves a bronzed or mottled look. They suck the plant sap from the leaves, which weakens the tree during the hottest part of the season. The two-spotted spider mite gains access to the tree from low-hanging branches. It is prevalent in dry, dusty soils.
San Jose Scale
San Jose scale (Quadraspidiotus perniciosus) is an unusual pest that looks like a grey or brown waxy bump on the woody parts of fruit trees. However, it can show up as red splotches on developing fruit. Although it is an insect, it remains in one location, sending its mouth-part into the tree to feed. As it feeds, it secretes a waxy substance around its body that hardens and protects it from predators and pesticides.