The Crepe Myrtle is one of the most common plants in our area of the planet. They are hearty with spectacular blooms and relatively trouble-free. However, insects like aphids and scale-like them as much as I do. Both are easy to control if caught early. My weapon of choice is the Ferti-lome Tree & Shrub Systemic Insect Drench. This product is not sprayed. Just follow the directions and water the plants. The roots will absorb the solution and put an end to the offending insect.