My Crapemyrtle Is Bringing Ants

Q: My house has been invaded by little black ants which the pest control person calls Argentine ants. He says the ants are attracted by the sap in my crepe myrtle trees and suggested I get rid of them. What are your thoughts on this? 

A: Crapemyrtles are commonly afflicted with aphids in the fall. These insects suck sap from leaves and then excrete a sweet honeydew that ants like. I am a big fan of using baits to control ants in your home. A bait product that contains borax (Terro, etc.) works very well. The first frost will kill all of the aphids but in the meantime spray insecticidal soap up into the crapemyrtle as high as you can to control aphids there. Wasps, yellowjackets, and spiders will feast on aphids higher up. There is no need to remove the tree.