Do you know if these butterfly nest work? I know my neighbor got bumblebee nest, but they decided to live in my shed and her hives are empty. They build a nest just above the ground, and when I am in the shed, I could hear them "playing a concert". One issue with loss of bees are people who destroying their nests because they are afraid to get stung. I have a nest of yellow jacket bees, and for all these years I was never stung.
Vitex or chaste tree is considered invasive in Texas. I like the chaste trees I seen them all over southern Europe, but I do not see many of them around in my neighborhood in USA. I planted chaste tree, and it grows very fast and attracts a lot of butterflies and bumblebees. I do not have issue to be self-seeding. On the other hand, hibiscus I have is very invasive, I would like to cut it down, but my spouse is against it. So I tolerate it on the backyard.
I noticed butterflies are also attracted to my yarrows, and butterfly milkweed. I have also three summersweet shrubs Ruby Spice. They are planted on the side of the house which gets sun whole day and plus they are dense enough to create privacy from neighbor. One advantage of summersweet is that they bloom in peak of the summer heat till September, when most shrubs except myrtle are done with blooming. They also attract bees and butterflies. My yellow jacket moved to my backyard year after I plant these, and they have nest just two three feet from them.