Aphids are very small insects that feed on the sap of some plants, including Crape Myrtles. They are a pale yellowish green with black spots on their undersides and are typically found in our area from May – September. The aphids feed on the sap inside of the crape myrtle’s leaves and excrete honeydew – a sticky, sugar rich liquid. An aphid infestation of your crape myrtles will make the leaves look shellacked from the honeydew the aphids leave behind.
A possible secondary issue to an aphid infestation is Black Sooty Mold. This mold loves feeding on the honeydew left behind by the aphids. The mold is easily washed off, but the best course of action is to get the aphid infestation under control. If the mold is left alone, it will interfere with the crape myrtle’s ability to photosynthesize – causing the leaves to drop early. Not to mention it’s not very attractive to look at.
Another insect that may infest your crape myrtle’s is scale. Scale also excretes honeydew onto the leaves and bark and will attract sooty mold. Thankfully, these infestations can be treated the same as an aphid infestation; even with the same product.