Reporting
The native/invasive issue is
The native/invasive issue is a separate one. Butterflies don't care if a plant is native or not and they do like buddleia blooms. In CT, they don't seem to be invasive: I have 3 in my small suburban garden for 5 or 6 years and never had a single offspring. My sister in the mid-Atlantic region found that to be more of a probem.