Aphids rarely cause lasting harm and are controlled by natural enemies and by providing the tree with adequate water. Spraying, which can kill the predators, isn't recommended. Borers - Insects such as bark beetles and carpenter ants chew small holes through trunks and branches. They can do extensive damage and eventually doom whole limbs. Remedies range from releasing predators or parasites to treating the tree trunk or soil against future infestations.
Caterpillars have many natural enemies and are usually temporary nuisances.
In severe cases, egg masses may have to be collected and destroyed. Scale insects - Another type of sapsucker, these pests are so small that they're much harder to detect than their honeydew, which is conducive to a sooty fungus that may stunt growth. Scale insects can usually be treated with horticultural oils. Spider mites - These tiny web spinners suck sap and cause leaf drop and reduced fruit yields. They belong to the arachnid family, so some insecticides are ineffective.