Noticed 2 of my 5 black diamond crapes I planted last year weren't blooming and found the white bark scale. Found this article online:
https://ipm.tamu.edu/2017/03/crape-myrtle-bark-scale-study-reveals-tree-treatments-to-fight-pest/

Am I too late for the imidacloprid treatment, and If so, will any Home Depot bifenthrin do? I saw a different article that said to scrub the scale off with soap and water, so I got after it with a mild solution last night, which seemed to help.

Better free advice than even Neil Sperry
Send ahead photos for best results
https://www.kamufm.org/programs/garden-success-kamu-fmhd-1

Fire is the best solution, especially on those weeds.

Then plant a live oak or some other hardwood.

We use a systemic soil drench like Bayer advanced. Best to apply it early spring.