How do I treat for crapemyrtle bark scale? Systemic insecticides work very well to control the bark scale, but the timing is most effective when applied in late winter/early spring. If you are just now spotting the problem, you can clean off the trunk with warm, soapy water to remove the black sooty mold.

To get rid of bark scale on crape myrtle, you can dislodge them off the tree using a dish soap solution, kill them using a systemic insecticide or a contact pesticide mix.