An insect infestation on a tree can be particularly hard to treat. This is because most trees can withstand some minor insect damage without any long-term ill affects. Insects only become a major issue when their presence is in such great numbers that the health the tree begins to fail or it becomes more susceptible to disease. Aphids, moths and their larva, and beetles are among the primary insect stressers for trees. The following are three things you can do to help manage a pest problem.
#1: Create a barrier
Insects that can't fly, like some aphids and larval pests, can sometimes be kept off of a tree by simply blocking their access to the foliage or upper branches. The simplest way to do this is to purchase a sticky product that prevents the pests from crossing the barrier. These products are smeared onto the trunk of the tree in a complete ring that is a couple of inches wide. The barrier also prevents insects like ants, which will sometimes "farm" harmful aphids, from reaching the pests to protect the. These barrier products are harmless for the tree, but they do need to be periodically reapplied as rain and weathering eventually washes them off.
#2: Improve general health
Stressed trees are more likely to fall prey to insect pests. Drought stress is the most common issue. Most landscape trees require several inches of water once or twice a month during the active spring and summer growing season. Trees in well-irrigated landscape area generally receive sufficient water. If a tree isn't regularly irrigated and your area goes more than a couple of weeks without significant rainfall, irrigate the tree manually. Also, consider providing an annual spring application of tree fertilizer to ensure the tree isn't stressed for proper nutrients, either.
#3: Prune out the major contributors
Insect colonies often begin on a single branch or just a few branches. If you catch them early, you may be able to prune out the most badly affected branches and then use spot treatments to manage the pests on the rest of the tree. Prune out any trees that have become badly damaged or deformed by the pests, by cutting the affected branch back to the nearest healthy wood. Wipe your saw or pruners down with a bleach solution after each cut so you don't inadvertently spread insects or their eggs to healthy branches.
Your best option is to contact a tree service so they can develop a multifaceted treatment plan, which may include tree pruning, general care, and pesticides.