Pretty much all the flowers in our garden are attractive to insects. I suppose that makes sense, because that’s what flowers are supposed to do, in order to get the insects to (inadvertently) pollinate the flowers. It’s interesting to me, though, that some flowers are attractive to many different insects but some seem to attract a specific subset. Yesterday, I was looking at the Monarda (bee balm) and noticed that the large bees were almost exclusively carpenter bees (Xylocopa virginica). Today I was looking at the gooseneck loosestrife (Lysimachia clethroides) shown here and the large bees were exclusively common eastern bumble bees (Bombus impatiens). Just interesting, that’s all.
On a mostly unrelated note, I really, really don’t recommend you plant any Lysimachia species in your garden. The bees love it, but there are other things they like that aren’t so overwhelming.