Honeydew Aphid– During the hot summer month you may begin to see what appears as rain or water falling from your Crepe Myrtles. This harmless-looking rain like occurrence is actually what is called Honeydew- a secretion from a specific type of aphid, once you see these insects or their damage you will need to apply a systemic insecticide that is labeled for this specific type of aphid. If not treated immediately it can lead to other more severe problems such as sooty mold which causes the leaves to drop.