MrILoveTheAnts. You must be commended on the pictures that you take, up close and personal with the bees. I like to take pictures that way and have some astounding beauties I have taken, too many to even begin to post on the forum.
About the Buddleia (butterfly bush), I guess now I have to tell a story. I love to do with deed, story telling is my baleywick.
So, years and years ago, I venture maybe 14, when I was firstly getting involved in developing my small nursery business using my greeehouse, I was on a search for fragrant plants to grow. I came upon the Butterfly Bush and thought, oh that sounds nice, a fragrant shrub, I can grow that too. So I did. I grew it from seed. The plants grew slowly and I was not able to sell any the first year because of the smallness of the seedlings, so I just planted them into my own garden.
They grew like stink over the summer, fall and spring and became small bushes with lilac flowers. Oooh, they stunk. I could not stand the stink of these flowers and really really quite annoyed, because I had gone to so much lengths to grow these on my property. So that was that year. I took them out. My youngest daughter, she was pregnant at that time, said that she loved the fresh outdoorsy fragrance, eeeks, I thought she was out of her mind.
So the years went by and my oldest daughter (who at that time lived in the mobile home on my property that my youngest daughter and family live in now) was still living there in the mobile home said that she would love to have a "butterfly garden" and could I make her one. Well, of course, I jumped for glee, I would want one too. So I delved into some research to find out what butterflies really liked and guess what I found out. Of course, Buddleia, Butterfly Bush. So, now I knew that I didn't like the lilac coloured ones at all, so I ordered some pretty white ones and dark purple. They bloomed the first year and yes, we had a butterfly garden.
My oldest daughter moved out to venture out on her own with her new (third) husband. Eeeeks, that poor girl (that goodness she has finally found "the one" that treats her like the beautiful Queen that she is). That is an aside.
I didn't want to have the butterfly garden anymore, I had other plans, like making a different garden for there. So out came the butterfly bushes. I was not all that impressed with them, especially the short time that the flower bunches last, and it seemed that every other day I had to deadhead these shrubs and that was more than I wanted to do. Man, can I ramble. You should never had set me onto telling a story, (heee, hee, too bad, suck it up!!!!!).
That was about 6 years ago. So I planted beautiful gardens, new grassy area, built a small rockery to keep some earth from eroding and planted more perennials and annuals.
The summer before last a Butterfly bush sprouted up in the area behind the rockery. What!!!!! It had been several years since the butterfly bushes were in the ground living. So I just let the bush be, obviously it had a quest to germinate some seeds from years before, I can only guess the weather conditions were perfect for germination (seeds can lie dormant for a long, long time until Mother Nature sets the right conditions for germination).
This beautiful bush grew big last summer, but didn't bloom, I cut it down to a couple of inches above ground, as I do with many of the perennials. This spring it took off like it was a rocket going to outer space. Covered in beautiful purple blooms. Beautiful, and yes, the bees love it, but not as much as the butterflies.
There are seedlings coming up everywhere, hundreds of them, I am finding them not even close to the large shrub, but everywhere on my property, I can see they will be becoming a nuisance and I will have to do some radical termination of seedlings come the spring or soon. They are way, way far away from anywhere butterfly bush was grown.
Back to your original question. The plant will set seeds and you will more than likely have seedlings coming up, but I cannot say for sure. Also, I am not sure about if the butterfly bush you have is a hybrid. If it is a hybrid, then the seeds may produce plants that may not be like your bush, it may be likened to the mother or father that produced this plant, but that is hard to say. Let some seeds go and produce some young seedlings, grow them on and see what you get. Why not? If you've got any extra room where you live, I would encourage this propogation of nature. Have a wonderful and beautiful day, Cindi