Here is an example of a crape myrtle tree that has been repeatedly attacked by aphids for the past several seasons. Notice how black it appears in this photo. This is the mold left behind, after the aphids did their work. This tree is one of about 50 trees in the parking lot of a major grocery chain in the Charlotte area. Shrub Doctor offered their services to free these trees of aphid decline, and were told their landscape service would resolve the issue. Two years later, no attention has been made to help the trees. I am sure the aphids will be back this year. If left alone, tens of thousands of dollars worth of trees will be lost.
Aphids are tiny insects that attack crepe myrtle trees during the summer months. They feed on the sap of the tree, and lay eggs on the undersides of the foliage. Multiple hatches occur during the season, and the infestation just gets worse. Symptoms of aphid activity is first detected by a “shiny wetness” to the tree. As the aphids feed on the sap, the sugary substance excretes from the aphid. We call this “honey dew”. It is a wet sticky substance that just coats the tree, and drips on everything below it. A black dusty mold will begin to grow on the honey dew. We call this “sooty mold”. The mold coats the leaves of the tree, and its trunk. The mold clogs the pores of the foliage, and the tree begins to suffocate. Leaves will then begin to yellow, and drop away.
Avoiding aphid attacks is a simple process. First, have your trees properly pruned to reduce a comfortable habitat for them to live. Keep your trees properly watered to eliminate stress during the summer. Maintain strength and vigor to the trees through regular feeding and nutrition. If you have experienced aphid activity in the past seasons, applying a time-released systemic insect control to the soil will protect the tree during the upcoming season. Allow atleast six weeks for the insect control to translocate to the foliage. Applying insect controls in late March is the best practice for the Charlotte Metro region.
