I was unable to get a clear picture but there were dozens swarming the ajuga right at dusk. They were small, maybe 1.5 to 2 inches from nose to tail with clear wings. We were just enchanted!
I am just north of Fort Worth, TX.
Congrats!! I welcome little Thisbe into my garden every summer.
They like to nectar on Agastache and lay eggs on Honeysuckle and other members of that family.