Crape myrtle aphids are around every year and very rarely get out of hand enough to
warrant insecticide treatment. Although on the most stressed trees or those tended by ants we have seen severe damage on occasion. Regardless, natural enemies frequently keep these aphids from getting out of control. I feel the aphids are actually a good thing to have because they attach and support predators in your landscape without causing much damage to trees. These and other innocuous herbivores are important for conserving natural enemies so don’t go after them unnecessarily. Remember, no herbivores = no natural enemies. Another interesting thing about this aphid is that no natural enemies are know to parasitize it. It is not native to the US (of course neither is its host) but efforts in it home range have also not turned up parasitoids.