Identifying Tree Insect Problems

Insect holes in trees usually exude some kind of fluid. In most cases, borer infestations in trees are due to stress or previous damage to the tree.

Insect problems in trees take the form of holes, defoliation, drying twigs, foliage discoloration or growth malformations.

Don't blame the ants.

Insect holes in trees usually exude some kind of fluid. In most cases, borer infestations in trees are due to stress or previous damage to the tree. Usually, people blame ants for damaging a tree, but it's more likely that they were attracted to the tree after damage was done, perhaps to feed on insects already infesting the tree.

Caterpillars defoliate…

Defoliation may be caused by caterpillars or scale insects; although stress can cause it in some cases. Caterpillars, such as the buck moth in early spring, are easy to find.

Scales are sneaky…

Scales are a little more secretive in that you're not likely to notice their damage until large populations have developed. In addition to foliage discoloration or spotting, scales may cause tip die back.

If you have a lumpy tree…

Several gall forming insects may cause malformations on trees. Stems may become swollen and misshapened. Buds may be retarded or killed. Leaves may have fluffy, fuzzy or unusual growths on them. The galls may be caused by small wasps, flies or mites. Many of these formations, when they first start, appear decorative. However, persistent, continuous infestations can cause terminal die-back.

Disease and insect damage may look similar.

Many of these insect-like problems must be carefully checked because some diseases may cause the same symptoms, particularly where galls and scale damage are involved.

For more information on identifying tree insect problems; contact your local County Extension Office.